1. INTRODUCTION:

In the search for safe, economical and efficient means of providing for the health and wellbeing of mankind, modern science has produced numerous active agents through the methods of drug discovery that manipulate the biological environment around and within us. However, inability to deliver these agents to their targets at the right time and in right amounts cause some inefficiency that makes a useful drug unsuitable. This inability results in their loss, undesirable side effects.^[1]

The term drug delivery can be defined as technique that is used to get the therapeutic agent inside the human body. Conventional drug therapy requires periodic doses of therapeutic agents. These agents are formulated to produce maximum stability, activity and bioavailability.

1.1 Oral Solid Dosage Form ^[2]

Most of drug formulations are administered orally by means of solid dosage forms such as tablets and capsules. Preparations of these solid forms require the presence of other additives. These are included in the formulations to facilitate easy handling, enhance the physical appearance and improve stability and aid in the delivery of the drug to the blood stream after administration.

Fluoxetine Hydrochloride is an antidepressant which differs structurally and pharmacologically from the tricyclic agents. It has been shown to selectively inhibit the reuptake of serotonin in presynaptic neurons. Fluoxetine Hydrochloride is also used in a variety of disorders in addition to depression. Beneficial responses have been reported in obsessive compulsive disorders, pain syndromes including diabetic neuropathy and fibrositis, panic disorders and nervous bulimia.

1.1 (A) Gastro Intestinal Administration-The Oral Route ^[2]

Orally administered drug be absorbed through the gut which depends on number of factors such as gastric empting, intestinal motility, mucosal surface area degradation of drug in the stomach and first pass effect. The absorption rate varies from stomach to the intestine owing to the increased surface area (about 4500 cm²), the intestinal mucosa and greater velocity of blood (1000 ml/min) through the intestinal capillaries compared to the capillaries of other regions.

1.2 Immediate Release dosage form ^{[3- 7]}

Immediate release typically means that 75% of the API is dissolved within 45 minutes. Lately the terms rapidly dissolving (85% in 30 minutes) and very rapidly dissolving (85% in 15 minutes) became popular and important in dissolution testing.

The following media should be considered for immediate release products during development studies

Ø pH 6.8 buffer (or simulated intestinal fluid without enzymes)

Ø pH 4.5 buffer

Ø pH buffer (simulated gastric fluid without enzymes) or 0.1 N hydrochloric acid

Ø Water may be considered as an additional medium

For development purpose the generation of dissolution profile at short intervals such as 10, 15, 20, 30 and 45 minutes in the above dissolution media are strongly recommended for immediate release product formulation.

Immediate release oral dosage forms, i.e., tablets and capsules, are most widely used drug delivery systems available. These products are designed to disintegrate in the stomach followed by their dissolution in the fluids of the gastrointestinal tract [Fig. 1.2(a)]^[^4]. Dissolution of the drug substance, under physiological conditions, is essential for its systemic absorption. For this reason, dissolution testing is typically performed on solid dosage forms to measure the drug release from the drug product as a test for product quality assurance/product performance and to determine the compliance with the dissolution requirements when stated in the individual monograph. In limited number of cases, an in vitro–in vivo correlation is established between the drug release and drug product absorption necessary for therapeutic effects. Disintegration test is also a standardized pharmacopoeial test and is primarily used as a quality assurance tool to confirm complete disintegration of solid oral dosage forms within the prescribed time limit when placed in a liquid medium under the experimental conditions described as per respective official monographs. Disintegration test neither implies nor tests for the complete solution of the drug or the dosage form. The difference between these two tests is that in case of the disintegration test, the test measures the time required for a product to disintegrate and de-aggregate into multi particulate system in a given medium, while in case of the dissolution test, the test measures the concentration of the drug product in a given medium at a specified time ready for absorption . Thus, disintegration of a solid dosage form may not be a measure of dissolution of the drug substance in the dosage form.

The recent International Conference on Harmonization (ICH) Q6A ^[6] guideline provides specifications and acceptance criteria which should be established for all new drug substances and new drug products that have not been registered previously in the ICH region. The guidance recommends using a single-point measurement test to measure the release of drug substance from immediate-release drug products. This guidance also provides an option where dissolution testing may be replaced by disintegration testing for some immediate release solid oral drug products, containing high solubility drug over a pH range. In such cases, ICH allows disintegration time with an upper time limit to be used as the drug release acceptance criteria if following conditions are satisfied.

1. The drug product is not designed to produce modified release.

2. The solubility of drug is high enough at 37±0.5°C so that dose/solubility <250 mL throughout the physiological pH range (1.2–6.8).

3. Greater than 80% dissolution is achieved in 15 min at pH 1.2, 4.0, and 6.8.

4. A relationship has been determined and established between disintegration and dissolution or disintegration is more discriminating than dissolution.

5. Dissolution does not affect bioavailability.

6. Changes in formulation or manufacturing variables do not affect dissolution.

Fig 1.2 (a) Relationship between dissolution and disintegration of an oral solid dosage form ^[7]

1.2 (A) Product requirement for Immediate Release Capsule ^[8]

One of the key advantages in formulating as immediate release hard gelatin capsules is that it is a way of ensuring that each capsule contains the exact dose and that this dose is released as quickly as possible to ensure bioavailability. For optimum machine-filling performance, the powder must have right flow and density; the densities of the excipients and the drug should therefore must be similar.

When formulating hard gelatin capsules for immediate release, attention should be paid to establishing a reproducible product dissolution profile. In the fluid environment of the stomach, the shell of the capsule starts to soften and dissolve within one or two minutes, and comes apart at its weakest point, the capsule shoulder consequently, the uncompressed or only slightly compacted content comes into contact with water. If the capsule formulation is sufficiently hydrophilic or contains disintegrant or a wetting agent, water can penetrate the powder. The capsule disintegrates and its contents are released. Hard gelatin capsules are fully disintegrated within 10 minutes.

1.3 Capsule ^{[9, 10]}

Capsule may be defined as a solid dosage form, which consists of a container, usually made of gelatin, filled with a medicinal substance. There are many forms of capsules and they can be divided into two main categories ‘hard’ and ’soft’. The hard capsule of two separate parts, each semi-closed cylinder in shape. One part, the ‘cap’, has a slightly larger diameter than the other, which is called the ‘body’ and is longer. The cap fits closely over the body to form a sealed unit. The gelatin capsule was made as the need to mask the obnoxious taste of many medicinal substances, which were in vogue at that time.

1.3 (A) Advantages of capsules ^{[9, 10]}

1. Capsules, because of their elongated shape, are easy to swallow, which is one reason for the number of capsule-shaped tablets manufactured today.

2. Flexibility of formulation is another advantage of the capsule dosage form. However the biggest formulation advantage of capsules is that there is less for additional excipients.

3. The formulation of a rapid-release hard gelatin capsule can be largely deducted from the physicochemical properties of drug active. Usually, only a limited number of excipients are necessary and these are simply mixed the active and directly filled into the capsule.

4. The choice available in terms of capsule type, the range of sizes and the capsule’s color or combination of colors, as well as possibility directly onto the capsule, means that patient compliance, product recognition and product differentiation can be markedly improved.

5. Since capsules are tasteless, they effectively mask any unpleasant taste or order of their contents.

6. They offer rapid release characteristics, due to the rapid dissolution rate of the capsules.

7. The use of hard gelatin capsules is also a common feature in clinical trials, as the filling of capsule themselves will blind the dosage forms studies.

8. Controlled release can be achieved using capsules. Dry powder mixtures, granules, pellets and tablets can be filled into hard capsules. Moreover combination of two or three types (i.e. dry powder mixtures, tablets or pellets) also can be put into capsules.

9. Further advantage are improved uniformity of content for low dose products, the avoidance of cross-contamination during production and reduced packaging costs, due to the predefined dimensions of hard gelatin capsules.

Manufacturing steps ^[9,
10]

For Tablet:

For Capsules:

Dispensing

Sifting

Mixing

Granulation

Drying

Dry

Lubricating

Compression

Coating

Packaging

Screening

Dispensing

Sifting

Mixing

Granulation

Drying

Dry

Lubricating

Capsule Filling

Packaging

Screening

1.4 Selection of the capsule size ^[9]

The volume of material that was to be filled into the capsule determined the size of the capsule that needed. Generally, capsules of sizes “0” to “4” were readily available in the market and the relationship between the capsule size and related body volume are shown below in table 1.3 (a). For pharmaceutical products it is unusual to use a size larger than “0” because of the difficulty in swallowing larger size capsules, while size “5” is rarely used due to difficulties in the automatic filling process.

1.4 (A) Empty capsules ^[9]

The ones most commonly employed for human use range from size “0”, the largest, to size “5”, the smallest. Size “00” capsules may occasionally be required because of volume of material to be filled, but this size is not used commercially in large volume. Although capsules change dimensions to some extent with varied moisture content and conditions encountered before use, In below table 1.3 (a) an approximation of volume that may be contained in the various sizes, along with the amounts of some powders that can be contained in these sizes. The powder weights listed are approximate and vary with the amount of pressure employed in hand filling or with the amount type of equipment utilized in machine filling.

Much consideration should be given to techniques for handling and storage of empty capsules in any production facility. This is of great importance when use rates are high, as when high-speed filling equipment is used.

Table 1.4 (a):- Filling capacity of empty capsule ^[9]

Capsule size	Approximate Volume (ml)	Quinine Sulfate (g)	Sodium Bicarbonate (g)	Acetyl Salicylic Acid(g)	Bismuth Sub nitrate (g)
“0”	0.75	0.33	0.68	0.55	0.80
“1”	0.55	0.23	0.55	0.33	0.65
“2”	0.40	0.20	0.40	0.25	0.55
“3”	0.30	0.12	0.33	0.20	0.40
“4”	0.25	0.10	0.25	0.15	0.25
“5”	0.15	0.07	0.12	0.10	0.12

Capsules are received from the supplier generally have moisture content between 12 o 15 % and these levels are maintained during storage in the original container. Storage under high temperature conditions (above 100˚F) must not be prolonged. Exposure to extremely high or extremely low humidity conditions for extended period after the containers are opened causes the capsules to either gain or lose moisture. At high moisture levels, the capsules absorb moisture, and may soften and become tacky. In severe cases, the capsules may absorb sufficient moisture to cause them under their own weight. At low moisture levels, they become brittle and suffer dimensional changes, which may cause handling problems in filling equipment.

Regarding the empty capsules only, handling is ideally carried in areas within the relative humidity range of approximately 30 to 45% since major moisture content do not occur within these limits. Strong consideration should be given to the use of air-conditioned facilities to control both temperatures and humidity when high-speed filling equipment is being operated.

1.5 Capsule Filling Operation ^[8]

1.5 (A) Powder filling in immediate release capsule ^[8]

Immediate release capsule with a simple powder filling are the best-known type of hard gelatin capsules. They require only a few manufacturing process steps. Usually, it is easy to mix the active substance with excipients and to fill into the capsules. Depending on the process a light pre-compression, to form a so-called ‘plug’, might also be necessary. In comparison with conventional tablet production, capsule production does not require expensive and time-consuming operations like repeated mixing and sieving or granulation and compression.

1.5 (B) Selection of capsule filling machine ^[8]

It is also necessary to take into account the type of the filling machine that was available and how each type of product is handled. Generally, there are two kinds of filling machines, viz. manually operated and automatic filling machines. For this study manual filling machine i.e. the method using the hand operated capsule filling was used for the manufacture of the Fluoxetine Hydrochloride capsules.

Fig 1.5 (a) Hand filling capsule machine

The equipment used for this study consisted of sets of stainless steel plates, while had predrilled holes to take 300 capsules of size “3” , empty “3” size capsules were placed into the holes by hand with bodies of the capsule filling snugly into the plate. The caps of the capsules were then removed, powder placed onto the surface of the body plate (plate containing the capsule bodies) and spread with a spatula so that it flowed into the empty capsule bodies. Because the uniformity of the fill weight was very dependent upon the good flow properties of the material filled body of the capsule and the two capsule parts rejoined using gentle pressure. The quantity of the powder that could be poured into the capsule was more or less established by a trial and error method.

1.5 (C) Selection of the excipients for capsule filling ^{[9, 10, 12]}

Normally, there are three types of excipients used in powder filling capsules i.e. diluents, glidants, lubricants.

The diluent, also known as the filler, is used to increase the bulk volume of the powder. It is also chosen for its plug forming properties and the most frequently used examples are: Lactose, Starch and Microcrystalline Cellulose.

The glidants are materials that reduce inter-particulate friction, so that there is improved flowability of the powder. Examples of glidants include Colloidal and Anhydrous Silica. The concentration of glidants used is important; quantities above 1% tend to decrease the flow rate of the mix while about 0.1% is usually adequate.

The lubricants reduce powder-to-metal adhesion and one example is Magnesium Stearate.

Table 1.5 (a) commonly used Excipients in formulation of immediate release hard gelatin capsule ^{[9, 10, 12]}

Diluents	Lubricants	Glidants	Disintegrants	Wetting agents/ Surfactants
Improved plug formation and compression	Improved flow properties and reduce powder adhesion to metal parts	Improved powder flow properties	TO ensure disintegration of powder mixture	Improved water penetration into powder mixture
Mannitol	Magnesium Stearate	Colloidal Silicon Dioxide	Croscarmellose	Sodium Lauryl Sulphate
Microcrystalline Cellulose	Glyceryl Monosterate	Talcum	Corn Starch	Tween 80
Lactose Monohydrate	Stearic Acid		Crospovidone
Corn Starch			Starch 1500®

1.6 Depression and Obsessive Compulsive Disorders (OCD) ^{[13, 14]}

1.6 (A) Depression:

1.6 (A.1) Definition: A state of being depressed marked especially by sadness, inactivity, difficulty with thinking and concentration, a significant increase or decrease in appetite and time spent sleeping, feelings of dejection and hopelessness, and sometimes suicidal thoughts or an attempt to commit suicide. Without treatment, symptoms can last for weeks, months, or years. Appropriate treatment, however, can help most people with depression.

1.6 (A.2) The signs and symptoms: include loss of interest in activities that were once interesting or enjoyable, including sex; loss of appetite (anorexia) with weight loss or overeating with weight gain; loss of emotional expression (flat affect); a persistently sad, anxious or empty mood; feelings of hopelessness, pessimism, guilt, worthlessness, or helplessness; social withdrawal; unusual fatigue, low energy level, a feeling of being slowed down; sleep disturbance with insomnia, early-morning awakening, or oversleeping; trouble concentrating, remembering, or making decisions; unusual restlessness or irritability; persistent physical problems such as headaches, digestive disorders, or chronic pain that do not respond to treatment; thoughts of death or suicide or suicide attempts. Alcohol or drug abuse may be signs of depression.

1.6 (B) Obsessive Compulsive Disorders (OCD):

1.6 (B.1) Definition: Obsessive Compulsive Disorder (OCD) is an anxiety disorder characterized by unreasonable thoughts and fears (obsessions) that lead you to do repetitive behaviors (compulsions). With obsessive-compulsive disorder, patient may realize that obsessions aren't reasonable, and may try to ignore or stop others. But that only increases his/her distress and anxiety. Ultimately, patient feels driven to perform compulsive acts in an effort to ease his/her stressful feelings. OCD obsessions are repeated, persistent and unwanted ideas, thoughts, images or impulses that have involuntarily and seem to make no sense.

1.6 (B.2) Obsessions often have themes, such as:

· Fear of contamination or dirt

· Having things orderly and symmetrical

· Aggressive or horrific impulses

· Sexual images or thoughts

1.6 (B.3) Obsession symptoms and signs may include:

· Fear of being contaminated by shaking hands or by touching objects others have touched

· Doubts that you've locked the door or turned off the stove

· Thoughts that you've hurt someone in a traffic accident

· Intense stress when objects aren't orderly or facing the right way

· Images of hurting your child

· Impulses to shout obscenities in inappropriate situations

· Avoidance of situations that can trigger obsessions, such as shaking hands

· Replaying pornographic images in your mind

· Dermatitis because of frequent hand washing

· Skin lesions because of picking at your skin

1.6 (B.4) Compulsion symptoms:

OCD compulsions are repetitive behaviors that you feel driven to perform. These repetitive behaviors are meant to prevent or reduce anxiety related to your obsessions. For instance, if you believe you hit someone with your car, you may return to the apparent scene over and over because you just can't shake your doubts. You may also make up rules or rituals to follow that help control the anxiety you feel when having obsessive thoughts.

1.6 (B.5) Compulsions typically have themes, such as:

· Washing and cleaning

· Counting

· Checking

· Demanding reassurances

· Performing the same action repeatedly

· Orderliness

1.6 (B.6) Compulsion symptoms and signs may include:

· Hand washing until your skin becomes raw

· Checking doors repeatedly to make sure they're locked

· Checking the stove repeatedly to make sure it's off

· Counting in certain patterns

· Arranging your canned goods to face the same way

Table 1.7 Pharmacology of Fluoxetine Hydrochloride ^[13,
14]

Indication	For the treatment of Major Depressive Disorders, Obsessive Compulsive Disorder
Pharmacodynamics	Fluoxetine Hydrochloride an antidepressant agent belonging to the selective serotonin reuptake inhibitors (SSIRs), is used to treat depression, premenstrual dysphonic disorder, panic disorder and post-traumatic stress. Fluoxetine Hydrochloride effects are thought to be associated with the inhibition of 5HT receptor, which leads to an increase of serotonin level.
Mechanism of action	Fluoxetine Hydrochloride is a Selective Serotonin Reuptake Inhibitor (SSIRs), it blocks the reuptake of Serotonin at the Serotonin reuptake pump of the neuronal membrane, enhancing the actions of Serotonin on 5HT1A auto receptors. SSRIs bind with significantly less affinity to Histamine, Acetylcholine, and Norepinephrine receptors than tricyclic antidepressant drugs.
Absolute bioavailability	72%
Absorption	Fluoxetine Hydrochloride is well absorbed from gastrointestinal track after oral administration
Tmax	1.2-4.8 hrs
Cmax/AUC	Cmax: 1.16 mcg/ml ; AUC: 26.719 mcg/ml.hr
Elimination half life	1-3 days
Route of elimination	The primary route of elimination appears to be hepatic metabolism inactive metabolites excreted by the kidney.
Plasma protein binding	Approximately 94.5 % of Fluoxetine Hydrochloride is bound in vitro to human serum proteins including Albumin and α1-glycoprotein
Plasma clearance	The mean steady state plasma clearance in healthy adults is 2.11 L/hr (28.9%); in patients 2.46 L/hr (27.3%).
Volume of distribution	20 to 40 L/kg
Effect of food	Food tends to enhance the rate and extend of Fluoxetine Hydrochloride absorption. Food does not appear to affect the systemic bioavailability of Fluoxetine Hydrochloride although it may delay its absorption inconsequentially. Thus Fluoxetine Hydrochloride may be administered with or without food.
Excretion	Mainly (about 60%) via the kidney

Ø Indications:

Depression:

· Fluoxetine Hydrochloride is indicated for the symptomatic relief of depression illness.

Obsessive Compulsive Disorder:

· Fluoxetine Hydrochloride has been shown to significantly reduce the symptoms of Obsessive Compulsive Disorder in double- blind, placebo-controlled clinical trials.

Ø Contraindications:

· Fluoxetine Hydrochloride is contraindicated in patients with known hypersensitivity to the drug.

· Monoamine Oxidase Inhibitors

Fluoxetine Hydrochloride should not be used in combination with a MAOI or within a minimum of 14 days of discontinuing therapy with a MAOI.

· Thioridazine

Thioridazine should not be administered with Fluoxetine Hydrochloride or within a minimum of 5 weeks after Fluoxetine Hydrochloride has been discontinued.

Ø Adverse Effects:

· The most commonly observed adverse effects associated with the use of Fluoxetine Hydrochloride are CNS complaints, including headache, nervousness, insomnia, drowsiness, fatigue or asthenia, anxiety, tremor and dizziness or light headedness; gastrointestinal complaints, including nausea, diarrhea, dry mouth and anorexia; and excessive sweating.

1.8 GENERIC DRUG ^{[15, 16, 35]}

Generic drug product, also referred to as a multisource pharmaceutical product, is considered to be “essentially similar” or bioequivalent to an innovator (brand name) drug product. Bioequivalence implies that a generic drug product is essentially identical to the brand name drug (reference) drug product in term of active ingredient, strength, dosage form, route of administration, quality, safety, efficacy, performance characteristics, and therapeutic identification. Generic drug products are typically sold at substantial discount from their brand name counterpart. Generic drug product development uses a different approach and strategy compared to that used to develop brand name drug product containing a new chemical entity.

FDA requires generic drug to have the same quality, strength, purity and stability as branded drug. The manufacturer of the generic drug product has certain constraints in formulation development that differ from the formulation development of branded drug product, for example a generic drug manufacturer may have to use the same or similar inactive ingredient or excipients as in the branded formulation.

Generic drugs are less expensive because generic manufacturers do not have the investment costs of the developer of new drug. New drugs are developed under patent protection; the patent protects the investment including research, development, marketing and promotion by giving the company the sole right to sell the drug while it is in effect. As patents near expiration, manufacturers do not have the same development cost, so they can sell their product at substantial discount. Moreover, once generic drugs are approved there is greater competition, which keeps the price down. Today almost half of all prescriptions are filled with generic drugs.

1.8 (A) Need for Generics:

Ø Generic helps to keep the health insurance premium down.

Ø It encourages the research based drug companies to keep finding newer and better medicines that have patent protection.

Ø Generic have long offered a safe and inexpensive alternative to the brand name drugs.

Ø Generic helps to keep the cost of drugs down. Because generic drug manufacturers do not have to pay as much as brand name drug manufacturers do for expensive research and development, sales, advertising and marketing.

Ø To obtain FDA approval, generic drug product must contain:

Ø It must Pharmaceutically Equivalents

Ø It should have same use indications.

Ø It should be bioequivalent.

Ø It must be manufactured under the same strict standards of FDA’s good manufacturing practice regulation as required for innovators products compared to brand name product.

1.8 (B) Pharmaceutical Equivalents:

Drug products are considered pharmaceutical equivalents if they contain the same active ingredient(s), are of the same dosage form, route of administration and are identical in strength or concentration (e.g., Chlordiazepoxide Hydrochloride, 5mg capsules). Pharmaceutically equivalent drug products are formulated to contain the same amount of active ingredient in the same dosage form and to meet the same or compendial or other applicable standards (i.e., strength, quality, purity, and identity), but they may differ in characteristics such as shape, scoring configuration, release mechanisms, packaging, excipients (including colors, flavors, preservatives), expiration time, and, within certain limits, labeling.

1.8 (C) Bioequivalent Drug Products:

This term describes pharmaceutical equivalent or alternative products that display comparable bioavailability when studied under similar experimental conditions viz. set of conditions under which a test and reference listed drug shall be considered bioequivalent. The rate and extent of absorption of the test drug do not show a significant difference from the rate and extent of absorption of the reference drug when administered at the same molar dose of the therapeutic ingredient under similar experimental conditions in either a single dose or multiple doses; or Where these above methods are not applicable (e.g., for drug products that are not intended to be absorbed into the bloodstream), other in vivo or in vitro test methods to demonstrate bioequivalence may be appropriate.

Bioequivalence may sometimes be demonstrated using an in vitro bioequivalence standard, especially when such an in vitro test has been correlated with human in vivo bioavailability data. In other situations, bioequivalence may sometimes be demonstrated through comparative clinical trials or pharmacodynamics studies.

Generic drugs can be legally produced for drugs where,

Ø The patent has expired,

Ø The generic company certifies the brand company's patents are either invalid, unenforceable or will not be infringed,

Ø For drugs which have never held patents,

Ø In countries where a patent(s) is/are not in force.

The expiration of a patent removes the monopoly of the patent holder on drug sales licensing. It is also becoming popular for the large pharmaceutical companies to preempt the expiry of their patent by producing their own generic product, or license their own product to be branded by generic companies. Thus, in some cases, the "generic" product is actually the brand product but inside a different box.

The generics market offers immense opportunities to the developing countries such as India, China, and Korea, where the cost of production is low and the manpower costs are also relatively low. Quite a few Indian companies have aggressively filed Abbreviated New Drug Applications (ANDAs) in the US and have received approval for many of them. Some of the Indian companies who have successfully entered the generics market of the US and Europe are Wockhardt Limited, Ranbaxy laboratories Limited, Dr. Reddy’s Laboratories Limited, Alembic Pharma Limited Torrent Limited etc.

When generic drug products are submitted or approval through the abbreviated new drug application process in the US, they must be both pharmaceutically equivalent and bioequivalent to be considered therapeutically equivalent and therefore approvable.

Bioequivalence means the absence of the significant difference in the rate and extent to which the active ingredient becomes available at the site of drug action when administered at the same molar dose under similar condition in an appropriately designed study.

1.9 (A) Key Provision for Generic Drug Filling:

Paragraph certification

Paragraph I certification- No patent information on the drug product that is the subject of the ANDA has been submitted to FDA.

Paragraph II certification- there was patent, which has expired.

Paragraph III certification- such patent will be expired on particular date.

Paragraph IV certification- such patent is invalid, will not be infringed by manufacturer, use or sale of the drug product for which the ANDA is submitted.

2.0 RESEARCH ENVISAGED AND PLAN OF WORK

2.1 AIM

Ø The aim of the present work is to formulate immediate release capsule (20mg) of Fluoxetine Hydrochloride for oral administration having anti-depressant activity, by using commonly approved excipients which shows comparable dissolution profile with the Reference Listed Drugs (RLD).

2.2 OBJECTIVE OF WORK

Ø To design, develop and evaluate different prototypes of immediate release hard gelatin capsule dosage form of Fluoxetine Hydrochloride which is Selective Serotonin Reuptake Inhibitors.

Ø The concept of formulating immediate release containing Fluoxetine Hydrochloride offers a suitable and practical approach in serving desired objective of rapid disintegration and dissolution characteristics with increased bioavailability.

Ø Fluoxetine Hydrochloride has a low bulk density and shows very poor flow properties. So trials were taken by using Microcrystalline Cellulose (Avicel PH 102®) along with Lactose Monohydrate (Granulac 200®) and Colloidal Sillicon Dioxide (Aerosil 200®) to improve the flow property of the blend. Development was carried out by using different granulation process, methods, steps and also employing different filling process.

3.0 PLAN OF WORK

Ø Literature survey.

Ø Drug and Excipient characterizations.

Ø Preformulation studies.

v Organoleptic Characteristics

v Partical Size

v Bulk Density

v Tapped Density

v Carr’s Index

v Hausner’s Ratio

Ø Formulation development

Ø Evaluation of Powder Blends (granules made by suitable optimized methods.)

v Bulk Density

v Tapped Density

v Carr’s Index

v Hausner Ratio

v Sieve Analysis

Ø Evaluation of filled capsules (manually or Hand filling machine)

v Weight Variation

v Disintigration test

v In-vitro Dissolution Study

Ø Stability study of selected formulation.

4.0 EXPERIMENTAL WORK:

4.1 Drug Profile

Table 4.1 (a) Description of Fluoxetine Hydrochloride:

Name	Fluoxetine Hydrochloride
Category	Selective Serotonin Reuptake Inhibitors (SSRIs), Anti-depressants, Second Generation Serotonin Uptake Inhibitors
Description	White to off white crystalline powder
Taste	Bitter
Molecular weight	345.79g/mol
Melting point	216-218˚C
pKa	8.7
BCS class	Class-I
Pharmacopoeial status	Official in USP

Table 4.1 (b) Physical Property of Fluoxetine Hydrochloride:

Bulk density(g/ml)	0.319
Tap density(g/ml)	0.496
Compressibility index (%)	35.68
Hausner’s ratio	1.55

4.2 Excipients Profile ^{[29, 30]}

4.2 (A) Microcrystalline Cellulose (MCC) ^{[29, 30]}

Ø Synonyms:

Avicel PH; Celex; cellulose gel; Celphere; Ceolus KG; crystalline cellulose; E460; Emcocel; Ethispheres; Fibrocel; Pharmacel; Tabulose; Vivapur

Ø Empirical Formula: (C₆H₁₀O₅)_n Where n is 220.

Ø Molecular Weight: 36,000

Ø Grade available:

Avicel PH-101, Avicel PH-102, Avicel PH-103, Avicel PH-105, Avicel PH-112, Avicel PH-113, Avicel PH-200, Avicel PH-301, Avicel PH-302, Celex 101, Ceolus KG-802, Emcocel 50M, Emcocel 90M, MCC Sanaq 101, MCC Sanaq 102, MCC Sanaq 200, MCC Sanaq 301, MCC Sanaq 302, MCC Sanaq UL-002, Vivapur 101, Vivapur 102 and Vivapur 12

Ø Functional Category:

Adsorbent; suspending agent; tablet and capsule diluent; tablet disintegrant.

Ø Description:

Microcrystalline cellulose is a purified, partially depolymerized cellulose that occurs as a white, odorless, tasteless, crystalline powder composed of porous particles. It is commercially available in different particle sizes and moisture grades that have different properties and applications.

Ø Applications in Pharmaceutical Formulation or Technology:

Microcrystalline cellulose is widely used in pharmaceuticals, primarily as a binder/diluent in oral tablet and capsule formulations where it is used in both wet-granulation and direct-compression processes. In addition to its use as a binder/diluent, microcrystalline cellulose also has some lubricant and disintegrant properties that make it useful in tableting. Microcrystalline cellulose is also used in cosmetics and food products;

Table 4.2 (a) Use of MCC in different concentration (%)

Use	Concentration (%)
Adsorbent	20–90
Anti-adherent	5–20
Capsule binder/diluent	20–90
Tablet disintegrant	5–15
Tablet binder/diluent	20–90

Solubility:

Slightly soluble in 5%w/v sodium hydroxide, hydroxide solution; practically insoluble in water, dilute acids and most organic solvents.

Ø Incompatibilities

Microcrystalline cellulose is incompatible with strong oxidizing agents.

4.2 (B) Lactose, Monohydrate ^[29]

Ø Synonyms:

CapsuLac; GranuLac; Lactochem; lactosum monohydricum; Monohydrate; Pharmatose; PrismaLac; SacheLac; SorboLac; SpheroLac; SuperTab 30GR; Tablettose

Ø Empirical Formula: C₁₂H₂₂O₁₁. H₂O

Ø Molecular Weight: 360.31

Ø Functional Category:

Dry powder inhaler carrier; lyophilization aid; tablet binder; tablet and capsule diluent; tablet and capsule filler.

Ø Grade available:

Ø DMV-Fonterra Excipients: Pharmatose 50M, Pharmatose 60M, Pharmatose 70M, Pharmatose 80M, Pharmatose 90M, Pharmatose 100M, Pharmatose 110M, Pharmatose 125M, Pharmatose 130M, Pharmatose 150M, Pharmatose 200M, Pharmatose 350M, Pharmatose 450M, SuperTab 30GR

Ø Meggle GmbH: CapsuLac 60, GranuLac 70, GranuLac 140, GranuLac 200, GranuLac 230, PrismaLac 40, SacheLac 80, SorboLac 400, SpheroLac 100, Tablettose 70, Tablettose 80, Tablettose 100

Ø Sheffield Pharma Ingredients: Monohydrate 80M, Monohydrate Impalpable.

Ø Applications in Pharmaceutical Formulation or Technology:

Lactose is widely used as a filler or diluent in tablets and capsules, and to a more limited extent in lyophilized products. Lactose is also used as a diluent in dry-powder inhalation. Various lactose grades are commercially available that have different physical properties such as particle size distribution and flow characteristics. This permits the selection of the most suitable material for a particular application; for example, the particle size range selected for capsules is often dependent on the type of encapsulating machine used. Usually, fine grades of lactose are used in the preparation of tablets by the wet-granulation method or when milling during processing is carried out, since the fine size permits better mixing with other formulation ingredients and utilizes the binder more efficiently. Direct-compression grades of lactose monohydrate are available as granulated/agglomerated a-lactose monohydrate, containing small amounts of anhydrous lactose. Direct compression grades are often used to carry lower quantities of drug and this permits tablets to be made without granulation. Other directly compressible lactoses are spray-dried lactose and anhydrous lactose.

Table 4.2 (b) Solubility of Lactose, Monohydrate in different solvent:

Solvent	Solubility at 20°C unless otherwise stated
Chloroform	Practically insoluble
Ethanol	Practically insoluble
Ether	Practically insoluble
Water	1 in 5.24 1 in 3.05 at 40°C 1 in 2.30 at 50°C 1 in 1.71 at 60°C 1 in 0.96 at 80°C

Ø Incompatibilities

A Maillard-type condensation reaction is likely to occur between lactose and compounds with a primary amine group to form brown, or yellow-brown-colored products. Lactose is also incompatible with amino acids, aminophylline, amfetamines, and lisinopril.

4.2 (C) Colloidal Silicon Dioxide ^[29]

Ø Synonyms:

Aerosil; Cab-O-Sil; Cab-O-Sil M-5P; colloidal silica; fumed silica; fumed silicon dioxide; hochdisperses silicum dioxid; SAS; silica colloidalis anhydrica; silica sol; silicic anhydride; silicon dioxide colloidal; silicon dioxide fumed; synthetic amorphous silica; Wacker HDK

Ø Empirical Formula: SiO2

Ø Molecular Weight: 60.08

Ø Functional Category

Adsorbent; anticaking agent; emulsion stabilizer; glidant; suspending agent; tablet disintegrant; thermal stabilizer; viscosity-increasing agent.

Ø Applications in Pharmaceutical Formulation or Technology

Colloidal silicon dioxide is widely used in pharmaceuticals, cosmetics, and food products. Its small particle size and large specific surface area give it desirable flow characteristics that are exploited to improve the flow properties of dry powders in a number of processes such as tableting and capsule filling. Colloidal silicon dioxide is also used to stabilize emulsions and as a thixotropic thickening and suspending agent in gels and semisolid preparations. With other ingredients of similar refractive index, transparent gels may be formed. The degree of viscosity increase depends on the polarity of the liquid (polar liquids generally require a greater concentration of colloidal silicon dioxide than nonpolar liquids). Viscosity is largely independent of temperature. However, changes to the pH of a system may affect the viscosity. In aerosols, other than those for inhalation, colloidal silicon dioxide is used to promote particulate suspension, eliminate hard settling, and minimize the clogging of spray nozzles. Colloidal silicon dioxide is also used as a tablet disintegrant and as an adsorbent dispersing agent for liquids in powders. Colloidal silicon dioxide is frequently added to suppository formulations containing lipophilic excipients to increase Colloidal silicon dioxide is also used as an adsorbent during the preparation of wax microspheres as a thickening agent for topical preparations and has been used to aid the freeze-drying of nanocapsules and nanosphere suspensions.

Table 4.2 (c) Use of Colloidal Silicon Dioxide in different concentration (%)

Use	Concentration (%)
Aerosols	0.5–2.0
Emulsion stabilizer	1.0–5.0
Glidant	0.1–1.0
Suspending and thickening agent	2.0–10.0

Ø Incompatibilities:

Colloidal silicon dioxide is incompatible with diethylstilbestrol preparations.

4.3 List of Raw Materials:

The Fluoxetine Hydrochloride and Excipients used in the development are listed in the table below.

Table 4.3 (a) List of Excipients and Fluoxetine Hydrochloride

Sr. No	Raw materials / Brand Name	Function	Manufacturer
1	Fluoxetine Hydrochloride (Anti-depressent)	API	Alembic ltd
2	Micro Crystaline Cellulose (Avicel PH 200)	Direct compressible material	FMC Biopolymer
3	Micro Crystaline Cellulose (Avicel PH 102)	Diluent, Anti-adherent	FMC Biopolymer
4	Lactose Monohydrate (Granulac 200)	Diluent	Meggle
5	Povidone (Polyvinylpyrrolidone K 30)	Binder	ISP ltd
6	Colloidal silicon dioxide (Aerosil 200)	Glidant	Degussa

4.4 List of Equipment:

Table 4.4 (a) Name of Equipment used

Sr. No	Instruments	Manufacturer/Suppliers
1	Electronic Balance	Mettler toledo
2	Disintegration test apparatus	Electro lab
3	Capsule filling machine	Cisa scientific
4	Tablet dissolution tester	Electro lab
5	Tap density tester	Electro lab
6	H.P.L.C	Schimadzu
7	Conta blender	Gansons ltd
8	Halogen moisture analyser	Mettler toledo
9	Sieve shaker	Cisa scientific
10	Rapid mixer granulator	Saral
11	Rapid dryer	Retsch

4.5 Pharmaceutical Preformulation Studies:

Preformulation is a branch of pharmaceutical sciences that utilizes Bio- pharmaceutical principles in the determination of physicochemical properties of a drug substance. Pre-formulation studies are the first step in the rational development of dosage form of a drug substance. Pre-formulation can be defined as investigation of physical and chemical properties of drug substance alone and when combined with excipients.

Pre-formulation investigations are designed to identify those physicochemical properties and excipients that may influence the formulation design, method of manufacture, and pharmacokinetic-biopharmaceutical properties of resulting product. Followings are the tests carried out for pre-formulation study.

A thorough understanding of these properties may ultimately provide a rationale for formulation design. Also it will help in minimizing problems in later stages of drug development, reducing drug development costs and decreasing product's time to market.

4.5 (A) Scope:

The use of pre-formulation parameters maximizes the chances in formulating an Acceptable, safe, efficacious and stable product.

Followings are the tests carried out for the pre-formulation study.

Ø Organoleptic Characteristics

Ø Solubility of Fluoxetine Hydrochloride

Ø Bulk Density

Ø Tap Density

Ø Carr’s Index

Ø Hausner’s Ratio

Organoleptic Characteristics:

The color, odor, and taste of the drug were characterized and recorded using descriptive terminology.

Table 4.5 (a) Properties of Fluoxetine Hydrochloride

Properties	Results
Description	Crystalline solid
Taste	Bitter
Color	White to off-white

Ø Solubility of Fluoxetine Hydrochloride:

Drug is BCS Class I drug. It is freely soluble in methanol and ethanol, sparingly soluble in water, methylene chloride.

Solubility of Fluoxetine Hydrochloride in different solvent is mentioned below.

Table 4.5 (b) Solubility of Fluoxetine Hydrochloride in different solvent

Name of solvent	Solubility (mg/ml)
Water	14 mg/ml
Methanol, Ethanol	>100 mg/ml
Acetone, Acetonitrile, Chloroform	33-100 mg/ml
Dichloromethane	5-10 mg/ml
Ethyl acetate	2-2.5 mg/ml
pH 5 pH 7 pH 9	15.0 mg/ml 6.8 mg/ml 5.4 mg/ml

Table 4.5 (c) Effect of Carr’s Index and Hausner’s Ratio on Flow Property ^{[9, 10]}

Carr’ Index	Flow Character	Hausner’s Ratio
5-15	Excellent (free flowing granules)	1.00-1.11
12-16	Good (free flowing powdered granules)	1.12-1.18
18-21	Fair (powdered granules)	1.19-1.25
23-28	Passable (very fluid powder)	1.26-1.34
28-35	Poor (fluid cohesive granules)	1.35-1.45
35-40	Very poor (fluid cohesive powders)	1.46-1.59
>40	Extremely poor (cohesive powders)	>1.60

4.6 Drug-Excipients Compatibility Studies:

This study was conducted to determine the possible interaction between the API and excipients. The ratio of Fluoxetine Hydrochloride and excipient was selected as per their percentage in final formulation. Drug-Excipients mixtures were subjected to 40°±2˚C/75±5% RH for one month in glass vial pack. Samples were observed after one month and noted for physical change. Samples were analyzed for Description, Related substances and water after 1 month time interval for 40°±2˚C/75±5% RH.

Table 4.6 (a) Observations in different condition after specific time

PERIOD	Conditions	Observation
Initial	Room temperature	color change
30 Days	40°±2˚C/75±5% RH	color change

Table 4.6 (b) Ratio of Fluoxetine Hydrochloride and excipients and final results

Sample no.	Composition	Ratio (Active: Inactive)	Results
1	Fluoxetine Hydrochloride	1:00	No color change
2	Fluoxetine Hydrochloride: Lactose Monohydrate (Granulac 200)	1:5	No color change
3	Fluoxetine Hydrochloride: Microcrystalline Cellulose (Avicel PH 200)	1:1	No color change
4	Fluoxetine Hydrochloride: Microcrystalline Cellulose (Avicel PH 102)	1:1	No color change
5	Fluoxetine Hydrochloride: Colloidal silicon dioxide (Aerosil 200)	1:0.5	No color change
6	Fluoxetine Hydrochloride: Povidone (Polyvinyl pyrrolidone K 30)	1:1	No color change

4.6 (A) procedure:

Fluoxetine Hydrochloride and excipients are to be thoroughly mixed in predetermined ratio given in above table and passed through the sieve no.30. The blend was to be filled in transparent glass vials and are closed with gray rubber stoppers and sealed with aluminum seal and charged in to tress condition at room temperature, 40°±2˚C/75±5% RH. Similarly API shall also be kept at all condition as per the sample. Samples are to be withdrawn for analysis within two day of sampling date as per the compatibility study plan.

4.6 (B) Physical Observations:

Physical observation of sample was done at initial, and after four week for any color change or lumps formation.

4.7 Methodology for product development:

4.7 (A) Batch No. 1

Preparation of Granules:

1. Weighing:

Ø Weigh all the ingredients as per the above given formula.

2. Sifting:

Ø Fluoxetine Hydrochloride, MCC (Avicel 200®) and Lactose Monohydrate (Granulac 200®), Colloidal Silicon Dioxide (Aerosil 200®) were sifted through the 30# sieve.

3. Mixing:

Ø The excipients along with Fluoxetine Hydrochloride were mixed in a conta-blender® for 5 minutes at 16 rpm.

4. Filling of capsules:

Ø The above lubricated blend was filled at desired weight of 150mg using manual hand operated capsule filling machine.

4.7 (B) Batch No. 2

Preparation of Granules:

1. Weighing:

Ø Weigh all the ingredients as per the above given formula.

2. Sifting:

Ø Fluoxetine Hydrochloride, MCC (Avicel 102®) and Lactose Monohydrate (Granulac 200®), half quantity of Colloidal Silicon Dioxide (Aerosil 200®) were shifted through the 30# sieve.

3. Mixing:

Ø The excipients along with Fluoxetine Hydrochloride were mixed in a conta blender® for 5 minutes at 16 rpm.

4. Dry Granulation (slugging):

Ø In slugging, round, flat-faced punches (22mm) were used.

Ø The parameters were set to get the slug 1gm in weight and hardness between 5 to 7kp with optimum thickness.

5: Sifting of slugs:

Ø Slugs were milled through 1.5mm multi-mill® and then collected on butter paper.

Ø These granules were allowed to pass from 60# sieve without applying any hand pressure.

Ø 60# sieve retained were collected in polybag and 60# sieve passed were slugged again.

Ø Four cycles were carried out to achieve final granules.

6. Blending:

Ø The remained half quantity of Aerosil 200® was sifted through 30# and mixed with above prepared granules in conta-blender® for 5 minutes at 16 rpm.

7. Filling of Capsules:

Ø The above lubricated blend was filled at desired weight of 150mg using manual hand operated capsule filling machine but weight variation was observed due to poor flow of granules.

5.2 (A) Evaluation of Granules:

Table 5.2 (a) Particle Size Distributions of Granules:

Sieve Size	Batch 1	Batch 2	Batch 3	Batch 4	Batch 5	Batch 6 (Optimized Batch)	Batch 7 (Reproduced Batch)
30#	0%	0%	13%	03%	04%	02%	02%
40#	09%	20%	25%	21%	07%	03%	04%
60#	29%	30%	39%	28%	12%	16%	18%
80#	21%	22%	14%	20%	27%	43%	41%
Pan	41%	28%	09%	28%	36%	36%	35%
60#(retained: pass)	38 : 62	50 : 50	77 : 23	52 : 42	23 : 77	21 : 79	24:76

Table 5.2 (b) Physical Parameters of Granules:

Physical parameters	Batch 1	Batch 2	Batch 3	Batch 4	Batch 5	Batch 6 (Optimized Batch)	Batch 7 (Reproduced Batch)
Bulk density (g/ml)	0.5566	0.5617	0.5897	0.5782	0.5642	0.5788	0.5937
Tap density (g/ml)	0.7682	0.8771	0.6459	0.6837	0.7362	0.7413	0.7524
Compressibility index (%)	27.54	35.97%	8.701%	15.43%	23.36%	21.86%	21.14%
Hausner’s ratio	1.38	1.56	1.09	1.18	1.31	1.28	1.26
Powder characteristics	Poor flow (Powdered granules)	Very poor flow (Fluid cohesive granules)	Excellent flow (Free flowing granules)	Good flow (Free flowing powdered granules)	Passable flow (very fluid powders)	Fair flow (powdered granules)	Fair flow (powdered granules)
LOD (%w/w)	0.64%	0.82%	1.32%	0.79%	1.13%	0.70%	0.87%

5.2 (B) Evaluations of Capsules:

Table 5.2 (c) Description of empty capsule:

Capsule filling	Weight of size “3” capsule shell	Target weight of filled capsule
Hand filling machine	47-51 mg	200 mg
Description	Dark Blue opaque / Light Blue opaque Size “3” hard gelatin capsule filled with white to off-white powders.

5.2 (d) Weight Variation Test of capsules ^[31]:

Sr. No	Batch 1 (Direct dry mixing)	Batch 2 (Dry granulation /slugging)	Batch 3 (Wet granulation with binder solution)	Batch 4 (Wet granulation /Intra granular, MCC)	Batch 5 (Wet granulation /Extra granular, MCC)	Batch 6 (Optimized Batch) (Wet granulation /Half Intra granular and half Extra granular MCC)	Batch 7 (Reproduced Batch) (Wet granulation /Half Intra granular and half Extra granular MCC)
Individual weight of capsule in mg
1	163.2	185.2	213.5	203.0	189.7	201.5	204.5
2	180.7	204.3	210.4	202.2	188.4	206.1	211.2
3	195.2	157.4	204.6	210.2	206.4	205.4	199.4
4	154.3	202.4	200.7	216.5	175.8	201.1	214.9
5	230.4	205.8	194.3	203.3	186.4	200.0	197.3
6	187.3	187.4	210.6	204.1	208.3	198.5	207.4
7	198.3	192.3	203.1	213.4	220.3	200.5	201.3
8	203.0	173.5	207.4	193.4	198.3	199.5	200.9
9	201.3	205.4	204.5	207.5	205.7	203.8	209.5
10	163.2	175.2	200.4	201.3	201.5	202.8	202.5

5.2 (d) Cont.---

Sr. No	Batch 1 (Direct dry mixing)		Batch 2 (Dry granulation /slugging)	Batch 3 (Wet granulation with binder solution)	Batch 4 (Wet granulation /Intra granular, MCC)	Batch 5 (Wet granulation /Extra granular, MCC)	Batch 6 (Optimized Batch) (Wet granulation /Half Intra granular and half Extra granular MCC)	Batch 7 (Reproduced Batch) (Wet granulation /Half Intra granular and half Extra granular MCC)
Individual weight of capsule in mg
11	223.9	212.3		204.3	202.9	198.4	205.7	200.8
12	215.4	173.4		211.2	200.0	187.4	201.3	201.3
13	157.5	221.4		210.9	207.7	186.5	200.9	207.1
14	195.4	203.8		197.4	208.2	213.9	204.0	204.6
15	207.1	178.4		200.3	204.1	195.3	200.2	199.9
16	174.9	196.3		199.4	207.1	200.7	199.5	200.1
17	187.3	159.5		204.5	208.8	185.9	201.4	201.4
18	189.3	198.4		201.1	210.8	203.8	199.7	211.6
19	215.8	204.8		202.8	205.5	204.7	200.0	204.9
20	217.3	178.4		208.3	209.2	178.3	201.7	205.3
Ave.	194.1	190.8		204.5	206.1	196.8	201.7	204.3
Min.	154.3	157.4		194.3	200.0	175.8	198.5	197.3
Max.	230.4	221.4		213.5	216.5	220.3	206.1	214.9

Table 5.2 (e) Disintegration Test ^{[31, 33]}

Sr. No.	Batch 1 (Direct dry mixing)	Batch 2 (Dry granulation /slugging)	Batch 3 (Wet granulation with binder solution)	Batch 4 (Wet granulation /Intra granular, MCC)	Batch 5 (Wet granulation /Extra granular, MCC)	Batch 6 (Optimized Batch) (Wet granulation /Half Intra granular and half Extra granular MCC)	Batch 7 (Reproduced Batch) (Wet granulation /Half Intra granular and half Extra granular MCC)
1	2.04	2.33	6.48	3.39	3.11	4.25	4.38
2	1.97	2.41	6.32	3.23	3.21	4.33	4.47
3	2.08	2.28	6.43	3.39	2.58	4.29	4.29
4	1.91	2.43	6.29	3.47	3.02	4.18	4.35
5	2.05	2.35	6.56	3.27	3.24	4.37	4.42
6	2.09	2.49	6.41	3.44	3.08	4.27	4.31
Avg.	2.02	2.38	6.42	3.37	3.04	4.28	4.37
Min.	1.91	2.28	6.29	3.23	2.58	4.18	4.29
Max.	2.09	2.49	6.56	3.44	3.24	4.37	4.42
Locking length (mm)	16.02- 16.08	16.03- 16.09	16.03- 16.08	16.03- 16.09	16.02- 16.09	16.03- 16.09	16.03- 16.09

5.3 Dissolution comparison of Innovator and Final batches ^[31]

5.3 (A) Comparative release of Fluoxetine Hydrochloride in Innovator, Batch 6 (Optimized Batch) and

Batch 7 (Reproduced Batch) in Water

Medium: Water

Volume: 900 ml

Apparatus: Apparatus-II (paddle)

Speed: 50 RPM

Temperature: 37˚C±0.5˚C

Table 5.3 (a) Comparative release of Innovator, Batch 6 (Optimized Batch) and Batch 7 (Reproduced Batch) in Water

Capsule (20 mg)
Time in minutes	Cumulative % release of Fluoxetine Hydrochloride in Water
Time in minutes	Innovator	Batch 6 (Optimized Batch)	Batch 7 (Reproducible Batch)
00	00	00	00
10	88	85	86
15	94	93	95
30	96	95	96
45	96	97	98
60	97	98	98

Batch No	Difference factor	Similarity factor
6(Optimized Batch)	1	87
7(Reproducible Batch)	1	88

Fig 5.3 (a) Comparative releases of Innovator and batch 6, 7 products in water

5.3 (B) Comparative release of Innovator and Batch 6 (Optimized Batch) and

Batch 7 (Reproducible Batch) in 0.1 N HCl:

Medium: 0.1 N HCl

Volume: 900 ml

Apparatus: Apparatus-II (paddle)

Speed: 50 RPM

Temperature: 37˚C±0.5˚C

Table 5.3 (b) Comparative release of Innovator and Batch 6 (Optimized Batch) and Batch 7 (Reproducible Batch) in 0.1 N HCl

Capsule (20 mg)
Time in minutes	Cumulative % release of Fluoxetine Hydrochloride in 0.1 HCl
Time in minutes	Innovator	Batch 6 (Optimized Batch)	Batch 7 (Reproduced Batch)
00	00	00	00
10	95	92	91
15	99	94	95
30	100	96	97
45	100	98	98
60	100	99	98

Batch No	Difference factor	Similarity factor
6(Optimized Batch)	3	75
7(Reproducible Batch)	3	76

Fig 5.3 (b) Comparative releases of Innovator and batch 6, 7 products in 0.1N HCl

5.3 (C) Comparative release of Innovator and Batch 6 (Optimized Batch) and

Batch 7 (Reproducible Batch) in Phosphate buffer (pH 6.8):

Medium: Phosphate buffer (pH 6.8)

Volume: 900 ml

Apparatus: Apparatus-II (paddle)

Speed: 50 RPM

Temperature: 37˚C±0.5˚C

Table 5.3 (c) Comparative release of Innovator and Batch 6 (Optimized Batch) and Batch 7 (Reproducible Batch) in Phosphate buffer (pH 6.8):

Capsule (20 mg)
Time in minutes	Cumulative % release of Fluoxetine Hydrochloride in Phosphate Buffer (pH 6.8)
Time in minutes	Innovator	Batch 6 (Optimized Batch)	Batch 7 (Reproduced Batch)
00	00	00	00
10	74	80	73
15	89	84	80
30	95	89	88
45	96	93	96
60	99	97	101

Batch No	Difference factor	Similarity factor
6(Optimized Batch)	5	68
7(Reproducible Batch)	4	66

Fig 5.3 (c) Comparative releases of Innovator and batch 6, 7 products in phosphate buffer (pH 6.8)

5.4 Stability Studies:

Table 5.4 (a) Stability condition, duration and packaging used

Condition	40±2˚C/75±5% RH
Duration	1 month
Packaging	HDPE bottle with plastic cap, sealed with Aluminum layer

5.4 (b) Comparative release of batch 7 product initially and after 1 month stability study (40˚C/75% RH) in Water (OGD media):

Capsule (20 mg)
Time In minute	Cumulative % release of Fluoxetine Hydrochloride in Water
Time In minute	Batch 7 (Reproducible Batch, Initially)	Batch 7 (Stability for 1 Month, 40±2˚C/75±5% RH)
00	00	00
10	86	85
15	95	91
30	96	95
45	98	98
60	98	99

Batch No

Difference factor

Similarity factor

7 (stability study

for 1 month)

Fig 5.4 (a) Comparative release of batch 7 product Initially and after 1 month Stability study (40˚C/75% RH) in Water (OGD media)

5.5 DISCUSSION:

The purpose of the present work was to formulate and evaluate an immediate release capsule for antidepressant Fluoxetine Hydrochloride. Immediate release capsule was prepared by wet granulation method using different grades of microcrystalline cellulose.

Before the development of batches immediate release capsule various preformulation tests were carried out to see the Fluoxetine Hydrochloride, Excipient compatibility. Fluoxetine Hydrochloride and excipients were mixed in require ratio as per their requirement and permissible level in formulation. The powder mixture filled vials subjected at (40±2˚C/75±5% RH). The color change of mixture was observed initially and after 1 month.

Initial formulation Batch 1 was taken with Fluoxetine Hydrochloride 22.36mg/cap, MCC (Avicel 200®), 28mg/cap, and Lactose monohydrate (Granulac 200®) 99.24mg/cap in intra granular as a diluent. Colloidal silicon dioxide (Aerosil 200®) 0.4mg/cap was added as a glidant. This formulation was done by simple direct dry mixing. Granules had poor flow property and capsules were filled by using Hand filling capsule machine. But due to poor flow weight variation was observed so next trial planned by dry granulation.

Batch 2 was carried with Fluoxetine Hydrochloride 22.36mg/cap, MCC (Avicel 102®), 28mg/cap, and Lactose monohydrate (Granulac 200®) 99.24mg/cap in intra granular as a diluent, by dry granulation/slugging method but the flow was found to be very poor after adding Colloidal silicon dioxide (Aerosil 200®) 0.4mg/cap as a glidant. Capsules were filled by using Hand filling capsule machine but weight variation observed. Disintegration time of capsules was fast compared to innovator so another batch was prepared by wet granulation with binder water solution.

Batch 3 was formulated by wet granulation in RMG with Fluoxetine Hydrochloride 22.36mg/cap, MCC (Avicel 102®), 28mg/cap as diluent, anti-adherent, Lactose monohydrate (Granulac 200®) 95.74mg/cap in intra granular as a diluent, binder Povidone (Polyvinylpyrrolidone K 30®) 3.50mg/cap. The granulation was carried out with binder water solution and extra water. Colloidal silicon dioxide (Aerosil 200®) 0.4mg/cap was added as a glidant after passing the dried granules from 30# sieve. Granules had excellent flow property and capsule were filled by using Hand filling capsule machine but due to present of binder disintegration time of capsules was more above 6 minutes compared to innovator so in next batch binder was removed from formula and only water used for granulation.

Batch 4 was taken by wet granulation in RMG with Fluoxetine Hydrochloride 22.36mg/cap, MCC (Avicel 102®), 28mg/cap as diluent, anti-adherent and Lactose monohydrate (Granulac 200®) 99.24mg/cap in intra granular as a diluent, granulation was done only with water. The obtained granules was dried passed from 40# sieve than Colloidal silicon dioxide (Aerosil 200®) 0.4mg/cap was added as a glidant.. The flow of final granules were found good so capsule were filled by using Hand filling capsule machine but disintegration time of capsules was slightly less compared to innovator so in further batch MCC(Avicel 102®) was added in extra granular stage.

Batch 5 was taken by wet granulation in RMG with Fluoxetine Hydrochloride 22.36mg/cap, Lactose monohydrate (Granulac 200®) 99.24mg/cap in intra granular as a diluent, granulation was done only with water. The obtained granules was dried and passed from 40# sieve. MCC (Avicel 102®), 28mg/cap was incorporated in extra granular step as diluent, anti-adherent and Colloidal silicon dioxide (Aerosil 200®) 0.4mg/cap was added as a glidant. The flow of final granules was found passable capsule were filled by using Hand filling capsule machine. The weight variation was observed due to passable flow also Disintegration time of capsules was slightly more compared to innovator so in further batch new approach was implemented.

Batch 6 was taken by wet granulation in RMG with Fluoxetine Hydrochloride 22.36mg/cap, Lactose monohydrate (Granulac 200®) 99.24mg/cap, half quantity of MCC (Avicel 102®) 14mg/cap in intra granular as diluent, granulation was done only with water. The obtained granules was dried and passed from 40# sieve. MCC (Avicel 102®), 14mg/cap was incorporated in extra granular step as anti-adherent and Colloidal silicon dioxide (Aerosil 200®) 0.4mg/cap was added as a glidant. The flow of final granules was found good so capsules were filled by using Hand filling capsule machine. Disintegration time of capsules was in comparable to innovator so next reproducible batch planned.

Batch 7 was prepared by using the same excipients. This batch was taken to check the reproducibility of optimized batch and robustness.

In vitro dissolution analysis of batch 6(optimized batch), batch 7 (reproduced batch) were performed in USP TYPE 2(paddle) apparatus in water (OGD media), 0.1 N HCl, phosphate buffet (pH 6.8).

Granules and capsule characteristics were within the acceptable range for laboratory scale up batch as the release profile of batch 7 was found to be comparable with innovator in OGD media, 0.1 N HCl, Phosphate Buffer (pH 6.8) initially as well as after stability study 40±2˚C/75±5% RH in HDPE bottle for 1 month.

The batch was stable for 1 month at accelerated stability condition 40±2˚C/75±5% RH.

6.0 SUMMARY AND CONCLUSION:

The aim of present investigation was to formulate and evaluate a hard gelatin capsule of Fluoxetine Hydrochloride having anti-depressant activity.

Development was achieved is summarized as follows:

Initial trials showed the blend has poor flow and weight variation issue by simple dry mixing and dry granulation/slugging. Disintegration is little faster compared to innovator. To solve this problem wet granulation was done with binder water solution, it was observed that there is formation of hard granules due to presence of binder and disintegration time was more compared to innovator but excellent flow property compared to earlier batches. To decrease the disintegration time binder was removed and wet granulation was done with water only and adding intra granular and extra granular MCC in respective two batches.

Next batch was taken with combined approach of half quantity of MCC intra granular and half quantity of MCC extra granular and flow was found good and disintegration time was in accordance with innovator. Further laboratory scale up batch was taken which was comparable with innovator product in all dissolution media. Reproducible batch study helped to know about important parameters like granulating fluid, kneading time, drying time required to develop immediate release capsule with good characteristics granules.

The final weight of developed capsule is 71% to the innovator capsule, also disintegrant or surfactant was not used so formulation is economic compared to innovator. An immediate release formulation of an Anti-depressant Fluoxetine Hydrochloride was successfully formulated having attributes comparable with innovator. The formulation developed by doing above experiment is well comparable to innovator.

6.1 Future Scope:

This research project has a wide future scope to carry remaining steps of the project due to lack of time,

Ø Bioequivalence studies.

Ø Scale up batch can be taken if,

(1) Dissolution analysis data are in accordance with innovator after stability studies as per ICH guidelines,

(2) Successful bioequivalence study of scale up batches as per the regulatory bodies requirements.

(3) Process optimization study by challenging the parameters.

Ø Different strength of capsules can be developed by using this optimized formula such as 40 mg, 60 mg as per innovator.

7.0 REFERENCES:

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Received on 25.04.2014 Accepted on 15.05.2014

Asian J. Pharm. Res. 4(2): April-June 2014; Page 92-113

Parameter	Impeller	Chopper	Time
Dry mixing	250rpm	Off	180 Sec
Binder water solution (100 ml)	150rpm	Off	120 Sec
Water (50ml)	150rpm	Off	120 Sec
Kneading	200rpm	1800rpm	60 Sec

Parameter	Impeller	Chopper	Time
Dry mixing	250rpm	Off	180 Sec
water (100 ml)	150rpm	Off	120 Sec
Extra water addition (50ml)	150rpm	Off	120 Sec
Kneading	200rpm	1800rpm	60 Sec

FLUOXETINE HYDROCHLORIDE IMMEDIATE RELEASE CAPSULE(20 mg)
Serial Number	Ingredients	Function	mg/capsule	For 4000 Capsules (gm)
Wet granulation/Extra granular(MCC)
Intra granular
1	Fluoxetine Hydrochloride	API	22.36	89.44
2	Lactose Monohydrate (Granulac 102)	Diluent	99.24	396.96
3	Colloidal silicon dioxide (Aerosil 200)	Glidant	0.40	1.6
4	Purified water	solvent	q.s	q.s
Extra granular
5	Microcrystalline Cellulose (Avicel PH 102®)	Anti-adherent, Diluent	28	112
Capsule Net Weight			150 mg	600 gm

Parameter	Impeller	Chopper	Time
Dry mixing	250rpm	Off	180 Sec
water (100 ml)	150rpm	Off	120 Sec
Extra water addition (50ml)	150rpm	Off	120 Sec
Kneading	200rpm	1800rpm	60 Sec

Parameter	Impeller	Chopper	Time
Dry mixing	250rpm	Off	180 Sec
water (100 ml)	150rpm	Off	120 Sec
Extra water Addition (50ml)	150rpm	Off	120 Sec
Kneading	200rpm	1800rpm	60 Sec

Attribute	Observations (20mg)
Label claim	Each capsule contains 20mg of Fluoxetine Hydrochloride
Shape, size, and color	Size “3” capsules of opaque green cap and white body
Average weight of Capsule (mg)(n=20)	268-283
Fill weight(mg)(n=20)	218-232
Lock length (mm)	16.05-16.09
Disintegration Time (min : sec)	4:31-4.47

Capsule (20 mg)
Time in minutes	Cumulative % release of Fluoxetine Hydrochloride in Water (OGD media)
00	00
10	88
15	94
30	96
45	96
60	97

Capsule (20 mg)
Time in minute	Cumulative % release of Fluoxetine Hydrochloride
Time in minute	0.1 N HCl	Phosphate Buffer (PH 6.8)
00	00	00
10	95	74
15	99	89
30	100	95
45	100	96
60	100	98

*Corresponding Author E-mail:

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Paragraph IV certification- such patent is invalid, will not be infringed by manufacturer, use or sale of the drug product for which the ANDA is submitted.

2.0 RESEARCH ENVISAGED AND PLAN OF WORK