UV Spectrophotometric Method Development and Validation of Carbimazole in Bulk and Tablet Dosage form

 

Zainab A. Bagalkote*, Dr. Ganesh Gajeli

D.S.T.S. Mandal’s College of Pharmacy, Solapur.

*Corresponding Author E-mail: bagalkotezainab123@gmail.com

 

ABSTRACT:

Objective: A new, simple, sensitive, precise, reproducible UV visible spectrophotometric method was developed for the estimation of Carbimazole in Tablet dosage form. Methods: The UV spectrum of Carbimazole in methanol and distilled water (30:70) showed λ max at 289.6nm. Beer’s law is valid in the concentration range of 10-50µg/ml. This method was validated for linearity, accuracy, precision, ruggedness and robustness. Results: The method has demonstrated excellent linearity over the range of 10-50µg/ml with the regression equation y = 0.0232x + 0.0466, and regression coefficient i.e, r2= 0.9992 moreover, the method was found to be highly sensitive with LOD (1.818µg/ml) and LOQ (5.509µg/ml). Conclusion: From the results it can be concluded that the given method can be successfully applied for assay of Carbimazole in Tablet dosage form.

 

KEYWORDS: Carbimazole, UV spectroscopy, Method development and Validation, Methanol and Distilled Water, Tablet formulation.

 

 


INTRODUCTION:

Hyperthyroidism is a condition characterized by increased in synthesis and secretion of thyroid hormones from thyroid gland.1 Carbimazole is an antihyperthyroidism drug.2 It is a pro-drug and after absorption it gets converted to active form, methimazole.3 Methimazole acts by preventing the thyroid peroxidase enzyme and reducing the production of the thyroid hormones T3 and T4 (thyroxine).4

 

Carbimazole is rapidly and almost completely converted to methimazole, either in the gastrointestinal tract or immediately after absorption, because drug concentrations of methimazole but not carbimazole are detected in the serum and thyroid gland after ingestion. Carbimazole (CBZ) is rapidly metabolized in serum to methimazole (MMI).5

 

Figure 1: Chemical Structure of Carbimazole

 

The Chemical name of Carbimazole is (Ethyl 3-methyl-2-sulfanylidene-2,3-dihydro-1H-imidazole-1-carboxylate).6 The molecular formula of Carbimazole is C7H10N2O2S and molecular weight is 186.232gm/mol. Carbimazole is white powder and has melting point 122o to 125oC. It is freely soluble in water, methanol, ethanol and chloroform.7,8 The aim of this study is to introduce a new, simple, sensitive, precise and reproducible UV spectroscopic method for the estimation of Carbimazole in bulk and tablet formulation.

 

MATERIALS AND METHODS:

Chemicals:

Carbimazole was taken as a gift sample from Aadhar life Sciences, Pvt. Ltd. Chincholi, Solapur. Distilled water and methanol was taken of analytical grade.

 

Instruments:

Analytical balance (AczetCY224C), Sonicator (Labman), UV-Visible Double Beam Spectrophotometer (Systronic 2201).

 

Experimental:

Preparation of standard stock solution:

Accurately weighed 10mg of Carbimazole was transferred to 10ml volumetric flask. It was dissolved in small quantity of methanol: distilled water (30:70) and sonicated for 2 minutes. The volume was made up to the mark with same diluent to make up final strength. (1000µg/ml).

 

Preparation of Working stock solution:

1ml of standard stock solution was transferred in 10ml volumetric flask and 5ml of diluent was added, mixed for 2 minutes. The volume was made upto the mark with same diluent. (100µg/ml).

 

Determination of Absorption maxima:

Working stock solution (100µg/ml) was scanned in the range of 200-800nm for the analysis of absorption maxima of Carbimazole. The absorbance was measured at wavelength 289.6nm using blank solution.

Procedure for plotting calibration curve:

For plotting of calibration curve, in a series of 10ml volumetric flasks, 1ml, 2ml, 3ml, 4ml and 5ml of working stock solution (100µg/ml) was pipetted out separately. The volume was made upto the mark using methanol: distilled water (30:70) to get 10µg/ml, 20 µg/ml, 30µg/ml, 40µg/ml, 50µg/ml respectively.

 

Assay of Carbimazole:

a. Tablet stock solution (TSS):

10 tablets were weighed and average weight of tablet was calculated and tablets were crushed in mortar and pestle. Accurately weighed powder equivalent to 10 mg of Carbimazole was weighed and transferred into 10 ml volumetric flask and 5ml methanol: distilled water (30:70) was added, sonicated for 10 minutes and volume was made upto mark with same diluent. (1000µg/ml)

 

b. Tablet sample:

1 ml of filtered TSS was transferred to 10ml volumetric flask and 5ml diluent was added, sonicated for 10 minutes and the volume was made to 10ml with diluent (100 µg/ml). Further again 3ml of this solution was pipetted out and diluted upto 10ml using same diluent (30µg/ml). The % purity of Carbimazole was calculated.

 

RESULTS AND DISCUSSION:

The absorption spectrum shows λ max of Carbimazole at 289.6nm.

 


Figure 2: UV-visible Spectra of Carbimazole

 


Method Validation9:

1.     Linearity:

Five different concentrations of Carbimazole were prepared and analysed at wavelength 289.6nm. The regression coefficient was found to be 0.9992. The absorbance was found in limit i.e, 0-1. Hence the analysed parameter was found to be validated (Refer Table No.1)

 

 

Table 1: Results of Linearity

Sr No.

Conc (ug/ml)

Absorbance

1

10

0.277

2

20

0.514

 3

30

0.734

4

40

0.992

5

50

1.199

 

Figure 3: Calibration curve for Carbimazole

 

 

2.     Range:

The analytical parameter range is the difference between upper and lower concentration limit. The range was found to be 10-50µg/ml.

 

3.     Accuracy:

The concentration 24µg/ml, 30µg/ml and 36µg/ml was taken as 80%, 100% and 120% by spiking 2.4 ml,3ml, and 3.6ml of Carbimazole stock solution of 100µg/ml. Samples were injected in triplicate to calculate % RSD % recovery was found to be in range 99%-101%. Hence the parameter was found to be validated. (Refer Table No.2)


Table 2: Accuracy results of Carbimazole

Name of Drug

Recovery Level in %

Concentration µg/ml

Amount Recovered

% recovery with SD

 

80

24

24.01

100.04±0.003

Carbimazole

100

30

29.98

99.93±0.002

 

120

36

35.92

99.7±0.003

 

Name of Drug

Recovery Level in %

Concentration

Amount Recovered

% recovery with SD

Carbimazole

 

80

24 µg/ml

24.01

100.04±0.003

100

30 µg/ml

29.98

99.93±0.002

120

36µg/ml

35.92

99.7±0.003

 


4.     Precision:

In precision intra-day and inter-day precision studies were performed at concentration 30µg/ml. The obtained results were found within limit i.e, less than 2% RSD. (Refer Table No.3 a and b)

 

Table 3: (a) Result for precision (Intra-day)

Sr. No.

Concentration

Absorbance

1

 

 

30(µg/ml)

0.734

2

0.735

3

0.734

4

0.737

5

0.734

6

 

0.735

 

SD

0.001169

%RSD

0.15909

 

Table 3: (b) Result for precision (Inter day)

Sr No.

Concentration

Absorbance (Day1)

Absorbance (Day2)

1

 

 

30(µg/ml)

0.734

0.736

2

0.735

0.735

3

0.734

0.736

4

0.737

0.734

5

0.734

0.734

6

 

0.735

0.733

SD

0.001169

0.01211

%RSD

0.15909

0.164845

 

5.     Limit of Detection (LOD) and Limit of Quantitation (LOQ):

The sensitivity of developed method was determined in terms of LOD and LOQ and it was calculated using standard deviation method. LOD (1.818µg/ml) and LOQ (5.509µg/ml).

 

6.     Ruggedness:

The change in analyst and laboratories with same concentration of 15µg/ml and environmental conditions didn’t affect the results. Hence the parameter was found to be validated. (Refer Table No.5)

 

7.     Robustness:

The deliberate change in wavelength (289nm and 292nm) and concentration (15µg/ml) in the same environmental conditions didn’t affect the results. Hence the parameter was found to be validated. (Refer Table No.5)

 

Assay:

The assay was performed by using Carbimazole Tablets I.P 5mg at concentration 30µg/ml. The % purity was found to be (Refer Table No.4)

 

Table 4: Assay results of Carbimazole

Formulation

Labeled Amount

Amount obtained

% recovery

Carbimazole Tablet

5mg

4.98mg

98.4

 

Summary of parameters:

Table 5: Summary of parameters of developed method

Parameters

Results

Detection Wavelength

289.6

Beer’s Law (µg/ml)

10-50

Correlation Coefficient (r2)

0.9992

Regression Equation

y = 0.0232x + 0.0466

Slope (m)

0.0232

Intercept (c)

0.0466

Accuracy (%mean recovery):

 

80% level

100.04%

100% level

99.93%

120% level

99.7%

Precision:

Intra-day

0.15909

Inter-day

0.15909-0.164845

LOD

1.818µg/ml

LOQ

5.509µg/ml

Ruggedness

Analyst1 and Analyst2

0.000816 and 0.001049

Robustness

 

At 289nm and 292nm

0.000816 and 0.000753

 

CONCLUSION:

An analytical UV spectrophotometric method was developed and validated thoroughly for quantitative estimation of Carbimazole in Tablet Formulation. The presented method was found to be simple, precise, accurate, and reproducible gives an acceptable recovery of the analyte, which can be directly and easily applied to the analysis of pharmaceutical Tablet formulation of Carbimazole.

 

ACKNOWLEDGEMENT:

Authors are thankful to the Principal, D.S.T.S. Mandal’s College of Pharmacy, Solapur, for providing necessary facilities.

 

REFERENCES:

1.      S. De Leo, S.Y. Lee, L.E. Braverman Hyperthyroidism. LANCET, 388(2016), pp. 906-908

2.      Abeer A. Sharfalddin, Mostafa A. Hussien. Bivalence metal complexes of antithyroid drug Carbimazole: synthesis, characterization, computational simulation, and biological studies. Journal of molecular structure 2021,1228,129725

3.      Lewis A, Tzilivakis J, warner D and Green. An International journal 2016;22(4):1050-1064

4.      Antithyroid drug carbimazole and its analogues: Synthesis and inhibition of peroxidase –Catalyzed iodination of L-tyrosin –Journal of medicinal chemistry.2008;51:7313-7317.

5.      Determination of methimazole in urine by liquid chromatography. Talanta 2007; 71: 2121-2124.

6.      Barzegar M, Jabbari A, and Mousavi F. Anal. Chem. 2004; 51: 363-366

7.      https://www.drugbank.ca/drugs/DB00389

8.      Avinash V., et al. “Quantitative estimation of carbimazole by UV derivative spectrophotometry in bulk drug and tablet formulation”. American Journal of Pharm Tech Research. 2012; 2:67-68.

9.      ICH Q2 (R1) validation of analytical procedures: text and methodology, International Conference on Harmonization, November, 1996, 1-15.

 

 

 

Received on 27.03.2021            Modified on 05.05.2021

Accepted on 02.06.2021   ©Asian Pharma Press All Right Reserved

Asian J. Pharm. Res. 2021; 11(3):163-166.

DOI: 10.52711/2231-5691.2021.00030