Formulation and Evaluation of Antimicrobial Gels using Essential Oils

Vaishali Kulkarni*, Nayana Jain, Rutuja Shinde, Swarda Kamble

Sinhgad College of Pharmacy, Vadgaon, Pune, Maharashtra, India.

*Corresponding Author E-mail: vaishalikulkarni115@gmail.com, jnayana690@gmail.com, psrutu96@gmail.com, swarda.kamble@gmail.com

ABSTRACT:

Herbal Formulation has been accepted as a therapeutic agent for several diseases, due to its efficiency AND fewer side effect. This present research has been undertaken with the aim to formulate & evaluate herbal antimicrobial gels using essential oils (Rose Oil, Almond oil, Lemon Oil, Citronella Oil) gel formulations were prepared using Carbopol 940, ethanol, PEG 400 and required amount of distilled water. The physical parameters of formulated gels like colour, homogeneity, pH, viscosity and spreadability were evaluated. The gels were evaluated for antibacterial efficiency by the agar diffusion method against S. Aureus, E. coli. The herbal gels showed that formulations containing Essential oils have better antibacterial activity.

KEYWORDS: Essential Oils, Rose Oil, Almond oil, Lemon Oil, Citronella Oil, Antimicrobial gels.

INTRODUCTION:

Since ancient times, herbal- or plant-based medicines have served as a platform for the prevention and cure of diseases and to date, many more constituents of these natural sources are yet to be explored. This has enlightened scientists to find newer compounds from herbal sources to treat many infectious diseases. Reports show that most medicinal plants possess antimicrobial, antioxidant, and anti-inflammatory properties, which have paved the way for the prevention of many infectious diseases and potential benefits for society.¹ The present scenario of infectious diseases shows that there has been an alarming increase in the incidence of new and remerging infectious diseases.² Essential oils are one of the most notorious natural products used for medical purposes. Combined with their popular use in dermatology, their availability, and the development of antimicrobial resistance, commercial essential oils are often an option for therapy.³

Therefore, the present study aimed to develop and evaluate antimicrobial gels for topical purposes in the treatment of skin conditions like acne, boils, folliculitis, impetigo, etc and perform a comparative study of the antimicrobial actions of different essential oils like rose and almond oil.

MATERIALS AND METHODS:

Essential oils used are rose oil, almond oil, lemon oil, Citronella oil purchased from Store Kelkar Frgrances Pune.

Formulation and Development of antimicrobial herbal Gels:

Carbopol 940 was mixed in sufficient quantity of water to form a clear gel with thick consistency and left overnight for swelling. Rose oil, almond oil, Lemon Oil and Citronella Oil were individually dissolved in equal amount of ethanol for each Bach. Further PEG 400 were added. The liquid solutions of essential oils were mixed with the gel base using mechanical stirrer for 10-15mins. Tabel no.1 shows the all the ingredients with each Bach and essential Oil 6

Tabel no.1 Formulation of Antimicrobial gel using volatile Oils.

	Almond Oil gel			Rose Oil gel			Lemon Oil gel			Citronella Oil gel
Ingredients	F1	F2	F3	F1	F2	F3	F1	F2	F3	F1	F2	F3
Essential oil (ml)	1	2	3	1	2	3	1	2	3	1	2	3
Carbopol 940 (g)	0.15	0.15	0.15	0.15	0.15	0.15	0.15	0.15	0.15	0.15	0.15	0.15
Ethanol (ml)	0.4	0.4	0.4	0.4	0.4	0.4	0.4	0.4	0.4	0.4	0.4	0.4
PEG 400(g)	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5	0.5
Distilled Water (Q.S)upto10(m)	10	10	10	10	10	10	10	10	10	10	10	10

a. F1, F2. F3- Formulation Trial batches

Evaluation parameters:

Physical Evaluation:

The prepared antimicrobial gel was inspected for visual appearance (colour, homogeneity, and consistency), olfactory (smell), and tactile (feel upon application).⁷

pH:

The pH was determined by pH meter⁸.

Viscosity: The viscosity of antimicrobial gel is measured by Brookfield viscometer⁹.

Spreadability:

The spreadability of gel formulations was determined by measuring the spreading diameter of 1g of gel between two horizontal plates.⁴

Stability Studies:

Anti-microbial gels were subjected for stability studies for a period of 15 days at different temperatures for physical stability and pH¹⁰

Antibacterial activity:

The antibacterial screening of herbal gels was done by disc diffusion method. The gels were tested against bacterial agents namely S. aureus and E. coli. A loopful of the pure bacterial culture was suspended in nutrient broth and incubated for 24hours. Nutrient agar media was sterilized and poured into petri plates. After solidification, 0.1ml of the inoculum was spread over the agar evenly using a rod. 6mm diameter cavity was prepared and formulated gel is placed in the cavity. A standard, povidone iodine was used as the control. The inoculated plates are incubated for 24hours. Later, the zone of inhibition around the disc was measured and recorded. It is a circular area around the cavity, in which antimicrobial gel is poured and where the bacterial colonies cannot grow or are killed. It was measured using Vernier caliper.⁵

RESULTS:

Physical evaluation:

All the prepared gels using different Essential Oils in different concentrations were white to light yellowish in colour which feels smooth on application. The prepared gel have an aromatic odourShown in Table no. 2.

pH:

The pH of all the four formulations was in the range of the pH of the skin i.e. 4 to 5.5 which are in range shown in Table no.2.

Viscosity:

Viscosities of the gels were measured by the Brookfield viscometer in centipoises. The viscosity of different formulations at different rpm are given in table no.2.

Table 2: Physical Evaluation, pH, Viscosity, Spreadability Studies of Antimicrobial Gels.

Formulations		Appearance	Texture of gel	Odour	pH	Viscosity (2r/min) Cp	Spreadability (mm)
Almond Oil gel	F1	Off-white	Smooth	Aromatic	5.4	1223	38
	F2	Off-white	Smooth	Aromatic	5.5	1206	35
	F3	Off-white	Smooth	Aromatic	5.5	1201	34
Rose Oil gel	F1	White, Clear	Smooth	Aromatic	5.9	1250	48
	F2	White, Clear	Smooth	Aromatic	5.1	1245	46
	F3	White, Clear	Smooth	Aromatic	5.1	1241	45
Lemon Oil gel	F1	Yellowish	Smooth	Aromatic	5.4	1240	44
	F2	Yellowish	Smooth	Aromatic	5.1	1238	43
	F3	Yellowish	Smooth	Aromatic	5.3	1230	41
Citronella Oil gel	F1	Yellowish	Smooth	Aromatic	5.3	1229	39
	F2	Yellowish	Smooth	Aromatic	5.4	1220	37
	F3	Yellowish	Smooth	Aromatic	5.6	1200	34

Tabel No. 3 Antimicribial Activity of herbal gels

Test	Rose Oil				Almond Oil				Lemon Oil				Citronella Oil
organism	STD	F1	F2	F3	STD	F1	F2	F3	STD	F1	F2	F3	STD	F1	F2	F3
S. Aureus (cm)	2.7	1.0	2.8	3.4	2.7	2	2.9	3.8	2.7	1.2	2.6	3.2	2.7	1.6	2.4	3.1
E. Coli (cm)	2.5	0.8	3.0	3.6	2.5	0.9	3.1	3.7	2.5	0.7	2.8	3.4	2.5	1.2	2.1	2.8

Table No. 4: Stability Study of Antimicrobial gels

Test parameter		Lemon oil gel			Citronella oil gel			Rose oil gel			Almond oil gel
pH	Storage conditions	F1	F2	F3	F1	F2	F3	F1	F2	F3	F1	F2	F3
	Intermediate	5.8	5.9	5.1	5.1	5.2	5.5	5.6	5.8	5.9	5.3	5.4	5.3
	Accelerated ambient	5.4	5.7	5.9	5.9	5.2	5.3	5.5	5.6	5.7	5.2	5.4	5.1
	Accelerated refrigerated	5.9	5.6	5.3	5.2	5.4	5.7	5.9	5.1	5.1	5.4	5.5	5.5

Spreadability:

All the prepared gels using different polymers in different concentrations were spreadable. The formulation F-1 showed the maximum Spreadability followed by second and third shown in table no.2.

Anti-microbial study: the antimicrobial activity of antimicrobial gel was found to be better than standard Povidone iodine as the zone of inhibition of antimicrobial gel was found to be better than against both the bacteria S. aureus and E. coli and the values are given in the Table no. 3.

It was found that F-3 gels formulation was having best antimicrobial activity when compared with F-1, F-2 and standard.

Stability studies:

After 15 days of storage at room temperature, humidity chamber and refrigerated temperature there is no microbial growth and no change in the appearance of the prepared gel formulations. However, the pH of the gels kept in the refrigerator remained constant while that of the gels kept in humidity temperature and room temperature had slightly decreased but were still in the limits of skin pH, results as shown in table no.4.

DISCUSSION:

The colour of all the formulated herbal gels was white to yellowish and all the herbal gels were good in homogeneity. The pH of all the formulated gels was in the range of 5.1 - 5.9 matching with skin pH range. Viscosity of all the herbal gels was ranging from 1200 -1250 cp at 2rpm measured with Brookfield viscometer. The spreadability of all herbal gels was in the range of 34-48mm. The antibacterial activity of all the formulated herbal gels showed good results of zone of inhibition against skin pathogens.

CONCLUSION:

From the present investigation, it has been revealed that herbal gels different essential oils can be formulated using carbopol 940 as polymer with other ingredients and the evaluation of physical parameters shown satisfactory results. From the antibacterial activity it was found that prepared herbal gels of essential oils were significantly active against tested pathogens which was comparable with standard antibiotic. Hence, from the overall results, finally it was concluded that the formulated herbal gels have significant antimicrobial properties and hence will be better, safe and effective than allopathic medications.

ACKNOWLEDGEMENT:

The authors would like to thank authorities Sinhgad College of Pharmacy, Vadgaon, Pune for providing necessary facilities and support for carrying out this Research work.

REFERENCES:

1. Bhatia L, Bishnoi H, Chauhan P, Kinja K, Shailesh S. In-vitro comparative antioxidant activity of ethanolic extracts of glycosmis pentaphylla and bauhinia variegate. Recent Res Sci Technol. 2011; 3: 1–3.

2. Vidya V., Aleykutty NA, Jaykar B, Zachariah SM, Thomas L. Studies on antimicrobial and antioxidant activity of Methanolic extract of Samadera indica. Int J Pharma Sci Rev Res. 2011; 11: 59-64.

3. Ané O., Sandy V. Commercial Essential Oils as Potential Antimicrobials to Treat Skin Diseases Evidence-Based Complementary and Alternative Medicine. 2017; 92-94.

4. Ajinkya MB., Manjusha ND. Formulation and evaluation of herbal antimicrobial gel containing Musa acuminata leaves extract. J Pharamcog Phytochem. 2016; 5(1): 1-3.

5. Sandeep DS., Prashant N., Jobin J., Rishal R., Sumana DR. Formulation and evaluation of antibacterial herbal gels of Murraya koenigii leaves extract. Research Journal of Pharmacy and Technology. 2017; 10(6): 1-4.

6. Pooja S., Ujjwal N. Formulation and evaluation of anti-microbial gel using lavender oil and rosemary oil. International Journal of Health and Clinical Research. 2020; 3(1): 1-6.

7. K. Kumari et al.Formulation and evaluation of topical hydrogel of Mometasoncfuroate using different polymers. International Journal of Pharmaceutical and Chemical Sciences. 2013; 2 (1): 89-100.

8. Patel Japan, Patel B. Formulation and Evaluation of topical Aceclofenac gel using different gelling agent. International Journal of Drug Development and Research. 2011; 3(1): 156-164.

9. Chandira R.M. Design, Development and formulation of Antiacne Dermatological gel. Journal of Chemical and Pharmaceutical Research. 2010; 2(1): 401-404.

10. Lognathan V, Manimaran S, Jaswanth A, Sulaiman A, Reddy MVS, Kumar BS, Rajaseskaran A. The effects of polymers and permeation enhancers on the releases of flurbiprofen from gel formulations. Indian J Pharm Sci.2001; 63(3): 200-204.

11. J. P. Noudogbessi, P. Sessou, V. D. Wotto, G. Figueredo, P. Chalard, J. C. Chalchat, K. Dansou, D. C. K. Sohounhloué. Chemical Compositions and Preventive Activity of Essential Oils Extracted from the Leaves of two varieties of Tephrosia (Leguminosae-papilionoideae) collected in Benin on Callosobruchus maculatus (Fabricius). Asian J. Research Chem. 2012; 5(12): 1431-1436.

12. Shruthi Chandrasekaran, Geetha. R.V. Antibacterial Activity of the Three Essential Oils on Oral Pathogens- An In-vitro Study. Research J. Pharm. and Tech. 2014; 7(10): 1128-1129

13. S. Subasree, Geetha R. V. Essential oils in prevention of Dental Caries - An In-Vitro study. Research J. Pharm. and Tech. 2015; 8(7): 909-911.

14. Rim M. Harfouch, Manal Darwish, Wisam Al-Asadi, Ali F. Mohammad, Nour M. Gharib, Mohammad Haroun. Antibacterial Activity of Essential Oils of Rosmarinus officinalis, Salvia officinalis and Anthemis nobilis Widespread in the Syrian Coast. Research J. Pharm. and Tech. 2019; 12(7):3410-3412.

15. Monika Gupta, Aditi Gupta, Sudhakar Gupta. Insecticidal Activity of Essential Oils Obtained from Piper nigrum and Psoralea corylifolia Seeds against Agricultural Pests. Asian J. Research Chem. 2013; 6(4): 360-363.