INTRODUCTION:

A generic drug is a chemically equivalent, lower cost version of brand name drug, costing 30-80 percent less. A brand name drug and its generic version must have the same active ingredient, dosage, safety, strength, usage direction, quality performance and intended use. When a doctor is writing a prescription, or a consumer is buying an over-the-counter medicine, they may have a choice between a branded medicine and the generic version of that medicine. Generic medicines are sometimes cheaper than brand-name medicines, but the active ingredient is the same in both. Medicines also contain inactive ingredients, which are used to formulate the active ingredient into a tablet, liquid, cream or other preparation.

These inactive ingredients are called excipients, and different manufacturers do not always use the same ones when formulating their product. This is why medicines containing the same active ingredient, but made by different manufacturers, may vary in appearance. The excipients used may create small differences between them, such as in color, or the amount of time it takes for a tablet to dissolve in the gut and be absorbed into the bloodstream. However, these differences are rarely significant, which is why generic and branded medicines are (with a few exceptions) interchangeable. The availability and utilization of generic alternatives to brand-name drugs has had a significant effect on cost savings for health care consumers. On average, generic medications are 87% less expensive than their branded counterparts.⁴

Clotrimazole Cream:

Clotrimazole Cream USP, 1% contains clotrimazole, a synthetic antifungal agent having the chemical name {1-(o-Chloro-α, α-diphenylbenzyl) imidazole}; the molecular formula C₂₂H₁₇ClN₂; a molecular weight of 344.84. Clotrimazole is a broad-spectrum antifungal agent that is used for the treatment of dermal infections caused by various species of pathogenic dermatophytes, yeasts, and Malassezia furfur. The primary action of clotrimazole is against dividing and growing organisms.⁵

Dosage and Administration:

Gently massage sufficient Clotrimazole Cream into the affected and surrounding skin areas twice a day, in the morning and evening.⁶

MATERIALS:

Fungid B antifungal cream , Bestochem Formulations (India) is selected as model branded drug which contains 1% clotrimazole and base ,a generic antifungal drug with similar composition was selected as model generic drug, pH meter with glass electrode (Hanna ltd) were used for pHdetermination, Spreadablity apparatus (Telmo India) were used to determine spreadablity of cream, Franz diffusion cell (Unico India) were used for absorption study, fungal culture of Candida albican were obtained from RCP Kasegaon for antifungal assay.

METHODS:

Evaluation Tests of Cream:

1) Physical Characteristics

a) Color:

Color of both branded and generic cream was examined behind both black and white background.

b) pH:

pH of both creams generic and branded were determined on the calibrated pH meter.⁶

c) Spread Ability:

The spread ability determination: excess of sample was applied in between two glass slides and compressed to uniform thickness by placing 500gm weight for five minute. 80 gm weight was added to pan. The time required to separate the two slides i.e. time in which the upper glass slide moved over lower plate was taken measure spread ability.

Spraedability (S) - M x L/t (in cm.gm/sec.)

Where:-

M= Weight of pan,

L= Distance travelled by upper slid and

t=Time required to cover distance.³

d) Determination of Permeability:

The absorption of both the formulation were determined with Franz diffusion cell and compared. Franz diffusion cells with a diffusion area of 4.7cm² and 37ml capacity were used. Cellophane membrane between the donor and receptor compartment of the cell were placed. Receptor compartment with approximately 37ml of phosphate buffer pH 5.8 was filled and temperature of cell was maintained at 37 c by means of circulating contents of a thermostatic water bath by a pump through the surrounding layer of the cell. Content of receptor compartment were stirred at 600 rpm with Teflon-coated magnetic bar placed inside cell throughout experiment. 1gm of Clotrimazole cream was placed in a donor compartment and donor cell were covered with aluminum foil to avoid evaporation.1ml of sample from receptor compartment was removed and immediately replaced with 1ml receptor solution at the same temperature. Sample was analyzed on UV spectrophotometer at the 270nm.²

e) Antifungal activity:

The antifungal activity of both branded and generic drugs were determined and compared by cup plate method. Sabouraud dextrose agar was used for assay. After growth of fungi two bores were prepared in Petri dish by using flame sterilized cork borer of same internal dimensions. Then both antifungal cream of same composition was poured in the two separate bores. The dose of both creams for assay was kept same i.e. 0.8 gms in both bores and antifungal activity was determined and compared.¹

RESULTS:

1) Physical and rheological properties of generic and branded clotrimazole cream

Table 1. Physical and rheological properties

Physical and Rheological parameters	Branded cream (Candid-B)	Generic cream (Fungdid-B)
Color	White	white
Ph	5.70	6.50
Spraedability	86.66 cm/gm.sec	172.8 cm/gm.sec

2) Permeability study of generic and branded clotrimazole cream

Table 2. Determination of permeability

Sr. No.	Time (min)	Absorbance (Branded)	Absorbance (Generic)
1	10	0.137	0.052
2	20	0.225	0.080
3	30	0.275	0.082
4	40	0.245	0.099
5	50	0.245	0.100
7	70	0.286	0.103
8	80	0.287	0.103
9	90	0.329	0.105
10	100	0.393	0.105

3) Antifungal activity

Table 3. Antifungal activity

Types of cream	Zone of inhibition ( in cm)	Average zone of inhibition ( in cm)
Branded cream ( Candid – B)	1.1	0.42
	0.4
	0.1
	0.1
Generic cream ( Fungdid – B)	1	0.4
	0.3
	0.2
	0.1

CONCLUSION:

From experimental evaluation here we conclude that generic drug in antifungal cream category has been shown similar antifungal activity as branded drug through also has been shown less absorption by comparing price structure of both drug, the generic drug are much more patient compliant than branded drug .

REFERENCES:

1. Kokare C. Pharmaceutical Microbiology, Experiments And Techniques, 3^{rd edition}, Career Publications

2. Mehta RM. Dispensing Pharmacy, 4^thedition, Vallabh Prakashan.

3. Dias RJ, Bhise SB, Dhawale SC, Mali KK, Laboratory Manual of Biopharmaceutics and Pharmacokinetics, Trinity Publishing House.

4. Suzanne Dunne, Bill Shannon, Colum Dunne and Walter Cullen, A review of the differences and similarities between generic drugs and their originator counterparts, including economic benefits associated with usage of generic medicines, using Ireland as a case study, Pharmacology and Toxicology 2013, 14:1.

5. Xiao fang Zhou, Ting Li, Shangrong Fan,1,2,3 Yuxia Zhu,1 Xiaoping Liu,4 Xuedong Guo1 and Yiheng Liang1, The efficacy and safety of clotrimazole vaginal tablet vs. oral fluconazole in treating severe vulvovaginal candidiasis, Mycoses, 2016, 59, 419–428.

6. G Rajalakshimi,N Damodharan,Chaudhary Vijay KumarVaghaji Bhai and Pogal Janardhan Reddy R,

7. Formulation and evaluation of Clotrimazole and Ichthamol ointment, International journal of pharma and bioscience, Vol.1/Issue-4/Oct-Dec.2010

Received on 06.09.2016 Accepted on 20.11.2016

Asian J. Res. Pharm. Sci. 2016; 6(4): 205-207.

DOI: 10.5958/2231-5659.2016.00029.1

ABSTRACT: