Indian J. Pharm. Biol. Res. 2020; 8(3): 1-11 ISSN: 2320-9267 Indian Journal of Pharmaceutical and Biological Research (IJPBR) Journal homepage: www.ijpbr.in ORIGINAL ARTICLE Novel Emulsion Base for Vaginal Yeast Infection with Half Drug Concentration Rigved Nagarkar 1 *, Manan Patel 1,2 , Almas Babar 1 ABSTRACT The dissolution of the drug in the vaginal cavity strongly infuences the efcacy of the product due to insufcient moisture at the vaginal site. This study was undertaken to develop semi-solid dosage forms of miconazole nitrate to optimize its release. Formulations containing miconazole nitrate at 2% were developed using hypromellose gel, non- ionic emulsion, and cationic emulsion. The efect of penetration enhancers such as propylene glycol, dimethyl sulfoxide (DMSO), and diethylene glycol monoethyl ether at various concentrations was studied. Difusion studies were carried out to evaluate the drug release and compared it against a commercial product. Formulation with the highest drug release was further evaluated at half (1%) drug concentration. Formulation with reduced drug levels along with the commercial product was evaluated for drug release for an extended time using human cadaver skin. The general order of average cumulative drug release from three bases was observed to be cationic emulsion > hydroxypropyl methylcellulose >non- ionic emulsion. Among all samples, the cationic emulsion with 5% DMSO gave a maximum drug release of 7.27 ± 0.2 mg/cm 2 with a fux of 0.70 mg/cm 2 /min compared to only 3.09 ± 0.1 mg/cm 2 drug release with 0.51 mg/cm 2 /min fux for brand product. The average cumulative drug release for formulation with half (1%) drug and brand (2% drug) over a period of 12 h through human cadaver skin was observed to be 8.28 ± 0.9 mg/cm 2 and 8.71 ± 0.9 mg/cm 2 , respectively. This observation was in conformance with the in vitro antifungal studies showing an equivalent zone of inhibition. Keywords: Cationic emulsion, Drug release, Dimethylsulfoxide, In vitro antifungal study. Indian J. Pharm. Biol. Res. (2020): https://doi.org/10.30750/ijpbr.8.3.1 INTRODUCTION In recent years, the pharmaceutical industry is investing a maximum of their R&D eforts into the development of delivery systems, rather than pouring millions of dollars in inventing new molecules. This approach of new drug delivery systems is a potential pathway through which companies can optimize drug-formulation systems to have a maximum therapeutic beneft with minimum toxic efects. To achieve this goal, the area in focus is the improvement of formulation characteristics to improve or enhance its clinical efcacy. Drugs are delivered and marketed in various drug delivery systems, namely, oral, parenteral, sublingual, and topical. Topical drug delivery has taken a noticeable growth in recent years due to its obvious advantages such as avoiding frst-pass metabolism, patient compliance, and others. [1] Topical dosage form includes creams, ointments, gel, solution, lotion, and spray. [2] Creams are mostly emulsion-based products which are either water in oil or oil in water type. Emulsions are a mixture of the oil phase and water phase stabilized by surfactant(s). [3] The nature and concentration of surfactants play an important role in the emulsion type and stability. For instance, a surfactant with a high hydrophilic-lipophilic balance (HLB) will form an oil- in-water emulsion, whereas a low HLB value surfactant 1 Department of Pharmaceutical Sciences, Arnold and Marie Schwartz College of Pharmacy, Long Island University, 1 University Plaza, Brooklyn, New York 11201, USA 2 Department of Research and Development, Biolink Life Sciences, 250 Quade Dr, Cary, New York 27513, USA Corresponding Author: Rigved Nagarkar, Department of Pharmaceutical Sciences, Arnold and Marie Schwartz College of Pharmacy, Long Island University, 1 University Plaza, Brooklyn, New York 11201, USA. Tel.: (516) 444 8882. E-mail: rigved.n@ gmail.com How to cite this article: Nagarkar R, Patel M, Babar A. Novel Emulsion Based for Vaginal Yeast Infection with Half Drug Concentration. Indian J. Pharm. Biol. Res. 2020;8(3):1-11. Source of support: Nil Conficts of interest: None Received: 28/05/2020 Revised: 20/06/2020 Accepted: 15/07/2020 Published: 30/09/2020 ©2020 The Author(s). This is an open access article distributed under the terms of the Creative Commons Attribution License (http:// creativecommons.org/ licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. will form a water in oil emulsion. Surfactants, based on the charge on the molecule, can be classifed as anionic, cationic, and non-ionic. Permeation enhancers are a class of substances which stimulate the absorption of the drug through the skin. [4] Permeation enhancers or permeability enhancers increase the absorption of the drug by two diferent techniques. Some group of enhancers increases