314 J. Cosmet. Sci., 73, 314–328 (September/October 2022) Address all correspondence to S. Nagalakshmi, nagalakshmi.s@sriramachandra.edu.in Design, Development, and Evaluation of Microsponge Loaded Topical Gel Using Design Expert With Benzoyl Peroxide for the Treatment of Acne Vulgaris ALLAN JOSHUA I., A. ROSHINI, R. JAGADEESH KUMAR, S. VARSHINI, S. MANIKANDAN AND S. NAGALAKSHMI Department of Pharmaceutics, Sri Ramachandra Faculty of Pharmacy at SRIHER, Porur, Chennai, India (A.J.I., A.R., R.J.K., S.V., S.M., S.N.) Accepted for publication December 19, 2022. Synopsis This study involves the fabrication of a dosage form for acne treatment. A semi-solid dosage form of microsponge loaded topical gel with benzoyl peroxide and poly lactic-co-glycolic acid (PLGA) was developed. Formulation was prepared using PLGA, span, and polyvinyl alcohol. Optimization of the formulation was done by design of experiments response surface methodology using a central composite method. The microsponge was prepared by a quasi-emulsion solvent diffusion method. Central composite experimental design was used for optimization of the formulation with respect to entrapment efficiency and in vitro drug release. A benzoyl peroxide–loaded PLGA microsponge formulation was prepared and characterized with respect to drug content, drug release, and morphology. Drug release was found to be 52.42% for PLGA-loaded microsponges. The optimized microsponges containing PLGA were converted into a topical gel using benzoyl peroxide as a drug. Carbopol was used as a gelling agent for the optimized microsponge formulation containing PLGA. The gel showed pseudoplastic behavior with a high value of spreading capacity. It was translucent without the presence of foreign particles. Evaluation parameters for microsponges loaded topic gel, such as determination of pH (5.82), spreadability (5.9), viscosity 50 rpm (1253 cp), drug content (98.07%), and in vitro drug release (50.42), were performed for the designed topical semi-solid dosage form. INTRODUCTION Acne is one of the most common skin conditions, affecting people across the universe. It commonly starts during puberty (between the ages of 10–13), is more prominent in people with oily skin, and usually disappears during the early 20 ages (1). Acne is mainly driven by male hormones, which usually become active during the teenage years (2). Sensitivity to such hormones, combined with surface bacteria on the skin, Propionibacterium acne, and lipids (fatty acids) within sebaceous (oil) glands causes acne (3).

315 Microsponge Loaded Topical Gel A microsponge is a polymeric delivery system comprised of porous microspheres. It has a large, porous surface with small sponge-like spherical particles. It provides good stability with reduced side effects and favors modified drug release. This technology has many constructive characteristics, which makes it a unique drug-delivery vehicle (4). Microsponges are based on microscopic, polymer-based microspheres and encapsulate a wide range of drug substances that can be incorporated into various dosage forms, such as gel, cream, liquid, or powder (5). Benzoyl peroxide is effective for treating acne lesions, and it does not induce antibiotic resistance. It may be combined with salicylic acid, sulfur, erythromycin, clindamycin (antibiotics), or adapalene (synthetic retinoid). Two common combination drugs include benzoyl peroxide/ clindamycin and adapalene/benzoyl peroxide, an unusual formulation considering most retinoids are deactivated by peroxide combination products such as benzoyl peroxide/clindamycin and benzoyl peroxide/salicylic acid, which appear to be slightly more effective than benzoyl peroxide alone for the treatment of acne lesions (6). The combination tretinoin/benzoyl peroxide was approved in 2021. Benzoyl peroxide for acne treatment is typically applied to the affected areas as a gel, cream, or liquid in concentrations of 2.5% increasing through 5.0% (7). In general gels are preferred over solutions and liquids because of their semi-solid consistency, which contributes to the retention of the active substance at the site of application for a prolonged time, as well as their excellent spreading properties, cooling effect due to solvent evaporation, and aesthetically pleasing qualities (8). Considering poly lactic-co-glycolic acid’s (PLGA) natural antibacterial properties, wound-healing properties, and calming effect, as well as its biodegradable and biocompatible features, PLGA-based hydrogels might be preferred over conventional gelling agents such as cellulose derivatives. Considering this information, the aim of this study is to design and develop the formulation of a topical, semi-solid dosage form, carbopol-based gel with microsponges loaded with benzoyl peroxide and PLGA. Sorbitan monooleate is a nonionic surfactant used as emulsifying agents in the preparation of emulsions, creams, and ointments for pharmaceutical and cosmetic use. It has various types of span 20, span 40, span 60, and span 80. The sustained drug release at the site of action, reduced side effects, and frequency of application are expected to result in better efficacy of acne treatment and improved patient compliance (9). MATERIALS AND METHODS The benzoyl peroxide and PLGA were supplied from Carbanio.com. The polyvinyl alcohol (PVA) and carbopol were supplied from Sigma Aldrich (Chennai, India). The sorbitan monooleate 80, propylene glycol, methyl paraben. and propyl paraben were supplied from Nice Chemicals Pvt. Ltd (Chennai, India). DETERMINATION OF SOLUBILITY PROFILE Aqueous solubility is an important physiochemical property of drug substances as it determines systemic absorption and in turn therapeutic efficacy (10). The solubility of benzoyl peroxide in water was carried out per US Pharmacopoeia monograph. The solubility of drugs in methanol, ethanol, and chloroform was determined by adding an excess of the drug in the solvent (11).