Formulation and Evaluation of Clindamycin Phosphate Microsponge Gel for Topical Drug Delivery

Abstract

Clindamycin is a potent lincosamide antibiotic against susceptible anaerobic bacteria and gram-positive aerobes. Furthermore, CLN also has anti-inflammatory activities. It is applied topically in the management of acne vulgaris.The current research was focused on gel loaded for the topical delivery to Clindamycin phosphate to overcome short half life problem of the drug and to minimize the side effects of drug with conventional gel. The FTIR study revealed that there was no interaction between drug and polymer and the combination is suitable for preparation of microsponges. Clindamycin phosphate loaded microsponges were prepared by oil in oil emulsion solvent diffusion method as the drug is highly water soluble and belongs to BCS class III. The microsponges were prepared by using ethyl cellulose as the polymer and incorporated into carbopol gel. The microsponges were evaluated for visual inspection, % yield, % drug content, % entrapement efficiency and particle size. The effect of formulation variables like stirring speed and drug:polymer ratio were evaluated on microsponges. The optimized formulation with drug:polymer ratio of 1:1, stirring speed of 1000rpm had the drug content of 78.69% and percent entrapement efficiency was found to be 87.94% The results concluded that as the drug:polymer ratio increases, drug content and entrapement efficiency decreases. The particle size of optimized batch of microsponges was found to be 37.44μm. The results of particle size analysis concluded that as the drug:polymer ratio increases, particle size increases. The microsponges of batch CLPA1-CLPA9 were subjected to in-vito drug release study by Franz diffusion cell apparatus. The batch showed the controlled release of 95.49% of drug release at 10 hrs. The results of in-vitro drug release showed that as the drug:polymer ratio increases, more controlled release formulation is obtained. The microsponges were incorporated into carbopol gel was evaluated for visual inspection, pH, spreadability and stability of gel at room temperature for 1 month. The transparent white microsponge gel had the pH of 6.38 with spreadability of 7.05 g cm/s. The gel was found to be stable after 1 month. In-vitro antibacterial activity was observed for microsponge gel and compared with marketed 1%w/w CLP gel (Clindac A).