Development of Clindamycin Loaded Oral Microsponges (Clindasponges) for Antimicrobial Enhancement: In Vitro Characterization and Simulated in Vivo Studies.

Clindamycin phosphate (CLP) is a broad-spectrum antibiotic that is used widely for different types of infections. It has a short half-life and hence it should be taken every six hours to ensure adequate antibiotic blood concentration. On the other hand, microsponges are extremely porous polymeric microspheres, offering the prolonged controlled release of the drug. The present study aims to develop and evaluate innovative CLP-loaded microsponges (named Clindasponges) to prolong and control the drug release and enhance its antimicrobial activity, consequently improving patient compliance. The clindasponges were fabricated successfully by quasi-emulsion solvent diffusion technique using Eudragit S100 (ES100) and ethyl cellulose (EC) as carriers at various drug-polymer ratios. Several variables were optimized for the preparation technique including the type of solvent, stirring time, and stirring speed. The clindasponges were then characterized in terms of particle size, production yield, encapsulation efficiency, scanning electron microscopy, Fourier Transform Infrared Spectroscopy analysis, in vitro drug release with kinetic modeling, and antimicrobial activity study. Moreover, in vivo, pharmacokinetics parameters of CLP from the candidate formula were simulated based on the convolution method and in vitro-in vivo correlation (IVIVC-Level A) was built up successfully. Uniform spherical microsponges with 82.3 µm mean particle size with a porous spongy structure were evident. ES2 batch exhibited the highest production yield and encapsulation efficiency (53.75 and 74.57%, respectively) and it was able to exhaust 94% of the drug at the end of 8 h of the dissolution test. The release profile data of ES2 was best fitted to Hopfenberg kinetic model. ES2 was significantly (p < 0.05) effective against Staphylococcus aureus and Escherichia coli compared to the control. Also, ES2 displayed a twofold increase in the simulated area under the curve (AUC) compared to the reference marketed product.