Formulation and Characterization of Simvastatin-Loaded Nanosponges: An Innovative Technique for Colon-Targeted Drug Delivery

Abstract

Background:: To enhance the solubility of simvastatin by improving the surface area of the drug particle by preparing nanosponges that are enclosed in a tablet and capsule oral solid dosage forms, which in turn helps maintain the drug's stability. Objective:: The present investigation aimed to develop a simvastatin nanosponge containing Eu-dragit as a polymer with different ratios of drug-to-polymer concentration to increase its solubility and further improve the oral bioavailability by using nanosponges’ formulation technique. Methods:: The emulsion solvent diffusion method was used to prepare simvastatin nanosponges by using Eudragit S 100, Eudragit L 100, and a combination of both in different drug-to-polymer ratios, i.e., 1:0.5, 1:1, 1:1.5, and 1:2. To characterize the conductivity, molecular changes, and size of the prepared nanosponges, a variety of evaluation parameters, including the compressibil-ity index, Hausner's ratio, angle of repose, microscopy, production yield, entrapment efficiency, drug content, in vitro drug release studies, DSC, XRD, FTIR, and SEM were evaluated. Opti-mized formulation was used to prepare colon-targeted tablets and capsules by taking nanosponges equivalent to 20 mg of simvastatin. Results:: The percentage yield, drug content, and entrapment efficiency of the final formulation were observed at 81 ± 0.26%, 92.4%, and 97 ± 0.56%, respectively. The in vitro drug release of the optimized formulations was 91.42 % at 12 hrs. The drug release followed the Peppas model with a super case II transport mechanism. Conclusion:: The use of the nanosponge delivery system increased the solubility of simvastatin seven times, which in turn increased the drug's bioavailability.