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

Abstract

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. 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. 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. 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. The use of the nanosponge delivery system increased the solubility of simvastatin seven times, which in turn increased the drug's bioavailability.