Solubility Enhancement of Nevirapine Using Β-Cyclodextrin Nanosponges

Aim: Beta-cyclodextrin-based nanosponges were used to augment solubility and dissolution of Biopharmaceutical Classification System (BCS) class II drug Nevirapine. Materials and Methods: Nanosponges (NS) were prepared using β-cyclodextrin (β-CD) crosslinked with diphenyl carbonate and subjected to spray drying. Binary mixtures of NVP with β-CD, NS, & SDNS were prepared by solvent evaporation. Characterization was done by phase solubility studies and saturation solubility in different media and in vitro dissolution studies. Spectral analysis by Fourier transforms infrared spectroscopy, differential scanning calorimetry, powder X-ray diffraction, field emission scanning electron microscopy & stability studies were performed. Results: Spectral characterization confirmed the formation of inclusion complexes. The stability constant for the NVP-SDNS complex was found to be 1584m-1, indicating stable complex formulation. Saturation solubility was 2-4 folds more with NVP-SDNS complex in D.W. and 2-10 folds greater in 0.1N HCl. NVP displayed a noteworthy enhancement in solubility in relevant media. Binary mixtures show a 31-65% increase in dissolution in 0.1N HCl, with the highest dissolution rate compared to phosphate buffer pH 6.8, D.W, FaSSIF & FeSSIF. The percentage decrease in crystallinity of NVP-β-CD, NVP-NS, & NVP-SDNS complexes was found to be in the range of 34-59%. Gas chromatography by solvent residue analysis indicated the evaporation of DCM from the NVP-SDNS complex. Conclusion: The NVP-SDNS binary mixture showed higher saturation solubility & Dissolution rate than other binary mixtures. It was inferred that the solubility of NVP was enhanced by using β-Cyclodextrin nanosponges.