Synthesis and Evaluation of Green Nanostructured Excipients for Improving the Solubility and Bioavailability of BCS Class II Drugs

Abstract

The greatest disadvantage of oral delivery of BCS Class II drugs is poor aqueous solubility and this translates into low bioavailability and unpredictable therapeutic effects. This paper set out to review and analyze green nanostructured excipients with plant-based extracts to improve the bioavailability and solubility of a BCS Class II model drug. Interestingly, nanoparticles were synthesized through a green synthesis method that involved the utilization of plant phytochemicals as reducing and stabilization agents, and they were analyzed by UV-vis spectrophotometry, FTIR, XRD, TEM and DLS. The nanostructures that were synthesized were spherical, had particle sizes of about 40 nm, evenly distributed, and colloidal. Nanoparticle drug formulations showed a strong rise in solubility in aqueous, buffer and simulated gastric environments to a high of 6.9 fold increase relative to the solubility of the pure drug. In vitro dissolution analysis revealed the rapid and almost complete release of the drug in 45 minutes, whereas the in vivo pharmacokinetic analysis demonstrated that the relative bioavailability was increased three-fold, with significant increases in C max and AUC values in the in vivo environment. The compatibility tests established that the drug and the green excipients do not have any negative interactions. The results suggest that the green nanostructured excipients are a safe, sustainable and highly effective approach to address solubility and bioavailability challenges in BCS Class II drugs, which offers possible future pharmaceutical preparations.

Keywords: BCS Class II drugs, green nanostructured excipients, solubility enhancement, bioavailability, plant-mediated nanoparticles