Enhanced Oral Bioavailability of Epalrestat SBE(7)-β-CD Complex Loaded Chitosan Nanoparticles: Preparation, Characterization and in-vivo Pharmacokinetic Evaluation

BACKGROUND: Epalrestat (EPL) is a carboxylic acid derivative with poor aqueous solubility and its pharmacokinetic features are not fully defined. PURPOSE: Current research aimed to fabricate inclusion complexation of EPL with SBE(7) β-CD (IC) and EPL/SBE(7) β-CD CS NPs (NP). METHODS: EPL was complexed with SBE(7) β-CD using the co-precipitation method, and the prepared complex was fabricated into nanoparticles using the ionic gelation method. The prepared formulations were characterized for particle size analysis, surface morphology, and in vitro dissolution study. The % inhibition of EPL against α-glucosidase enzyme was also conducted to check the drug’s antidiabetic activity. Finally, an in vivo pharmacokinetic investigation was carried out to determine the concentration of EPL in rabbit plasma of the prepared formulation. In vivo pharmacokinetic studies were conducted by giving a single dose of pure EPL, IC, and NP. RESULTS: The size of NP was found to be 241.5 nm with PDI 0.363 and zeta potential of +31.8 mV. The surface of the prepared NP was non-porous, smooth and spherical when compared with pure EPL, SBE(7) β-CD and IC. The cumulative drug release (%) from IC and NP was 73% and 88%, respectively, as compared to pure drug (25%). The % inhibition results for in vitro α-glucosidase was reported to be 74.1% and the predicted binding energy for in silico molecular docking was calculated to be −6.6 kcal/mol. The calculated C(max) values for EPL, IC and NP were 4.75±3.64, 66.91±7.58 and 84.27±6.91 μg/mL, respectively. The elimination half-life of EPL was 4 h and reduced to 2 h for IC and NP. The AUC(0-α) for EPL, IC and NP were 191.5±164.63, 1054.23±161.77 and 1072.5±159.54 μg/mL*h, respectively. CONCLUSION: Taking these parameters into consideration it can be concluded that IC and NP have prospective applications for greatly improved delivery and regulatedt release of poorly water soluble drugs, potentially leading to increase therapeutic efficacy and fewer side effects.