Abstract
Diabetes is one of the most prevalent diseases worldwide. Vildagliptin is a drug which overcomes the existing problems of anti-diabetic drugs. However, the short half-life (2-3 h) of vildagliptin remains an important concern. Recently there is growing interest in using metal nanoparticles for sustained drug delivery. In the present study, we aimed to formulate vildagliptin (VD) conjugated gold and silver nanoparticles to enhance the stability, prolong the drug release, increase the postprandial glycemic control, decrease side effects, and improve patient compliance. Two formulations of vildagliptin conjugated with gold (Au-VNP), and silver (Ag-VNP) nanoparticles were prepared by a chemical reduction method. UV-visible and FTIR spectroscopy, and atomic force microscopy (AFM) were used for characterization. The drug encapsulation efficiency was determined through HPLC. In vitro DPP-IV inhibitory activity, and enzyme kinetic studies were performed to compare the efficacy of the synthesized nanoparticles with the standard drug. The results revealed a good drug entrapment efficacy of 95%, and 78% for silver, and gold nanoparticles, respectively. Interestingly, the drug loaded nanoparticles improved the effect of vildagliptin, and a two fold increment was seen in the in vitro DPP-IV inhibitory activity. This study provides the first ever evidence for the conjugation of vildagliptin with gold and silver nanoparticles. The improved efficacy of the drug conjugated nanoparticles as compared to the reference solution opens new opportunities for clinical implications of these formulations, which certainly merits further investigation.