In Vitro Release Kinetics of Nystatin and Tannic Acid in Artificial Body Fluids from Hydrogels Prepared by Using Polyvinylpyrrolidone Crosslinked with Tannic Acid

Abstract

Biocompatible hydrogels of polyvinylpyrrolidone (PVP) with tannic acid (TA) in the weight ratios of 1 : 0.70 (70 %)–1 : 0.60 (60 %) were prepared and loaded with the antifungal drug, nystatin (NYS). The hydrogel is expected to exhibit a two‐fold (anti‐bacterial and anti‐fungal) characteristics. Infrared spectroscopy (IR), viscometry and differential scanning calorimetry (DSC) were used to investigate interactions between PVP and TA. In vitro release kinetics of NYS in simulated body fluid (SBF) and sweat (SS) were studied using ultra‐violet spectroscopy (UV) and high‐performance liquid chromatography (HPLC). An increase in the glass transition temperature (Tg) of PVP accompanied with changes observed in the OH stretching, C=O and the C−O−C regions in the IR spectrum in dried PVP/TA hydrogel suggested physical crosslinking. The swelling of the hydrogels in distilled deionized water (DDW), SBF and SS decreased with increasing TA concentration and showed pH sensitivity. TA release followed the Korsmeyer‐Peppas kinetic model regardless of swelling media while NYS followed the Korsmeyer‐Peppas and Hixson‐Crowell cube root law in SS and SBF respectively. TA was active against Escherichia coli and Staphylococcus aureus while NYS against Candida albicans. A topical patch was prepared by adhering the drug loaded PVP/TA hydrogel onto silicone strips.