Controlled release of aspirin from pH‐sensitive chitosan/poly(vinyl alcohol) hydrogel

Abstract

The aim of this study was to develop a cheap, pH-sensitive enteric coating of aspirin with biocompatible polymers. A novel approach was used to develop enteric coating from chitosan (CS) and poly(vinyl alcohol) (PVA). Solutions of CS and PVA (5 : 1 mol ratio) were mixed and selectively crosslinked with tetraethoxysilane. IR analysis confirmed the presence of the incorporated components and the existence of siloxane linkages between CS and PVA. The crosslinking percentage and thermal stability increased with increasing amount of crosslinker. The response of the developed coating in different media, such as water, pH (nonbuffer and buffer), and ionic media showed hydrogel properties. All hydrogels showed low swelling in acidic and basic pH media, whereas maximum swelling was exhibited at neutral pH. This pH sensitivity of the hydrogel has been exploited as enteric coating for commercial aspirin tablets. The dissolution test of enteric-coated aspirin tablet in simulated gastric fluid (pH 1.2) showed 7.11% aspirin release over a period of 2 h, whereas a sustained release of remaining aspirin (83.25%) was observed in simulated intestinal fluid (pH 6.8). V C 2011 Wiley Periodicals, Inc. J Appl Polym Sci 124: [4184][4185][4186][4187][4188][4189][4190][4191][4192] 2012

In-situ crosslinked nanofiber mats of chitosan/poly(vinyl alcohol) blend: Fabrication, characterization and MTT assay with cancerous bone cells

“…Attempts have also been made for the electrospinning of *Corresponding author: dratifislam@gmail.com chitosan and its blends [16][17][18]. PVA is amongst the suitable polymers used for this purpose due to its non-toxic, biocompatible and biodegradable nature [19][20][21]. PVA nanofibers have engrossed much research importance for impending biomedical applications.…”

An Investigation of Ac Impedance and Dielectric Spectroscopic Properties of Conducting Chitosan-silane Crosslinked-poly (Vinyl Alcohol) Blended Films

“…The existence of siloxane linkage in the blends resulted by the silane reaction was confirmed by the presence of bands in the range of 1020 (Si-O-Si) and 1060 cm -1 (Si-O-C) 8,9,11,27 . The intensity of these peaks remained the same as the crosslinker amount endured constant in all blends.…”

“…These electrochemical devices have high selectivity and ionic conductivity, acid, base and solvent resistance, excellent contact between synthetic and biological systems, pH sensitive and good mechanical properties 1,2,7 . Chitosan (poly-β(1,4)-D-glucosamine) is an abundant, naturally occurring cationic biopolymer with reactive hydroxyl and amino group and has many electrical, chemical, and biological properties [8][9][10][11] . It has been used extensively for biomedical applications like drug delivery systems, tissue engineering, separation membranes, and artificial corneas, adhesives etc.…”

“…PVA has non-polar carbon backbone and polar hydroxyl group and have good ionic conductivity due to more charge carriers 15 . It is a synthetic polymer which is biodegradable, non-toxic, biocompatible, and easy to process, have good film forming properties, and is highly hydrophilic with exceptional mechanical, chemical and thermal properties 2,8,9,19,20 . Impedance spectroscopy is a technique in which real and imaginary parts of complex planes are determined which measures the electrical quantity as a function of the frequency of applied electric field 21,22 .…”

“…The effect of increase in PVA concentration and temperature on the electrical properties of blended films was studied. Silane crosslinker was used for blended crosslinked film which is simple, cheap, and safe used widely in biomaterials 8,9,11,27 . The blend films were characterized by Fourier transform infrared spectroscopy for structural elucidation and impedance spectroscopy for the measurement of conductive properties.…”