Preparation and in-vitro evaluation of poly[N-vinyl-2-pyrrolidone-polyethylene glycol diacrylate]-chitosan interpolymeric pH-responsive hydrogels for oral drug delivery.

Biocompatible and biodegradable pH-responsive hydrogels based on N-vinyl pyrrolidone (NVP), polyethylene glycol diacrylate (PAC) and chitosan were prepared for controlled drug delivery. These interpolymeric hydrogels were synthesized by a free radical polymerization technique using azobisisobutyronitrile (AIBN) as initiator and N,N'-methylenebisacrylamide (BIS) as crosslinker. These hydrogels were subjected to equilibrium swelling studies in enzyme-free simulated gastric and intestinal fluids (SGF and SIF). These swelling studies clearly indicated that these hydrogels were swollen more in SGF when compared to SIF. Theophylline and 5-fluorouracil (5-FU) were entrapped into these hydrogels and equilibrium-swelling studies were carried out for the drug-entrapped gels in enzyme-free SGF and SIF. The in-vitro release profiles of the drugs were established in enzyme-free SGF. More than 50% of the entrapped drugs were released in the first 2 h at gastric pH and the rest of the drug release was slower.

[1]  A. Hoffman,et al.  Graft copolymers that exhibit temperature-induced phase transitions over a wide range of pH , 1995, Nature.

[2]  Ping I. Lee,et al.  Probing the mechanisms of drug release from hydrogels , 1991 .

[3]  Y. Bae,et al.  Electrically credible polymer gel for controlled release of drugs , 1991, Nature.

[4]  K. P. Rao,et al.  Preparation, swelling characteristics and evaluation of hydrogels for stomach specific drug delivery , 1997 .

[5]  R. Langer,et al.  Drug delivery and targeting. , 1998, Nature.

[6]  Y. Osada,et al.  A polymer gel with electrically driven motility , 1992, Nature.

[7]  Jindřich Kopeček,et al.  Permeability of membranes containing ionogenic groups , 1971 .

[8]  Nikolaos A. Peppas,et al.  Hydrogels and drug delivery , 1997 .

[9]  S. Asher,et al.  Polymerized colloidal crystal hydrogel films as intelligent chemical sensing materials , 1997, Nature.

[10]  N. Yui,et al.  Modulated degradation of hydrogels with thermo-responsive network in relation to their swelling behavior , 1998 .

[11]  T. Okano,et al.  Comb-type grafted hydrogels with rapid deswelling response to temperature changes , 1995, Nature.

[12]  K. P. Rao,et al.  Synthesis and Characterization of Poly[N-Vinyl-2-Pyrrolidone-Polyethylene Glycol Diacrylate] Copolymeric Hydrogels for Drug Delivery , 1997 .

[13]  Toyoichi Tanaka,et al.  Phase transition in polymer gels induced by visible light , 1990, Nature.

[14]  Toyoichi Tanaka,et al.  Saccharide-sensitive phase transition of a lectin-loaded gel , 1991, Nature.