title: pH-sensitive freeze-dried chitosan-polyvinyl pyrrolidone hydrogels as controlled release system for antibiotic delivery.
abstract: The aim of this study was to develop a pH-sensitive chitosan/polyvinyl pyrrolidone (PVP) based controlled drug release system for antibiotic delivery. The hydrogels were synthesised by crosslinking chitosan and PVP blend with glutaraldehyde to form a semi-interpenetrating polymer network (semi-IPN). The semi-IPN formation was confirmed by Fourier transform infrared spectroscopic (FTIR) analysis. Semi-IPNs, viz, air-dried and freeze-dried, were compared for their surface morphology, wettability, swelling properties and pH-dependent swelling. Air- and freeze-dried membranes were also incorporated with amoxicillin and antibiotic release was studied. Porous freeze-dried hydrogels (pore diameter, 39.20+/-2.66 microm) exhibited superior pH-dependent swelling properties over non-porous air-dried hydrogels. A high octane contact angle (144.20+/-0.580) of hydrogel was indicative of its hydrophilic nature. Increased swelling of hydrogels, under acidic conditions, was due to the protonation of a primary amino group on chitosan, as confirmed by FTIR analysis. Freeze-dried membranes released around 73% of the amoxicillin (33% by air-dried) in 3 h at pH 1.0 and, thus, had superior drug-release properties to air-dried hydrogels. Freeze-dried membranes could serve as potent candidates for antibiotic delivery in an acidic environment.
authors.affiliation: School of Biomedical Engineering, Indian Institute of Technology, Bombay, Powai, 400 076, Mumbai, India.
authors.forename: M V
authors.initials: MV
authors.lastname: Risbud
authors.forename: A A
authors.initials: AA
authors.lastname: Hardikar
authors.forename: S V
authors.initials: SV
authors.lastname: Bhat
authors.forename: R R
authors.initials: RR
authors.lastname: Bhonde
mesh_terms: D000890:Anti-Infective Agents / Q000008:administration & dosage*; D002686:Chitin / Q000008:administration & dosage / Q000031:analogs & derivatives*; D048271:Chitosan; D016503:Drug Delivery Systems / Q000379:methods*; D005612:Freeze Drying / Q000379:methods; D020100:Hydrogels / Q000008:administration & dosage*; D006863:Hydrogen-Ion Concentration; D010592:Pharmaceutic Aids / Q000008:administration & dosage; D011205:Povidone / Q000008:administration & dosage
chemical_list: D000890:Anti-Infective Agents; D020100:Hydrogels; D010592:Pharmaceutic Aids; D002686:Chitin; D048271:Chitosan; D011205:Povidone