ACETAMINOPHEN RELEASE FROM POLYVINYL ALCOHOL CRYOGEL PLATFORMS

Objective. The main objective of this study was to characterize release profile of a water soluble drug model from polyvinyl alcohol (PVOH) cryogels made at different polymer concentrations and thicknesses. Background. PVOH is a hydrophilic linear polymer, and its aqueous solutions can form a gel when exposed to repeated freeze-thaw cycles. The cryogels prepared as such possess unique mechanical, elastic and swelling properties which can be applicable for pharmaceutical and biomedical applications. Methods. Aqueous PVOH solutions were prepared by dissolving the polymer in deionized water at 90oC under mechanical mixing. Acetaminophen (10mg/g), a water soluble drug model was dissolved in two different PVOH solutions (5 and 10 wt%), and the corresponding cryogels were prepared by subjecting the solutions to two freeze-thaw cycles of freezing at -10oC for 4 hr and thawing at 25oC for 2 hr. Acetaminophen release from the cryogels was evaluated using a USP dissolution apparatus type II @ 37±20C and 50rpm, and a UV-Visible spectrometer @243nm. Results. After six hours, the amount of acetaminophen released from 2.4mm, 3.6mm and 4.8mm cryogel slabs were found to be 100, 80 and 50%, respectively. Difference in acetaminophen release from cryogels with same thickness prepared at different polymer concentrations was found statistically insignificant. Acetaminophen-loaded cryogels also swelled in the dissolution medium, which suggests a diffusion-controlled mechanism for the drug release. Conclusion. Drug release from a PVOH-based cryogel can successfully be controlled by varying the cryogel dimensions, so that an immediate to controlled release profiles can be achieved when a water-soluble drug such as acetaminophen is loaded into such platform. Grants. NSU grants# 335867 and 335489