Title
Chitosan/poly(vinyl alcohol) hydrogels for entrapment of drug loaded liposomes
Authors
BOGDAN C. CIOBANU ANCA N. CADINOIU MARCEL POPA JACQUES DESBRIERES and CATALINA A. PEPTU

Received August 26, 2013
Published Volume 48 Issue 5-6 May-June
Keywords chitosan, poly, vinyl alcohol, hydrogels, drug, liposomes

Abstract
The paper describes the modeling of drug release from chitosan/poly(vinyl alcohol) hydrogels obtained by using a double crosslinking technique. These complex hydrogel systems were able to reduce the burst effect observed in control hydrogels and to prolong the drug release from 24-48 hours to two weeks. The principle consists in drug entrapment in phosphatidylcholine based liposomes of different sizes and lamellarity along with their subsequent dispersion in hydrogels during the preparation process.
Liposomes containing calcein as a model hydrophilic drug diffuse from the prepared matrices as a function of the network characteristics and the liposome diameter. Multilamellar vesicles (MLVs) containing calcein were detected in the supernatant, due to their better stability, and were covered by multiple lipid bilayers. On the contrary, small unilamellar vesicles (SUVs) containing calcein were less stable during the diffusion through the hydrogel and released their content mostly during their movement inside the matrix. The drug release can be adjusted by modeling the release of liposomes from such hydrogels. Considering the biocompatibility and biodegradability of the components, these hydrogels could be applied in the medical field, when a long period of drug release is needed.