Abstract:
Carboxymethyl chitin (CM-chitin), chitosan, and the blend films of both polymers with polyvinylalcohol (PVA) and polyvinylpyrrolidone (PVP) were prepared by solution casting technique. Glutaraldehyde was used as a crosslinking agent. Salicylic acid and theophylline were used as model drugs. Drug release characteristics of CM-chitin, chitosan and the blend films were studied by using a modified Franz diffusion cell. The amounts of released drug were determined by UV-visible spectroscopy. For CM-chitin films, the percentage of releasing of salicylic acid and theophylline decreased with increasing drug concentration. For the chitosan films containing salicylic, the sequence of releasing of drug was 0.5%>1.0%>0.2%. For the chitosan films containing theophylline, the sequence was 0.1%>0.5%>1.0%. The amounts of drug released from CM-chitin and chitosan films decreased with increasing crosslinking level. In CM-chitin/PVA blend films, the release of salicylic acid decreased with increasing PVA contents. Similar results were obtained for pure chitosan and its blend films. In the CM-chitin/PVP blend films, the blend film with 1:1 ratio of CM-chitin and PVP gave the highest amount of released salicylic acid. Increasing the blend composition of PVP in the blend film to 75% resulted in decreasing drug release. In case of the chitosan/PVP blend films, the presence of PVP in the blend films increased the releasing rate of drug as compared to pure chitosan film.
