POLY(VINYLPYRROLIDONE)-CHITOSAN HYDROGELS AS MATRICES FOR CONTROLLED DRUG RELEASE

In this study, hydrogels based on poly(vinylpyrrolidone) and chitosan, derived from different mixing ratios of poly(vinylpyrrolidone)/chitosan, were synthesized by the freeze-drying technique with the aim of obtaining new systems that could be used to release tetracycline hydrochloride (TH). Freeze-drying methods were also used to prepare the hydrogels containing TH. The hydrogels were characterized using Fourier transform infrared spectroscopy and scanning electron microscopy, as well as in terms of dynamic water vapour sorption capacity. The poly(vinylpyrrolidone)/chitosan hydrogels were evaluated with regard to the release of TH. The release profiles of TH from the poly(vinylpyrrolidone)/chitosan hydrogels depended on the chitosan content. It could be seen that if the concentration of chitosan was too high, the release was delayed and not fully achieved, because the release of the drug was prevented by the crystalline areas of the chitosan. According to the release study, the drug release mechanism of the poly(vinylpyrrolidone)/chitosan hydrogels loaded with TH perfectly fitted the Higuchi and the Korsmeyer-Peppas models. The highest value of water vapor sorption capacity was obtained for the hydrogel with the poly(vinylpyrrolidone)/chitosan ratio of 50/50. PVP-CS loaded with 3 wt% TH may potentially be used for the controlled delivery of tetracycline to treat oral infections.

Automated summary

Hydrogels based on poly(vinylpyrrolidone) and chitosan were synthesized for the release of tetracycline hydrochloride. The release of TH from the hydrogels depended on the chitosan content, with too high concentration delaying the release. The drug release mechanism of the hydrogels fit the Higuchi and Korsmeyer-Peppas models, with the highest water vapor sorption capacity found in a hydrogel with a poly(vinylpyrrolidone)/chitosan ratio of 50/50.