Controlled delivery system for norethindrone based on biodegradable poly-alpha,beta-(hydroxyalkyl)-DL-aspartamide.

摘要

The article describes the preparation of poly-(hydroxyalkyl)-DL-aspartamide (PHAA) by a (ring) opening reaction by hydroxyalkylamino; norethindrone (NET), as a model drug, was coupled to the polymers via hydroxyalkylamino spacers. PHAA and NETPHAA conjugates were characterized by FTIR, DSC, x-ray,(13)C NMR, and scanning electron microscopy and their structure were confirmed. The biocompatibility of PHAA was tested. The study showed that PHAA was a hydrophilic, nontoxic in vivo, nonantigenic material and had good biocompatibility as a drug carrier. The effect on drug release from the polymer of length of side chain, initial drug loading, and particle size of the polymer drug were investigated in tris-HCl buffer solution (pH 7.4, t = 37 degrees C). In vivo release in rabbits also was performed for 120 days. The experiment indicated that the concentration of NET in rabbits can be 1-2 microg/ml serum after 1 month; 10% of NET had been released from the polymer.