Study on influencing factors of the in vitro release rate of doxorubicin hydrochloride sustained release implants for glioma / 中国药学杂志

ABSTRACT

OBJECTIVE: To study the factors affecting the in vitro release rate of doxorubicin hydrochloride sustained release implants for glioma to provide information for pharmacodynamic evaluation in animals. METHODS: The implants were prepared by incorporating doxorubicin hydrochloride into poly(lactide-co-glycolide) (PLGA) matrix. The in vitro release rate of the implants was determined by UV. The copolymer ratio and molecular weight (Mw) of PLGA, and the drug loading were examined to study their effects on the in vitro release rate of the implants. RESULTS: The release rate of 10% drug-loaded implants was greater than that of 5% drug-loaded ones, and it was enhanced by an increase in the proportion of copolymerized glycollic acid in PLGA. The cumulative release rate of the implants with LA-GA ratio of 50 50 was 90% at 35 d, while that of the implants with LA-GA ratio of 75 25 was only about 60%. The molecular weight of PLGA was inversely proportional to the release rate of the implants. The release rate of the implants with Mw of 20748 was greater than that with Mw of 30834. CONCLUSION: The factors affecting the in vitro release rate of the implants include the copolymer ratio of PLGA, the molecular weight of PLGA and the drug loading, among which the copolymer ratio and molecular weight of PLGA are the major factors. The drug release rate of the implants can be well controlled by regulating the copolymer ratio and molecular weight of PLGA matrix. Copyright 2012 by the Chinese Pharmaceutical Association.