Modeling of drug release from biodegradable triple-layered microparticles.
Numerous models that predict drug release from nonerodible reservoir-membrane sphere systems have been presented. Most of these models cater only to a phase of drug release from a constant reservoir. All these models, however, are not applicable to drug release from biodegradable triple-layered microparticle system, in which the drug-loaded core (reservoir) is surrounded by nondrug holding outer layers (membrane). In this article, a mathematical model was developed for ibuprofen release from degradable triple-layered microparticles made of poly(D,L-lactide-co-glycolide, 50:50) (PLGA), poly(L-lactide) (PLLA), and poly(ethylene-co-vinyl acetate, 40 wt % vinyl acetate) (EVA), where ibuprofen was localized within the nonconstant reservoir (EVA core). The model postulated that the drug release through the bulk-degrading PLLA and PLGA layers consisted of two mechanisms: simple diffusional release followed by a degradation-controlled release through a rate-limiting membrane. The proposed model showed very good match with the experimental data of release from microparticles of various layer thicknesses and particle sizes. The underlying drug release mechanisms are dictated by three parameters determined by the model, including constant characteristic of diffusion, end time point of simple diffusion-controlled release and partition coefficient of drug. The presented model is effective for understanding the drug release mechanisms and for the design of this type of dosage form.
School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.
Wei Li
WL
Lee
Wen-Xiong
WX
Shi
Zheng Yang
ZY
Low
Shuzhou
S
Li
Say Chye Joachim
SC
Loo
D001672:Biocompatible Materials / Q000737:chemistry*; D001673:Biodegradation, Environmental; D004058:Diffusion; D016503:Drug Delivery Systems; D007052:Ibuprofen / Q000494:pharmacology*; D019344:Lactic Acid / Q000737:chemistry*; D008956:Models, Chemical; D008970:Molecular Weight; D010316:Particle Size; D011091:Polyesters / Q000737:chemistry*; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011145:Polyvinyls / Q000737:chemistry*; D013997:Time Factors
D001672:Biocompatible Materials; D011091:Polyesters; D011145:Polyvinyls; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; C016438:ethylenevinylacetate copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; C033616:poly(lactide); D007052:Ibuprofen