Preparation and subsequent degradation of poly(l-lactic acid) microspheres suitable for aerosolisation: a physico-chemical study

Autor:	Ian W. Kellaway, Mark A Phipps, Mokhtar M. El-Baseir
Rok vydání:	1997
Předmět:	chemistry.chemical_classification Annealing (metallurgy) Stereochemistry Pharmaceutical Science Polymer Dosage form Lactic acid Crystallinity chemistry.chemical_compound chemistry Particle size Fourier transform infrared spectroscopy Chemical decomposition Nuclear chemistry
Zdroj:	International Journal of Pharmaceutics. 151:145-153
ISSN:	0378-5173
Popis:	The encapsulation of nedocromil sodium and beclomethasone dipropionate with microspheres of poly( l -lactic acid) has been studied and preparation conditions optimised for entrapment efficiency and microsphere size suitable for inhalation. DSC was used to characterise the microspheres both in terms of drug/polymer interaction and influence of annealing conditions on the Tg and degree of crystallinity. The absence of molecular interaction was confirmed by FTIR. Incubation of the microspheres in phosphate buffer at 37°C for 8 days demonstrated no chemical degradation of the polymer as evidenced by IR spectral analysis and estimates of percentage crystallinity. Surface morphology (SEM) and internal structure (TEM) were consistent with a homogeneous degradation pattern.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::c68187235d975dc64531f763ee6de616 https://doi.org/10.1016/s0378-5173(96)04873-9 Zobrazit plný text záznamu Full Text from ScienceDirect