چکیده (انگلیسی):

The purpose of this study was to develop poly(d,l-lactic-coglycolic
acid) (PLGA)–based anastrozole microparticles for
treatment of breast cancer. An emulsion/extraction method
was used to prepare anastrozole sustained-release PLGAbased
biodegradable microspheres. Gas chromatography
with mass spectroscopy detection was used for the quantitation
of the drug throughout the studies. Microparticles
were formulated and characterized in terms of encapsulation
efficiency, particle size distribution, surface morphology,
and drug release profile. Preparative variables such as
concentrations of stabilizer, drug-polymer ratio, polymer viscosity,
stirring rate, and ratio of internal to external phases
were found to be important factors for the preparation of
anastrozole-loaded PLGA microparticles. Fourier transform
infrared with attenuated total reflectance (FTIR-ATR) analysis
and differential scanning calorimetry (DSC) were employed
to determine any interactions between drug and polymer.
An attempt was made to fit the data to various dissolution
kinetics models for multiparticulate systems, including the
zero order, first order, square root of time kinetics, and biphasic
models. The FTIR-ATR studies revealed no chemical
interaction between the drug and the polymer. DSC results
indicated that the anastrozole trapped in the microspheres
existed in an amorphous or disordered-crystalline status in
the polymer matrix. The highest correlation coefficients were
obtained for the Higuchi model, suggesting a diffusion mechanism
for the drug release. The results demonstrated that
anastrozole microparticles with PLGA could be an alternative
delivery method for the long-term treatment of breast
cancer.