Preparation and characterization of D, L-PLA loaded 17-β-Estradiol valerate by emulsion/evaporation methods

• Published in: Journal of microencapsulation 2009-05, Vol.26 (3), p.202-213
• Main Authors: Machado, Silvia R. P., Lunardi, Laureluci O., Tristão, Alan. P., Marchetti, Juliana M.
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Delayed-Action Preparations - chemistry; Delayed-Action Preparations - metabolism; Drug Compounding - methods; Emulsions; estradiol; Estradiol - administration & dosage; Estradiol - analogs & derivatives; General pharmacology; L-PLA; Lactic Acid - chemistry; Lactic Acid - metabolism; Male; Medical sciences; Microparticles; Microspheres; Particle Size; Pharmaceutical technology. Pharmaceutical industry; Pharmacology. Drug treatments; Polyesters; Polymers - chemistry; Polymers - metabolism; Rats; Rats, Wistar
• ISSN: 0265-2048; 1464-5246
• DOI: 10.1080/02652040802233786

PLA microparticles containing 17-β-estradiol valerate were prepared by an emulsion/evaporation method in order to sustain drug release. This system was characterized concerning particle size, particle morphology and the influence of formulation and processing parameters on drug encapsulation and in vitro drug release. The biodegradation of the microparticles was observed by tissue histological analysis. Scanning electron microscopy and particle size analysis showed that the microparticles were spherical, presenting non-aggregated homogeneous surface and had diameters in the range of 718-880 nm (inert micro-particles) and 3-4 µm (drug loaded microparticles). The encapsulation efficiency was ∼80%. Hormone released from microparticles was sustained. An in vivo degradation experiment confirmed that microparticles are biodegradable. The preparation method was shown to be suitable, since the morphological characteristics and efficiency yield were satisfactory. Thus, the method of developed microparticles seems to be a promising system for sustained release of 17-β-estradiol.