Micro e nanopartículas biodegradáveis para liberação controlada de esteroides em bovinos

Abstract

In this work were conducted studies about production of particles the base of poly(3- hydroxybutirate-co-3-hydroxivalerate) (PHBV) biodegradable polymer loaded of steroids (progesterone and medroxyprogesterone) to veterinarian use to contribute for steroids control release at Fixed Time Artificial Insemination (FTAI) bovine. Particles at scale of micro and nanometers were produced using different techniques at high and low pressure how to: conventional single emulsion, supercritical anti-solvent precipitation process (SAS), supercritical fluid extraction of emulsion process (SFEE) and a new technique to promote a emulsion followed by supercritical extraction of solvent in unique time. Studies of PHBV molecular weight reduction was conducted with objective of evaluate the polymer viscosimetric mass and the particles size. The particles obtained were characterized in terms of size and morphological aspects. An initial study of loading of steroids in the PHBV particles was conducted in two different methods with objective of to evaluate the best condition in terms of encapsulation efficiency and time of drug release. The experimental studies of release curve of steroids loaded in PHBV particles were conducted by in vitro system and evaluated via mathematical model with adjust in kinetics of first and second order.