Filmes poliméricos a base PHB e PHB-V utilizados como sistemas de liberação controlada de hormônio de crescimento humano recombinante

Abstract

Due to its short half-life and necessity for daily subcutaneous injections, recombinant human growth hormone (rhGH) would best be administered in a controlled release formulation. One approach to this is the use of potentially biodegradable films implants based on both polyesters poly(3-hydroxybutyrate) (PHB) and poly(hydroxybutyrate-covalerate) (PHB-V). These polymers are being explored in the health area due to their hydrolytic degradation that occurs by surface erosion, which make them attractive materials for controlled release applications. PHB and PHB-V films were designed using the solvent casting technique. Two different amounts of PEG, 5% and 65% (w/w), were introduced in films formulations to investigate its leaching and plasticizing effect. Morphologic analysis by Scanning Electron Microscopy (SEM) showed the presence of porosity for films with 67% (w/w) PEG. In this work, some investigations on the in vitro release of rhGH entrapped in the films, are reported. The kinetics of rhGH release from matrices were examined and the results indicate that the release practically occurs in the first 2 hours.