Release kinetics of fluphenazine from biodegradable microspheres.
Fluphenazine-loaded microspheres were prepared using biodegradable lactide and lactide-co-glycolide polymers. Sustained release of fluphenazine was achieved with fluphenazine loadings of up to 30 per cent in both the lactide and lactide-co-glycolide polymers. Fluphenazine release from microspheres was found to increase with increasing drug loading and was most rapid from the poly-L-lactide-co-glycolide microspheres. The release profiles showed a 'lag' period followed by an accelerating release phase and in some cases a decay period, i.e. the release profiles were sigmoidal and fitted the Prout-Tomkins equation (Prout and Tompkins 1944). Consequently it was considered that polymer degradation, the primary rate-determining step controlling drug release, occurred by a mechanism involving propagation of active sites, drug release reflecting the spread of this degradation throughout the polymer.
Ramtoola
Z
Z
Department of Pharmaceutics, School of Pharmacy, Trinity College, Dublin, Ireland.
Corrigan
O I
OI
Barrett
C J
CJ
D001673:Biodegradation, Environmental; D003692:Delayed-Action Preparations; D005476:Fluphenazine / Q000008:administration & dosage / Q000737:chemistry*; D007700:Kinetics; D008863:Microspheres; D012995:Solubility
D003692:Delayed-Action Preparations; D005476:Fluphenazine