title: PLGA microparticles with zero-order release of the labile anti-Parkinson drug apomorphine.
abstract: The treatment of patients suffering from advanced Parkinson's disease is highly challenging, because the efficacy of the "gold standard" levodopa declines with time. Co-administration of the dopamine receptor agonist apomorphine is beneficial, but difficult due to the poor oral bioavailability and short half-life of this drug. In order to overcome these restrictions, PLGA-based microparticles allowing for controlled parenteral delivery of this morphine derivative were prepared using (solid-in-)oil-in-water extraction/evaporation techniques. Particular attention was paid to minimize spontaneous oxidation of the labile drug and to optimize the key features of the microparticles, including encapsulation efficiency, initial burst release and particle size. Various formulation and processing parameters were adjusted in this respect. The systems were thoroughly characterized using SEM, EDX, DSC, laser diffraction, headspace-GC as well as in vitro drug release measurements in agitated flasks and flow-through cells. Importantly, apomorphine could effectively be protected against degradation during microparticle preparation and within the delivery systems upon exposure to phosphate buffer pH 7.4 (containing 0.2% ascorbic acid) at 37 °C: 90% intact drug was released at a constant rate during about 10d.
authors: University of Lille, College of Pharmacy, 3 Rue du Prof. Laguesse, 59006 Lille, France.
authors: C
authors: C
authors: Regnier-Delplace
authors: O
authors: O
authors: Thillaye du Boullay
authors: F
authors: F
authors: Siepmann
authors: B
authors: B
authors: Martin-Vaca
authors: N
authors: N
authors: Degrave
authors: P
authors: P
authors: Demonchaux
authors: O
authors: O
authors: Jentzer
authors: D
authors: D
authors: Bourissou
authors: J
authors: J
authors: Siepmann
mesh_terms: D000978:Antiparkinson Agents / Q000008:administration & dosage* / Q000737:chemistry; D001058:Apomorphine / Q000008:administration & dosage* / Q000737:chemistry; D002152:Calorimetry, Differential Scanning; D004337:Drug Carriers / Q000737:chemistry*; D004339:Drug Compounding; D004355:Drug Stability; D005612:Freeze Drying; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D010316:Particle Size; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D012995:Solubility; D013499:Surface Properties; D014961:X-Ray Diffraction
chemical_list: D000978:Antiparkinson Agents; D004337:Drug Carriers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D001058:Apomorphine