title: Solid lipid microparticles for the stability enhancement of a dopamine prodrug.
abstract: The oral or peripheral administration of dopamine for the treatment of Parkinson's disease is hampered by its extensive metabolism and inability to cross the blood-brain barrier. Consequently, the enhancement of dopamine stability in physiologic environments and its brain targeting appear useful in formulation development. We propose the preparation and characterization of solid lipid microparticles based on tristearin as a sustained delivery system for dopamine. The microparticles were produced by conventional hot emulsion techniques. The synthesis of a new valeroyl ester of dopamine (3,4-O-divaleroyl-dopamine, DVD) was necessary to obtain its encapsulation in the microparticles. DVD appeared totally hydrolyzed to dopamine in human plasma within 40 s. The amount of encapsulated DVD in microparticles was 2.67 ± 1.2%. The mean diameter of particles was 14.2 ± 4.8 µm. The DVD release from microparticles was characterized by an initial burst of 20% of incorporated prodrug and a continuous slow release thereafter. The microparticles were able to stabilize DVD in its solid form. In human plasma, DVD encapsulated in microparticles hydrolyzed with a markedly reduced rate in comparison with free prodrug: after 15 min, 35.8% of DVD was still detectable. The DVD-loaded microparticles could represent a potential system for dopamine uptake in the brain, following nasal administration.
authors.affiliation: Department of Pharmaceutical Sciences, University of Ferrara, via Fossato di Mortara 19, 44100 Ferrara, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Dalpiaz
authors.forename: Barbara
authors.initials: B
authors.lastname: Cacciari
authors.forename: Matteo
authors.initials: M
authors.lastname: Mezzena
authors.forename: Mariangela
authors.initials: M
authors.lastname: Strada
authors.forename: Santo
authors.initials: S
authors.lastname: Scalia
mesh_terms: D003692:Delayed-Action Preparations / Q000737:chemistry*; D004298:Dopamine / Q000008:administration & dosage* / Q000737:chemistry / Q000378:metabolism; D015259:Dopamine Agents / Q000008:administration & dosage* / Q000737:chemistry / Q000378:metabolism; D004339:Drug Compounding; D004355:Drug Stability; D006801:Humans; D006868:Hydrolysis; D010300:Parkinson Disease / Q000188:drug therapy; D010316:Particle Size; D010949:Plasma / Q000378:metabolism; D011355:Prodrugs / Q000008:administration & dosage* / Q000737:chemistry / Q000378:metabolism; D014280:Triglycerides / Q000737:chemistry*
chemical_list: D003692:Delayed-Action Preparations; D015259:Dopamine Agents; D011355:Prodrugs; D014280:Triglycerides; C022618:tristearin; D004298:Dopamine