title: In vitro evaluation of suspoemulsions for in situ-forming polymeric microspheres and controlled release of progesterone.
abstract: One possibility to obtain a higher dose of drug in a lower formulation volume can be by using of saturated quantity of drug in one of the phases of an emulsion. These formulations are called suspoemulsions (S/O/W). When a hydrophobic polymer is added to the organic phase of suspoemulsions, these formulations can be used to entrap the drug inside microspheres after in situ precipitation of the polymer-drug-excipients mix. In this work, performance and stability of progesterone suspensions in triacetin as organic phase of suspoemulsions were evaluated. These formulations were compared with O/W emulsions. Mathematical models were used to study in vitro release profiles. The results confirmed that S/O/W systems could be an attractive alternative to O/W formulations for the entrapment of progesterone inside poly(d,l-lactide-co-glycolide) microspheres. Diffusive-based models fit the in vitro release of progesterone from in situ-formed microspheres. For longer release periods, a time-dependent diffusion coefficient was successfully estimated.
authors.affiliation: a Laboratorio de Química Fina , Instituto de Desarrollo Tecnológico para la Industria Química (INTEC), Universidad Nacional del Litoral (UNL), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Predio CONICET Santa Fe , Santa Fe , Argentina.
authors.forename: Ludmila N
authors.initials: LN
authors.lastname: Turino
authors.forename: Rodolfo N
authors.initials: RN
authors.lastname: Mariano
authors.forename: Luciano N
authors.initials: LN
authors.lastname: Mengatto
authors.forename: Julio A
authors.initials: JA
authors.lastname: Luna
mesh_terms: D002626:Chemistry, Pharmaceutical; D003692:Delayed-Action Preparations; D004058:Diffusion; D004337:Drug Carriers; D016503:Drug Delivery Systems; D004655:Emulsions; D005079:Excipients; D019344:Lactic Acid / Q000737:chemistry; D008863:Microspheres; D008962:Models, Theoretical; D020442:Poloxamer / Q000737:chemistry; D011100:Polyglycolic Acid / Q000737:chemistry; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000737:chemistry; D011136:Polysorbates / Q000737:chemistry; D011374:Progesterone / Q000008:administration & dosage* / Q000737:chemistry; D014215:Triacetin / Q000737:chemistry
chemical_list: D003692:Delayed-Action Preparations; D004337:Drug Carriers; D004655:Emulsions; D005079:Excipients; D011108:Polymers; D011136:Polysorbates; D020442:Poloxamer; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D011374:Progesterone; D014215:Triacetin
keywords: Microparticles; S/O/W; poly(d,l-lactide-co-glycolide); release modeling