title: Topical delivery of urea encapsulated in biodegradable PLGA microparticles: O/W and W/O creams.
abstract: This study describes the formulation and characterization of O/W and W/O creams containing urea-loaded microparticles prepared with poly (D, L-lactic-co-glycolic acid) (PLGA) in order to encapsulate and stabilize urea. The solvent evaporation method was used for preparing PLGA microparticles containing urea. The microparticles size was evaluated by laser light diffractometry. The resulting microparticles were then incorporated in O/W and W/O creams and stability and the release pattern from the creams was evaluated by UV-spectrophotometry. The particle size of PLGA microparticles was in the range of 1-5 microm and most microparticles had a particle size smaller than 3 microm. The encapsulation efficiency was calculated as 40.5% +/- 3.4. This study also examined release pattern of urea which varied among different formulations. The results showed that the release from O/W creams followed Higuchi kinetics while the release from W/O creams showed the zero order kinetics and the creams containing microparticulated urea had slower release than free urea creams.
authors.affiliation: Shaheed Beheshti University of Medical Sciences and Health Services, School of Pharmacy, Tehran, Iran.
authors.forename: Azita
authors.initials: A
authors.lastname: Haddadi
authors.forename: Reza
authors.initials: R
authors.lastname: Aboofazeli
authors.forename: Mohammad
authors.initials: M
authors.lastname: Erfan
authors.forename: Effat Sadat
authors.initials: ES
authors.lastname: Farboud
mesh_terms: D000287:Administration, Topical; D001672:Biocompatible Materials / Q000737:chemistry*; D002214:Capsules; D002626:Chemistry, Pharmaceutical / Q000379:methods; D004339:Drug Compounding / Q000379:methods; D015195:Drug Design; D006801:Humans; D019344:Lactic Acid / Q000008:administration & dosage*; D009821:Oils; D010316:Particle Size; D011100:Polyglycolic Acid / Q000008:administration & dosage*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000737:chemistry*; D015595:Skin Aging / Q000187:drug effects*; D012997:Solvents / Q000737:chemistry; D014508:Urea / Q000008:administration & dosage*; D014867:Water
chemical_list: D001672:Biocompatible Materials; D002214:Capsules; D009821:Oils; D011108:Polymers; D012997:Solvents; D014867:Water; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D014508:Urea