title: Increasing sodium pantoprazole photostability by microencapsulation: effect of the polymer and the preparation technique.
abstract: Pantoprazole sodium is a proton pump inhibitor, used in acid-related disorders, like peptic ulcers and gastroesophageal reflux. This drug is unstable in acid solution and in the presence of salts. The aim of this work was to study the photostability under UVC radiation of pantoprazole and to determine its kinetics. A methanol solution and the solid pantoprazole were evaluated by HPLC within 120 min and 10 days, respectively. The work was also dedicated to evaluate and compare the ability of microencapsulation in stabilizing pantoprazole after UVC radiation. Pantoprazole-loaded microparticles prepared by emulsification/solvent evaporation or spray drying were compared. Pantoprazole was encapsulated using Eudragit S100 or its blend with poly(epsilon-caprolactone) or HPMC. In methanol solution, pantoprazole was completely degraded after 120 min and presented zero-order kinetics with t1/2 of 6.48 min. In the solid form, after 10 days, pantoprazole concentration was reduced to 27% following zero-order kinetic. The microparticles prepared only with Eudragit S100 demonstrated an increase of the drug photostability. After 10 days of irradiation, 56 and 44% of the drug was stable when encapsulated by emulsification/solvent evaporation and spray drying, respectively. The use of polymer blends did not improve the pantoprazole photostability.
authors: Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul (UFRGS), Brazil.
authors: R P
authors: RP
authors: Raffin
authors: L M
authors: LM
authors: Colomé
authors: E E S
authors: EE
authors: Schapoval
authors: A R
authors: AR
authors: Pohlmann
authors: S S
authors: SS
authors: Guterres
mesh_terms: D053799:2-Pyridinylmethylsulfinylbenzimidazoles / Q000008:administration & dosage* / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D003890:Desiccation; D004339:Drug Compounding; D004355:Drug Stability; D004655:Emulsions; D005079:Excipients; D008027:Light; D000432:Methanol; D053758:Nanoparticles; D000077402:Pantoprazole; D010316:Particle Size; D010777:Photochemistry; D011108:Polymers; D054328:Proton Pump Inhibitors / Q000008:administration & dosage* / Q000737:chemistry*; D012996:Solutions; D012997:Solvents; D014466:Ultraviolet Rays
chemical_list: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D004655:Emulsions; D005079:Excipients; D011108:Polymers; D054328:Proton Pump Inhibitors; D012996:Solutions; D012997:Solvents; D000077402:Pantoprazole; D000432:Methanol