title: Tretinoin-loaded nanocapsules: Preparation, physicochemical characterization, and photostability study.
abstract: The aim of this study was to prepare and characterize tretinoin-loaded nanocapsules as well as to evaluate the influence of this nanoencapsulation on tretinoin photostability. Tretinoin-loaded nanocapsules (0.5 mg ml(-1)) were prepared by interfacial deposition of preformed polymer (poly-epsilon-caprolactone) using two different oily phases: capric/caprylic triglycerides and sunflower seed oil. Tretinoin-loaded nanocapsules presented drug content close to the theoretical value, encapsulation efficiencies higher than 99.9%, nanometric mean size with a polydispersity index below 0.25, and pH values between 5.0 and 7.0. Regarding photodegradation studies, tretinoin methanolic solution showed a half-life time around 40 min according to a first order equation, whereas tretinoin nanocapsule suspensions showed a half-life between 85 and 100 min (twofold higher than in methanolic solution) according to a zero order equation. Tretinoin-loaded nanocapsules improved tretinoin photostability, independently on the type of oily phase used in this study, and represent a potential system to be incorporated in topical or systemic dosage forms containing tretinoin.
authors.affiliation: Curso de Farmácia, Departamento de Farmácia Industrial, Universidade Federal de Santa Maria (UFSM), Av. Roraima 1000, 97105-900 Santa Maria, RS, Brazil.
authors.forename: A F
authors.initials: AF
authors.lastname: Ourique
authors.forename: A R
authors.initials: AR
authors.lastname: Pohlmann
authors.forename: S S
authors.initials: SS
authors.lastname: Guterres
authors.forename: R C R
authors.initials: RC
authors.lastname: Beck
mesh_terms: D002210:Caprylates / Q000737:chemistry; D002626:Chemistry, Pharmaceutical; D003652:Decanoic Acids / Q000737:chemistry; D003879:Dermatologic Agents / Q000737:chemistry / Q000528:radiation effects*; D004339:Drug Compounding; D004355:Drug Stability; D005240:Feasibility Studies; D006207:Half-Life; D007700:Kinetics; D053769:Nanocapsules; D010316:Particle Size; D010782:Photolysis; D010938:Plant Oils / Q000737:chemistry; D011091:Polyesters / Q000737:chemistry; D012995:Solubility; D000074242:Sunflower Oil; D013678:Technology, Pharmaceutical / Q000379:methods; D014212:Tretinoin / Q000737:chemistry / Q000528:radiation effects*; D014280:Triglycerides / Q000737:chemistry; D014466:Ultraviolet Rays
chemical_list: D002210:Caprylates; D003652:Decanoic Acids; D003879:Dermatologic Agents; D053769:Nanocapsules; D010938:Plant Oils; D011091:Polyesters; D000074242:Sunflower Oil; D014280:Triglycerides; C016240:polycaprolactone; D014212:Tretinoin