title: Development and validation of a method for allantoin determination in liposomes and pharmaceutical formulations.
abstract: The aim of this work was to develop and validate an ultraviolet derivative spectrophotometric (UVDS) method for the quantitative determination of allantoin (ALL) in liposomes, gels and creams. Liposomes were prepared by methods of thin film hydration and mechanical agitation. Solutions of ALL in 0.1 mol/L NaOH with ethanol:water (70:30, v/v) were prepared in order to destroy liposome vesicles. Spectral interference from components of liposomes, cream, gel and ALL degradation products was eliminated using the second-order derivative of the zero-order spectrum. Characterization of ALL in 0.1 mol/L NaOH was carried out by direct infusion mass spectrometry. Absorbances of ALL solutions were measured at 266.6 nm of the second-derivative spectrum and linearity was observed in the ALL concentration range of 50-300 μgmL(-1) (correlation coefficient (r)=0.9961). The mean recovery percentage was 100.68 ± 1.61, repeatability expressed as relative standard deviation (RSD) was 1.07 and 2.12%, and intermediate precision (RSD) was 2.16%. The proposed UVDS method was found to be linear, precise, accurate, robust and selective, providing rapid and specific determination of ALL in raw materials and in topical formulations.
authors.affiliation: Departamento de Medicamentos, Faculdade de Farmácia, UFRJ, Rio de Janeiro, Brazil. raquel.braga@pbiotech.com
authors.forename: Raquel Rennó
authors.initials: RR
authors.lastname: Braga
authors.forename: Juliana
authors.initials: J
authors.lastname: Sales
authors.forename: Rita de Cassia Elias Estrela
authors.initials: Rde C
authors.lastname: Marins
authors.forename: Gisela Maria Dellamora
authors.initials: GM
authors.lastname: Ortiz
authors.forename: Sheila
authors.initials: S
authors.lastname: Garcia
mesh_terms: D000481:Allantoin / Q000032:analysis*; D003358:Cosmetics / Q000737:chemistry*; D005782:Gels / Q000737:chemistry; D016014:Linear Models; D008081:Liposomes / Q000737:chemistry*; D004364:Pharmaceutical Preparations / Q000737:chemistry*; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet / Q000379:methods*
chemical_list: D003358:Cosmetics; D005782:Gels; D008081:Liposomes; D004364:Pharmaceutical Preparations; D000481:Allantoin