title: Determination of ketoconazole in capsules by high-performance liquid chromatography and microbiological assay.
abstract: The development and validation of an HPLC-UV method and a microbiological assay were performed for the analysis of ketoconazole in capsule formulations. The bioassay was developed using a specific agar diffusion technique with the strain of Candida albicans ATCC 18804 as the test organism. The effect of the mobile phase pH in the range of 2.5-7.5 on the retention and tailing factors of the ketoconazole peak was analyzed in the chromatography method and a pH value of 4.5 was considered to be adequate. A prospective validation of both methods showed adequate linearity (r2 > 0.99 for the two methods), precision, (RSD = 2.42% for intraday and 2.69% for interday precision for bioassay; RSD = 0.74% for intraday and 0.66% for interday precision for HPLC-UV), and accuracy (mean recoveries were 103 +/- 1.0% for bioassay and 99 +/- 1.0% for HPLC-UV). Student's t-test revealed no significant difference between the results obtained by the two methods (P < 0.05). The contents found for three capsule samples showed a strong correlation, as attested by Pearson's coefficient value (r = 0.9998), which also evidenced the concordance between the studied methodologies.
authors.affiliation: Universidade Vale do Rio Doce, Faculdade de Ciências da Saúde, Laboratório de Microbiologia, Rua Israel Pinheiro, 2000, Bairro Universitário, 35020-220, Governador Valadares, Minas Gerais, Brazil.
authors.forename: Paulo Marcelo Andrade
authors.initials: PM
authors.lastname: Lima
authors.forename: Nathália Duque
authors.initials: ND
authors.lastname: Prado
authors.forename: Maria-Luiza Martins
authors.initials: ML
authors.lastname: Silva
authors.forename: Rosiane Dias Lopes
authors.initials: RD
authors.lastname: Diniz
authors.forename: Kelly Marques
authors.initials: KM
authors.lastname: Queiroz
authors.forename: Isabela da Costa
authors.initials: Ida C
authors.lastname: César
authors.forename: Gérson Antônio
authors.initials: GA
authors.lastname: Pianetti
authors.forename: Daniel Assis
authors.initials: DA
authors.lastname: Santos
mesh_terms: D000935:Antifungal Agents / Q000032:analysis* / Q000494:pharmacology*; D001681:Biological Assay; D002176:Candida albicans / Q000187:drug effects; D002214:Capsules; D002851:Chromatography, High Pressure Liquid; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D007654:Ketoconazole / Q000032:analysis* / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D012015:Reference Standards; D015203:Reproducibility of Results; D013056:Spectrophotometry, Ultraviolet
chemical_list: D000935:Antifungal Agents; D002214:Capsules; D007202:Indicators and Reagents; D007654:Ketoconazole