title: Compatibility studies of nevirapine in physical mixtures with excipients for oral HAART.
abstract: Nevirapine is a hydrophobic non-nucleoside reverse transcriptase inhibitor, used in first line regimens of highly active antiretroviral therapy (HAART). The drug has more than one crystalline form, which may have implications for its behaviour during production and also for its in vivo performance. This study was aimed at exploring the suitability of thermoanalytical methods for the solid-state characterization of commercial crystalline forms of nevirapine. The drug powder was characterized by ultraviolet spectrophotometry, stereoscopy, scanning electron microscopy, wide-angle X-ray diffraction, measurements of density, flowability, solubility and intrinsic dissolution rate (IDR), differential scanning calorimetry, thermogravimetric analysis, and photostability measurements. The results showed that nevirapine has high stability and is not susceptible to degradation under light exposure. The drug showed compatibility with the excipients tested (lactose, microcrystalline cellulose, polyvinylpyrrolidone and polyvinyl acetate copolymer (PVP/PVA), and hydroxypropylmethylcellulose (HPMC)). Nevirapine has low solubility, an acid medium being the most appropriate medium for assessing the release of the drug from dosage forms. However, the data obtained from IDR testing indicate that dissolution is the critical factor for the bioavailability of this drug.
authors.affiliation: Department of Pharmacy, Faculty of Pharmaceutical Health, University of São Paulo, São Paulo 05508-900, Brazil.
authors.forename: G G G
authors.initials: GG
authors.lastname: de Oliveira
authors.affiliation: Department of Pharmacy, Faculty of Pharmaceutical Health, University of São Paulo, São Paulo 05508-900, Brazil.
authors.forename: H G
authors.initials: HG
authors.lastname: Ferraz
authors.affiliation: Department of Biotechnological Processes, School of Chemical Engineering, University of Campinas, Campinas 13083-970, Brazil; Department of Pharmaceutical Technology, Faculty of Health Sciences, Fernando Pessoa University, Porto 4200-150, Portugal.
authors.forename: P
authors.initials: P
authors.lastname: Severino
authors.affiliation: Department of Pharmaceutical Technology, Faculty of Health Sciences, Fernando Pessoa University, Porto 4200-150, Portugal; Institute for Biotechnology and Bioengineering, Centre for Genomics and Biotechnology, University of Trás-os-Montes e Alto Douro (IBB-CGB/UTAD), 5001-801 Vila Real, Portugal. Electronic address: eliana@ufp.edu.pt.
authors.forename: E B
authors.initials: EB
authors.lastname: Souto
mesh_terms: D000284:Administration, Oral; D044966:Anti-Retroviral Agents / Q000008:administration & dosage / Q000737:chemistry*; D023241:Antiretroviral Therapy, Highly Active; D002152:Calorimetry, Differential Scanning; D004355:Drug Stability; D005079:Excipients / Q000737:chemistry*; D019829:Nevirapine / Q000008:administration & dosage / Q000737:chemistry*; D012995:Solubility; D013816:Thermodynamics; D013818:Thermogravimetry
chemical_list: D044966:Anti-Retroviral Agents; D005079:Excipients; D019829:Nevirapine