title: Comparison of the in vivo pharmacokinetics and in vitro dissolution of raltegravir in HIV patients receiving the drug by swallowing or by chewing.
abstract: The pharmacokinetics of raltegravir (RAL) in HIV patients is characterized by high interpatient/intrapatient variability. We investigated the potential contribution of the drug pharmaceutical formulation to RAL pharmacokinetics. We first compared in vivo the pharmacokinetics of RAL for 67 patients to whom the drug was administered by swallowing the intact tablet with those obtained from 13 HIV-infected patients who chewed the RAL tablet due to swallowing difficulties. Subsequently, we evaluated in vitro the dissolution of RAL tablets under different conditions. In the in vivo study, we found that patients given RAL by chewing the tablets presented pharmacokinetic profiles characterized by significantly higher RAL absorption than did patients receiving the drug by swallowing. The in vitro studies showed that when the whole tablets were exposed to an acidic medium, the release of RAL was very low, whereas when the tablets were crushed, the profiles presented significantly higher concentrations of RAL. Crushed tablets tested in water or in a pH 6.8 buffer exhibited prompt and complete dissolution of RAL. HIV-infected patients receiving RAL by chewing the tablet showed higher drug absorption and reduced pharmacokinetic variability compared with patients swallowing the intact tablet. This is related to problems in tablet disintegration and to erratic drug absorption. The amelioration of the RAL pharmaceutical formulation could improve drug pharmacokinetics.
authors.affiliation: Department of Infectious Diseases, L. Sacco University Hospital, Milan, Italy. cattaneo.dario@hsacco.it
authors.forename: Dario
authors.initials: D
authors.lastname: Cattaneo
authors.forename: Sara
authors.initials: S
authors.lastname: Baldelli
authors.forename: Matteo
authors.initials: M
authors.lastname: Cerea
authors.forename: Simona
authors.initials: S
authors.lastname: Landonio
authors.forename: Paola
authors.initials: P
authors.lastname: Meraviglia
authors.forename: Emanuela
authors.initials: E
authors.lastname: Simioni
authors.forename: Valeria
authors.initials: V
authors.lastname: Cozzi
authors.forename: Serena
authors.initials: S
authors.lastname: Fucile
authors.forename: Andrea
authors.initials: A
authors.lastname: Gazzaniga
authors.forename: Emilio
authors.initials: E
authors.lastname: Clementi
authors.forename: Massimo
authors.initials: M
authors.lastname: Galli
authors.forename: Giuliano
authors.initials: G
authors.lastname: Rizzardini
authors.forename: Cristina
authors.initials: C
authors.lastname: Gervasoni
mesh_terms: D000284:Administration, Oral; D000328:Adult; D023241:Antiretroviral Therapy, Highly Active; D019540:Area Under Curve; D002626:Chemistry, Pharmaceutical; D002851:Chromatography, High Pressure Liquid; D003679:Deglutition; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000378:metabolism; D019428:HIV Integrase Inhibitors / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics*; D006801:Humans; D008297:Male; D013058:Mass Spectrometry; D008409:Mastication; D008875:Middle Aged; D011760:Pyrrolidinones / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics*; D000068898:Raltegravir Potassium; D012995:Solubility; D013607:Tablets; D013649:Taste
chemical_list: D019428:HIV Integrase Inhibitors; D011760:Pyrrolidinones; D013607:Tablets; D000068898:Raltegravir Potassium