title: [Dependence of rifabutin properties and liposome entrapment on pH of the medium].
abstract: Rifabutin solubility within pH 3.0 to 11.0 was determined. Potentiometry, spectrophotometry and computation revealed ionization of three groups with pKa 3.5, 6.5 and 9.5 in the rifabutin molecule. On the basis of the pKa values of certain fragments of the rifabutin molecule computed by the ACD/pKa programme they were related to ionization of the following groups: imidazole residue nitrogen, aromatic hydoxyl and piperidin nitrogen respectively. Interaction of rifabutin with model membranes, i. e. large unilamellar vesicules was studied. At lower pH of the medium, entrapment of rifabutin to the large unilamellar vesicules increased that was evident of satisfactory correlation with the decrease in the rifabutin distribution coefficient in the system multilamellar vesicules/water under the experimental conditions.
authors.forename: Iu N
authors.initials: IuN
authors.lastname: Shakina
authors.forename: V V
authors.initials: VV
authors.lastname: Vostrikov
authors.forename: G M
authors.initials: GM
authors.lastname: Sorokoumova
authors.forename: A A
authors.initials: AA
authors.lastname: Selishcheva
authors.forename: V I
authors.initials: VI
authors.lastname: Shvets
mesh_terms: D000995:Antitubercular Agents / Q000737:chemistry*; D008081:Liposomes; D010713:Phosphatidylcholines / Q000737:chemistry*; D017828:Rifabutin / Q000737:chemistry*; D013025:Glycine max; D014867:Water
chemical_list: D000995:Antitubercular Agents; D008081:Liposomes; D010713:Phosphatidylcholines; D014867:Water; D017828:Rifabutin