RESUMEN
Developing an in vitro dissolution test that gives good correlation with in vivo data for a particular drug product is an important objective. Available dissolution data of vincamine prolonged-release preparations show different in vitro release behavior at different pH using the conventional dissolution techniques. This does not allow development of an in vitro-in vivo correlation (IVIVC). In the present work, the flow-through cell (FTC) dissolution system (USP apparatus 4) was utilized to compare the release rate of three marketed prolonged-release oral formulations of vincamine; namely, a brand innovator formulation used as the reference and two formulations from different manufacturers as test products. Both the open and closed systems of FTC were used at variable pH. A comparative bioavailability study was then conducted in 16 healthy volunteers for a test versus the reference product by administering a single dose of 60 mg in a crossover design. Vincamine plasma concentrations were analyzed by a sensitive high-performance liquid chromatography (HPLC) method. This was followed by assessment of IVIVC according to level A as specified by USP 23; the absorbed fraction of vincamine was determined using the Wagner-Nelson method. The results indicated that the pH of the medium affects the release rate pronouncedly. The relative bioavailability based on Cmax and AUC0-12 were found to be 83.15% and 84.15%, respectively. Good correlation was obtained between fraction absorbed in vivo and fraction dissolved in vitro by applying the open system of the FTC. This technique gave the most favorable results with regard to the percentage vincamine released and the IVIVC.
Asunto(s)
Antihipertensivos/farmacocinética , Vincamina/farmacocinética , Adulto , Disponibilidad Biológica , Preparaciones de Acción Retardada , Humanos , Técnicas In Vitro , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Análisis de RegresiónRESUMEN
The volatile constituents of Tirmania nivea (white desert truffle) have been analysed, using gas chromatography/mass spectrometric technique. 11 compounds have been identified in the ascocarp volatiles. The major components were found to be unsaturated fatty acids; whereas hexadecanoic [correction of haxadecanoic] acid represented 49% of the volatiles isolate.
Asunto(s)
Ascomicetos/química , Ácidos Grasos Insaturados/análisis , Análisis de los Alimentos/métodos , Cromatografía de Gases y Espectrometría de Masas , Ácidos Palmíticos/análisisAsunto(s)
Antineoplásicos Fitogénicos/aislamiento & purificación , Plantas Medicinales/análisis , Alcaloides de Pirrolicidina/aislamiento & purificación , Animales , Carcinoma de Ehrlich/tratamiento farmacológico , Cromatografía en Capa Delgada , Egipto , Ratones , Extractos Vegetales/análisis , Extractos Vegetales/farmacología , Alcaloides de Pirrolicidina/farmacologíaRESUMEN
A double-blind study has been performed to search for the possible effect of khellin in psoriasis. 10 patients were treated orally with khellin and subsequently exposed to sunlight for 4 months; a total of 8 cases responded positively with variable degrees of clearance. None of 10 controls had any response. A relapse-free duration of 3 years was recorded for 6 out of the 8 responders. This study would introduce the nonpsoralen compound khellin as a possible agent for the therapy of psoriasis.
Asunto(s)
Khellin/administración & dosificación , Psoriasis/tratamiento farmacológico , Adolescente , Adulto , Método Doble Ciego , Femenino , Helioterapia , Humanos , Masculino , Persona de Mediana EdadRESUMEN
An anticipated effect of khellin, related to its chemical structure, in the photochemotherapy of amelanosis has been investigated. In a double-blind clinical study, khellin has been orally administered to 30 vitiligo patients for 4 months with subsequent exposure to natural sunlight. At the end of the trial period, 5 patients out of 30 (16.6%) repigmented 90-100%; 7 cases (23.3%) repigmented 50-60% of the vitiliginous areas treated; 11 (36.6%) repigmented 25% or less, and 7 subjects (23.3%) showed negative response. 30 control subjects failed to repigment at all. The achieved repigmentation was stable after drug cessation for a period of 1 year. These data add a previously unreported effect for the non-psoralen compound, khellin, in the therapy of vitiligo.