In vitro intestinal permeability studies, pharmacokinetics and tissue distribution of 6-methylcoumarin after oral and intraperitoneal administration in Wistar rats

ABSTRACT 6-Methylcoumarin (6MC) is a semisynthetic coumarin with important in vitro and in vivo anti-inflammatory activity. In order to continue the pre-clinical characterization of this molecule, in vitro intestinal permeability, plasma profile and tissue distribution after oral administration in rats were studied. The permeability of 6MC was evaluated by the Caco-2 cellular model in both the apical-basal (A-B) and basal-apical (B-A) directions. The pharmacokinetics and biodistribution were evaluated in rats after oral and intraperitoneal administration at doses of 200 mg/kg. Transport experiments with Caco-2 cells showed that 6MC presented high permeability at all concentrations evaluated. This finding suggested that 6MC could be transported across the gut wall by passive diffusion. The plasma concentration-time curve showed that the maximum concentration (Cmax) was 17.13 ± 2.90 µg/mL at maximum time (Tmax) of 30 min for the oral route and Cmax 26.18 ± 2.47 µg/mL at 6.0 min for the intraperitoneal administration, with elimination constant of (Ke ) 0.0070 min-1 and a short life half time of (T1/2 ) lower that 120 min. The distribution study showed that 6MC has high accumulation in the liver, and widespread distribution in all the organs evaluated.

Diseño y preparación de formas farmacéuticas sólidas de Benznidazol para el tratamiento de la Enfermedad de Chagas / Design and Preparation fo Pharmaceutical Solid Dosage Forms of Benznidazole for the Treatment of Chagas Disease

INTRODUCCIÓN: En Argentina se emplea el benznidazolcomo terapéutica de primera línea para el tratamiento etiológico del Chagas. Desde su lanzamiento (hace más de 40 años), sólo se dispone de comprimidos convencionales de 100 mg; no se han desarrollado nuevas formas farmacéuticas que aumenten la eficacia y seguridad, ni alternativas con dosis pediátricas. OBJETIVOS: Desarrollar formas farmacéuticas de benznidazol que ofrezcan ventajas farmacoterapéuticas. MÉTODOS: Preformulación y diseño de nuevas formulaciones de benznidazol, con caracterización físico-química y selección de las formulaciones más favorables. Frente a la discontinuidad de producción del ingrediente activo benznidazol, se desarrolló una metodología de extracción a partir de 8520/8520/nica alternativa comercial disponible. RESULTADOS: Se obtuvieron nuevas formulaciones de comprimidos de 50 y 100 mg debenznidazol, con una rápida disolución del producto de referencia. Además, se obtuvieron formulaciones masticables de 50 mg bajo la forma de hidrogeles azucarados, con un efectivo enmascaramiento del mal sabor. Todas las formulaciones cumplieron los ensayos de evaluación de las propiedades farmacotécnicas y biofarmacéuticas, superando los perfiles de referencia. CONCLUSIONES: Se desarrollaron nuevas alternativas farmacéuticas de benznidazol de rápida disolución, que podrían mejorar el tratamiento etiológico de la enfermedad(especialmente en pediatría) y convertirse en herramientas aptas para su explotación comercial

INTRODUCTION: In Argentina, benznidazole is the drug of choice for the etiological treatment of Chagas disease. Since it was launched (more than 40 years ago), there are only 100 mg tablets available; the development included neither new pharmaceutical forms improving efficacy and safety, nor a pediatric dosage option. OBJECTIVES: To develop pharmaceutical form sof benznidazole with pharmacotherapeutic advantages. METHODS: Preformulation and design of new formulation sof benznidazole, with physicochemical characterization and selection of the most favorable formulations. Due to the discontinuity in the production of the active ingredient benznidazole, a specific methodology was developed in order to obtain it from the only commercially available alternative. RESULTS: New benznidazole tablet formulations were obtained (50 and 100 mg), with a rapid dissolution of the reference product, as well as chewable formulation sof 50 mg as sugar hydrogels featuring an effective taste masking. All formulations passed the evaluation tests for pharmacotechnical and biopharmaceutical properties, out performing the reference profiles. CONCLUSIONS:New fast-dissolving pharmaceutical dosage forms of benznidazole were developed, which could improve the etiological treatment of the disease (especially in the pediatric field) and become a proper tool for its commercial exploitation

Apparent molar volumes of the anesthetic drugs procaine-HCl and lidocaine-HCl in water at temperatures from 278.15 to 313.15 K / Volúmenes molares aparentes de los anestésicos procaína-HCl y lidocaína-HCl en agua a temperaturas entre 278.15 y 313.15 K

Lidocaine-HCl and procaine-HCl are local anesthetic drugs widely used in minor chirurgic procedures, nevertheless, physicochemical information about their volumetric behavior, as well as for other aqueous properties, is not complete at present. In this context, in this article, densities of aqueous solutions of both drugs have been measured as a function of concentration (from 0.0500 to 0.5000) mol kg–1 at several temperatures, i.e. 278.15, 283.15, 288.15, 293.15, 298.15, 303.15, 308.15, and 313.15 K. The apparent molar volumes and partial molar volumes at infinite dilution for the electrolyte drugs were calculated, whereas, the partial molar volumes at infinite dilution and partial molar expansibilities for the molecular forms were also calculated. The dependence of these properties with temperature is shown. The results are interpreted in terms of interaction solute-solvent.

La lidocaína-HCl y procaína-HCl son anestésicos locales ampliamente usados en procedimientos quirúrgicos menores, sin embargo la información fisicoquímica acerca de su comportamiento volumétrico, así como de otras propiedades fisicoquímicas, aún es incompleta en la actualidad. Por esta razón, en este artículo se presentan los valores de densidad de algunas soluciones acuosas de estos dos fármacos en función de la concentración (desde 0,0500 hasta 0,5000) mol kg–1 a diferentes temperaturas (278,15, 283,15, 288,15, 293,15, 298,15, 303,15, 308,15 y 313,15 K). Así mismo se presentan los volúmenes molares aparentes y volúmenes molares parciales a dilución infinita de los fármacos como electrolitos, y de otro lado, los volúmenes molares parciales a dilución infinita de los fármacos moleculares y las expansibilidades molares, los cuales fueron calculados a partir de los valores de densidad y composición de las mezclas. Los resultados obtenidos se interpretan en términos de interacciones soluto-solvente.