Keelia HubbardKeelia Hubbard
|
 |
Subsequently, diffusion, partitioning and metabolic parameters were compared under in vitro and in vivo conditions. The present skin diffusion/bioconversion model joint with computer analysis enables us to comprehensively account for diffusion, drugstore no prescription pharmacy partitioning and metabolism during in vivo antibiotics percutaneous consumption. Human plasma proteins were selectively precipitated by the addition of 7% perchloric acid to spiked plasma samples or to the plasma samples obtained after Acyclovir / Aciclovir administration to human volunteers and the separateness was spun at 1000 g for 10 min. Moreover, the excretion and absorption profiles were also very different for each prodrug. Although total penetration amounts at the end of the experiment were similar for the three prodrugs, the ratio of intact prodrug to total penetration amount differed significantly. In vivo penetration profiles were then estimated by employing a deconvolution method and the penetration of Acyclovir / Aciclovir prodrugs was analyzed using a diffusion model. In order to evaluate the in vivo penetration of prodrugs which undergo metabolism in skin, we analyzed the in vivo penetration profiles of Acyclovir / Aciclovir prodrugs based on a two-layer skin diffusion model in consideration of metabolic process. Unchanged Acyclovir / Aciclovir has antibiotics been quantified without the introduction of an internal standard using the present method. Rapid, simple and sensitive high-performance liquid chromatographic method for detection and determination of Acyclovir / Aciclovir in human plasma and its use in bioavailability studies.A rapid, simple and sensitive reversed-phase high-performance liquid chromatographic (HPLC) method has been developed for the measurement of Acyclovir / Aciclovir concentrations in human plasma and its use in bioavailability studies is evaluated. The present method has been successfully applied to samples from bioavailability studies.. The mobile phase consisted of octane sulfonic acid buffer (pH 2.5) and methanol (92:08). Enzymatic hydrolysis rate constants calculated under in vivo conditions were considerably larger than those obtained in the skin homogenate and in vitro penetration experiments. In vivo evaluation of Acyclovir / Aciclovir prodrug penetration and metabolism through rat skin using a diffusion/bioconversion model.PURPOSE. Acyclovir / Aciclovir prodrugs (e.g., valerate, isovalerate and pivarate) were used as model prodrugs and the amounts excreted in urine were measured after percutaneous application. The limit of quantitation for Acyclovir / Aciclovir in plasma was 20 ng/ml, which enabled the determination of the area under the curve (AUC) more precisely, that is, it is much closer to its extrapolated value. Nevertheless, different enzymatic hydrolysis rate constants obtained under both in vivo and in vitro conditions demonstrate the obstacle of obtaining accurate values for in vivo enzymatic activity from related in vitro experiments. The supernatant was directly injected into a Novaflex C18 column and detected at 254 nm.
|