Publications by authors named "Daisuke Tsunashima"

This study is focused on the development of a microhydraulic turbine that can stably and efficiently generate electricity even in channel where snow masses frequently flow down. A hydraulic turbine of an undershot cross-flow type was installed in an irrigation channel, and the change in the turbine performance was measured when spherical snowballs were released one by one from the upstream. The observation of the snowballs passing through the turbine was also conducted.

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Objectives: We aimed to prepare a once-daily modified-release oral formulation of tacrolimus by utilizing an extended-release granules (ERG).

Methods: Extended-release granules were prepared using ethylcellulose (EC), hydroxypropylmethylcellulose (HPMC) and lactose via a solvent evaporation method with ethanol. Physicochemical and biopharmaceutical studies were performed to determine the formulation with optimum release profile of tacrolimus from ERG.

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Objectives: Tacrolimus is a poorly water-soluble compound that is used to prevent allograft rejection. We aimed to prepare an extended release formulation of tacrolimus to achieve both an extended release profile and improved solubility of tacrolimus.

Methods: Extended release granules (ERG) of tacrolimus were prepared with lactose, ethylcellulose (EC) and hydroxypropylmethylcellulose (HPMC) via the solvent evaporation method.

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Background: Tacrolimus is an established immunosuppressant used for the prevention and treatment of allograft rejection in solid organ transplantation. An immediate-release oral formulation of tacrolimus has been commercially available since 1994 that is administered orally BID. To improve the compliance and quality of life of transplant patients, a once-daily modified release (MR) formulation is an attractive option.

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A novel approach to establishing the design space for the oral formulation manufacturing process was investigated. A response surface method incorporating multivariate spline interpolation was applied to overcome the nonlinear problem, which is always problematic in pharmaceutical development studies, and a bootstrap resampling technique, polynomial approximation technique, and 95% confidence intervals based on a nonparametric approach were applied to estimate the reliability of the established design space derived from the nonlinear response surface model. The critical quality attributes (CQAs) of intermediate material rather than the critical process parameters (CPPs) were chosen as the causal factors for the response variables, which were CQAs of the final product to avoid scale-gap and equipment-gap.

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