The proportion of society composed of elderly individuals has risen, indicative of increased longevity.1) Hence, it is of increasing importance to address the medicinal needs of this segment of the population in terms of conventional dosage forms such as powders, tablets and capsules.2) In this regard, to improve the quality of life and treatment compliance of such patients, a fast dissolving oral dosage in the form of rapidly disintegrating tablets (RDT) appears to be a suitable alternative for oral medication, accounting for difficulties associated with swallowing often encountered by this segment of the population. 3,4) Upon placement of tablets of this type within the oral cavity, saliva quickly penetrates into the pores, causing rapid tablet disintegration. Thus, disintegration time is an important property of tablets, but it must be evaluated. In vitro disintegration time can be tested via the Japanese Pharmacopoeia (JP) XIII disintegration test; however, according to the literature, this approach does not appear to be convenient for measuring the disintegration time of RDT. [5][6][7][8] As an alternative to the apparatus described in JP XIII, we developed a novel approach in order to evaluate the disintegration time of RDT employing a CCD camera. We attempted to predict the in vivo disintegration time and to clarify the disintegration mechanism of RDT with this device. For these purposes, three RDT samples were designed with mannitol and different types of binders, including polyvinylpyrrolidone, polyvinylalcohol and hydroxypropylcellulose. ExperimentalMaterials D-Mannitol (Mannit P, Towa Chemical Industry Co., Ltd., Tokyo) (particle size of 52 mm in median diameter by the laser scattering method, LA-910, Horiba, Ltd., Kyoto) was utilized. Polyvinylpyrrolidone JP (PVP-K30, ISP Technologies Inc., New Jersey), 88 mol% hydrolyzed polyvinylalcohol (PVA205C, Kuraray Co., Ltd., Tokyo) and hydroxypropylcellulose JP (HPC-L, Nihon Soda Co., Ltd., Tokyo) were employed as binders. Ethanol was of analytical grade of not less than 99.5% (Junsei Chemical Co., Ltd., Tokyo). Other chemicals were of a commercial grade.Preparation of the Test Tablets Formulations employed in this study are presented in Table 1. Test tablets involved in the evaluation and prediction of oral disintegration were prepared with various binder types and quantities in order to assess the suitability of the CCD-camera method with respect to the examination of in vivo disintegration. A schematic diagram of the preparation technique of the test tablets is shown in Fig. 1. D-Mannitol was crushed in a high-speed mixer equipped with 3-l vessel (Mechanomil MM-10, Okada Seiko Co., Ltd., Tokyo). Binder was dissolved in a solvent composed of a 50% (w/w) ethanol solution. The amount of the solvent used was 13% (w/w) to the tablet weight. D-Mannitol was kneaded with the binder solution in order to achieve uniform moisture. Subsequently, the wet powder was compressed by a novel molding tableting system, 9-11) which consisted of a molding tableting machine and...

An artificial synthetic gene coding for human eIF-4E was cloned into an expression vector and direct expression was attempted in Escherichia coli [BL21(DE3) strain] under the control of T7 promoter. The active gene product which was induced in high yield (ca. 4 mg/100 ml) by isopropyl-beta-D-thiogalactopyranoside was purified to homogeneity by a two-step chromatographic procedure with a good yield (ca. 74%), and was confirmed to be recombinant human eIF-4E by amino acid composition and sequence analyses, isoelectric focusing, and absorption spectral measurements. The identity of three-dimensional structures between the recombinant and native human eIF-4Es was confirmed by CD and fluorescence measurements.

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Using a taste sensor in theˆeld of medical products has the following four main purposes: (1) Ensuring that investigational product and placebo are indistinguishable; (2) Formulation design; (3) Quality control; (4) Benchmark test. Unlike evaluating a taste of food, roughly predicting a taste of drug without human sensory test and quantitative evaluation using small quantity of drug sample are more important than evaluation of the nuances of homogeneous taste and preference. Here are some examples of using taste sensor for these purposes. (1) We predicted a taste of suspension of phosphatic drug substance in an early phase of development using a taste sensor. As a result, the suspension seemed to have sour and bitter taste. Then we made placebo solution of citric acid similar taste as much like active suspension to ensure indistinguishable taste from each other. (2) A taste of orally disintegrating tablet (ODT) in the mouth is important to drug adherence. The taste of an ODT was then evaluated in chronological order by combining the taste sensor with the new disintegration testing apparatus to design easy-to-take formulation. (3) We evaluated taste variation of a commercial product in batch-to-batch and identiˆed the cause of the variation. (4) We did benchmark test for easy-totake of commercial ODTs in vitro. There is great variability among these products in the disintegrating proˆle and the taste.

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