Osamu Hosoya

Mutation analysis concerning possibility of cancer of unknown primary new treatment

Abstract Anti-epidermal growth factor receptor monoclonal antibodies are approved and effective only in KRAS wild-type patients with advanced colorectal carcinoma. The present retrospective study investigated the role of KRAS gene

Safety evaluation of dermal exposure to phthalates: Metabolism-dependent percutaneous absorption

ABSTRACT Phthalates, known as reproductive toxicants and endocrine disruptors, are widely used as plasticizers in polyvinyl chloride products. The present study was conducted for risk identification of dermal exposure to phthalates. When dibutyl phthalate was applied to the skin of hairless rats and humans, only monobutyl phthalate appeared through the skin, and the permeability of the skin was higher than that after the application of the monoester directly. The inhibition of skin esterases made the skin impermeable to the metabolite following dermal exposure to dibutyl ester, whereas removal of the stratum corneum from the skin did not change the skin permeation behavior. Similar phenomena were observed for benzyl butyl phthalate. The skin permeability of monobenzyl phthalate was higher than that of monobutyl phthalate in humans, although the reverse was observed in rats. Species difference in skin permeation profile corresponded to the esterase activity of the skin homogenate. Di(2‐ethylhexyl) phthalate, which was not metabolized by esterases in the skin, was not transported across the skin. These results suggest that highly lipophilic phthalates may be transported easily across the stratum corneum lipids. The water‐rich viable layer may become permeable to these phthalates by their metabolism into monoesters, which are relatively hydrophilic. Skin metabolism is essential to the percutaneous absorption of phthalates. Because esterase activity has large inter‐individual differences, further study will be needed for individual risk identification of dermal exposure to phthalates. HIGHLIGHTSMonophthalate, permeated through the skin after diphthalate application.Characteristics of human skin cannot be determined from those of rat skin.An accurate estimation of esterase activity in the skin requires a risk assessment.

[Effect of Adhesives on the Properties of Adhesion, Drug Release and Skin Permeation of Lidocaine Tapes].

A generic drug is defined as a drug product that is comparable to a brand name drug in terms of dosage, form, strength, route of administration, quality, performance characteristics, and indicated use. Generic drugs for topical use, in the case of sheet-like products, are required to be the same as the original drug in terms of application area and dosage form. The composition of such generic drug formulations may differ from that of the original product. The adhesive of any pharmaceutically-active tape that directly contacts the skin plays a role in delivering the active ingredient into the skin, and affects the sensation and ease of handling. Therefore, adhesives are an important ingredient in these products. Thus, the aim of this study was to characterize original and generic lidocaine tape products, and to evaluate the adhesive properties of each. The tack force, peel strength and shear adhesion were measured as adhesive properties. In addition, in vitro drug releasing profiles and skin permeation profiles of the products were evaluated. In vivo transdermal absorption was also evaluated to predict the possibility of adverse effects. Adhesive properties differed among the three analyzed products. These differences may have been caused by differences in the adhesives. Drug-releasing profiles and skin permeation profiles also differed among the three products, even though the pharmacokinetics were not significantly different. By obtaining an adequate understanding of the characteristics of original and generic products, we will be able to provide better tailor-made medications for drug therapies for patients.