Japanese NHI Generics And Substance Patents

Several generic drug products which were added to Japan's National Health Insurance price list in July (Marketletter August 1) are covered by substance patents.

They include generic versions of Glaxo and Sankyo's Zantac (ranitidine) manufactured by Taisho Yakuhin and Choseido Pharmaceutical, named Rantic and Seochitozin respectively, and Yoshindo's Ringereaze, a generic version of Sankyo's Loxonin (loxoprofen). Glaxo and Sankyo's substance patent (Form 1) for ranitidine is valid until August 1997, and Sankyo's patent for loxoprofen runs to April 1997.

Generics manufacturers in Japan are generally reluctant to involve themselves in producing drugs which are covered by substance patents, as these provide very tough protection, being superior to both process and application patents. The strength of these patents means the generic manufacturers cannot guarantee continuous NHI supplies of the product, according to a report in Pharma Japan. Moreover, during the hearings conducted before the NHI list was drawn up, officials of the Ministry of Health and Welfare had warned generics manufacturers that they must be able to guarantee to provide stable supplies of products for which they had applied for a NHI listing, and that they should therefore review the situation concerning drugs which could be expected to cause problems with the original manufacturers.