[Study on environmental risk assessment of drugs: excretion forms to environment]

Environmental risk assessment of human pharmaceuticals is needed to protect aquatic life from the toxic exposure because unaltered drugs and/or the metabolites are released to environment after human use. Application for new drugs shall be accompanied by an evaluation report of environmental risk assessment on basis of predicted use volume, already in US and near future in EU. In Japan, the specialists are reviewing methodology of environmental risk assessment of drugs now. To provide the basic information, we investigated excretion forms of drugs after human use for two groups of Japanese drugs; high sale products top 20 in the 2004 fiscal year and new molecular entities approved in 2004 and 2005. The assessment targets are materials produced for direct use in US, but those are active substances or active metabolites, excluding orphan drugs, vitamins, amino acids, peptides and proteins, in EU. According to EU condition, almost two thirds of 20 high sale products and one third of recently approved new molecular entities were identified to be the targets for environmental risk assessment.