[Clinical questions on bioavailability and proff of efficacy (author's transl)]

The problems referring to bioavailability may be considered as follows: up to now extact informations on bioavailability as to the determined substances to meet the requirements of therapy are not obtainable. Obvious is the lack of precise investigations about what kind of bioavailability is desirable in respect to rate of rise of the drug, its course of time and its quantity under consideration for the different groups of disease. For this reason and excluding special cases, only common suggestions can be given at present. Difficulties are also presented by the entitled demand for the proof of efficiency. Test of new substances in man are confined to compromises either on the significance of the tests or the security of the patient.