[Bioavailability of drug forms of tetracycline-group semisynthetic preparations for internal use].

Bioavailability of methacycline capsules manufactured by two different firms was studied and it was shown that they had statistically significant differences. Conditions for investigation of the rate of methacycline transfer from the pharmaceutical form into solution were developed with the use of a "rotating basket". Such investigations provided in vitro prediction of the drug bioavailability. The effect of additives on bioavailability of methacycline capsules was found. Study of bioavailability of doxycycline capsules manufactured by the same two firms revealed no differences.