IS ONE PARACETAMOL SUPPOSITORY OF 1000 MG BIOEQUIVALENT WITH 2 SUPPOSITORIES OF 500 MG

A common belief is that one tablet or suppository containing, e.g. 100 mg of a drug can be substituted, without any changes in the therapeut ic effect, with two units of the same brand containing 50 mg of the dr ug. In the present study a single dose of paracetamol was administered to healthy volunteers as (a) two tablets of 500 mg, Cb) two supposito ries of 500 mg, and (c) one suppository of 1000 mg. There were statist ically significant differences in all bioavailability parameters (t(ma x), C-max and AUG) between the three treatments. The relative bioavail ability of the 500 mg suppositories was 77% and that of the 1000 mg su ppositories 66%. The absorption rate from suppositories was markedly l ower than from the tablets. Especially low absorption rate was obtaine d with the suppository of 1000 mg. The two strengths, although having the same trade name, were not therefore bioequivalent.