Bioavailability and in-vitro evaluation of marketed allopurinol tablets

ABSTRACT

The in vitro evaluation of 12 commercial br and s of allopurinol tablets marketed in Egypt was studied. All tested products conformed to the USP XXII dissolution limit, i.e. 75% dissolution after 45 minutes, yet different release rates were observed. The two tablet br and s exhibiting minimum [79%] and maximum [100%] drug release after 45 minutes, in addition to a st and ard product [Zyloric-300], were subjected to in vivo evaluation. The study was carried out according to a cross-over design on six healthy male volunteers. Following a single oral dose of 300 mg, the plasma concentrations of allopurinol and its major metabolite oxypurinol were determined by HPLC. The three products were found statistically bioequivalent. The USP XXII dissolution test proved to be quite satisfactory for the prediction of allopurinol bioavailability and bioequivalence