[Formulations and bioavailability of propyphenazone in lyophilized tablets].

The present work reports some facts about the preparation and release characteristics of the tablets of propiphenazone made by lyophilizing method (lyoc); they are compared with the classic tablets obtained by simple compression. Our substance, the propiphenazone, is a stable one, but we can talk about its poor solubility. Therefore, in order to obtain the lyoc tablets, we chose the method of paste. This tablets had a spongy aspect, with a desaggregation time of 1-2 min.; the latter (classic tablets) were regularly and the desaggregation time in about 9 min. The kinetics of propiphenazone absorbtion would be expected to differ in these structurally-distinct tablets types. Indeed, the concentration was really appreciable for the lyoc tablets after 30 min., with the peak at 60 min.; for the classic tablets the peak was remarkably only after 90 min. The relative bioavailability for these two types of tablets pointed out the differences, confirming the evident advantages for using the lyoc tablets in analgesic, antipyretic therapy.