RESUMEN
Four brands of paracetamol tablets manufactured in Egypt, an imported brand [Panadol tablets] and an expertimental tablet were evaluated for in vitro dissolution and in vivo availability of the drug. The results of the study demonstrated that the different tablets appear to follow first order dissolution kinetics. Three dissolution media were used in this study. The highest dissolution rate constant was obtained in 0.1N hydrochloric acid for all the products. The dissolution of the drug from the different tablets was a function of their disintegration. The cumulative amounts of paracetamol excreted in urine after 24 hours were above 84% of the administrated dose in all cases. Brand V was shown to give the best in vitro and in vivo availability. Comparable data were given by brand I. A good linear correlation was obtained between the maximum amount of the drug dissoluted and the percentage of the dose excreted in urine after 24 hours