In Vitro andIn Vivo availability of some commercial prednisolone tablets

The in vitrodissolution rates of prednisolone from five commercially available 5- mg prednisolone tablets were determined in distilled water. The dissolution studies were repeated on the fastest- and slowest-dissolving brands using 0.01% polysorbate 80 in 0.1 NHCl as the dissolution medium. A two-way crossover bioavailability study was performed in 12 human male adult volunteers comparing the fastest- and slowest-dissolving brands. The plasma samples were assayed for prednisolone by a radioimmunoassay method. Statistical analysis of the data for the two brands showed no significant differences between average plasma levels of prednisolone at any sampling time. The results suggest that on the average the in vivorates of dissolution of the two brands were essentially the same, and in vitrodissolution in 0.01% polysorbate 80–0.1 NHCl medium was better correlated with these in vivoresults than dissolution in water.Supported by Contract CPF69-22, Food and Drug Administration, Washington, D.C., and in part by Public Health Service Grant 5-P11-GM15559.