[Liberation of active substance from pharmaceutical suspensions I. Effect of surfactants on the active substance dissolving].

Liberation of active agent from suspensions containing sulfadimidine was investigated. There are three physico-chemical steps of the process: (i) dissolving active agent in the vehicle of suspension, (ii) partitioning dissolved molecules between the membrane and the suspension, and (iii) diffusion of active substance through membrane into the acceptor phase. The vehicle of suspensions contained surface active agents in 0.