Dissolution and enzymatic hydrolysis of chloramphenicol palmitic and stearic esters

The dissolution rate of the polimorphs A and B of chloramphenicol palmitic and stearic esters, has been compared to the enzymatic hydrolysis rate by pancreatine in the same experimental conditions.The enzymatic hydrolysis rate does not depend on a normal process of dissolution and the assumption is made that the pancreatic enzyme acts at the solid-liquid interface on the film of molecules of the esters which are going into solution, thus favouring an "eased release" of the molecules from the crystal according to the conformational differences of the molecules themselves.As for polymorphs B, it has also been possible to note a good correlation between the in vitro data related to chloramphenicol release in enzymatic hydrolysis and the in vivo data concerning the absorption rate and the blood levels of the antibiotic after peroral administration of its esters.