The rate of diffusion of chloramphenicol and tetracycline-HCI from white petrolatum wasfoundtoincreaseinthepresenceofeitherwoolwaxesorwool wax derivatives; the effect being more pronounced in conjunction with the latter group. Forbothantibiotics,thereleasingproperties were found tokeep increasing with increasing wax (local Merino) concentration; however, for each antibiotic the increase followsaspecialpattem.Therateof1iberationof the antibiotics could not be correlated to any investigated individual physico-chemical property of the waxes or wax derivatives.