Abstract: A material capable of forming hydrogen bonds or covalent bonds with loading materials incorporated in loaded cells is introduced into the cells with the loading materials to inhibit the destruction of the cell membranes by the loading material after the permeability of the membranes is brought back down to its normal value. In order to provide for the hydrogen bond formation with common loading materials, such as methotrexate, proteins such as albumin and sugars such as sucrose are effective. The time period during which these materials inhibit a destructive effect on the membranes of loaded cells is well defined.