Sterile masses suitable for use as medicinal depot carriers, depot base substances, masses for infusion and plastic fillings, are prepared by heating a paste or solution of polyvinyl alcohol or a derivative thereof capable of dissolving or swelling in water containing an iron or chromium compound, a dyestuff of the Congo Red group or sodium acetate, to a temperature above 100 DEG  C. in a closed vessel.  Therapeutic agents (such as alkaloids, cardiacs and gland preparations) or electrolytes accelerating the resorption of the mass may be added.  Resorption of the mass may be retarded by treatment with rays.  The consistency may be modified by addition of oils, hydrocarbons, or glycerine.  In examples: (1) aqueous polyvinyl alcohol is mixed with Congo Red and after sterilization blended with sterile dilute hydrochloric acid and thyreotropic hormone to yield a mass which solidifies in the body after injection; (2) aqueous polyvinyl alcohol is heated with ammonium bichromite to yield a paste which may be used as a joint lubricant; (3) aqueous polyvinyl alcohol is heated with benzopurpurin to yield a product that may be used for stiffening tissues, for supporting the mediastinum, or for filling cavities; (4) aqueous polyvinyl alcohol is heated with Congo Red and lactic acid to yield a mass that may be injected into the body. Specifications 476,314 and 476,426 are referred to.  The Specification as open to inspection under Sect. 91 refers in general to the use of polyvinyl alcohol or a derivative thereof capable of swelling in water as medicinal depot carriers, masses for infusion or plastic fillings.  This generalization does not appear in the Specification as accepted.ALSO:Sterile masses, suitable for use as medicinal dep<\>zot carriers, dep<\>zot base substances, masses for infusion and plastic fillings, are prepared by heating a paste or solution of polyvinyl alcohol, or a derivative thereof capable of dissolving or swelling in water, containing an iron or chromium compound, a dyestuff of the Congo Red group, or sodium acetate to a temperature above 100 DEG  C. in a closed vessel.  Theurapeutic agents (such as alkaloids, cardiacs and gland substances) or electrolytes varying the rate of resorption may be added.  Resorption of the mass may be retarded by treatment with various rays.  In examples: (1) aqueous polyvinyl alcohol is mixed with Congo red, sterilized, and blended with thyreotropic hormone to yield a mass solidifying in the body after injection; (2) aqueous polyvinyl alcohol is heated with ammonium bichromate to yield a pasty joint lubricant; (3) aqueous polyvinyl alcohol is heated with benzopurpurin to yield a product suitable for sticking tissues, supporting the mediastinum and for filling cavities; (4) aqueous polyvinyl alcohol is heated with Congo Red and lactic acid to yield a mass suitable for injection.  Specifications 476,314 and 476,426, [both in Group IV], are referred to.  The Specification as open to inspection under Sect. 91 refers to the use, in general, of polyvinyl alcohol or a water-swellable derivative thereof as medicinal dep<\>zot carriers, masses for infusion or plastic fillings.  This generalization does not appear in the Specification as accepted.