Abstract: Disclosed are multivesicular liposomes (MVLs) containing IGF-I with substantially full bioavailability, wherein the loading of the IGF-I into the liposomes is modulated by adjusting the osmolarity of the aqueous component into which the agents are dissolved prior to encapsulation. In the making of MVLs, the process involves dissolving the IGF-I, an osmolarity excipient, and a pH modifying agent sufficient to solubilize the IGF-I in a first aqueous component used during manufacture of the MVLs. To increase the loading of the IGF-I, the osmolarity of the aqueous component used during manufacture of the MVLs is reduced, whereas the osmolarity of the aqueous component is increased to obtain the low load formulations. The rate of release of the active agent into the surrounding environment in which the liposomes are introduced can be simultaneously controlled by incorporating into the lipid component used in the formulation at least one long chain amphipathic lipid.

Abstract: Disclosed is a method for making liposomes, for example multivesicular liposomes (MVLs), containing one or more biologically active agents, wherein the loading of the active agents into the liposomes is modulated by adjusting the osmolarity of the aqueous component into which the agents are dissolved prior to encapsulation. To increase the loading of the active agent, the osmolarity of the aqueous component is reduced, and to decrease the loading of the active agent, the osmolarity of the aqueous component is increased. In the making of MVLs, the process involves dissolving the active agent and an optional osmotic excipient in a first aqueous component encapsulated within the liposomes. For any given concentration of drug, the osmolarity of the first aqueous component can be adjusted by increasing or decreasing the concentration or molecular weight of the osmotic excipients used therein.

Abstract: Muteins of IL-2 in which one of the amino acids of the mature native sequence of IL-2 is replaced by a cysteine residue are prepared and conjugated through the replaced cysteine residue to a polymer selected from polyethylene glycol homopolymers or polyoxyethylated polyols, wherein said homopolymers are unsubstituted or substituted at one end with an alkyl group. These muteins are made via host expression of mutant genes encoding the muteins that have been changed from the genes for the parent proteins by site-directed mutagenesis. In addition, other species of IL-2 may be conjugated via the cysteine residue at position 125 of the mature IL-2 protein that is not necessary for the biological activity of the IL-2.

Abstract: A biologically active CSF-1 protein is selectively conjugated via certain amino acid residues or carbohydrate moieties to a water-soluble polymer selected from polyethylene glycol or polypropylene glycol homopolymers, polyoxyethylated polyols, or polyvinyl alcohol. The resulting conjugated CSF-1 is biologically active and has increased circulating half-life in mammals, compared to that of the unconjugated protein. The conjugated CSF-1 may be used to stimulate the immune response or to provide more cells to be stimulated.

Abstract: The present invention is a process for preparing a pharmaceutical composition comprising a biologically active conjugated protein. It comprises a polyethylene glycol or a polyoxyethylated polyol conjugated to IL-2. This protein is conjugated to reduce its immunogenicity, and increase its solubility, and increase its circulating in vivo half-life.

Abstract: The present invention is a pharmaceutical composition for proteins which are not stably soluble. The preferred protein is IL-2 and the preferred composition includes amino acids, vitamins, polymers, fatty acids or low molecular weight acids.

Abstract: A pharmaceutical composition is prepared wherein biologically active conjugated interleukin-2 is dissolved in an aqueous carrier medium without the presence of a solubilizing agent. The unconjugated IL-2, which is not water soluble or not readily soluble in water at pH 6-8 without such solubilizing agent, is selectively conjugated to one or more succinyl groups by reaction with succinic anhydride.

Abstract: A pharmaceutical composition is prepared wherein a biologically active conjugated protein which is .beta.-interferon, interleukin-2, or an immunotoxin is dissolved in an aqueous carrier medium without the presence of a solubilizing agent. The unconjugated protein, which is not water-soluble or not readily soluble in water at pH 6-8 without such solubilizing agent, is selectively conjugated to a water-soluble polymer selected from polyethylene glycol homopolymers or polyoxyethylated polyols.

Abstract: The present invention is a process for preparing a pharmaceutical composition comprising a biologically active conjugated protein. It comprises a polyethylene glycol or a polyoxyethylated polyol conjugated to IL-2. This protein is conjugated to reduce its immunogenicity, and increase it solubility, and increase its circulating in vivo half-life.

Abstract: A biologically active CSF-1 protein is selectively conjugated via certain amino acid residues or carbohydrate moieties to a water-soluble polymer selected from polyethylene glycol or polypropylene glycol homopolymers, polyoxyethylated polyols, or polyvinyl alcohol. The resulting conjugated CSF-1 is biologically active and has increased circulating half-life in mammals, compared to that of the unconjugated protein. The conjugated CSF-1 may be used to stimulate the immune response or to provide more cells to be stimulated.

Abstract: A pharmaceutical composition is prepared wherein a biologically active conjugated protein which is .beta.-interferon, interleukin-2, or an immunotoxin is dissolved in an aqueous carrier medium without the presence of a solubilizing agent. The unconjugated protein, which is not water-soluble or not readily soluble in water at pH 6-8 without such solubilizing agent, is selectively conjugated to a water-soluble polymer selected from polyethylene glycol homopolymers or polyoxyethylated polyols.