HIGH AND LOW LOAD FORMULATIONS OF IGF-I IN MULTIVESICULAR LIPOSOMES

摘要

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. Use of the long chain amphipathic lipid in the lipid component is particularly helpful in controlling the release rate from high drug load formulations.