Temperature-controlled active agent dispenser
AssigneeLandec Labs, Inc.
InventorRay F. Stewart
Life of this patent
Estimating the term…
Abstract
Temperature-controlled diffusional active agent dispensers that use a side-chain crystallizable polymer in a form that is not free to flow above its melt temperature as a rate-controlling matrix are disclosed. The polymer may be crosslinked to render it nonflowable, be supported, or grafted to a permeable support. Elements that facilitate or permit heating by radiation or electrical conductance/inductance may be included in the dispenser. At temperatures below the melt temperature of the polymer, the polymer is substantially impermeable to the agent. At tempertures at or above the melt temperature the polymer is substantially permeable to the agent.
Claims30
A temperature controlled agent dispenser that provides a reversible, substantial change in agent dispensing rate at a selected temperature comprising a body that maintains its integrity at the selected temperature and is comprised of an agent and a side-chain crystallizable polymer which (i) is in a form that retains its shape and is not free to flow wholly at the selected temperature, (ii) exhibits a phase transition at the selected temperature, (iii) has substantially greater permeability to the agent at temperatures equal to or greater than the selected temperature than at temperatures below the selected temperature, and (iv) is interposed between the agent and an environment into which the agent is to be dispensed whereby the rate at which the agent is dispensed to the environment at a temperature equal to or greater than the selected temperature is dependent upon the rate at which the agent diffuses therethrough.
A temperature-controlled diffusional matrix for regulating transport of an agent from a source of the agent to an environment of use for the agent comprising a body of (a) a solid support phase and (b) a side-chain crystallizable polymer phase which (i) exhibits a phase transition at a selected temperature and (ii) has substantially greater permeability to the agent at temperatures equal to or greater than the selected temperature than at temperatures below the selected temperature, wherein there is at least one continuous path through the body that is defined by the side-chain crystallizable polymer phase and the side-chain crystallizable polymer is immobilized.
A temperature-controlled diffusion matrix for regulating transport of an agent from a source of the agent to an environment of use for the agent comprising (a) an agent-permeable polymer membrane and (b) a layer of side-chain crystallizable polymer grafted to the surface of the membrane, the side-chain crystallizable polymer (i) exhibiting a phase transition at a selected temperature and (ii) having substantially greater permeability to the agent at temperatures equal to or greater than the selected temperature than at temperatures below the selected temperatures.
A temperature-controlled diffusion matrix for regulating transport of an agent from a source of the agent to an environment of use for the agent comprising a laminated composite of (a) a layer of side-chain crystallizable polymer that (i) exhibits a phase transition at a selected temperature and (ii) has substantially greater permeability to the agent at temperatures equal to or greater than the selected temperature than at temperatures below the selected temperatures sandwiched between (b) layers of an agent-permeable polymer that are bonded to each other to prevent relative motion therebetween.
Dependencies are inferred from the claim text.