Capsule loading technique
AssigneeDamon Biotech, Inc.
InventorWen-Ghih Tsang
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Abstract
Disclosed is a method for loading capsules having a semipermeable membrane with a chemically active substance to be released over time. The method first involves gradually deflating and dehydrating the capsules and subsequently soaking the deflated capsules in a solution containing the substance to be encapsulated. After loading, the permeability of the capsule may be adjusted to accommodate the requirements of the end use. The loaded capsules of this invention may be used in a variety of applications, including use as a bioimplantable drug or biochemical delivery system.
Claims23
A composition of matter comprising a previously formed, and deflated, dehydrated cpsule having an intact, selectively permeable membrane defining a substantially empty interior volume, said membrane being expandable upon rehydration with a solute and aqueous solution at a given concentration to produce a capsule containing said solution and capable of sustained release of said solute.
A method of preparing a composition of deflated, dehydrated semipermeable capsules having intact membranes which define a substantially empty interior volume wherein said deflated, dehydrated, semipermeable capsules are capable of being reexpanded and rehydrated, said method comprising the step of dehydrating preformed capsules having hydrogel membranes by treating said preformed capsules with successive aqueous wash solutions having increasing concentrations of a dehydrating agent and thereafter removing residual dehydrating agent.
A method of producing a sustained release composition, said method comprising the steps of:
- (a) providing preformed hydrated capsules each having a semipermeable, porous hydrogel membrane defining an intracapsular volume;
- (b) deflating and dehydrating said capsules with successive aqueous wash solutions having increasing concentrations of a dehydrating agent to obtain deflated, dehydrated capsules, each having intact, semipermeable membranes which define a substantially empty interior volume;
- and
- (c) loading said deflated, dehydrated capsules with a solute and aqueous solution by soaking the deflated, dehydrated capsules in the solute-containing aqueous solution to diffuse said solute into the intracapsular volume to yield a reconstituted, rehydrated capsule, having a reservoir of time-releasable solute.
Dependencies are inferred from the claim text.