Controlled release preparation of insulin and its method
AssigneeM.I. Tech Co., Ltd.
InventorsChan-Hwa Kim, Jai-Hyun Kwon, Sung-Hee Choi
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Abstract
A controlled release preparation of insulin and its method are provided. The controlled release preparation of insulin contains microparticles obtained by microencapsulation of uniform microcystals of insulin using biodegradable polymeric materials. Since the denaturation of insulin that may occur during microencapsulation is reduced, the stability of the preparation can be increased. Also, the ratio of insulin to a polymer carrier is increased, which is suitable for pulmonary delivery. Further, the controlled release preparation of insulin can continuously exhibit pharmaceutical efficacy in vivo in a stable manner for an extended period of time.
Claims13
A controlled release preparation of insulin containing microparticles having a volume average diameter of 10 μm or less obtained by microencapsulation using a double emulsion method, wherein the microparticles capable of functioning as seeds in the insulin solution are formed while varying the pH of an acidic insulin solution up to approximately 9 to approximately 10.5 in pH level of an acidic insulin solution at an isoelectric point or below, the solubility of the insulin solution is lowered to obtain insulin microcrystals having a volume average diameter of 10 μm or less, the insulin microcrystals are suspended in a solution of pH 4.5 to 6.5, which is an isoelectric precipitation zone, and added to a biodegradable polymer to make a primary emulsion, an emulsifier is added to the resultant to make a secondary emulsion, and then the secondary emulsion is stirred.
A method of producing a controlled release preparation comprising the steps of:
- (a) forming microparticles capable of functioning as seeds in the insulin solution while varying the pH of an acidic insulin solution up to approximately 9 to approximately 10.5 in pH level of an acidic insulin solution at an isoelectric point or below and the solubility of the insulin solution is lowered to obtain insulin microcrystals having a volume average diameter of 10 μm or less;
- (b) suspending the insulin microcrystals obtained in step (a) in a solution of pH 4.5 to 6.5, which is an isoelectric precipitation zone, adding the suspended solution to a biodegradable polymer to make a primary emulsion, adding an emulsifier to the resultant to make a secondary emulsion, and stirring the secondary emulsion to obtain microparticles having a volume average diameter of 10 μm or less;
- and
- (c) preparing formulations by a general pharmaceutical method by adding pharmaceutically acceptable supportive ingredients or additives to the microparticles obtained in step (b).
Dependencies are inferred from the claim text.