EP0256726A2
Expired / Lapsed
EP
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Encapsulation of TRH or its analog
Assignee: Takeda Pharmaceutical Co Ltd
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Filing: 1987-07-31
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Granted: —
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Expires: 2007-07-31
Abstract
Abstract The present invention relates to a microcapsule containing TRH, its analog or a salt thereof and a method of producing the same which attains the release of the active ingredient stably for a prolonged period of time with high rates of incorporation of the active ingredient thereinto and with little possibility of excessive initial release or burst.
Inventors
- 👤 Toshiro Heya
- 👤 Hiroaki Okada
- 👤 Yasuaki 77-42 Koaza-Tanita Ogawa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 03:37
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/48; A61K9/14; A61K9/16; A61K9/1605; A61K9/1629; A61K9/1641; A61K9/1647; A61K38/00; A61K38/04; A61K38/06; A61K38/066
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
37 words
A microcapsule which comprises 2 to 15 % by weight, based on a polymer, of TRH, its analog or a salt thereof with a weak acid having a pKa of not less than 4.0 and said polymer.
Claim 2
Dependent Claim
37 words
A microcapsule which comprises 2 to 15 % by weight, based on a polymer, of TRH, its analog or a salt thereof with a weak acid having a pKa of not less than 4.0 and said polymer.
Claim 3
Dependent Claim
55 words
The microcapsule according to Claim 1, wherein the TRH or its analog is a compound of the formula: wherein X is 4, 5- or 6-membered heterocyclic group, Y is imidazol-4-yl or 4-hydroxyphenyl, R¹ and R² are the same or different and each is hydrogen or lower alkyl and R³ is hydrogen or optionally substituted aralkyl.
Claim 4
Dependent Claim
9 words
The microcapsule according to Claim 2, wherein X is
Claim 5
Dependent Claim
13 words
The microcapsule according to Claim 2, wherein R¹ and R² are each hydrogen.
Claim 6
Dependent Claim
12 words
The microcapsule according to Claim 2, wherein R³ is hydrogen or 3,4-dihydroxyphenylethyl.
Claim 7
Dependent Claim
14 words
The microcapsule according to Claim 2, wherein the compound is pyroGlu-His-ProNH₂, α-butyrolactonecarbonyl-His-ProNH₂ or orotyl-His-ProNH₂.
Claim 8
Dependent Claim
16 words
The microcapsule according to Claim 1, wherein the TRH or its analog is a free form.
Claim 9
Dependent Claim
23 words
The microcapsule according to Claim 1, wherein the TRH or its analog is a salt with an inorganic acid or an organic acid.
Claim 10
Dependent Claim
15 words
The microcapsule according to Claim 8, wherein the organic acid is lower alkane monocarboxylic acid.
Claim 11
Dependent Claim
20 words
The microcapsules according to Claim 1, wherein the polymer is a homopolymer or a copolymer of poly fatty acid esters.
Claim 12
Dependent Claim
18 words
The microcapsules according to Claim 10, wherein the polymer is a copolymer of lactic acid and glycolic acid.
Claim 13
Dependent Claim
11 words
The microcapsule according to Claim 1, wherein the polymer is polyorthoester.
Claim 14
Dependent Claim
25 words
The microcapsule according to Claim 10 or 12, wherein an average molecular weight of the polymer is within the range of about 1,000 to 100,000.
Claim 15
Dependent Claim
23 words
The microcapsule according to Claim 1, wherein an average diameter of the microcapsule is within the range of about 0.5 to 400 µm.
Claim 16
Dependent Claim
83 words
A method of producing the microcapsule according to Claim 1, which comprises causing an oil phase containing a polymer and an aqueous phase containing 2 to 15% by weight, based on said polymer, of TRH, its analog or a salt thereof with a weak acid having a pKa of not less than 4.0 to form a W/O emulsion, mixing the emulsion with an aqueous solution of a dispersing agent to thereby form a W/O/W emulsion, and then distilling off the oil phase solvent.
Claim 17
Dependent Claim
21 words
The method according to Claim 15, wherein the oil phase is essentially consisting of the polymer dissolved in an organic solvent.
Claim 18
Dependent Claim
13 words
The method according to Claim 16, wherein the organic solvent is halogenated alkane.
Claim 19
Dependent Claim
31 words
The method according to Claim 15, wherein the aqueous phase contains the TRH, its analog or the salt thereof and water in a peptide weight ratio of about 5 to 80%.
Claim 20
Dependent Claim
21 words
The method according to Claim 15, wherein the emulsifying operation to form the W/O emulsion is conducting by a dispersion method.
Claim 21
Dependent Claim
18 words
The method according to Claim 19, wherein the viscosity of the W/0 emulsion is 150 to 10,000 centipoises.
Claim 22
Dependent Claim
35 words
The method according to Claim 15, wherein the emulsifying operation to form the W/0/W emulsion is dispersing the W/0 emulsion to the third aqueous layer containing a dispersion agent under an adjustment of a temperature.
Claim 23
Dependent Claim
16 words
The method according to Claim 21, wherein he dispersing agent is polyvinyl alcohol, carboxymethylcellulose or gelatin.
Claim 24
Dependent Claim
17 words
The method according to Claim 21, wherein the temperature is adjusted to about 0°C to about 35°C.
Claim 25
Dependent Claim
18 words
The method according to Claim 21, wherein the distillation of the oil phase solvent is conducted by stirring.
References Cited (Backward Citations)
No citation records indexed.
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