US4016100A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of preparing a controlled release liquid pharmaceutical composition
Assignee: Tanabe Pharma Corp
•
Filing: 1976-01-26
•
Granted: 1977-04-05
•
Expires: 1996-01-26
Abstract
Abstract A pharmaceutical composition is prepared by the steps of dispersing a phospholipid uniformly in water to give an aqueous phospholipid dispersion, adding a medicament to the aqueous dispersion, freezing the thus-obtained aqueous dispersion, thereby entrapping the medicament in the lipid spherules, and then thawing the frozen dispersion to give an aqueous suspension of the medicament entrapped in the lipid spherules having a diameter of less than 5.0 μ. The pharmaceutical composition prepared above is used as a controlled release pharmaceutical preparation.
Inventors
- 👤 Akira Suzuki
- 👤 Hiroshi Miura
- 👤 Saburo Matsuda
- 👤 Takashi Ohsawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:47
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/10; A61K9/127; A61K9/1277; A61K9/1278; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2984
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
83 words
A method of preparing a controlled release pharmaceutical composition, which comprises the steps of dispersing a phospholipid uniformly in water to give an aqueous phospholipid dispersion having lipid spherules, adding a medicament to the aqueous phospholipid dispersion to form a medicament dispersion, freezing said medicament dispersion thereby entrapping the medicament in the lipid spherules, and then thawing the frozen dispersion to give an aqueous suspension of the medicament entrapped in said lipid spherules, said spherules having a diameter of less than 5.0 μ.
Claim 2
Independent Claim
83 words
A method of preparing a controlled release pharmaceutical composition, which comprises the steps of dispersing a phospholipid uniformly in water to give an aqueous phospholipid dispersion having lipid spherules, adding a medicament to the aqueous phospholipid dispersion to form a medicament dispersion, freezing said medicament dispersion thereby entrapping the medicament in the lipid spherules, and then thawing the frozen dispersion to give an aqueous suspension of the medicament entrapped in said lipid spherules, said spherules having a diameter of less than 5.0 μ.
Claim 3
Dependent Claim
30 words
The method according to claim 1, wherein the phospholipid is selected from the group consisting of egg-yolk phospholipids, soybean phospholipids, phosphatidyl choline, phosphatidyl ethanolamine, sphingomyelin, phosphatidyl serine and dipalmitoyl lecithin.
Claim 4
Dependent Claim
12 words
The method according to claim 1, wherein the phospholipid is egg-yolk phospholipids.
Claim 5
Dependent Claim
12 words
The method according to claim 1, wherein the phospholipid is soybean phospholipids.
Claim 6
Dependent Claim
42 words
The method according to claim 1, wherein the phospholipid is employed in an amount of 0.001 to 0.2 g per ml of said water, and the medicament is employed in an amount of 0.01 to 1.0 g per g of the phospholipid.
Claim 7
Dependent Claim
37 words
The method according to claim 1, wherein said freezing is carried out at a temperature below -5° C and said thawing is carried out by allowing it to stand at a temperature of 5° to 40° C.
Claim 8
Dependent Claim
21 words
The method according to claim 1, further including the step of centrifuging the aqueous suspension to separate the entrapped medicament therefrom.
Claim 9
Independent Claim
111 words
A method of preparing a controlled release pharmaceutical composition which comprises dispersing 0.001 to 0.2 g of a phospholipid per ml of water to give an aqueous phospholipid dispersion having lipid spherules, addng 0.01 to 1.0 g of a medicament per g of said phospholipid to the aqueous dispersion to form a medicament dispersion, freezing said medicament dispersion at a temperature below -5° C, thereby entrapping the medicament in the lipid spherules, and then allowing the frozen dispersion to stand at a temperature of 5° to 40° C to give an aqueous suspension of the medicament entrapped in the lipid spherules, said spherules having a diameter of less than 5.0 μ.
Claim 10
Independent Claim
111 words
A method of preparing a controlled release pharmaceutical composition which comprises dispersing 0.001 to 0.2 g of a phospholipid per ml of water to give an aqueous phospholipid dispersion having lipid spherules, addng 0.01 to 1.0 g of a medicament per g of said phospholipid to the aqueous dispersion to form a medicament dispersion, freezing said medicament dispersion at a temperature below -5° C, thereby entrapping the medicament in the lipid spherules, and then allowing the frozen dispersion to stand at a temperature of 5° to 40° C to give an aqueous suspension of the medicament entrapped in the lipid spherules, said spherules having a diameter of less than 5.0 μ.
Claim 11
Dependent Claim
12 words
The method according to claim 8, wherein the phospholipid is egg-yolk phospholipids.
Claim 12
Dependent Claim
12 words
The method according to claim 8, wherein the phospholipid is soybean phospholipids.
Claim 13
Dependent Claim
21 words
The method according to claim 8, further including the step of centrifuging the aqueous suspension to separate the trapped medicament therefrom.
References Cited (Backward Citations)
US3056728A
Cited
US3780195A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-04-04 | 1980-10-04 | 1981-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-04 | 1984-10-04 | 1985-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-04 | 1988-10-04 | 1989-04-05 | $7700.00 | Window Closed / Lapsed |