Claims
- 1. An improved osmotic delivery device, wherein the device comprises a semipermeable wall comprising cellulose acetate butyrate and surrounding an internal compartment containing a beneficial agent or medicament formulation and a fluid-activated expandable driving member, and exit means in the semipermeable wall; and wherein the improvement comprises selecting and using as the cellulose acetate butyrate component of the semipermeable wall cellulose acetate butyrate having an acceptable differential scanning calorimetry ("DSC") profile, which, if analyzed on a Du Pont Thermal Analyzer 2100 set to equilibrate the sample at a temperature of 30.degree. C., and heat the sample to 270.degree. C. at 20.degree. C. per minute, would exhibit a DSC profile wherein the profile has a primary minimum temperature peak above 228.degree. C. and an area under the secondary minimum temperature peak which is equal to or less than about 30% of the total combined areas of the primary and secondary DSC peaks wherein the use of such selected cellulose acetate butyrate produces a device exhibiting minimum delay to reach a steady-state pumping rate.
- 2. An improved osmotic delivery device according to claim 1 which further comprises a density element.
- 3. An improved osmotic delivery device according to claim 2 wherein the the beneficial agent formulation comprises ivermectin mixed with a wax, and the device further comprises a partition layer between the beneficial agent formulation and the expandable driving member.
- 4. An improved osmotic delivery device according to claim 1 which further comprises a partition layer between the beneficial agent formulation and the expandable driving member.
- 5. An improved osmotic delivery device according to claim 1 which is prehydrated.
- 6. An improved osmotic delivery device according to claim 3 which is prehydrated.
- 7. An improved osmotic delivery device, wherein the device comprises a semipermeable wall comprising cellulose acetate butyrate and surrounding an internal compartment containing a beneficial agent or medicament formulation and a fluid-activated expandable driving member, and exit means in the semipermeable wall; and wherein the improvement comprises the cellulose acetate butyrate component of the semipermeable wall having a butyryl content of less than or equal to 18.2%, an acetyl content of greater than or equal to 29.1% and a hydroxyl content of less than or equal to 1.0% and further having an acceptable differential scanning calorimetry ("DSC") profile, which, if analyzed on a Du Pont Thermal Analyzer 2100 set to equilibrate the sample at a temperature of 30.degree. C., and heat the sample to 270.degree. C. at 20.degree. C. per minute, would exhibit a DSC profile wherein the profile has a primary minimum temperature peak above 228.degree. C. and an area under the secondary minimum temperature peak which is equal to or less than about 30% of the total combined areas of the primary and secondary DSC peaks wherein the use of such cellulose acetate butyrate produces a device exhibiting minimum delay to reach a steady-state pumping rate.
- 8. An improved osmotic delivery device according to claim 7 wherein the cellulose acetate butyrate component has a butyryl content within the range of 16.5-18.2% and an acetyl content within the range of 29.1-31.0%.
- 9. An improved osmotic delivery device according to claim 7 which further comprises a density element.
- 10. An improved osmotic delivery device according to claim 8 wherein the beneficial agent formulation comprises ivermectin mixed with a wax, and the device further comprises a partition layer between the beneficial agent formulation and the expandable driving member, and a density element.
- 11. An improved osmotic delivery device according to claim 7 which further comprises a partition layer between the beneficial agent formulation and the expandable driving member.
- 12. An improved osmotic delivery device according to claim 7 which is prehydrated.
- 13. An improved osmotic delivery device according to claim 10 which is prehydrated.
- 14. An improved semipermeable membrane comprising cellulose acetate butyrate, wherein the improvement comprises the cellulose acetate butyrate component of the semipermeable membrane having an acceptable differential scanning calorimetry ("DSC") profile, which, if analyzed on a Du Pont Thermal Analyzer 2100 set to equilibrate the sample at a temperature of 30.degree. C., and heat the sample to 270.degree. C. at 20.degree. C. per minute, would exhibit a DSC profile wherein the profile has a primary minimum temperature peak above 228.degree. C. and an area under the secondary minimum temperature peak which is equal to or less than about 30% of the total combined areas of the primary and secondary DSC peaks.
- 15. An improved semipermeable membrane comprising cellulose acetate butyrate, wherein the improvement comprises the cellulose acetate butyrate component of the semipermeable membrane having a butyryl content of less than or equal to 18.2%, an acetyl content of greater than or equal to 29.1% and a hydroxyl content of less than or equal to 1.0% and further having an acceptable differential scanning calorimetry ("DSC") profile, which, if analyzed on a Du Pont Thermal Analyzer 2100 set to equilibrate the sample at a temperature of 30.degree. C., and heat the sample to 270.degree. C. at 20.degree. C. per minute, would exhibit a DSC profile wherein the profile has a primary minimum temperature peak above 228.degree. C. and an area under the secondary minimum temperature peak which is equal to or less than about 30% of the total combined areas of the primary and secondary DSC peaks.
- 16. An improved semipermeable membrane according to claim 15 wherein the cellulose acetate butyrate component has a butyryl content within the range of 16.5-18.2% and an acetyl content within the range of 29.1-31.0%.
Parent Case Info
This application is a division of application Ser. No. 08/387,967, filed Feb. 10, 1995, pending, and benefit of the filing date of said earlier filed application is claimed under 35 U.S.C. .sctn.120.
US Referenced Citations (24)
Divisions (1)
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Number |
Date |
Country |
Parent |
387967 |
Feb 1995 |
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