The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 11, 1997
Filed:
Feb. 10, 1995
David L Rivera, San Jose, CA (US);
Sonya Merrill, Redwood City, CA (US);
James B Eckenhoff, Los Altos, CA (US);
Jeremy C Wright, Los Altos, CA (US);
James L Osborne, Mountain View, CA (US);
ALZA Corporation, Palo Alto, CA (US);
Abstract
The present invention relates to an improvement in an 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, a fluid-activated expandable driving member, optionally a partition layer between the agent formulation and the driving member, and, optionally a density member, and exit means in the semipermeable wall; and wherein the improvement comprises the cellulose acetate butyrate component of the semipermeable wall having a differential scanning calorimetry ('DSC') profile wherein the main or primary DSC peak has a minimum temperature peak above 228.degree. C. and the secondary DSC peak area is equal to or less than about 30% of the total combined areas of the primary and secondary DSC peaks. The invention also relates to the improved semipermeable membrane produced from cellulose acetate butyrate having a differential scanning calorimetry ('DSC') profile wherein the main DSC peak is at a temperature above 228.degree. C. and the secondary DSC peak area is equal to or less than about 30% of the total combined area of the primary and secondary DSC peaks, the semipermeable membrane providing a substantially improved uniform rapid startup performance for osmotic delivery devices.