Controlled release delivery system by an osmotic bursting mechanism
Patent 3952741 Issued on April 27, 1976. Estimated Expiration Date: 
April 27, 1993. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
April 27, 1993. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3247066 3710795 3760984 3765414 3797492 3832458 3840009 InventorAssigneeApplicationNo. 539637 filed on 01/09/1975US Classes:424/405, Biocides; animal or insect repellents or attractants (e.g., disinfectants, pesticides, etc.)222/491, OUTLET ELEMENT OPERATED BY PRESSURE OF CONTENTS222/54, Temperature responsive or soluble controller424/497Containing solid synthetic polymersExaminersPrimary: Medbery, Aldrich F.AbstractAn osmotic dispenser comprised of (1) a water permeable membrane forming part or all of the walls of an enclosure surrounding (2) an active agent, and in some cases (3) an additional compound known as an osmotic attractant which together exhibits an osmotic pressure against water. When placed in an aqueous environment water is osmotically drawn into the enclosure by the combined action of the agents (2) and (3) which distends and swells the enclosure until the membrane or some other part of the enclosure wall reaches the point of ultimate elongation and a portion of the wall yields and ruptures releasing the contents of the enclosure to the environment. | |
