Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form – Tablets – lozenges – or pills
Patent
1996-01-17
1998-10-27
Phelan, D. Gabrielle
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
Tablets, lozenges, or pills
424451, 424464, 424489, 6048921, A61K 924
Patent
active
058275380
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
Osmotic delivery systems based on semipermeable coatings have been described in the literature (e.g., Baker, R. W., "Controlled Release of Biologically Active Agents", pp.132-133, 1987; Smith, K. L. and Herbig, S. M., "Controlled Release" in Membrane Handbook, Ho, W. S. W., and Sirkar, K. K., eds., pp. 915-935, 1992) and produced commercially for several years. Osmotic delivery systems have been developed that release the beneficial agent either in a sustained manner or as a bolus (osmotic bursting systems; e.g., U.S. Pat. Nos. 3,247,066, 3,952,741, B1 4,016,880 and 4,177,256). These delivery systems rely on semipermeable coatings to allow influx of water and to contain the beneficial agent within the core until it is released.
Generally, semipermeable coatings are either dense, microporous, or asymmetric in structure (e.g., U.S. Pat. Nos. 3,845,770, 4,968,507, and European Patent Application 89308716.3, Publication No. 0357369). In addition, typically the semipermeable membranes must be wetted by an aqueous solution to allow for release of the beneficial agent (Batt, B. C., "An Experimental Study of Osmotic Pumping by Highly Microporous Polymer Membranes," M.S. thesis, University of Kansas, 1982; U.S. Pat. Nos. 4,0851,228 and 4,340,054). Also, a delivery port(s) must be formed in thesemipermeable coating (e.g.,by drilling a hole(s), or by forming pores in the coatings) for sustained delivery of a beneficial agent. Alternatively, the beneficial agent can be released by bursting the coating as a result of hydrostatic pressure generated in the core by osmosis.
Osmotic devices have been described that have a combination of a hydrophilic semipermeable membrane covering a portion of the device and a hydrophobic porous membrane covering another portion of the device. The devices contain hydrophobic liquids (e.g., oils) which inherently wet the hydrophobic membrane (i.e., are entrained in the membrane pores; the pores are typically less than 100 .mu.). Water is imbibed through the hydrophilic semipermeable membrane into the device and the resultant hydrostatic pressure forces the oils out through the hydrophobic membrane pores. Thus, these devices facilitate the osmotic delivery of oils or beneficial agents dissolved in oils. Such devices are described in Merfeld, A. E., Haslam, J. L. and Rork, G. S., "An In Vitro Release Method for Lipoidal Materials", Inter. Journal of Pharm., Vol. 69, No.1, pp.63-67, 1991; U.S. Pat. No. 4,685,918; and International Application WO 92/05775.
In contrast to osmotic devices, diffusional release of beneficial agents through pores in hydrophobic "nonsemipermeable" coatings has also been described in the literature (e.g., Junginger, H. E., and J. Verhoven, "Controlled Release of Drugs with Microporous Polymers", Proceedings of 11th International symposium on Controlled Release of Bioactive Materials, Controlled Release Society, Lincolnshire, Ill., pp.4-5, 1984; Kruisbrink, J., and G. J. Boer, Journal of Pharm. Sci., Vol.73, No. 12, pp. 1713-1718, Dec. 1984; and U.S. Pats. Nos. 4,871,542, 4,756,844, 4,002,458). Generally these coatings have large pores (e.g., >100 .mu.). In general, the beneficial agent (or solution containing beneficial agent) must wet the pores of the coating. The large pores facilitate wetting of the pores by an aqueous beneficial-agent-containing solution. Thus, the microporous membranes control the release of beneficial agent by controlling the surface area available for diffusion into the environment of use.
One particular device is described in commonly assigned U.S. patent application Ser. No. 07/982,815 entitled "Supported Liquid Membrane Delivery Devices" the disclosure of which is hereby incorporated by reference. This application discloses supported liquid membrane delivery devices that release a beneficial agent to an aqueous environment following exposure to an environmental trigger. A microporous hydrophobic support membrane surrounds a beneficial agent-containing hydrophilic formulation. A hydrophobic liquid is held with
REFERENCES:
patent: 3832252 (1974-08-01), Higuchi
Cussler Edward L.
Herbig Scott M.
Smith Kelly L.
van Eikeren Paul
Benson Gregg C.
Olson A. Dean
Pfizer Inc.
Phelan D. Gabrielle
Richardson Peter C.
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