ALZA Corporation

The simplest osmotic dosage form, ALZA Corporation s OROS elementary osmotic pump (Fig. 7), combines the dmg and sometimes an osmotic agent in a monolithic core and deflvers the dmg in solution (102). The mass dehvery rate with time dm df) of the dmg solution is described by equation 4, where is the hydrauHc permeabiUty of the membrane, a is the membrane reflection coefficient, Atz is the osmotic pressure gradient, APis the hydrostatic back pressure, A is the area of the membrane, C is the dissolved concentration of the dmg, and b is the membrane thickness. 

David Edgren Harold Leeper Kirstin Nichols Jeremy Wright ALZA Corporation... 

Osmotic Control. Several oral osmotic systems (OROS) have been developed by the Alza Corporation to allow controUed deHvery of highly water-soluble dmgs. The elementary osmotic pump (94) consists of an osmotic core containing dmg surrounded by a semi-permeable membrane having a laser-drilled deHvery orifice. The system looks like a conventional tablet, yet the outer layer allows only the diffusion of water into the core of the unit. The rate of water diffusion into the system is controUed by the membrane s permeabUity to water and by the osmotic activity of the core. Because the membrane does not expand as water is absorbed, the dmg solution must leave the interior of the tablet through the smaU orifice at the same rate that water enters by osmosis. The osmotic driving force is constant until aU of the dmg is dissolved thus, the osmotic system maintains a constant deHvery rate of dmg until the time of complete dissolution of the dmg. 

Alusuisse Lonza Group (Algroup) Ltd., 147 ALZA Corporation, 216 Amano Enzyme Inc., 180 Amantech Chemicals Pvt. Ltd., 168 Amber Chemical Company, 206 AMBUSH , permethrin, 12 AMCOL International Corporation, 216 Amerada-Hess Corporation, 216... 

The required acid sensitivity can be achieved by preparing polymers with ortho ester linkages in their backbone. The first poly-(ortho ester) has been described in a series of patents by Choi and Heller (3-6), assigned to the ALZA corporation. These proprietary materials were first designated with the trade name Chronomer and later Alzamer. They are prepared by a transesterification as follows ... 

Ethylene vinyl acetate has also found major applications in drug delivery. These copolymers used in drug release normally contain 30-50 wt% of vinyl acetate. They have been commercialized by the Alza Corporation for the delivery of pilocarpine over a one-week period (Ocusert) and the delivery of progesterone for over one year in the form of an intrauterine device (Progestasert). Ethylene vinyl acetate has also been evaluated for the release of macromolecules such as proteins. The release of proteins form these polymers is by a porous diffusion and the pore structure can be used to control the rate of release (3). Similar nonbiodegradable polymers such as the polyurethanes, polyethylenes, polytetrafluoroethylene and poly(methyl methacrylate) have also been used to deliver a variety of different pharmaceutical agents usually as implants or removal devices. 

Hans E. Junginger Leiden/Amsterdam Center for Drug Research Leiden, The Netherlands Felix Theeuwes Alza Corporation Palo Alto, California... 

For this reason much work has been done at the ALZA Corporation and elsewhere to increase the water permeation rates by various technologies. For example, ALZA scientists utilized a composite membrane in the development of their first commercial product with this technology [21,22], In this system they first applied a CA membrane containing a high concentration of porosigens. A second dense membrane containing only CA was added. In this way the overall fluid permeability was increased, since the thickness of the dense portion of the film could be proportionately reduced. 

ALZA Corporation. Coley Pharmaceutical Group. Medarex Selective Genetics. 

The authors acknowledge helpful ideas and suggestions from C. Davidson and L. Gehrlein, from Purdue Pharma L.P., A. Wong from Alza Corporation and R. Majors from Agilent Technologies. 

Aruna Datla (335) ALZA Corporation, 1015 Joaquin Rd, Mountain... 

This work was supported in part by grants from Liposome Technology Inc., later SEQUUS Pharmaceuticals (LTI, Menlo Park, California, U.S.A.), then ALZA Corporation, Mountain View, California, and the Barenholz Fimd. This manuscript is based on studies done since 1988 and still ongoing by many students and researchers of the Laboratory of Membrane and Liposome Research at the Hebrew University-Hadassah Medical School, Jerusalem, Israel, headed by the author. The most important contributors are Drs. G. Haran, R. Cohen, O. Garbuzenko, and S. Clerc. 

Doxorubicin Doxil (Caelyx) Alza-corporation AIDS-related Kaposi s sarcoma... 

Choi, N.S. and Heller, J. (1976). Poly(Carbonates). Alza Corporation, Mountain View, CA. 

Felix Theeuwes Alza Corporation Palo Alto, California... 

L-ORO drug delivery technology, a proprietary controlled-release delivery system invented by ALZA Corporation (Mountain View, California), combines drug solubilization technology enabling... 

Hans E. Junginger Felix Theeuwes Leiden/Amsterdam Center Alza Corporation... 

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