this page talks about transport systems and pill manufacture process. Hope this isn't a repeat. Here is a bit followed by the link.
Post 0051 (not existing) In preferred embodiments, the polymer coat (26) will be insoluble in the fluid of a first environment of use, such as gastric juices, acidic fluids, or polar liquids, and soluble or erodible in the fluid of a second environment of use, such as intestinal juices, substantially pH neutral or basic fluids, or apolar liquids. A wide variety of other polymeric materials are known to possess these various solubility properties and can be included in the polymer coat (26). Such other polymeric materials include, by way of example and without limitation, cellulose acetate phthalate (CAP), cellulose acetate trimelletate (CAT), poly(vinyl acetate) phthalate (PVAP), hydroxypropyl methylcellulose phthalate (HPMCP), poly(methacrylate ethylacrylate) (1:1) copolymer (MA-EA), poly(methacrylate methylmethacrylate) (1:1) copolymer (MA-MMA), poly(methacrylate methylmethacrylate) (1:2) copolymer, Eudragit L-30-D.TM. (MA-EA, 1:1), Eudragit L-100-55.TM. (MA-EA, 1:1), hydroxypropyl methylcellulose acetate succinate (HPMCAS), Coateric.TM. (PVAP), Aquateric.TM. (CAP), AQUACOAT.TM. (HPMCAS) and combinations thereof. The polymer coat (26) can also comprise dissolution aids, stability modifiers, and bioabsorption enhancers.
Post 0052 (not existing) When the polymer coat (26) is intended to be dissolved, eroded or become detached from the core in the colon, materials such as hydroxypropylcellulose, microcrystalline cellulose (MCC, Avicel.TM. from FMC Corp.), poly (ethylene-vinyl acetate) (60:40) copolymer (EVAC from Aldrich Chemical Co.), 2-hydroxyethylmethacrylate (HEMA), MMA, terpolymers of HEMA: MMA:MA synthesized in the presence of N,N'-bis(methacryloyloxyethyloxycarbonylamino)-azobenzene, azopolymers, enteric coated timed release system (Time Clock.RTM. from Pharmaceutical Profiles, Ltd., UK) and calcium pectinate can be included in the polymer coat (6).
Post 0053 (not existing) A preferred polymeric material for use in the polymer coat (26) involves enteric materials that resist the action of gastric fluid avoiding permeation through the semipermeable wall while one or more of the materials in the core (25) are solubilized in the intestinal tract thereby allowing delivery of a drug in the core (25) by osmotic pumping to begin. A material that easily adapts to this kind of requirement is a poly(vinylpyrrolidone)-vinyl acetate copolymer, such as the material supplied by BASF under its Kollidon VA64 trademark, mixed with magnesium stearate and other similar excipients. The polymer coat (26) can also comprise povidone, which is supplied by BASF under its Kollidon K 30 trademark, and hydroxypropyl methylcellulose, which is supplied by Dow under its Methocel E-15 trademark. The materials can be prepared in solutions having different concentrations of polymer according to the desired solution viscosity. For example, a 10% P/V aqueous solution of Kollidon K 30 has a viscosity of about 5.5-8.5 cps at 20.degree. C., and a 2% P/V aqueous solution of Methocel E-15 has a viscosity of about 13-18 cps at 20.degree. C.
Post 0054 (not existing) The polymer coat (26) can also comprise other materials suitable which are substantially resistant to gastric juices and which will promote either enteric or colonic release. For this purpose, the polymer coat (26) can comprise one or more materials that do not dissolve, disintegrate, or change their structural integrity in the stomach and during the period of time that the osmotic device (21) resides in the stomach. Representative materials that keep their integrity in the stomach can comprise a member selected from the group consisting of (a) keratin, keratin sandarac-tolu, salol (phenyl salicylate), salol beta-naphthylbenzoate and acetotannin, salol with balsam of Peru, salol with tolu, salol with gum mastic, salol and stearic acid, and salol and shellac; (b) a member selected from the group consisting of formalized protein, formalized gelatin, and formalized cross-linked gelatin and exchange resins; (c) a member selected from the group consisting of myristic acid-hydrogenated castor oil-cholesterol, stearic acid-mutton tallow, stearic acid-balsam of tolu, and stearic acid-castor oil; (d) a member selected from the group consisting of shellac, ammoniated shellac, ammoniated shellac-salol, shellac-wool fat, shellac-acetyl alcohol, shellac-stearic acid-balsam of tolu, and shellac n-butyl stearate; (e) a member selected from the group consisting of abietic acid, methyl abictate, benzoin, balsam of tolu, sandarac, mastic with tolu, and mastic with tolu, and mastic with acetyl alcohol; (f) acrylic resins represented by anionic polymers synthesized from methacrylate acid and methacrylic acid methyl ester, copolymeric acrylic resins of methacrylic and methacrylic acid and methacrylic acid alkyl esters, copolymers of alkylacrylic acid and alkylacrylic acid alkyl esters, acrylic resins such as dimethylaminoethylmethacrylate-butylmethacrylate-methylmethacrylate copolymer of 150,000 molecular weight, methacrylic acid-methylmethacrylate 50:50 coploymer of 135,000 molecular weight, methacrylic acid-methylmethacrylate-30:70copolymer of 135,000 mol. wt., methacrylic acid-dimethylaminoethyl-methacrylate-ethylacrylate of 750,000 mol. wt., methacrylic acid-methylmethacrylate-ethylacrylate of 1,000,000 mol. wt., and ethylacrylate-methylmethacrylate-ethylacrylate of 550,000 mol. wt; and, (g) an enteric composition comprising a member selected from the group consisting of cellulose acetyl phthalate, cellulose diacetyl phthalate, cellulose triacetyl phthalate, cellulose acetate phthalate, hydroxypropyl methylcellulose phthalate, sodium cellulose acetate phthalate, cellulose ester phthalate, cellulose ether phthalate, methylcellulose phthalate, cellulose ester-ether phthalate, hydroxypropyl cellulose phthalate, alkali salts of cellulose acetate phthalate, alkaline earth salts of cellulose acetate phthalate, calcium salt of cellulose acetate phthalate, ammonium salt of hydroxypropyl methylcellulose phthalate, cellulose acetate hexahydrophthalate, hydroxypropyl methylcellulose hexahydrophthalate, polyvinyl acetate phthalate diethyl phthalate, dibutyl phthalate, dialkyl phthalate wherein the alkyl comprises from 1 to 7 straight and branched alkyl groups, aryl phthalates, and other materials known to one or ordinary skill in the art.
Post 0055 (not existing) As used herein, the term "preformed passageway" refers to a passageway or passageway precursor that has been formed on the semipermeable membrane by mechanical means, such as by a laser, drill and/or etching apparatus. A preformed passageway is optionally plugged after initial formation, such as depicted in FIG. 6. If a water soluble plug is used, the preformed passageway will increase in size even after all of the plug has been removed from the preformed passageway. The term "preformed passageway" is not intended to cover pores, holes, apertures, channels or other similar structures formed in the semipermeable membrane by incorporation of pore formers, water soluble particulates, or similar materials known to those of ordinary skill, into the semipermeable membrane during manufacture of the osmotic device. The invention does include, however, an osmotic device having a preformed passageway and one or more other pores, holes apertures, channels or other similar structures known to those of ordinary skill.
also it apears that electrolytes and sodium ions assist in absorbtion of nutrients into the blood through the intestine.....hmm salt water eeh?