Abstract: A gastro-retentive drug delivery system for controlled release of drugs in the stomach or upper gastro-intestinal track provides one or more polymers that hydrate and swell to immobilize the drug in situ in a protective, degradable envelope or cocoon. In one embodiment, oppositely charged polyelectroytes are admixed with the drug and filled in a capsule having a dissolution profile in stomach acid at body temperature. The dissolution profile of the capsule promotes formation of a poyelectrolyte gel complex. The gel complex increases retention time of the drug and reduces dosing requirements, increases absorption, reduces dose-dependent side effects, and provides reproducible, time-controlled drug residence in the GI tract.

Abstract: The invention comprises a polymeric amphiphilic stabilizing agent and its use in the inverse-emulsion and inverse-suspenion polymerization of acrylic monomers. The stabilizing agent produces inverse-emulsions and inverse-suspensions having good stability, polymers with high molecular weights, high solid content, low coagulum and which can be branched providing a means to prepare branched, or structured, dry polymers. The stabilizing agent is amphiphilic copolymer that is prepared from a mixture of linear alkylmethacrylates monomers and acrylic or methacrylic acid co-monomers. Typically, the mixture of alkylmethacrylates is comprised of esters having alkyl moieties that are from 14 to 20 carbon atoms in length. The stabilizing agent copolymers typically have number average molecular weights from about 500 to 50,000 g/mol, or weight average molecular weights from 50,000 to 100,000 g/mol.

Abstract: The invention is a polymeric powder that is useful as a flocculant and an associated process for preparing the same. The powder is prepared from spraying a liquid containing a water-soluble polymer into a fluidized bed of porous substrate particles. The spraying process coats the polymer onto the substate and removes the water through evaporative cooling. Polymeric powders prepared according to the invention rapidly dissolve in water and have improved viscosities over thermally dried polymer powders. Polymers that are useful in the invention include polyacrylamides, polyamines, and the like. The substrate is a porous material that can be either organic or inorganic, and typically has a porosity from about 1 to 1,000 m2/g.

Abstract: A high molecular weight water soluble acrylamide based polymer having improved flocculating and dewatering properties is provided. The polymer is prepared by a process in which a small quantity of a chain branching agent is added to the polymerization reaction mixture continuously or stepwise while the monomers are polymerized. The polymer is useful in solid/liquid separations such as flocculants and coagulants in wastewater treatment applications, and as thickening agents.

Abstract: A high molecular weight water soluble acrylamide based polymer having improved flocculating and dewatering properties is provided. The polymer is prepared by a process in which a small quantity of a chain branching agent is added to the polymerization reaction mixture continuously or stepwise while the monomers are polymerized. The polymer is useful in solid/liquid separations such as flocculants and coagulants in wastewater treatment applications, and as thickening agents.

Abstract: A high molecular weight water soluble acrylamide based polymer having improved flocculating and dewatering properties is provided. The polymer is prepared by a process in which a small quantity of a chain branching agent is added to the polymerization reaction mixture continuously or stepwise while the monomers are polymerized. The polymer is useful in solid/liquid separations such as flocculants and coagulants in wastewater treatment applications, and as thickening agents.

Abstract: A high molecular weight water soluble acrylamide based polymer having improved flocculating and dewatering properties is provided. The polymer is prepared by a process in which a small quantity of a chain branching agent is added to the polymerization reaction mixture continuously or stepwise while the monomers are polymerized. The polymer is useful in solid/liquid separations such as flocculants and coagulants in wastewater treatment applications, and as thickening agents.

Abstract: A high molecular weight water soluble acrylamide based polymer having improved flocculating properties is provided. The polymer is prepared by a process, in which a small quantity of a chain branching agent is added to the polymerization reaction mixture continuously or semi-continuously while the monomers are polymerized. The polymer is useful in solid/liquid separations such as flocculants and coagulants in waste water treatment applications, and as thickening agents.