National Research Development Corporation

University of Strathclyde

Other

British Technology Group Limited

Lloyds Bank Plc

Neil B Graham

Marion E McNeill

Robert A Szmidt

Koritala P Rao

David A Wood

Mostyn P Embrey

Abdul Rashid

Brian Culshaw

Christopher Raymond Moran

Walter Craig Michie

Ernst R Huehns

Ralph Christie Kirkwood

Charles Martin

Mostyn P Embry

Peter Thomas Gardiner

Jianwen Mao

Robert E Howells

Donald S Ross

Mostyn Embrey

Christopher R Moran

Microgels

A solution polymerization process for the preparation of a polymeric material having a weight average molecular weight from 5,000 to 20,000,000 and comprising cross-linked particles which are capable of forming a sol in the reaction solvent, which process comprises:

Solution polymerization to form sol of crosslinked particles

a porous solid material for plant propagation which includes granules of a porous expanded mineral, such as perlite or vermiculite, distributed within a porous, open-cell foamed hydrophilic water-retentive polyurethane matrix. The material may be molded into sheets of break-off units for seed germination and propagation.

Porous solid material

Apparatus for detecting aqueous environments

Measurement of water content

A temperature- and/or polar fluid-sensitive device which comprises a mechanically strained semi-crystalline hydrophilic polymer.

Polyethylene oxide temperature - or fluid-sensitive shape memory device

The invention provides a method of plant growing in which method one or more plants are grown in a growing medium comprising hydrogel particles charged with aqueous nutrient solution for the plant and plants, the growing medium being housed in a substantially water-impermeable container and the plants extending out of the container, and, when the water content within the hydrogel particles falls below a predetermined level, introducing further nutrient solution into the container.

Plant growth media comprising cross-linked hydrogel particles

Control valves and method of plant growing using flow control

Polymeric materials

An envelope having flexible water-permeable or porous walls contains a quantity of particulate water-insoluble hydrogel. The quantity of hydrogel in the envelope is such that, when the hydrogel is fully swollen at 20.degree. C., its volume is at least 66%, preferably at least 100%, of the maximum non-stretched internal volume of the envelope. Thus, the envelope according to the invention is limp and floppy under dry conditions but in a wet environment the hydrogel absorbs water and swells accordingly causing the envelope to swell and take on a more rigid configuration. The envelope is particularly useful for the administration of sustained release pharmaceutically or veterinarily active ingredients. Thus the limp dry envelope may for example be rolled up for introduction through the throat but will swell up and therefore be retained in the stomach for sustained release of the active ingredient therein.

Hydrogel containing envelopes

A non-crosslinked derivative formable by reacting at least one substituted or unsubstituted, saturated or unsaturated, mono-, di- or poly-carboxy, hydroxy or mercapto hydrocarbon with at least one cyclic unsaturated (thio)ether.

Sustained release compositions

A controlled release composition comprising an active substance other than a prostaglandin and a polymeric carrier therefor comprising residues having a ratio of number average molecular weight to functionality greater than 1000 which comprises polyethylene oxide and are cross-linked through urethane groups.

Controlled release compositions including polyethylene oxide with

A process for the preparation of a controlled release composition comprising a prostaglandin and a polymeric carrier therefor comprising residues having a ratio of number average molecular weight to functionality greater than 1,000 which comprise polyethylene oxide and are cross-linked through urethane groups.

Controlled release compositions (II)

A device for the sustained release of active substance comprises a wall defining a cavity for the reception of active substance, the wall being of impermeable material and having one or more ports therethrough. Sections of hydrogel material are within the cavity, the hydrogel, in use, being swollen to cover the ports in the cavity wall. Active ingredient is released from the container only through the hydrogel covering the ports. In this way sustained and controlled release of the active substance from the device is obtained.

Device for sustained release of active substance

A controlled release composition comprising a prostaglandin and a polymeric carrier therefor comprising residues having a ratio of number average molecular weight to functionality greater than 1,000 which comprise polyethylene oxide and are cross-linked through urethane groups.

Growing community of inventors

Bearsden, United Kingdom

Neil B Graham