Peritoneal dialysis solutions and preparation thereof

Claim 2

A peritoneal dialysis composition containing an osmotic agent comprising a glucose polymer mixture, said mixture including at least 15% by weight of glucose polymers of D.P. greater than 12.

Claim 3

The composition of Claim 1 wherein said mixture includes from 20 to 50% by weight of glucose polymers of D.P. greater than 12

Claim 4

The composition of Claim 1 wherein said mixture includes less than 3% by weight of glucose. 10

Claim 5

The composition of any of Claims 1 to 3 in the form of an aqueous solution containing 65 to 80% w/v of said glucose polymer mixture.

Claim 6

The composition of any of Claims 1 to 3 in the form of a peritonea] dialysis solution containing from 2 to 15% w/v of said glucose polymer mixture.

Claim 7

The composition of any of Claims 1 to 3 in the form of a continuous ambulatory peritoneal dialysis 15 solution containing from 2 to 4% w/v of said glucose polymer mixture.

Claim 8

A process for the preparation of a sterile aqueous solution of a glucose polymer mixture, the mixture containing less than 5% by weight of glucose amd more than 15% by weight of glucose polymers having a degree of polymerisation of more than 12, which comprises (i) gelatinising clean, pre-washed starch containing not more than 5% of 1,6-linkages in aqueous 20 suspension with from 0.05 to 0.13%, based on the weight of the suspension, of at least one thermophilic arnylase at a pH of from 6.0 to 6.8 and a temperature of Wto 1000C, (5) adjusting the pH of the aqueous mixture from step (i) to 4.5 to 5.0 by the addition of a physiologically acceptable organic acid and increasing the concentration of thermophilic arnylase to from 0.15 to 0.25%, on the same basis, by the addition of further arnylase and effecting dextrinisation of the gelatinised starch at a 25 temperature of Wto 950C so as to obtain a hydrolysis product predominantly consisting of glucose polymers having a degree of polymerisation of more than 12 and containing less than 1% by weight of glucose and less than 2% by weight of each of maltose and maltotriose, (iii) adjusting the pH of the aqueous mixture from step (ii), if required, to 3.5 to 4.5 by the addition of a physiologically acceptable organic acid and effecting hydrolysis of the dextrinised starch at a temperature of 30 Wto 75'C by means of a bacterial alpha-amylase which is capable, underthese conditions, of producing less than 5% of glucose, based on the weight of the dextrinised starch, and continuing hydrolysis under these conditions until a glucose polymer mixture of the desired composition is obtained, and (iv) adjusting the pH of the aqueous mixture from step (iii) to 2.0 to 3. 0 by the addition of a physiologically acceptable organic acid and heating the mixture ata temperature of Wto 1OWC so asto 35 inactivate the enzymes.

Claim 9

A process for the preparation of a sterile aqueous solution of a glucose polymer mixture, the mixture containing less than 5% by weight of glucose amd more than 15% by weight of glucose polymers having a degree of polymerisation of more than 12, which comprises (i) gelatinising clean, pre-washed starch containing not more than 5% of 1,6-linkages in aqueous 20 suspension with from 0.05 to 0.13%, based on the weight of the suspension, of at least one thermophilic arnylase at a pH of from 6.0 to 6.8 and a temperature of Wto 1000C, (5) adjusting the pH of the aqueous mixture from step (i) to 4.5 to 5.0 by the addition of a physiologically acceptable organic acid and increasing the concentration of thermophilic arnylase to from 0.15 to 0.25%, on the same basis, by the addition of further arnylase and effecting dextrinisation of the gelatinised starch at a 25 temperature of Wto 950C so as to obtain a hydrolysis product predominantly consisting of glucose polymers having a degree of polymerisation of more than 12 and containing less than 1% by weight of glucose and less than 2% by weight of each of maltose and maltotriose, (iii) adjusting the pH of the aqueous mixture from step (ii), if required, to 3.5 to 4.5 by the addition of a physiologically acceptable organic acid and effecting hydrolysis of the dextrinised starch at a temperature of 30 Wto 75'C by means of a bacterial alpha-amylase which is capable, underthese conditions, of producing less than 5% of glucose, based on the weight of the dextrinised starch, and continuing hydrolysis under these conditions until a glucose polymer mixture of the desired composition is obtained, and (iv) adjusting the pH of the aqueous mixture from step (iii) to 2.0 to 3. 0 by the addition of a physiologically acceptable organic acid and heating the mixture ata temperature of Wto 1OWC so asto 35 inactivate the enzymes.

Claim 10

The process of Claim 7 wherein the amount of bacterial alpha-amylase used instep (iii) is from 0.1 to 3.0% based on the total weight of the aqueous mixture.

Claim 11

The composition of any of Claims 1 to 6 wherein said glucose polymer mixture is produced by the process of Claim 7 or 8.

Claim 13

i 1 i 11. A peritoneal dialysis composition, ora glucose polymer mixture, according to claim 1, substantially as hereinbefore described with reference to any one of Examples 1 to 5.

Claim 14

A process according to claim 7, substantially as hereinbefore described with reference to anyone of 50 Examples 1 to 5.

Claim 15

A glucose polymer mixture, produced by the process of claim 12.

Claim 16

A method according to claim 10, substantially as hereinbefore described. Printed for Her Majesty's Stationery Office, by Croydon Printing Company Limited, Croydon, Surrey, 1984. Published by The Patent Office, 25 Southampton Buildings, London, WC2A lAY, from which copies may be obtained.