Back to results
US 4,028,355 AGranted
Cephalosporin purification process
AssigneeSmithKline Corporation
InventorDale W. Blackburn
Life of this patent
Estimating the term…
Abstract
A process for purifying semisynthetic cephalosporins is disclosed which uses alumina and/or a polymeric nonionic resin as adsorbents at a controlled pH. The process is more efficient than previously used methods.
Claims20
A process for the purification of a semisynthetic cephalosporin which contains a free carboxylic acid comprising
- a. contacting an aqueous solution of said semisynthetic cephalosporin, said solution having a pH of 3 to 6.5 so that said semisynthetic cephalosporin is about 99% ionized, with an adsorbent, said adsorbent being a nonionic macroreticular polymeric resin, said resin being a cross-linked styrene-divinylbenzene copolymer with an average pore size of 90 a or a cross-linked acrylic ester polymer with an average pore size of 80 to 250 A and eluting said semisynthetic cephalosporin from said adsorbent and adsorbed impurities with an eluant, said eluant being an aqueous solution having a pH of 3 to 8.5 so that said semisynthetic cephalosporin is maintained in the ionized form;
- b. acidifying the eluates which contain the semisynthetic cephalosporin to a pH below its pKa;
- and
- c. collecting the resulting precipitated semisynthetic cephalosporin.
1 more element
Dependencies are inferred from the claim text.