Process for purifying insulin and analogues thereof
A process is described for purifying insulin and insulin analogs that comprises high-pressure liquid chromatography with an acidic cation exchange medium performed under low to moderate pressure at an elevated temperature.
1. A process for isolating an insulin glargine heterodimer from impurities produced by an enzymatic digest of a precursor insulin glargine to purify the insulin glargine heterodimer by chromatography comprising the steps of:
(a) obtaining an acidic cation exchange column comprising an acidic cation exchange material comprising a high-capacity hydrogel polymerized within the pores of rigid ceramic beads and cross-linked to sulfo groups on the beads;
(b) loading the column with a sample solution comprising about 30% (v/v) hexylene glycol and the insulin glargine heterodimer obtained from the enzymatic digest;
(c) performing a chromatography that includes a step of washing the column with a first wash solution comprising a concentration of NaCl of about 20 mM followed by a step of washing the column with a second wash solution comprising NaCl at a concentration of about 37 mM wherein the first wash solution and the second wash solution each comprise about 30% (v/v) hexylene glycol; and
(d) eluting the insulin glargine heterodimer from the column with an eluting solution comprising about 30% (v/v) hexylene glycol and a concentration of NaCl of about 95 mM;
the process being performed under a column differential pressure of about 0.276 MPa and at an outlet temperature of about 42° C.
2. The process of claim 1 , wherein the sample solution comprises from about 3.0 to about 26.0 g of protein per liter of acidic cation exchange material.