Optimal placement of a robust solvent/detergent process post viral ultrafiltration of an immune gamma globulin

Abstract

The solvent-detergent (S/D) process is used to inactivate enveloped viruses in plasma products. While concentrations of 1.0% detergent and 0.3% tri-n-butyl phosphate solvent have been considered necessary for robust removal of viral activity, we show the effectiveness of solvent-detergent treatment after fractionation and nanofiltration of an immune gamma globulin preparation, which required significantly reduced concentrations of solvent and detergent. Reduced levels of solvent and detergent lead to greater efficiencies in their removal post-inactivation with the potential for greater yields and decreased processing costs.

1 - 15 . (canceled) 
   
   
       16 . A method of virus inactivation in a post-manufacture immunoglobulin solution containing virus, comprising:
 (a) reducing the potential virus load of the immunological solution using a method selected from the group comprising:   
     filtration, direct size exclusion filtration, tangential size exclusion filtration, depth filtration, ion exchange chromatography, precipitation affinity chromatography, nanofiltration, tangential flow filtration, affinity chromatography, electrophoresis, or a combination thereof;
 (b) and adjusting the protein concentration of the immunoglobulin solution to equal or less than 6.0% w/v; 
 (c) adjusting the pH of the immunoglobulin solution to 6.3-6.4; 
 (d) contacting the immunoglobulin solution with:
 0.03% to 0.06% w/v of a di- or tri-alkyl phosphate solvent and 
 0.1% to less than 0.2% w/v of a non-ionic detergent 
 for about 1 minute to about 1 hour 
 at a temperature of 15-25° C.; and 
 
 (e) removing the di- or tri-alkyl phosphate solvent and the non-ionic detergent. 
 
   
   
       17 . (canceled) 
   
   
       18 . The method of  claim 16  wherein the immunoglobulin is anti-D immunoglobulin. 
   
   
       19 . The method of  claim 18  wherein the di- or tri-alkyl phosphate is tri-n-butyl-phosphate and the nonionic detergent is an oxyethylated alkylphenol. 
   
   
       20 . The method of  claim 19  wherein the oxyethylated alkylphenol is a Triton®. 
   
   
       21 . (canceled) 
   
   
       22 . The method of  claim 20  wherein the di- or tri-alkyl phosphate is present at about 0.06% w/v and the non-ionic detergent is present at about 0.2% w/v. 
   
   
       23 . The method of  claim 16  wherein the solvent and detergent are removed from the immunoglobulin solution by a method selected from passage through a C-18 column, diafiltration through membranes, adsorption onto chromatographic supports, adsorption onto affinity chromatographic supports, ultrafiltration, filtration and adsorption, and admixture with adsorbent. 
   
   
       24 . The method of  claim 23  wherein the method is admixture with adsorbent. 
   
   
       25 . The method of  claim 24  wherein the adsorbent is a silica bead adsorbent material. 
   
   
       26 . The method of  claim 25  additionally comprising the step of removing the adsorbent from the immunoglobulin solution. 
   
   
       27 - 35 . (canceled) 
   
   
       36 . The method of  claim 16  wherein the potential virus load is reduced using nanofiltration.