Methods for sterilizing preparations of monoclonal immunoglobulins

Abstract

Methods are disclosed for sterilizing preparation of monoclonal immunoglobulins to reduce the level of active biological contaminants such as viruses, bacteria, yeasts, molds, mycoplasmas, prions and parasites.

We claim:  
     
         1 . A method for sterilizing a preparation of monoclonal immunoglobulins that is sensitive to radiation and has a residual solvent content, said method comprising: 
 (i) reducing said residual solvent content of a preparation of monoclonal immunoglobulins to a level effective to protect said preparation of monoclonal immunoglobulins from said radiation; and    (ii) irradiating said preparation of monoclonal immunoglobulins with a suitable radiation at an effective rate for a period of time effective to sterilize said preparation of monoclonal immunoglobulins, wherein said effective rate is not constant and comprises a rate between 0.1 kGy/hr to 3.0 kGy/hr for at least a portion of said period of time and a rate of at least 6.0 kGy/hr for at least another portion of said period of time.    
     
     
         2 . A method for sterilizing a preparation of monoclonal immunoglobulins that is sensitive to radiation, said method comprising: 
 (i) adding to a preparation of monoclonal immunoglobulins at least one stabilizer in an amount effective to protect said preparation of monoclonal immunoglobulins from said radiation; and    (ii) irradiating said preparation of monoclonal immunoglobulins with a suitable radiation at an effective rate for a period of time effective to sterilize said preparation of monoclonal immunoglobulins, wherein said effective rate is not constant and comprises a rate between 0.1 kGy/hr to 3.0 kGy/hr for at least a portion of said period of time and a rate of at least 6.0 kGy/hr for at least another portion of said period of time.    
     
     
         3 . A method for sterilizing a preparation of monoclonal immunoglobulins that is sensitive to radiation and has a residual solvent content, said method comprising: 
 (i) reducing said residual solvent content of a preparation of monoclonal immunoglobulins to a level effective to protect said preparation of monoclonal immunoglobulins from said radiation;    (ii) adding to said preparation of monoclonal immunoglobulins at least one stabilizer in an amount effective to protect said preparation of monoclonal immunoglobulins from said radiation; and    (iii) irradiating said preparation of monoclonal immunoglobulins with a suitable radiation at an effective rate for a period of time effective to sterilize said preparation of monoclonal immunoglobulins, wherein said effective rate is not constant and comprises a rate between 0.1 kGy/hr to 3.0 kGy/hr for at least a portion of said period of time and a rate of at least 6.0 kGy/hr for at least another portion of said period of time and further wherein steps (i) and (ii) may be performed in inverse order.    
     
     
         4 . The method according to  claim 1 , wherein said solvent is water.  
     
     
         5 . The method according to  claim 3 , wherein said solvent is water.  
     
     
         6 . The method according to  claim 4 , wherein said residual water content is reduced by the addition of an organic solvent.  
     
     
         7 . The method according to  claim 5 , wherein said residual water content is reduced by the addition of organic solvent.  
     
     
         8 . The method according to  claim 1 , wherein said solvent is an organic solvent.  
     
     
         9 . The method according to  claim 3 , wherein said solvent is an organic solvent.  
     
     
         10 . The method according to  claim 1 , wherein said preparation of monoclonal immunoglobulins is suspended in an organic solvent following reduction of said residual solvent content.  
     
     
         11 . The method according to  claim 3 , wherein said preparation of monoclonal immunoglobulins is suspended in an organic solvent following reduction of said residual solvent content.  
     
     
         12 . The method according to  claim 4 , wherein said preparation of monoclonal immunoglobulins is suspended in an organic solvent following reduction of said residual solvent content.  
     
     
         13 . The method according to  claim 5 , wherein said preparation of monoclonal immunoglobulins is suspended in an organic solvent following reduction of said residual solvent content.  
     
     
         14 . The method according to  claim 6 , wherein said preparation of monoclonal immunoglobulins is suspended in an organic solvent following reduction of said residual solvent content.  
     
     
         15 . The method according to  claim 7 , wherein said preparation of monoclonal immunoglobulins is suspended in an organic solvent following reduction of said residual solvent content.  
     
     
         16 . The method according to  claim 8 , wherein said preparation of monoclonal immunoglobulins is suspended in an organic solvent following reduction of said residual solvent content.  
     
     
         17 . The method according to  claim 9 , wherein said preparation of monoclonal immunoglobulins is suspended in an organic solvent following reduction of said residual solvent content.  
     
     
         18 . The method according to any one of claims  1 ,  2  or  3 , wherein said monoclonal immunoglobulins are selected from the group consisting of: IgG and fragments, derivatives, and metabolites thereof; IgM and fragments, derivatives, and metabolites thereof; IgA and fragments, derivatives, and metabolites thereof; IgD and fragments, derivatives, and metabolites thereof; IgE and fragments, derivatives, and metabolites thereof; and mixtures thereof.  
     
     
         19 . The method according to any one of claims  1 ,  2  or  3 , wherein said monoclonal immunoglobulins are IgG or fragments or derivatives or metabolites thereof.  
     
     
         20 . The method according to any one of claims  1 ,  2  or  3 , wherein said monoclonal immunoglobulins are IgM or fragments or derivatives or metabolites thereof.  
     
     
         21 . The method according to any one of claims  1 ,  2  or  3 , wherein said monoclonal immunoglobulins are IgA or fragments or derivatives or metabolites thereof.  
     
     
         22 . The method according to any one of claims  1 ,  2  or  3 , wherein said monoclonal immunoglobulins are IgD or fragments or derivatives or metabolites thereof.  
     
     
         23 . The method according to any one of claims  1 ,  2  or  3 , wherein said monoclonal immunoglobulins are IgE or fragments or derivatives or metabolites thereof.  
     
     
         24 . The method according to any one of claims  1 ,  2  or  3 , wherein said monoclonal immunoglobulins comprise immunoglobulin fragments selected from the group consisting of F (ab′) 2 , Fab′, Fab, Fc, Facb, pFc′, and Fd; or metabolites or derivatives thereof.  
     
     
         25 . The method according to any one of claims  1 ,  2 , or  3 , wherein said effective rate is at least 18.0 kGy/hour for at least another portion of said period of time.  
     
     
         26 . The method according to any one of claims  1 ,  2 , or  3 , wherein said effective rate is at least 45 kGy/hour for at least another portion of said period of time.  
     
     
         27 . The method according to any one of claims  1 ,  2  or  3 , wherein said preparation of monoclonal immunoglobulins is maintained in a low oxygen atmosphere.  
     
     
         28 . The method according to any one of claims  1 ,  2  or  3 , wherein said preparation of monoclonal immunoglobulins is maintained in an argon atmosphere.  
     
     
         29 . The method according to any one of claims  1 ,  2  or  3 , wherein said preparation of immunoglobulins is maintained in a vacuum.  
     
     
         30 . The method according to any one of claims  1 ,  2  or  3 , wherein said residual solvent content is reduced by at least one method selected from the group consisting of lyophilization, drying, concentration, addition of solute, evaporation, chemical extraction, spray-drying, and vitrification.  
     
     
         31 . The method according to any one of claims  1 ,  2  or  3 , wherein said residual solvent content is less than  10 %.  
     
     
         32 . The method according to any one of claims  1 ,  2  or  3 , wherein said residual solvent content is less than 5%.  
     
     
         33 . The method according to any one of claims  1 ,  2  or  3 , wherein said residual solvent content is less than 2%.  
     
     
         34 . The method according to any one of claims  1 ,  2  or  3 , wherein said residual solvent content is less than 1%.  
     
     
         35 . The method according to any one of claims  1 ,  2  or  3 , wherein said residual solvent content is less than 0.5%.  
     
     
         36 . The method according to any one of claims  1 ,  2  or  3 , wherein at least one sensitizer is added to said preparation of monoclonal immunoglobulins prior to said step of irradiating said preparation of monoclonal immunoglobulins.  
     
     
         37 . The method according to any one of claims  1 ,  2  or  3 , wherein said preparation of monoclonal immunoglobulins contains at least one prion as a biological contaminant.  
     
     
         38 . The method according to any one of claims  1 ,  2  or  3 , wherein said preparation of monoclonal immunoglobulins contains at least one virus as a biological contaminant.  
     
     
         39 . The method according to  claim 1 , wherein at least one stabilizer is added to said preparation of monoclonal immunoglobulins prior to said step of irradiating said preparation of monoclonal immunoglobulins.  
     
     
         40 . The method according to any one of claims  2  or  3 , wherein at least one of said stabilizers is an antioxidant.  
     
     
         41 . The method according to any one of claims  2  or  3 , wherein at least one of said stabilizers is a free radical scavenger.  
     
     
         42 . The method according to any one of claims  2  or  3 , wherein at least one of said stabilizers reduces damage due to reactive oxygen species.  
     
     
         43 . The method according to any one of claims  2  or  3 , wherein at least one of said stabilizers is selected from the group consisting of: ascorbic acid or a salt or ester thereof; glutathione; 6-hydroxy-2, 5, 7, 8-tetramethylchroman-2-carboxylic acid; uric acid or a salt or ester thereof; methionine; histidine; N-acetyl cysteine; lipoic acid; sodium formaldehyde sulfoxylate; gallic acid or a derivative thereof; propyl gallate; and mixtures of two or more of said stabilizers.  
     
     
         44 . The method according to  claim 43 , wherein said mixtures of two or more of said stabilizers are selected from the group consisting of: mixtures of ascorbic acid, or a salt or ester thereof, and uric acid, or a salt or ester thereof; mixtures of ascorbic acid, or a salt or ester thereof, and 6-hydroxy-2, 5, 7, 8-tetramethylchroman-2-carboxylic acid; mixtures of ascorbic acid, or a salt or ester thereof, uric acid, or a salt or ester thereof, and 6-hydroxy-2, 5, 7, 8-tetramethylchroman-2-carboxylic acid; and mixtures of uric acid, or a salt or ester thereof, lipoic acid, sodium formaldehyde sulfoxylate, gallic acid or a derivative thereof, propyl gallate and 6-hydroxy-2, 5, 7, 8-tetramethylchroman-2-carboxylic acid.  
     
     
         45 . The method according to any one of claims  2  or  3 , wherein at least one of said stabilizers is the dipeptide glycine-glycine.  
     
     
         46 . The method according to any one of claims  2  or  3 , wherein at least one of said stabilizers is diosmin.  
     
     
         47 . The method according to any one of claims  2  or  3 , wherein at least one of said stabilizers is silymarin.  
     
     
         48 . The method according to any one of claims  1 ,  2  or  3 , wherein said electromagnetic radiation is corpuscular radiation, electromagnetic radiation, or a mixture thereof.  
     
     
         49 . The method according to any one of claims  1 ,  2  or  3 , wherein said radiation is selected from the group consisting of radio waves, microwaves, visible light, invisible light, ultraviolet light, x-ray radiation, gamma radiation and combinations thereof.  
     
     
         50 . The method according to any one of claims  1 ,  2  or  3 , wherein said radiation is gamma radiation.  
     
     
         51 . The method according to any one of claims  1 ,  2  or  3 , wherein said radiation is e-beam radiation.  
     
     
         52 . The method according to any one of claims  1 ,  2  or  3 , wherein said radiation is visible light.  
     
     
         53 . The method according to any one of claims  1 ,  2  or  3 , wherein said radiation is ultraviolet light.  
     
     
         54 . The method according to any one of claims  1 ,  2  or  3 , wherein said radiation is x-ray radiation.  
     
     
         55 . The method according to any one of claims  1 ,  2  or  3 , wherein said radiation is polychromatic visible light.  
     
     
         56 . The method according to any one of claims  1 ,  2  or  3 , wherein said radiation is a combination of one or more wavelengths of visible and ultraviolet light.  
     
     
         57 . The method according to any one of claims  1 ,  2  or  3 , wherein said irradiating is conducted at ambient temperature.  
     
     
         58 . The method according to any one of claims  1 ,  2  or  3 , wherein said irradiating is conducted at a temperature below ambient temperature.  
     
     
         59 . The method according to any one of claims  1 ,  2  or  3 , wherein said irradiating is conducted below the freezing point of the monoclonal immunoglobulin.  
     
     
         60 . The method according to any one of claims  1 ,  2  or  3 , wherein said irradiating is conducted below the eutectic point of the monoclonal immunoglobulin.  
     
     
         61 . The method according to any one of claims  1 ,  2  or  3 , wherein the pH of said preparation of monoclonal immunoglobulins is less than 7.  
     
     
         62 . The method according to any one of claims  1 ,  2  or  3 , wherein the pH of said preparation of monoclonal immunoglobulins is less than 6.  
     
     
         63 . The method according to any one of claims  1 ,  2  or  3 , wherein the pH of said preparation of monoclonal immunoglobulins is less than 5.  
     
     
         64 . The method according to any one of claims  1 ,  2  or  3 , wherein the pH of said preparation of monoclonal immunoglobulins is less than 4.  
     
     
         65 . The method according to any one of claims  1 ,  2  or  3 , wherein the pH of said preparation of monoclonal immunoglobulins is less than 3.