Stabilized aqueous suspensions for parenteral use

Abstract

A pharmaceutical aqueous suspension formulation for parenteral administration having substantially stabilized pH, comprising a biologically active compound and a pH controlling effective concentration of L-Methionine. Preferably, the biologically active compound is a steroidal compound, for instance exemestane, medroxyprogesterone acetate and estradiol cypionate or a combination of medroxyprogesterone acetate and estradiol cypionate.

1 . A pharmaceutical aqueous suspension formulation for parenteral administration having substantially stabilized pH comprising a biologically active compound and a pH controlling effective concentration of L-Methionine.  
     
     
         2 . A pharmaceutical formulation according to  claim 1 , wherein the pH controlling effective concentration of L-Methionine is from about 0.005% w/v or w/w to about 5% w/v or w/w.  
     
     
         3 . A pharmaceutical aqueous suspension formulation for parenteral administration having substantially stabilized pH, comprising a biologically active compound, a buffering agent and L-Methionine in concentrations effective to produce a pH controlling superadditive effect.  
     
     
         4 . A pharmaceutical composition according to  claim 3 , wherein the buffering agent is a phosphoric acid salt in a concentration lower than 0.4% w/v or w/w.  
     
     
         5 . A pharmaceutical composition according to  claim 4 , wherein the concentration of the phosphoric acid salts is lower than 0.2% w/v or w/w.  
     
     
         6 . A pharmaceutical composition according to any preceding claims, wherein the pH range of the formulation is from about pH 3.0 to about pH 8.0.  
     
     
         7 . A pharmaceutical composition according to  claim 6 , wherein the biologically actiye compound is a steroidal compound.  
     
     
         8 . A pharmaceutical composition according to  claim 7 , wherein the biologically active steroidal compound is selected from exemestane, medroxyprogesterone acetate and estradiol cypionate or a mixture of medroxyprogesterone acetate and estradiol cypionate.  
     
     
         9 . Use of L-Methionine, in the preparation of a pharmaceutical aqueous suspension formulation having substantially stabilized pH, for parenteral administration of a biologically active compound, characterized in that a pH controlling effective concentration of L-Methionine is added thereto.  
     
     
         10 . Use of L-Methionine and a buffering agent in concentrations effective to produce a pH controllling superadditive effect, in the preparation of a pharmaceutically aqueous suspension formulation having substantially stabilized pH, for parenteral administration of a biologically active compound.