Stable parenteral formulations of duloxetine

Abstract

The present invention relates to a parenteral lyophilized formulation of duloxetine or a pharmaceutically acceptable salt thereof. Further, this invention relates to duloxetine dissolved in a suitable solvent system comprising one or more buffers, stabilizers, and other pharmaceutically acceptable excipients and subsequently lyophilized. The invention also describes combination formulation of Duloxetine with other active ingredients.

What is claimed is: 
     
         1 . A parenteral formulation comprising lyophilized duloxetine or a pharmaceutically acceptable salt thereof, optionally together with one or more pharmaceutically acceptable excipients. 
     
     
         2 . The formulation of  claim 1 , wherein the moisture content of the lyophilized cake is less than 5% w/w. 
     
     
         3 . The formulation of  claim 1 , wherein the content of Duloxetine Alcohol, Duloxetine Napthol 4-yl isomer, Alpha Napthol and Duloxetine Beta napthol-1-yl isomer individually is less than 0.5% w/w. 
     
     
         4 . The formulation of  claim 1 , wherein the pharmaceutically acceptable excipients are selected from the group comprising bulking agents, aqueous vehicle, stabilizers, and surfactants. 
     
     
         5 . The formulation of  claim 4 , wherein the bulking agents are selected from mannitol, dextrose, cyclodextrin, sodium chloride and sorbitol. 
     
     
         6 . The formulation of  claim 4 , wherein the aqueous vehicle is selected from one or more buffers selected from the group comprising acetate buffer, phosphate buffer, aspartic acid and boric acid buffer, citrate buffer and glycine buffer, histidine buffer, succinate buffer, alanine buffer, valine buffer, lactic acid buffer. 
     
     
         7 . The formulation of  claim 4 , wherein the surfactant is selected from the group comprising lecithin, soya lecithin, egg lecithin, PEG-PE and phosphatidyl choline. 
     
     
         8 . A kit comprising (i) a vial comprising lyophilized duloxetine, optionally with pharmaceutically acceptable excipients and (ii) a vial comprising a diluent 
     
     
         9 . The kit of  claim 8  wherein the diluent is selected from the group comprising water for injection, dextrose solution, normal saline, mannitol solution, dextrose normal saline solution, half saline solution. 
     
     
         10 . The kit of  claim 8 , wherein the pH of the reconstituted solution is between 4-8.