sodium the concentrate is added therein with 300 g sodium chloride and stirred for 4 hours at 25 u02dc 30 u00b0 c it is continuously stirred for next 2 hours at cooling temperature of 0 u02dc 5 u00b0 c to salt out the pravastatin sodium precipitate filtration is done to obtain the filtered cake containing pravastatin sodium purity 99 3 the salting out cake is dissolved in 120 ml water added with 1 0 g activated carbon and stirred for 2 hours for decoloring the solution is then filtered and the filtrate is then desalted by xad 4 or hp 20ss the pravastatin sodium elute is concentrated under reduced pressure to 30 w w and 4 0 liters acetone is added into the concentrate and stirred at 25 u02dc 30 u00b0 c for 4 hours then it is cooled to 0 u02dc 5 u00b0 c and stirred for 2 hours to crystallize the pravastatin sodium which is filtered under vacuum dried to obtain purified pravastatin sodium 16 5 g overall yield 55 and purity 99 5 a fermentation broth containing pravastatin sodium of 10 liters is centrifuged to remove microbial cell mass the supernatant is added with 10 n sodium hydroxide solution to.