The present invention relates to a stable oral pharmaceutical formulations comprising amorphous atorvastatin calcium. The atorvastatin formulation prepared according to the present invention involves use minimum amount of pH adjusting substance preferably below 5%, more preferably below 4% by the total weight of the composition to obtain stable formulation. Further formulation provides a pH less than pKa+l of atorvastatin calcium to an aqueous solution and simultaneously improved solubility characteristics of atorvastatin calcium.