A controlled release parenteral formulation for treatment of pain and inflammation is provided. The formulation includes an effective amount of: one or more active drug moiety. The drug moiety is selected from a group comprising aceclofenac or diclofenac or a combination thereof； One or more solvent moiety selected from a group comprising one or more of ethyl acetate, triacetin, di methyl iso sorbide, DMA, DMSO, PEG, PVP, PVA, Span 80, DCM, Benzyl alcohol, acetone or a combination thereof. The formulation, upon administration, has a release profile including an immediate burst release and the burst release is followed by a slow release of at least 18 to 24 hrs. The immediate burst release and the slow release of the drug moiety remains within the therapeutic window of the drug moiety.
