Figure 1: Chromatogram of PGE1 and PGA1 in the formulation. We observed a satisfactory separation by using mixture of phosphate buffer (KH2PO4 0.02 M: acetonitrile in the ratio of (63:37 v/v) pH 3 as a mobile phase and with a ramp of flow rate from 1 ml/min to 1.5 ml/min. Within these conditions, retention time of PGE1 and PGA1 were about 11 min and 29 min.