Formulation development of sustained realease 375 mg Cefaclor have been prepared,the step forward must assess the evalution of its drug release in comparison with the reference drug. Eight formulations were compared the drug release with the reference CeclorSR table of Lilly Suzhou Phanmaceutical Co.Ltd.Formulation 8 showed the equivalence of drug release persentages with the reference table (18,70
36,40
96,20
after 30, 60, 240 minutes versus 16,54
33,87
92,96
respectively) and fittet to the specification of USP 29. The based standards of this preparation were also constructed.