Incompatibility of sodium cefapyrin (CEPR) with 22 kinds of commercial intravenous drip infusion solutions, 44 kinds of injections and clinically used mixed injections was studied. The stability of this product was examined with thin-layer chromatography, bioautography and bioassay. The results are as follows: The CEPR solution, a mixed injection not containing unfusion solution, generally reduces its potency and changes appearance with time. The clinically used CEPR solutions containing infusion soultion remain stable for 6 hrs showing no change in appearance, pH and potency. Marked reduction in potency was, however, observed in 24 hrs in the CEPR solution containing amino acids or tathione (600mg).
