Spectrophotometric determination of the stability of an ampicillin-dicloxacillin suspension.

The degradation rate constants for ampicillin and for dicloxacillin in the suspension filtrate, and their solubility coefficients (at 25 degrees C) were determined by spectrophotometry employing a multicomponent computer program. The shelf life of the ampicillin-dicloxacillin suspension was then determined in terms of the stability of ampicillin, the least stable component.