PROCESSING AND STORAGE EFFECTS ON WATER-VAPOR SORPTION BY SOME MODEL PHARMACEUTICAL SOLID DOSAGE FORMULATIONS

Several excipients and their formulations were equilibrated at relativ e humidities and temperatures selected to simulate typical pharmaceuti cal storage and processing conditions. Three different water detection techniques-loss on drying, Karl Fischer coulometry and an automatic m oisture balance, were used to determine the moisture content of these systems. The excipients all possessed very different water sorption te ndencies, as did their formulations. Isothermal water sorption by the dry blends, granules and tablets of each formulation was identical, su ggesting that the processes involved in tablet manufacturing did not a ffect the water sorption behavior. Accurate water content predictions for the formulations were possible by adding the contribution of water from each excipient. Such predictions may be helpful for defining upp er and lower water content specifications and storage conditions for e xcipients and their formulations. (C) 1997 Elsevier Science B.V.