title: Aging of tablets made with dibasic calcium phosphate dihydrate as matrix.
abstract: The aging of direct compression tablets made using dibasic calcium phosphate dihydrate as the tablet matrix was investigated over 16 weeks. The formula included 6% amaranth as a dye tracer. Two sets of stress storage conditions were used: 25 degrees and 50% relative humidity and 45 degrees and 75% relative humidity. Tablets were evaluated periodically by visual inspection; determination of the weight of 10 separate tablets, the size of 10 tablets measured by a micrometer screw gauge, and the hardness of 10 tablets as indicated by a Strong-Cobb hardness tester; the USP disintegration time test; and the USP dissolution test. Tablets stored at 25 degrees and 50% relative humidity showed an  approximately linear increase in disintegration and dissolution time over 16 weeks with no other significant changes. Storage at 45 degrees and 75% relative himidity resulted in significant changes in most measured parameters; tablets showed blotching, substantial  weight loss, and complex changes in disintegration  and dissolution. The changes at elevated temperatures are related to loss of water of hydration; changes at 25 degrees must be due to other causes.
mesh_terms: D002130:Calcium Phosphates; D004355:Drug Stability; D005079:Excipients; D006244:Hardness; D006358:Hot Temperature; D006813:Humidity; D014677:Pharmaceutical Vehicles; D012995:Solubility; D013607:Tablets
chemical_list: D002130:Calcium Phosphates; D005079:Excipients; D014677:Pharmaceutical Vehicles; D013607:Tablets