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5321221 
Journal Article 
THE STABILITY OF ASPIRIN IN A MOISTURE CONTAINING DIRECT COMPRESSION TABLET FORMULATION 
Snavely, MJ; Price, JC; Jun, HW 
1993 
Yes 
Drug Development and Industrial Pharmacy
ISSN: 0363-9045
EISSN: 1520-5762 
19 
6 
729-738 
WOS:A1993KQ39400008 
Studies were conducted on the stability of a direct compression tablet formulation containing aspirin as a model hydrolabile drug. Emdex(R) (a mixed-sugar diluent containing approximately 8 percent moisture) and stearic acid (a lubricant) made up the remainder of the formulation. Both tablets and uncompressed powder blend were manufactured, packaged in storage containers and placed on stability at different storage temperatures. Stability samples were assayed for aspirin and salicylic acid using a stability indicating analytical method. Analysis of the stability data showed that the rate of aspirin decomposition accelerated with time. Also, the aspirin decompostion rate increased with temperature. The data were fit to the empirical equation y = 100 - kt(n)' where y is the percent aspirin remaining, t is time, and k and n are constants. The formulation showed good stability, with less than one percent decomposition occuring after 1.75 years of storage at room temperature. This result indicates that although the aspirin formulation contained approximately 8 percent moisture, at room temperature the majority of the moisture present in the formulation is not available to react with the aspirin. The apparent activation energy of the solid-state aspirin decomposition was 46 kcal/mole, which is higher than expected. This result may be due to a temperature dependent release of moisture from the Emdex(R). Further studies are needed to verify this explanation.