Significance of Salicylic Acid Sublimation in Stability Testing of Aspirin-Containing Solids

Surface Chemistry of Colloidal Silica and a Possible Application to Stabilize Aspirin in Solid Matrixes

“…However, the data presented in this study are insufficient to suggest which of the two concepts describes the adsorption properties of I. is not the only factor that helps stabilize aspirin in these formulations. The precise mechanism by which this effect occurs is not based on simple retention of water vapor by silica to limit its access to aspirin particles per se but probably involves a complex of considerations such as: ( a ) the state of equilibrium between the bound and free water within the microporous structure of the tablets, (6) changes in the tablet structure that affect the pore size distribution, and (c) the occlusion of pores by silicabound water or by partial deposition of sublimed salicylic acid on the surfaces of aspirin or silica particles (3,19). These phenomena could be explained further by the following hypothesis.…”

“…A t elevated temperatures in the presence of moisture, he theorized that the reaction takes place through solution of aspirin from the water vapor adsorbed and in contact with the aspirin surface. The sublimation of salicylic acid observed on the surface of aspirin tablets under stress conditions (3) suggests that other factors than those operating in a pure solution theory must be operable, since it seems unlikely that salicylic acid would sublime out of an aqueous solution. It also was suggested that the degradation reaction may be affected by the dissolution of aspirin in acetic acid as it forms, depending on the rates at which acetic acid volatilizes and is formed by hydrolysis (2).…”

Determination of the Decomposition of Aspirin

“…In their study on salicylic acid sublimation, Gore et al- (29) determined the hydrolysis rates for aspirin at temperatures ranging from 17.2 to 30.2 f 0.1 " at pH 7.4 and reading the resulting salicylic acid at 296.5 mp. Their data are summarized in Table 111.…”

“…A very much needed publication on the significance of salicylic acid sublimation in stability testing of aspirin-containing solids was presented by Gore et al (29). A more than negligible loss of salicylic acid formed from the decomposition of aspirin would preclude the common practice of analytically determining changes in salicylic acid content in solid dosage forms of aspirin as a measure of degrading aspirin.…”

Development and Validation of HPTLC Method for Studying Stress Degradation of Aspirin in Fulvic Acid Inclusion Complex

“…Aspirin (ASP) is chemically acetyl salicylic acid, a very old medication with high medical values, which possess various activities viz, antiinflammartory, analgesic, and anti-aggregatory activity [1,2]. The carboxyl and ester groups are present in the structure of acetyl salicylic acid, the ester group of ASP is sensitive to hydrolysis in the presence of moisture, which reduces its bioavailability and causes ulceration effects on the human stomach [3][4][5][6]. A strategy must to develop to reduce/inhibit the hydrolysis of ASP.…”