ABSTRACT
A simultaneous analysis of aspirin and nonaspirin salicylates in solid pharmaceutical dosage forms is described. Two separate extraction procedures are employed, one for plain aspirin tablets and one for tablets containing aspirin plus buffers or antacids. The analyses of the extracted samples are accomplished by a stabilized normal-phase high-performance liquid chromatographic (HPLC) procedure. Prepared samples and standards are stable for up to 24 h, and the methodology is suitable for an automated HPLC system.
Subject(s)
Aspirin/analysis , Salicylates/analysis , Antacids/analysis , Buffers/analysis , Chromatography, High Pressure Liquid/methods , Drug Stability , Salicylic Acid , Tablets/analysisABSTRACT
The analysis of aspirin and nonaspirin salicylates in buffered and plain tablet formulations employing nearly nonaqueous extraction is described. The results obtained compare favorably with those obtained from USP procedures. A simultaneous assay for aspirin and nonaspirin salicylates in buffered tablets involves the use of an acidified chromatographic siliceous earth column for the separation of the aspirin and nonaspirin salicylates from various buffers or antacids. The methods described here have definite advantages over USP XX procedures, and the buffered aspirin tablet procedures also is adaptable to aspirin formulations containing codeine, acetaminophen, propoxyphene, caffeine, and many antihistamines.
Subject(s)
Aspirin/analysis , Salicylates/analysis , Aluminum Hydroxide , Chromatography, Gas/methods , Hydrolysis , Magnesium Hydroxide , Tablets/analysisABSTRACT
A nonsolvolytic (solid-state) acetylation of codeine phosphate in the presence of aspirin to yield acetylcodeine phosphate is reported. GLC assays for the simultaneous determination of aspirin and salicylic acid and codeine and acetylcodeine are described. The apparent heat of activation for codeine phosphate is estimated, and the possible reaction mechanisms are discussed.