Comparative thermal properties of the monohydrates of sodium theophylline and theophylline.
The thermal properties of sodium theophylline monohydrate, as determined by differential scanning calorimetry (DSC), thermogravimetric (TG) analysis and hot stage microscopy, were studied and compared with those of theophylline monohydrate. The onset of dehydration of sodium theophylline monohydrate varied between 170 and 264 degrees C depending on the atmospheric conditions surrounding the sample. Under similar conditions, dehydration of theophylline monohydrate occurred at 18 to 65 degrees C. Sodium theophylline melted with the onset of a DSC endotherm at 391 degrees C. Possible effects of the physicochemical properties of sodium theophylline monohydrate on its dosage forms and the expected superiority of the sodium salt over theophylline and aminophylline are discussed.
Serajuddin
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D002152:Calorimetry, Differential Scanning; D003890:Desiccation; D004304:Dosage Forms; D008853:Microscopy; D013806:Theophylline; D013816:Thermodynamics; D013818:Thermogravimetry
D004304:Dosage Forms; D013806:Theophylline