Theophylline

Simultaneous high-performance liquid chromatographic determination of theophylline, ephedrine hydrochloride, and phenobarbital in tablets

“…The change in the detector attenuation during the chromatographic run did not affect the results. The wide variation in polarity, which necessitated the prior separation of ephedrine in the GLC methods (4,5), presented no problems under the proposed experimental conditions. The method also is applicable to the assay of individual tablets since the procedure is based on the quantities of drugs present in one tablet.…”

“…Quantitative determinations of single entities of theophylline or phenobarbital in various dosage forms and biological samples based on reversed-phase high-performance liquid chromatography (HPLC) were puhlished previously and reviewed (5,6). Some reversed-phase HPLC assays for ephedrine hydrochloride also were reported (7,s).…”

Rapid, Stability-Indicating, High-Pressure Liquid Chromatographic Determination of Theophylline, Guaifenesin, and Benzoic Acid in Liquid and Solid Pharmaceutical Dosage Forms

“…Cohen (25) stated that theophylline solutions subjected to strongly alkaline pH showed decomposition and apparent ring opening after several weeks and that theophylline was also susceptible to oxidation, resulting in the formation of 1,3-dimethyluric acid.…”

Theoretical and experimental studies on theophylline release from hydrophilic alginate nanoparticles

“…Solubility of THP in water is 8.3 mg/ml [38]. The high hydrophilic nature of the ALG matrix ensures that the drug is present in the dissolved form on contact with the simulated biological fluid.…”