Phenacetin caffeine

Similar methods with modifications such as the one by Schutz et al.8 have been in use for over 20 years. In 1968, Ferren and Shane9 published a paper on the differential spectrometric determination of caffeine in soluble coffee and drug combinations. It had the advantage of eliminating a preliminary separation that was required by the earlier method. While the method was successful for coffee, it was not as successful in the determination of caffeine in acetaminophen/phenacetin/caffeine tablets. They proposed that phenacetin was a limiting factor. The official AOAC methods for these methylxanthines in coffee and tea still involve similar methods.10... 

A2 Ethoxyresorufin, Phenacetin Caffeine (low turnover), Theophylline (low turnover), Acetanilide (mostly applied in hepatocytes) Furafylline a-Naphthoflavone (but also inhibits 3A4)... 

APC tablet (aspirin, phenacetin, caffeine, any supplier). If these tablets are not available, a laboratory mixture may be prepared by mixing 226.8 mg of acetylsalicylic acid (aspirin), 32.4 mg of caffeine, and 162 mg of phenacetin for this experiment. This laboratory mixture will suffice as an APC tablet. ... 

Phenacetin is an analgesic compound having molecuiar formula C10H13NO2. Once a common component in over-the-counter pain relievers such as APC (aspirin, phenacetin, caffeine), phenacetin is no longer used because of its liver toxicity. Deduce the structure of phenacetin from its NMR and IR spectra. 

Ternary eutectics are also possible. The binary eutectic points of three mixtures are as follows for aminophenazone-phenacetin 82°C for aminophenazone-caffeine 103.5°C and for phenacetin-caffeine IZS C. The ternary eutectic temperature of aminophenazone-phenacetin-caffeine is 81°C. In this mixture the presence of aminophenazone and phenacetin can be detected by the mixed melting point... 

In 1963 Hoffman and Mitchell described a method for determining in a single run the active ingredients in APC-tablets (= Acetylsalicylic acid, Phenacetin, Caffeine tablets). Due to the high ratio of phenacetin to caffeine (162 mg 32 mg) and the small differences in their retention times, it was not very satisfactory for the determination of caffeine. However, the means of several analyses yielded results close to either the labeled claim or the composition by synthesis. The results of a series of analyses of synthetic APC mixtures are listed in Table 20.3. 

Dechene et al. determined acetyl salicylic acid, phenacetin, caffeine and codeine in tablets. Acetyl salicylic acid and phenacetin were separated and determined on one packed column of DS 200 on Haloport by temperature programming, 100-180°C, whereas caffeine and codeine were separated on a packed column of SE-30 (10 %) on Chromosorb W AW by temperature programming, 195-260°C. Codeine and caffeine were extracted from the powdered tablet material with chloroform after the addition of alkali, and the chloroform solution used for the gas chromatographic assay. Results obtained with the method are listed in Table 20.4. 

Acetylsalic. acid Phenacetin Caffeine Codeine phosphate... 

In a paper on the gas chromatographic assay of phenacetin, caffeine, antipyrin and di-... 

Ethoxyresorufin, phenacetin, caffeine, acetanilide, methoxyresomfin Conmarin... 

Oi and Miyazaki (1967) have described an infrared compensation method for the rapid determination of small amounts of isopropamide in pharmaceutical preparations containing aminopyrine, phenacetin, caffeine, and isopropamide. The key band used for isopropamide was 702cm" in an acetone solvent. 

Quantitative Determination of Aspirin, Phenacetin, Caffeine, and Their Metabolites in Blood Plasma by Gas Chromatography Tohoku Yakka Daigaku Kenkyo Nempo 1979(25) 71-79 CA 91 186315p... 

In a study conducted by Allen [25], NIR was used for the determination of carisoprodol, phenacetin, and caffeine content in tablets. Twenty tablets were pulverized and an aliquot, dissolved in chloroform. A series of standard solutions of carisoprodol, phenacetin, and caffeine were scanned between 2750 and 3000 nm. All exhibited to Beer s law behavior (maximum 200 mg/ml). Carisoprodol and phenacetin were determined simultaneously at 2820 nm for carisoprodol and 2910 nm for phenacetin. Caffeine concentrations were determined at 3390 nm. Since chloroform is a strong absorber, carbon tetrachloride was substituted as the solvent. The NIR method provided a coefficient of variation (CV) for all three drugs of 1.4% or less. 

The IR and NMR spectra of phenacetin (C10H13NO2) are given in Fig. 17.7. Phenacetin is an analgesic and antipyretic compound and was the P of A-P-C tablets (aspirin-phenacetin-caffeine). (Because of its toxicity, phenacetin is no longer used medically.) When phenacetin is heated with aqueous sodium hydroxide, it yields phene-tidine (CsH 11 NO) and sodium acetate. Propose structures for phenacetin and phenetidine. 

I would like to mention next the combination of acetylsalicylic acid, phenacetin, caffeine, and codeine, commonly called APC C, of which there are great quantities sold in Canada every year. Despite the fact that these products have been on the market for about 25 years, until as recently as 1954-no satisfactory quantitative method for the determination of the codeine phosphate content was available. At that time two methods were developed in our laboratory in order to cope with these products. Briefly, the procedures are as follows. 

Cinchona alkaloids used 316 m/i for quinine alkaloids, 348 m/i for cinchonine alkaloids in cinchona bark Aspirin, phenacetin, caffeine spectrophotometric determination in mixtures... 

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