Barbiturates Sulphonamides

Olesen, 0. V., Determination of phenobarbital in serum in the presence of other barbiturates, sulphonamides, salicylates and other interfering drugs. Scand. J. Clin. Lab. Invest. 20, 109-112 (1967). 

Rubino (1989) has investigated the solid-state properties of the sodium salts of drugs (e.g., barbiturates, sulphonamides and hydantoins). When the logarithm of their aqueous... 

A plethora of weakly acidic pharmaceutical substances may be titrated effectively by making use of a suitable non-aqueous solvent with a sharp end-point. The wide spectrum of such organic compounds include anhydrides, acids, amino acids, acid halides, enols (viz., barbiturates), xanthines, sulphonamides, phenols, imides and lastly the organic salts of inorganic acids. 

The survey of literature provides ample evidence of the NMR spectra of a good number of medicinal compounds belonging to various categories, namely sulphonamides barbiturates amphetamines steroids antihistamines penicillins and cephalosporins to name a few. 

Non-aqueous titration of acidic groups is carried out in pharmacopoeial assays of barbiturates, uracils and sulphonamides. 

It is of interest that those who inherited acute intermittent porphyria and variegate porphyria suffered no biological disadvantage from the natural environment and bred as well as the normal population until the introduction of barbiturates and sulphonamides. They are now at serious disadvantage, for many other drugs can precipitate fatal acute attacks. 

Erythema multiforme e.g. NSAIDs, sulphonamides, barbiturates, phenytoin. 

Fixed eruptions are eruptions that recur at the same site, often circumoral, with each administration of the drug e.g. phenolphthalein (laxative self-medication), sulphonamides, quinine (in tonic water), tetracycline, barbiturates, naproxen, nifedipine. 

The pre-purification of barbiturates to be isolated from urine can likewise be carried out by acid ether extraction [43, 56, 166]. Methylene dichloride has been employed also [34]. Acidification with hydrochloric acid is preferable since, if this is performed with weaker, organic acids, amphoteric medicinal components like sulphonamides, are extracted at the same time [166]. After drying the organic phase with sodium sulphate, further purification on a charcoal or alumina column can be carried out [43, 166]. Urine colouring materials can be removed by shaking the ethereal solution with 5% lead acetate solution [56]. After purification, the... 

Albumin has a great avidity for anions and transports a wide variety of substances including fatty acids, bile acids, uric acid and bilirubin as well as Cu " ", Ca and Zn . It also combines with a number of drugs including aspirin, barbiturates, penicillin and sulphonamides and mops up excess vitamin A and C as well as histamine and various steroids. 

Shepherd proposed a colorimetric method for pyrimidines substituted in the 2-position based on the red colour formed with 2-thio-barbituric acid. Since no colour is produced when the pyrimidine is substituted in either the 4- or the 6-position this reaction may be used for the determination of sulphadiazine in the presence of other sulphonamides, including sulphamerazine and sulphadimidine. 

In 1965 Kuhnert-Brandstatter investigated by hot stage microscopy three common classes of drug 70% of barbiturates, 60% of sulphonamides and 23% of steroids exist in various polymorphic or solvate forms [9,10]. 

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