Sampling procedures pharmaceutical drugs

Sympathomimetic drugs can be determined by various procedures. Optimal reaction conditions have been developed for a FIA system with FLD, based on the reaction with 4-aminoantipyrine (78) in the presence of potassium hexacyauoferrate (equatiou 2). Pure samples or pharmaceutical formulations of etilefrine (155), orciprenaline (169), fenoterol (170), hexoprenaline (171) and reproterol (172) were determined, after dilution to the 2 to 50 ppm range. Results agreed with the official or the referee methods . 

Immunoaffinity procedures can be performed either on-line or off-line, and can be coupled to chromatographic systems [ 118,119] or even to immunoassays [120]. Many examples can be found in the literature regarding the use of immunoaffinity extraction of drugs and pharmaceuticals from biological matrices, as well as of organic pollutants such as pesticides from environmental samples [115,121-124]. 

In most instances, formulated drugs cannot be chromatographically analyzed without some preliminary sample preparation. This process can generally be categorized into sampling and sample cleanup steps with the overall goal of obtaining a representative subfraction of the batch. This chapter is a discussion of manual and automated sample preparation procedures for pharmaceutical formulations. 

Oxazepam and related compounds are converted by extractive alkylation into N,0-dimethyl derivatives and are analysed on 3% of OV-225 at 250°C [550]. Another procedure involves the extraction of the sample with benzene, hydrolysis with a strong acid and acylation of the benzophenone amino derivative produced with TFA anhydride [551], Extractive alkylation is used to advantage also for other pharmaceuticals, especially for their determination in plasma, urine and other biological materials. By this procedure hydrochlorothiazide was analysed in plasma, blood corpuscules and urine [552], furosemide in plasma [553] and chlorthalidone and related drugs in plasma and other biological samples [554,555],... 

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