Determination of pharmaceutical drug

Methods for the identification and determination of pharmaceutical drugs in the forensic setting are required in order to detect their abuse and misuse (e.g., accidental or suicidal overdosage, homicidal poisoning, illicit performance enhancement). Some pharmaceutical drugs may also enhance the toxic potential of illicit drugs and/or alcohol and their determination is necessary in order to ascertain cases of mixed-drug intoxications. 

Many of these electrochemical methods were dedicated towards the determination of pharmaceutical drugs. The electroanalytical determination of pharmaceutical drugs has been widely explored, and the methods need to present high sensitivity, especially for the determination of active ingredients in biological fluid samples. The work reported by... 

Refaat et al. [24] used a spectrophotometric method for the determination of primaquine, and 16 other tertiary amine drugs, in bulk or in pharmaceuticals. The method involved the condensation of malonic acid with acetic anhydride in the presence of a tertiary amine in an aliphatic or a heterocyclic system. The condensation product is highly fluorescent and allows the spectrofluorimetric determination of the drug in the ng/mL ranges (Xcx = 415 nm and >.em = 455 nm). 

Hassan et al [65] used a method for the determination of primaquine and other antimalarials, through ternary complex formation. The analytical aspects of the reaction between the widely used antimalarial drugs with cobalt and thiocyanate to form ternary complexes are described. Alternatively, determination of the cobalt content of the nitrobenzene extract using atomic absorption spectroscopy provided an indirect method for the determination of the drugs. Both methods are applied to the analysis of pharmaceutical preparation and the results obtained agreed well with those obtained with official methods. 

As liquid chromatography plays a dominant role in chemical separations, advancements in the field of LC-NMR and the availability of commercial LC-NMR instrumentation in several formats has contributed to the widespread acceptance of hyphenated NMR techniques. The different methods for sampling and data acquisition, as well as selected applications will be discussed in this section. LC-NMR has found a wide range of applications including structure elucidation of natural products, studies of drug metabolism, transformation of environmental contaminants, structure determination of pharmaceutical impurities, and analysis of biofiuids such as urine and blood plasma. Readers interested in an in-depth treatment of this topic are referred to the recent book on this subject [25]. 

HPLC Methods for the Determination of Pharmaceuticals, Hormones, and Drugs.546... 

HPLC METHODS FOR THE DETERMINATION OF PHARMACEUTICALS, HORMONES, AND DRUGS... 

Shah and Mehta described a calorimetric method for the estimation of diloxanide furoate in pharmaceutical formulations [27]. The method is based on its interaction with hydroxylamine in alkaline solution. This method was used for the determination of the drug either alone or when combined with other agents. 

New modified polymeric electrodes selective to procaine and other local anaesthetic compounds were reported [72]. The electrode was constructed by incorporating the ion-pair complex of procaine with tungsto-phosphoric acid into ethylene-vinyl acetate copolymer. Best results were obtained with 1 1 nitrobenzene-dioctyl phthalate as a plasticizer. The calibration graph was linear fi om 18 p to 10 mM of procaine. When these electrodes were applied to the determination of the drug in pharmaceutical formulations, the recoveries were found to be quantitative. 

Carmona et al. described a simple and rapid kinetic spectrophotometric method for the determination of procaine in pharmaceutical preparations [35]. The method was applied to the determination of the drug in various pharmaceutical samples. 

Dwivedi and Arnold (89) determined the thiazole moiety in thiamine by derivatizing first to form the TMS analog. Samples were chromatographed on 3% OV-17 on Chromosorb G (DMCS treated) at 110°C. Vitamin D2 (calciferol) and its analog Vitamin have been the subject of many applications in GC analyses. The compounds have been derivatized as the TMS analog and chromatographed on OV-17 (90) and SE-30 (91) and on 3% silicone on Celite after treatment with antimony trichloride (92). Several references to vitamine E (oi-tocopherol) are included in the review by Kern et al. (39) on GLC determinations of pharmaceuticals and drugs. The acetate was determined on 3% OV-17 on Chrom W-HP at 280°C. Vecci and Kaiser (93) determined Vitamin C as the TMS derivative on 3% SE-30 or 10% XE-60 on Anachrom ABS. Column... 

The Raman effect has also been broadly applied to online and bench-top quantitative applications, such as determination of pharmaceutical materials and process monitoring [4-6], in vivo clinical measurements [7], biological materials [8, 9], to name only a few. Because the absolute Raman response is difficult to measure accurately (sample presentation and delivered laser power can vary), these measurements are almost always calculated as a percentage with respect to the response from an internal standard. This standard is typically part of the sample matrix in a drug product, the standard may be an excipient in a biological sample, it is commonly water. 

The similar method using nickel (II) instead of cobalt, cadmium and manganese was also investigated by Salem et al. [49] for the quantitative determination of flufenamic, mefenamic and tranexamic acids, furose-mide, diclofenac sodium and thiaprofenic acid. Statistical analysis of the results compared to assays used in pharmacopoeias and the Amax methods revealed equal precision and accuracy. Furthermore, the assays were also applied for the determination of these drugs in pharmaceutical preparations. 

Optical methods have found a wide usage for quantitative determination of medical drugs, like tinidazole [1134,1454], metronidazole [1455-1458], In particular, a spectrophotometric method for the estimation of metronidazole and its benzoate in pure form and in pharmaceutical preparations has been used [1458], The method is based on the development of a stable pink color with potassium hydroxide in methanol-isopropyl alcohol solution which can be quantitatively measured at 370 nm. The authors of the work [1457] have stated that the method proposed by them has less error (3 4%) and is less complicated than the used before. The optical properties of organic luminescent microcrystals on the basis of nitrobenzofurazans have been studied [1459],... 

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