Determination of glucosamine and carisoprodol in pharmaceutical formulations by LC with pre-column derivatization and UV detection.
ABSTRACT A simple and reliable precolumn derivatization liquid chromatography method with ultraviolet detection has been developed and validated for the analysis of glucosamine (GS) in various dietary supplement formulations and raw materials. Additionally, the proposed method was used for analysis of carisoprodol (CR) found in ternary mixture with paracetamol (PR) and caffeine (CF). The linearity ranges were 1-100 μg/mL for GS, 1-150 μg/mL for CR, PR and CF. Derivatization was used with 1,2-naphthoquinone-4-sulphonic acid sodium salt in the presence of borate buffer. Chromatographic separation of GS-naphthoquinone derivative was achieved by using a mixture of acetonitrile and water (pH 7.3 adjusted with 0.1 M NaOH) in the ratio 10:90, v/v and flow-rate of 1.0 mL/min. UV detection was carried out at 280 nm. For PR, CF, and CR-naphthoquinone derivative, the chromatographic separation was achieved by using mixture of acetonitrile and 20 mM KH(2)PO(4) (pH 3.0 adjusted with phosphoric acid) in the ratio 20:80, v/v and flow-rate of 1.0 mL/min. UV detection was carried out at 275 nm. The limits of detection were 37.2, 35.9, 30.4 and 40.0 ng/mL for GS, CR, PR and CF, respectively.
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ABSTRACT: Baclofen (Lioresal), a lipophilic analogue of c-aminobutyric acid (GABA), and carisoprodol (Soma), a central nervous system depressant with an unknown mechanism of pharmacologic action, are categorized as muscle relaxants. Baclofen is used clinically in the management of spasticity and its sequelae secondary to severe chronic disorders such as multiple sclerosis and other types of spinal cord lesions. Carisoprodol is used for discomfort associated with acute and painful musculoskeletal conditions. Intoxication from these drugs occurs in both humans and animals necessitating a need for their detection in plasma/serum, tissue, and gastrointestinal contents samples. A sensitive and specific analytical method for detection and quantitation of these compounds using liquid chromatography with positive atmospheric pressure chemical ionization-mass spectrometry was developed. A rapid extraction procedure for both analytes from fortified bovine sera is described. Chromatographic separation was carried out on a C(18) reverse-phase column with a gradient elution of acetonitrile and 0.25% acetic acid. The effluent was directed to the mass spectrometer with fragmentation information for baclofen and carisoprodol obtained in a scan monitoring mode. Linear standard curves for baclofen and carisoprodol were constructed based on at least two corresponding extracted ions over a concentration range of 0.1-50 micro g/mL. The analysis of fortified sera samples demonstrates good accuracy and precision for the method with a limit of detection of 0.5 micro g/mL for carisoprodol (n = 3) and 1 micro g/mL for baclofen (n = 4) and a limit of quantitation of 2 micro g/mL for both compounds. Recoveries at the limit of quantitation were between 75 and 95% for both analytes, with a 4.8-9.3% range in standard deviation.Journal of analytical toxicology 27(5):275-83. · 2.11 Impact Factor
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ABSTRACT: Chronic pain patients are frequently maintained on one or more powerful opioid medications in combination with other psychoactive medications. Urine tests provide objective information regarding patient compliance status. Little information is available on testing this unique population. The goal of this study was to characterize drug disposition patterns in urine specimens collected from a large population of pain patients. Confirmation data for 10,922 positive specimens were collated into 11 drug Classes. The number of drug/metabolites tested (#) and number of confirmed positive specimens were as follows: amphetamines (7), 160; barbiturates (5), 308; benzodiazepines (6), 2397; cannabinoids (1), 967; carisoprodol (2), 611; cocaine (1), 310; fentanyl (1), 458; meperidine (2), 58; methadone (2), 1209; opiates (7), 8996; and propoxyphene (2), 385. Subdivision into 19 distinct drug Groups allowed characterization of drug use patterns. Of the 10,922 positive specimens, 15,859 results were reported as positive in various drug Classes, and 27,197 drug/metabolites were measured by gas chromatography-mass spectrometry. The frequency of illicit drug use (cannabis, cocaine, ecstasy) was 10.8%. Being the first study of this type, these data present a large array of information on licit and illicit drug use, drug detection frequencies, drug/metabolite patterns, and multi-drug use combinations in pain patients.Journal of analytical toxicology 11/2008; 32(8):530-43. · 2.11 Impact Factor
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ABSTRACT: Single laboratory validation of a method for determination of glucosamine in raw materials and dietary supplements containing glucosamine sulfate and/or glucosamine hydrochloride by with high-performance liquid chromatography FMOC-Su derivatization. Tests with 2 blank matrixes containing SAMe, vitamin C, citric acid, chondroitin sulfates, methylsulfonylmethane, lemon juice concentrate, and other potential interferents showed the method to be selective and specific. Eight calibration curves prepared over 7 working days indicated excellent reproducibility with the linear range at least over 2.0-150 microg/mL, and determination coefficients >0.9999. Average spike recovery from the blank matrix (n = 8 over 2 days) was 93.5, 99.4, and 100.4% at respective spike levels of 15, 100, and 150%, and from the sample matrix containing glucosamine (n = 3) was 99.9 and 102.8% at respective levels of 10 and 40%, with relative standard deviations <0.9%. The method was also applied to 12 various glucosamine finished products and raw materials. The stability tests confirmed that glucosamine-FMOC-Su derivative once formed is stable at room temperature for at least 5 days. Limit of quantitation was 1 microg/mL and limit of detection was 0.3 microg/mL. The method is ready to proceed for the collaborative study.Journal of AOAC International 87(5):1083-92. · 1.23 Impact Factor