Naproxen, analysis

Electropherograms of a urine sample (8 ml) spiked with non-steroidal anti-inflammatory drugs (10 p-g/ml each) after direct CE analysis (b) and at-line SPE-CE (c). Peak identification is as follows I, ibuprofen N, naproxen K, ketoprofen P, flurbiprofen. Reprinted from Journal of Chromatography, 6 719, J. R. Veraait et al., At-line solid-phase exti action for capillary electrophoresis application to negatively charged solutes, pp. 199-208, copyright 1998, with permission from Elsevier Science. 

Figure 3.2(a) shows a plot of log S versus pH for naproxen, based on re-analysis (unpublished) of the shake-flask [49, 77] and microtiter plate [20] data reported in the literature. The dashed curves in Fig. 3.2 were calculated with the simple Henderson-Hasselbalch equations. For pH pKa, the function reduces to the horizontal line log S = log Sq. For pH pXi, log S is a straight line as a function of pH, exhibiting a slope of 1 (and an intercept of log So-pKj). Where the slope is 0.5, the pH equals to the pKj. 

The phase transformation relationships for the solvatomorphs of naproxen sodium have been reported [71], The dihydrate phase is obtained upon crystallization from water, and a monohydrate phase could be prepared by the dehydration of the dihydrate phase in a desiccator (RH = 0%) for two days. The anhydrate phase could be obtained from either the monohydrate or dihydrate by drying the substance in an oven at 120 °C for two hours. Thermal analysis data was used to demonstrate the existence of two types of water in the dihydrate phase, and that each could be removed at a characteristic temperature. 

E. Samara, D. Avnir, D. Ladkani, M. Bialer, Pharmacokinetic Analysis of Diethyl-carbonate Prodrugs of Ibuprofen and Naproxen , Biopharm. Drug Dispos. 1995, 16, 201-210. 

The intercalation of these species has been studied using time-resolved EDXRD. For intercalation into the LiAl - Cl system, a kinetic analysis of the data for naproxen (Nx), diclofenac (Df) and 4-biphenylacetic acid (4-Bpaa) suggests that the reactions are 2D diffusion controlled processes following instantaneous nucleation. In a number of cases, the importance of nucleation decreases at higher temperatures (T > 60 °C), with a corresponding reduction in the value of n from 1 to 0.5. This latter value corresponds to a situation where nucleation plays no part in controlling the reaction rate. The data in Fig. 22 relate to the intercalation of Nx. 

Analysis of non-steroidal anti-inflammatory drugs (ibuprofen, ketoprofen, naproxen, fenoprofen, flurbiproen, and suprofen) Impurity profiling of ketorolac, a chiral nonsteroidal antiinflammatory drug Impurity profiling of a non-steroidal analgesic drug... 

Analysis is carried out on tablets containing naproxen 100 mg and aspirin 250 mg per tablet. A narrow range calibration curve is constructed within 20% of the expected concentration of the diluted tablet extract. UV monitoring of the column effluent is carried out at 278 nm. Suggest a column and mobile phase for this analysis both aspirin and naproxen are discussed earlier in this chapter. Suggest a suitable column and mobile phase for this analysis. The following data were obtained for the analysis ... 

Despite the resolving power of TLC-MS-MS, few applications in drug residue analysis have been reported. One application concerns the HPTLC-MS-MS analysis of a number of nonsteroidal anti-inflammatory drugs, including salicylic acid and its glycine conjugate salicylhippuric acid, diclofenac, indomethacin, naproxen, phenacetin, and ibuprofen (67). Another application describes the detection and identification of some of these compounds or their metabolites in urine by TLC-MS-MS (67). 

Figure 1.18. Comparison of MRM chromatograms following HPLC-MS/MS and UPLC-MS/ MS analysis of a mixture containing alprazolam, ibuprofen, d5-alprazolam, diphenhydramine, naproxen, and prednisolone. Each set of chromatograms was obtained from a single 100-ng/ mL injection of rat plasma. d5-Alprazolam was used as the internal standard for quantification of alprazolam. (Reprinted with pemnission from Yu et al., 2006.)...

A typical procedure is a follows An esterification solution was prepared by dissolving 3.5 g(+)-menthol,0.12 g DCC, 3 mg 4-dimethylaminopyridine (4-DMAP), and 3 mg 4-DMAP-HCI in one mL dry CH2CI2. For the analysis of a product sample, about 0.05mg of the compound in about 10 microliter dichloromethane is mixed well with 10(0.1 esterification solution at ambient temperature for 30 minutes. The final solution was analyzed on a Varian 370 GC with a 25-meter Chirasil-L-Val column at 195°C isothermally. Excellent baseline separations of the diasteromers are usually obtained. A calibration with naproxen of known optical purity is carried out before using this method for analysis. 

A reversed-phase HPLC post-column ion-pair extraction system was developed by Kim and Stewart [71, 72] for the analysis of carboxylic acid drugs and their salts (sodium formate, sodium acetate, 3-bromopropionic acid, 6-aminocaproic acid, 11-bromoundecanoic acid, 1-heptanesulfonic acid, / -n i t rophcny 1 acetic acid, sodium benzoate, sodium salicylate, valproic acid, probenecid, naproxen, ketoprofen, ibuprofen, mefenamic acid, flufenamic acid, and cefuroxime sodium) using a-(3,4-dimethoxy-phenyl)-4,-trimethylammoniummethylcinnamonitrile methosulfate... 

Information on the effect of COX-2-selective inhibitors on arterial blood pressure is scanty. In VIGOR, more patients developed hypertension with rofecoxib than naproxen. For rofecoxib, the mean increase in blood pressure was 4.6/1.7 mmHg compared with a l.O/O.l mmHg increase with naproxen (34). Previous work has shown that a 2 mmHg reduction in diastolic blood pressure can result in about a 40% reduction in the rate of stroke and a 25% reduction in the rate of myocardial infarction (57). The effect of celecoxib on blood pressure was evaluated in a post hoc analysis... 

In an analysis of nine double-blind, controlled studies, adverse reactions to naproxen in older and in younger subjects had similar incidences (29). 

Huaang WE, Hsiao EY, Wen YW, Tsai YW. Cardiovascular events associated with the use of four nonselective NSAIDs (etodolac, nabumetone, ibuprofen, or naproxen) versus a cyclooxygenase-2 Inhibitor (celecoxib) a population-based analysis InTaiwanese adults. Clinical Therapeutics 2007 28 1827-1836. 

The effect of antacids on gastric emptying rate is a factor which makes difficult a direct physicochemical analysis of the problem. The difficulty in predicting the effect of antacids is clearly shown by studies with naproxen, a... 

Figure 33-1 5 Typical separation by MECC. (a) Some test compounds 1 = methanol, 2 = resorcinol, 3 = phenol, 4 = p-nitroaniline, 5 = nitrobenzene, 6 = toluene, 7 = 2-naphthol, 8 = Sudan III capillary, 50-p.m inside diameter, 500 mm to the detector applied voltage, ca. 15 kV detection UV absorption at 210 nm. (b) Analysis of a cold medicine 1 = acetaminophen, 2 = caffeine, 3 = sulpyrine, 4 = naproxen, 5 = guaiphenesin, 10 = noscapine, 11 = chloropheniramine and tipepidine applied voltage, 20 kV capillary, as in (a) detection UV absorption at 220 nm. (From S. Terabe, Trends Anal. Client., 1989,8, 129.)...

A conformational analysis of naproxen anion and monensin sodium has been performed by the use of the /hc couplings. Especially extensive use of these couplings has been made by the authors in the case of the latter compound. They concluded that the conformation of monoensin in solution is very close to that in crystals. Further examples of the application of vicinal proton-carbon couplings in the conformational analysis of compounds include the NMR and quantum-chemical study of the stereochemistry of spiroepoxides obtained by oxidation of (Z)-3-arylidene-l-thioflavan-4-ones performed by Toth et and the elucidation of the structure of isomalyngamides A and B isolated from a collection of the cyanobacterium Lyngbya majuscula from Hawaiian waters by Kan et... 

PAMPA-pKa fiux optimized design (pOD)-permeabiiity Iso-pH mapping unstirred PAMPA was used to measure the effective permeability, Pe, as a function of pH from 3 to 10, of five weak monoprotic acids (ibuprofen, naproxen, ketoprofen, salicylic acid, benzoic acid), an ampholyte (piroxicam), five monoprotic weak bases (imipramine, verapamil, propranolol, phenazopyridine, metoprolol), and a diprotic weak base (quinine). The intrinsic permeability, Po, the UWL permeability, Pu, and the apparent pKa (pKa.fiux) were determined from the pH dependence of log Pg. The underlying permeability-pH equations were derived for multiprotic weak acids, weak bases, and ampholytes. The average thickness of the UWL on each side of the membrane was estimated to be nearly 2000 p, somewhat larger than that found in Caco-2 permeability assays (unstirred). As the UWL thickness in the human intestine is believed to be about forty times smaller, it is critical to correct the in vitro permeability data for the effect of the UWL. Without such correction, the in vitro permeability coefficient of lipophilic molecules would be indicative only of the property of water. In single-pH PAMPA (e.g., pH 7.4), the uncertainty of the UWL contribution can be minimized if a specially selected pH (possibly different from 7.4) were used in the assay. From the analysis of the shapes of the log Pe-pH plots, a method to improve the selection of the assay pH, called pOD-PAMPA, was described and tested. From an optimally selected assay pH, it is possible to estimate Pg, as well as the entire membrane permeability-pH profile. 

Milsom 1, Minic M, Dawood MY, et al. Comparison of the efficacy and safety of nonprescription doses of naproxen and naproxen sodium with ibuprofen, acetaminophen, and placebo in the treatment of primary dysmenorrhea A pooled analysis of five studies. Clin Ther 2002 24 1384-1400. 

The application of MIPs as the stationary phase in solid-phase extraction (SPE), often referred to as molecularly imprinted polymer solid-phase extraction (MIS P E), is a rapidly growing area [197-199]. With MISPE, highly specific enrichment of substances present at trace levels is possible. The technique has been applied to the analysis of drugs, for example, caffeine [200], scopolamine [201], naproxen [202], tetracycline [203], cholesterol [204] and local anesthetics [205], as well as environmental pollutants, exemplified by organophosphate flame retardants [206-208], triazines in soil and vegetable samples [71] and naphthalene sulfonates in river water [209]. 

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