Of -pseudoephedrine

Procedure. Prepare standard solutions of pseudoephedrine hydrochloride by weighing out accurately about 60 mg into a 500 mL graduated flask. Add about 50 mL 0.1M hydrochloric acid to dissolve the solid and then make up to the mark with 0.1 M hydrochloric acid. In a series of 50 mL graduated flasks place... 

A number of other types of chiral auxiliaries have been employed in enolate alkylation. Excellent results are obtained using amides of pseudoephedrine. Alkylation occurs anti to the a-oxybenzyl group.93 The reactions involve the Z-enolate and there is likely bridging between the two lithium cations, perhaps by di-(isopropyl)amine.94... 

Decongestants such as OTC pseudoephedrine are sympathomimetic agents that constrict capacitance vessels in the nasal turbinates.17 Decongestants effectively reduce nasal congestion and to some extent rhinorrhea associated with AR.8,12 The recommended dose of pseudoephedrine is 30 to 60 mg every 4 to 6 hours for a maximum daily dose of 240 mg.15 Systemic adverse effects such as irritability, dizziness, headache, tremor, tachycardia, and insomnia can occur. Additionally, use is associated with increased blood pressure and intraocular pressure and urinary obstruction.8,12... 

The infrared spectrum of pseudoephedrine hydrochloride is shown in Figure 1. It was obtained as a 0.2% dispersion of pseudoephedrine hydrochloride in KBr with a Nicolet Model 7199 FT-IR spectrophotometer.2 Table I gives the infrared assignments consistent with the structure of pseudoephedrine hydrochloride. 

The ultraviolet spectrum of pseudoephedrine hydrochloride in ethanol was obtained with a Beckman ACTA CIII ultraviolet spectrophotometer and is shown in Figure 3.4 Pseudoephedrine hydrochloride exhibits absorption maxima at 208, 251, 257, and 264 nm with extinction coefficients of 8300, 161, 201, and 161, respectively. 

The low resolution mass spectrum of pseudoephedrine hydrochloride is shown in Figure 4.5 It was obtained with a Varian MAT CH5-DF mass spectrometer. Direct probe at 80°C into the ion source was used to obtain the mass spectrum. 

Solubility of Pseudoephedrine Hydrochloride at 25°C Solvent Water Chloroform Ethanol Ether... 

The DSC curve of pseudoephedrine hydrochloride obtained with a Perkin Elmer DSC-1B differential scanning calorimeter is shown in Figure 5.7 The heating rate was 5°C/min. The heat of fusion is 6.4 Kcal/mol. The melting point (uncorrected) is 184°C. 

The crystal properties of pseudoephedrine hydrochloride were determined with a GE model XRD-6 x-ray diffractometer using Zr filtered MoK radiation on a crystal grown from water.8 Pseudoephedrine hydrochloride has an orthorhombic crystal system belonging to the P212121 space group. The cell dimensions are a=25.358 A, b=6.428 A, c=6.901 A with each cell containing four molecules. 

The major biotransformations of pseudoephedrine hydrochloride are parahydroxylation, N-demethylation, and oxidative deamination.14 The proposed pathways for the metabolism of pseudoephedrine are shown in Figure 6. 

In a study with human subjects, whose urine pH was controlled with sodium bicarbonate and ammonium chloride, it was found that 10-25% of the administered pseudoephedrine hydrochloride was metabolized to norpseudoephedrine and the elimination of pseudoephedrine and norpseudoephedrine was related to urine pH. As the urine pH increased, the serum half-life of pseudoephedrine and norpseudoephedrine increased.15 In another similar study it was found that a decrease... 

The results of the elemental analysis of pseudoephedrine hydrochloride are given in Table IV.6 The analysis was performed on a NF Reference Standard. 

Pseudoephedrine hydrochloride is dissolved in a mixture of glacial acetic acid and mercuric acetate test solution. A standardized solution of 0.1N perchloric acid is used to titrate the solution to a blue-green end point with crystal violet indicator. Each ml of 0.1N perchloric acid is equivalent to 0.1 mmole of pseudoephedrine hydrochloride.1... 

An ultraviolet spectrophotometric analysis is used to assay pseudoephedrine hydrochloride in tablets. A portion of finely powdered tablets equivalent to approximately 30 mg of pseudoephedrine hydrochloride is placed in a distilling flask which is part of a micro-steam distillation apparatus. Sodium chloride, water, and concentrated sodium hydroxide are added. A minimum of 30 ml of distillate is collected in a volumetric flask containing dilute hydrochloric acid. The flask is made to volume with distilled water and the absorbance of the solution is determined at 257 nm in 1 cm cells and compared to a solution of known concentration of NF Pseudoephedrine Hydrochloride Reference Standard.1... 

An ultraviolet spectrophotometric method based on the absorbance of a periodate oxidation product of pseudoephedrine hydrochloride will be the official method of analysis in the USP XX.19,20 A portion of tablets or syrup in water is placed in a separatory funnel. Sodium bicarbonate and sodium metaperiodate are added. After standing for 15 minutes, 1 N HC1 is added. The solution is extracted with hexane. The hexane extract is filtered and its absorbance determined at 242 nm in 1 cm cells. The amount of the oxidation product of pseudoephedrine hydrochloride is determined by comparison of the sample absorbance against the absorbance of a Pseudoephedrine Hydrochloride Reference Standard treated in the same manner. 

Paper chromatography has been used to separate and detect pseudoephedrine hydrochloride from other pharmacologically active amines. Whatman No. 1 paper developed in n-butanol water 95% acetic acid (4 5 1), n-butanol toluene water 95% acetic acid (10 10 5 5), ethyl acetate water 95% acetic acid (3 3 1), or chloroform water 95% acetic acid (10 5 4) gave Rf values of 0.73, 0.35, 0.57, and 0.52 for pseudoephedrine hydrochloride respectively. Visualization of pseudoephedrine hydrochloride was done by spraying the chromatogram with 0.5% bromcresol green in methanol or 0.2% nin-hydrin in acetic acid butanol 5 95.30... 

An on-column acetic anhydride derivatization technique has been described for pseudoephedrine hydrochloride. Immediately after injection of a solution of pseudoephedrine onto a 20% SE-30, 1.8 m x 7 mm i.d. glass column at 125°C, an injection of acetic anhydride was made. The pseudoephedrine derivative formed on column has a retention time of 55.5 minutes as compared to a retention time of 8.7 minutes for underivatized pseudoephedrine.34... 

The heptafluorobutyric anhydride derivative of pseudoephedrine and electron capture detector have been used to enhance the sensitivity of the gas chromatographic method. Lin and co-workers36 and Cummins and Fourier37 extracted basefied urine or serum with benzene. Heptafluorobutyric anhydride is added to the benzene extract. The heptafluoro-ibutyric anhydride derivative extracted was chromatographed... 

Explain how would you weigh gr iss of pseudoephedrine on a prescription balance with a sensitivity requirement of 6 mg and potential error of 2% or less. 

For the above problem if 5 g of a stock mixture containing 2 g of pseudoephedrine is provided, show how you would obtain the required quantity of pseudoephedrine. 

X = 244 mg aliquot of the stock mixture contains 97.5 mg of pseudoephedrine. Since the LWQ is 300 mg, dilute the stock mixture to twice its amount with lactose and weigh out 488 of the diluted stock mixture. 

Asymmetric Synthesis of a-Amino Acids by the Alkylation of Pseudoephedrine Glycinamide. Preparation of L-Allylglycine and N-Boc L-Allylglycine. 

Transformation of Pseudoephedrine Amides into Highly Enantiomerically Enriched Carboxylic Acids, Aldehydes, Alcohols, and Ketones. 

Methamphetamine is synthesized, or cooked, by a simple chemical reaction from its precursor pseudoephedrine (Figure 2.3), a stimulant commonly found in over-the-counter allergy and cold medications (such as Sudafed ). Because methamphetamine is made relatively easily from pseudoephedrine, many pharmacies and drug stores now restrict the amount of pseudoephedrine-containing medications that individual customers can buy to avoid the possibility of stockpiling pseudoephedrine for the purpose of making methamphetamine. Meth dealers and makers in the United States have also been... 

Commercial samples containing approximately 400 mg of ephedra per capsule yield roughly 5 mg of ephedrine, 1 mg of pseudoephedrine, and less than 1 mg of methylephedrine (White et al. 1997). For a dose of four capsules, yielding approximately 20 mg of ephedrine, the elimination half-life is 5.2 hours. The time to reach maxium concentration is 3.9 hours. Compared to pure ephedrine tablets, the elimination kinetics of ephedra are comparable. However, ephedra showed somewhat different absorption kinetics (e.g., lag time, area under the concentration-time curve, and maximum plasma concentration). So, ephedra tablets may vary from pure ephedrine in the onset of action, but the durations of action are grossly equivalent. 

Kaye and Fainstat 1987 Wooten et al. 1983). The risk of cerebral hemorrhage is even greater when combining ephedrine with other catecholamine stimulants such as the over-the-counter stimulant phenyl-propanolamine (StoessI et al. 1985). Pseudoephedrine may be safer than ephedrine in some respects (Porta et al. 1986). In a large sample (n > 100,000) of pseudoephedrine users, there were no reports of cerebrovascular disorders within 15 days after administration. The incidence of myocardial infarction, seizures, and neuropsychiatric disorders were no greater than base rates in the general population. 

Porta M, Jick H, Habakangas JA. (1986). Follow-up study of pseudoephedrine users. Ann Allergy. 57(5) 340-42. 

Tongjaroenbuangam W, Meksuriyen D, Govitrapong P, Kotchabhakdi N, Baldwin BA. (1998). Drug discrimination analysis of pseudoephedrine in rats. Pharmacol Biochem Behav. 59(2) 505-10. 

The large seizures of pseudoephedrine in Canada can be attributed to the enactment of necessary legislation in the country, which has enabled law enforcement authorities to take action against traffickers identified through tracking and backtracking... 

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