The performance of five reversed-phase columns which included a standard C18 phase, a polar embedded phase (amide group), a polyethyleneglycol phase, a cyano phase, and a perfluorinated phase, all coming from the same manufacturer, have been studied. They were systematically compared with a test mixture containing basic, neutral and acidic compounds of very different polarities, as well as diff...

Acetaminophen, phenylephrine and chlorpheniramine are frequently associated in pharmaceutical formulations against the common cold. Their quantification presents several problems. A HPLC method for the simultaneous determination of these compounds in pharmaceutical formulations such as capsules and sachets, including the separation of impurities and excipients has been developed and validated. ...

The appetite-suppressing effect of phenylpropanolamine (PPA) has been attributed to its inhibitory action on neuropeptide Y (NPY), an appetite stimulant. However, molecular mechanisms underlying this effect are not clear. This study aimed to investigate if cAMP response element binding protein (CREB) signaling was involved. Moreover, possible role of superoxide dismutase-2 (SOD-2) during PPA tr...

Neuropeptide Y (NPY) is an appetite-controlling neuromodulator that contributes to the appetite-suppressing effect of phenylpropanolamine (PPA). Aims of this study were to investigate whether protein kinase A (PKA) signaling is involved in regulating NPY gene expression and PPA-induced anorexia. Rats were given daily with PPA for 5 days. Changes in daily food intake and hypothalamic NPY, PKA, c...

CONTEXT Lifestyle changes to lose weight can be difficult; hence, both prescription and nonprescription diet products are appealing. Usage patterns of the nonprescription products phenylpropanolamine (PPA) and ephedra are of particular interest because of recent safety concerns. OBJECTIVE To estimate the prevalence of overall and specific nonprescription weight loss product use by demographic...

A new spectrophotometric method is developed for the determination of phenylpropanolamine HCl (PPA), ephedrine HCl (EPH) and pseudoephedrine HCl (PSE) in pharmaceutical preparations and spiked human urine. The method involved heat-catalyzed derivatization of the three drugs with 2,4-dinitrofluorobenzene (DNFB) producing a yellow colored product peaking at 370 nm for PPA and 380 nm for EPH and P...

The radiopharmaceutical, metaiodobenzylguanidine (MIBG) acts as an analog of norepinephrine (NE). Experiments in rats were carried out to determine how closely the movements of [125I]MIBG in the heart mimicked those of [3H]NE, and if the changes [125I] MIBG concentrations would reflect injury to, and function of, adrenergic neurons in the heart. Injury to adrenergic neurons by 6-hydroxydopamine...

For doping control, analyses of samples are generally achieved in two steps: a rapid screening and, in the case of a positive result, a confirmatory analysis. A two-step methodology based on ultra-high-pressure liquid chromatography coupled to a quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) was developed to screen and confirm 103 doping agents from various classes (e.g., beta-bloc...