Search results for "Phenylpropanolamine"
showing 10 items of 10 documents
Capillary electrophoretic and extraction conditions for the analysis of Catha edulis FORKS active principles
2013
A capillary electrophoretic method, which allowed the detection and separation of the active principles of Catha edulis, i.e. cathinone, cathine and phenylpropanolamine, was developed. A suitable internal standard (nicotinamide), which permitted the quantification of the analytes reducing the variability of the migration times due to EOF changes, was identified. The analytical method was validated, assessing linearity, sensitivity and repeatability, showing optimal features for the analysis of the vegetable material. Moreover extraction conditions were investigated to achieve the exhaustion of the plant material in the fastest and most efficient way to meet the requirements of the Court.
Application of solid-phase microextraction combined with derivatization to the enantiomeric determination of amphetamines.
2005
Abstract The utility of combining chiral derivatization and solid-phase microextraction (SPME) for the enantiomeric analysis of primary amphetamines by liquid chromatography has been investigated. Different derivatization/extraction strategies have been evaluated and compared using the chiral reagent o -phthaldialdehyde (OPA)– N -acetyl- l -cysteine (NAC) and fibres with a Carbowax-templated resin coating. Amphetamine, norephedrine and 3,4-methylenedioxyamphetamine (MDA) were used as model compounds. On the basis of the results obtained, a new method is presented based on the derivatization of the analytes in solution followed by SPME of the OPA–NAC derivatives formed. The proposed conditio…
Comparison of the performance of butanol and pentanol as modifiers in the micellar chromatographic determination of some phenethylamines
2000
Abstract A procedure was developed for the determination of several phenethylamines (amphetamine, arterenol, ephedrine, phenylephrine, phenylpropanolamine, mephentermine, methoxyphenamine, pseudoephedrine and tyramine), using micellar mobile phases of sodium dodecyl sulfate (SDS), a C18 column and UV detection. The drugs were eluted at short retention times with conventional acetonitrile–water or methanol–water mobile phases. In contrast, in the micellar system, they were strongly retained due to association with the surfactant adsorbed on the stationary phase, and needed the addition of butanol or pentanol to be eluted from the column. These modifiers allowed a simple way of controlling th…
Use of the Apparent Content Curves for the spectrophotometric identification of substances: identification of amphetamines
1994
The possibility of identification of substances which have similar spectral behaviour by means of Apparent Content Curves has been studied. This study is carried out with absorption, excitation and emission spectra of several amphetamines of widespread pharmaceutical use. Results obtained show that amphetamine, phenylpropanolamine, pseudoephedrine, phenylephrine, epinephrine, dopamine and methoxyamphetamine can be identified with a probability of >95%.
Detection of banned drugs in sport by micellar liquid chromatography
1992
Abstract A rapid method for the determination of banned drugs in sport (including stimulants, anabolic steroids and diuretics) based on micellar liquid chromatography is proposed. The mobile phase is an aqueous solution of a surfactant (sodium dodecyl sulphate in this instance) and the stationary phase is octadecylsilica. The retention parameters of the drugs were established and the effect of a mobile phase organic modifier on the chromatographic behaviour of the compounds was studied. Improvements in efficiency were achieved by control of the temperature of the mobile phase. This method allows the direct injection of urine samples for the determination of drugs excreted free in urine: ami…
Enantiomeric separation of amphetamine and related compounds by liquid chromatography using precolumn derivatization witho-phthaldialdehyde
2002
The utility of the derivatization reagento-phthaldialdehyde (OPA) in combination with the chiral thiol N-acetyl-L-cysteine (NAC) for the enantioselective analysis of primary amphetamines and structurally related substances has been investigated. The diastereomers obtained have been chromatographed on an achiral, reversed phase C18 column (125 mm×4 mm i.d., 5 μm), and detected fluorimetrically. The influence of parameters affecting the chromatographic separation as well as the derivatization reaction has been optimized, using amphetamine, norephedrine, norepinephrine and 3,4-methylenedioxyamphetamine (MDA) as model compounds. On the basis of the results obtained, possible conditions for the …
Stabilization of a nutraceutical omega-3 fatty acid by encapsulation in ultrathin electrosprayed zein prolamine.
2010
Docosahexaenoic acid (DHA) is a long chain polyunsaturated fatty acid of the omega-3 series (omega-3), which exerts strong positive influences on human health. The target of this study was the stabilization by encapsulation of this bioactive ingredient in zein ultrathin capsules produced by electrospraying. The zein ultrathin DHA encapsulation was observed by ATR-FTIR spectroscopy to be more efficient against degradation under both ambient conditions and in a confined space (so-called headspace experiment). In the latter case, that more closely simulates a sealed food packaging situation, the bioactive DHA was considerably more stable. By fitting the degradation data to a specific auto-deco…
A Comparison of the Efficacy and Tolerability of Solifenacin Succinate and Extended Release Tolterodine at Treating Overactive Bladder Syndrome: Resu…
2005
Abstract Objective: To compare two new generation antimuscarinics at their recommended doses for treatment of overactive bladder syndrome (OAB). Methods: A prospective, double blind, double-dummy, two-arm, parallel-group, 12-week study was conducted to compare the efficacy and safety of solifenacin 5 or 10mg and tolterodine extended release (ER) 4mg once daily in OAB patients. After 4 weeks of treatment patients had the option to request a dose increase but were dummied throughout as approved product labelling only allowed an increase for those on solifenacin. Results: Solifenacin, with a flexible dosing regimen, showed greater efficacy to tolterodine in decreasing urgency episodes, inconti…
Determination of active ingredients in cough-cold preparations by micellar liquid chromatography.
2000
The chromatographic behaviour of some active ingredients in cough-cold pharmaceutical preparations, the antihistamine chlorpheniramine (or the dextro enantiomer dexchlorpheniramine), and the phenethylamines phenylephrine, phenylpropanolamine and pseudoephedrine, has been studied using a C(18) column, micellar mobile phases of sodium dodecyl sulphate (SDS) and pentanol, and with UV detection. All possible combinations of chlorpheniramine/phenethylamine were resolved and determined using a mobile phase of 0.15 M SDS-6% (v/v) pentanol at pH 7, with analysis time below 7 min. Repeatabilities and within laboratory precisions were evaluated at four different drug concentrations in the range 0.5-2…
New strategies for medical management of overactive bladder in children.
2011
Purpose of review The medical treatment of children with non-neurogenic overactive bladder syndrome (OAB) is still limited to a small number of drugs approved for use in childhood according to the national regulations of each country. Recent findings Over the last few years, there were several studies on the use of antimuscarinics other than oxybutynin in children, as well as some on the use of extended release oxybutynin and tolterodine and transdermal oxybutynin. It was shown that the combination of two different anticholinergics might be a well tolerated and successful option in children with OAB refractory to monotherapy, as well as administration of a receptor-selective antimuscarinic …