Methylphenidate Multiphasic Release Tablet: Bioequivalence Assessment between Two Formulations Administered under Fasting and Fed Conditions.

Methylphenidate hydrochloride is used to treat children, adolescents, and adults with attention deficit/hyperactivity disorder (ADHD). Multiphasic release formulation has been used to control drug levels, mainly during children's school period. This study aimed to evaluate the bioequivalence between two methylphenidate hydrochloride extended-release tablets to meet regulatory requirements for registration in Brazil.

Development and validation of an LC-ESI-MS/MS method for the simultaneous quantification of naproxen and sumatriptan in human plasma: application to a pharmacokinetic study.

A sensitive and fast liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) method was developed and validated for the simultaneous quantification of naproxen and sumatriptan in human plasma. A simple liquid-liquid extraction procedure, with a mixture of ethyl acetate, methyl tert-butyl ether, and dichloromethane (4:3:3, v/v), was used for the cleanup of plasma. Naratriptan and aceclofenac were employed as internal standards.

Determination of 3-α-hydroxytibolone in human plasma by LC-MS/MS: application for a pharmacokinetic study after administration of a tibolone formulation.

A new method was developed for the quantitation of 3-α-hydroxy tibolone, in human plasma, after oral administration of a tablet formulation containing tibolone (2.5 mg). 3-α-Hydroxy tibolone was extracted by a liquid-liquid procedure, using cyproterone acetate as internal standard and chlorobutane as extraction solvent.

A rapid and sensitive HPLC-APCI-MS/MS method determination of fluticasone in human plasma: application for a bioequivalency study in nasal spray formulations.

A sensitive method for the determination of fluticasone in plasma was developed using high performance liquid chromatography with tandem mass spectrometric detection, whereas beclomethasone was used as internal standard. The analytes were extracted with a simple liquid-liquid extraction from the plasma samples and separated on an ACE C(18) 50 × 4.6 mm i.

Quantitation of glucosamine sulfate in plasma by HPLC-MS/MS after administration of powder for oral solution formulation.

A rapid method for the quantification of glucosamine in human plasma using high-performance liquid chromatography coupled to tandem mass spectrometry was developed and validated. The sample preparation includes a simple deproteinization step, using D-[1-¹³C] glucosamine hydrochloride as an internal standard. Chromatographic separation was performed on an ACE Ciano column using isocratic elution with acetonitrile and aqueous 2 mM ammonium acetate containing 0.

Development and validation of a high-performance liquid chromatography-electrospray ionization-MS/MS method for the simultaneous quantitation of levodopa and carbidopa in human plasma.

A sensitive and fast high-performance liquid chromatography-electrospray ionization-MS/MS method for the simultaneous quantitation of levodopa and carbidopa in human plasma was developed and validated. A simple protein precipitation step with perchloric acid was used for the cleanup of plasma, and methyldopa was added as an internal standard. The analyses were carried out using an ACE C(18) column (50 × 4.

Simultaneous quantitation of levodopa and 3-O-methyldopa in human plasma by HPLC-ESI-MS/MS: application for a pharmacokinetic study with a levodopa/benserazide formulation.

A sensitive and simple method was developed for the quantitation of levodopa and its metabolite 3-O-methyldopa, in human plasma, after oral administration of tablet formulations containing levodopa (200 mg) and benserazide (50 mg). The analytes were extracted by a protein precipitation procedure, using carbidopa as an internal standard. A mobile phase consisting of 0.

Determination of triamcinolone in human plasma by a sensitive HPLC-ESI-MS/MS method: application for a pharmacokinetic study using nasal spray formulation.

A liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) method for the quantitation of triamcinolone in human plasma after nasal spray application was developed and validated. Betamethasone was used as internal standard (IS). The analytes were extracted by a liquid-liquid procedure and separated on a Zorbax Eclipse XDB C(18) column with a mobile phase composed of 2 mM aqueous ammonium acetate pH 3.