Publications by authors named "D Karhu"

Objective: To characterize the pharmacokinetics, safety, and tolerability of an extended-release formulation of trazodone hydrochloride (HCl), Trazodone Contramid® Once-a-Day (TzCOAD) developed as scored 150-mg and 300-mg caplets for oncedaily administration.

Methods: Relative bioavailability studies compared the pharmacokinetics of TzCOAD and trazodone immediate-release (TzIR) tablets following single- and multiple-dose administration. In addition, the effect of food on the pharmacokinetics of TzCOAD was assessed.

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An extended-release trazodone HCl formulation, Trazodone Contramid OAD (TzCOAD), was developed as scored 150-mg and 300-mg caplets for once-daily administration. Dose proportionality of intact and bisected caplets (dose range, 75-375 mg) was evaluated in a single-dose, randomized, 5-way crossover study. Plasma trazodone and m-chlorophenylpiperazine (mCPP) levels were determined using a validated liquid chromatography-tandem mass spectroscopy method.

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An open-label, randomized, 2-way crossover study was conducted to compare the pharmacokinetics of Tramadol Contramid OAD 200 mg tablets and Monocrixo L.P. 200 mg capsules following single-dose administration under fasting conditions in 30 healthy adult volunteers.

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The pharmacokinetics of a once-daily formulation of tramadol (Tramadol Contramid OAD 200-mg tablets) following single-dose and multiple-dose administration was compared with that of an immediate-release product (tramadol IR 50-mg tablets) in 2 separate studies. In both studies, AUC parameters met bioequivalence criteria, whereas C(max) of Tramadol Contramid OAD was lower than that of tramadol IR following a 200-mg daily dosage. After single-dose administration, the mean tramadol concentration at 1 hour postdose was within the range associated with analgesic efficacy (>100 ng/mL), and the mean concentration remained above this level for the remainder of the dosing interval.

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A three-way crossover study in 27 human volunteers was conducted to characterize the pharmacokinetics and to assess the dose proportionality of 100 mg, 200 mg and 300 mg strengths of a novel once-a-day tramadol controlled-release tablet (Tramadol Contramid OAD) following single-dose administration. Serial blood samples were collected at predefined timepoints over a 48 h period and racemic tramadol and O-desmethyltramadol concentrations in plasma were determined using a validated LC-MS/MS method. Pharmacokinetic parameters were derived using noncompartmental methods.

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