Bioequivalence of exemestane in post-menopausal females.

The bioavailability of two exemestane tablet formulations was compared in 74 healthy post-menopausal females, aged 46 to 74 years, during a laboratory-blind, randomized, two-treatment, two-period, cross-over study under fed conditions. In each treatment phase subjects received a single dose (one tablet) of 25 mg exemestane (CAS 107868-30-4). Consecutive dosing was separated by a drug-free washout period of 21 d. Following each dosing, serial venous blood samples were collected over a period of 144 h for the determination of plasma exemestane concentrations by means of a validated LC-MS/MS method. The geometric mean Cmax of exemestane for the reference and test products was 21.48 and 20.14 ng/mL, respectively. The corresponding mean AUC(0-infinity) was 87.12 and 86.90 ng x h/mL. The median Tmax for both products under investigation appeared at 1.70 and 1.97 h, respectively. The test product was well tolerated and shown to be bioequivalent to the reference product with respect to all primary pharmacokinetic variables investigated.

Dose proportionality of once-daily trazodone extended-release caplets under fasting conditions.

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. Dose proportionality was assessed based on confidence intervals for logarithmically transformed, dose-normalized maximum plasma concentration (C(max)), area under the plasma concentration versus time data pairs (AUC(0-t)), and area under the curve from time 0 to infinity (AUC(0-∞)) in relation to the acceptance range of 80% to 125% (bioequivalence approach). The power method, combined with confidence interval criteria, was also used to assess proportionality. The conclusion of dose proportionality was generally supported using the bioequivalence approach. Based on the power model, values of the slope and corresponding 90% confidence interval for trazodone C(max), AUC(0-t), and AUC(0-∞) were 0.948 (0.899-0.997), 0.920 (0.875-0.964), and 0.913 (0.867-0.958), respectively. All were within the acceptance interval (0.861-1.139). Results for mCPP also fell within the acceptance interval. TzCOAD exhibits linear pharmacokinetics over doses ranging from 75 to 375 mg and maintains its controlled-release properties when the caplets are bisected along the score line.

Bioequivalence evaluation of rilmenidine in healthy volunteers.

The bioavailability of two rilmenidine tablet formulations was compared in healthy male (17) and female (8) subjects, aged 18 to 36 years, during a laboratory-blind, randomized, two-treatment, two-period, cross-over study under fasting conditions. In each treatment phase subjects received a single dose of 1.544 mg rilmenidine dihydrogen phosphate (CAS 85409-38-7), equivalent to 1 mg rilmenidine (CAS 54187-04-1). Consecutive dosing was separated by a drug-free wash-out period of 7 d. Following each dosing, serial venous blood samples were collected over a period of 48 h for the determination of plasma rilmenidine concentrations by means of a validated LCMS/MS method. The most frequently reported drug-related adverse events were dizziness and headache ranging from mild to moderate in intensity. The geometric mean C(max) of rilmenidine for the reference and test products was 3.73 and 3.97 ng/ml, respectively. The corresponding geometric mean AUC(0-infinity)) was 34.0 and 35.1 ng x h/ml. T(max) for both products under investigation appeared at 1.33 h. The test product was shown to be bioequivalent to the reference product with respect to all pharmacokinetic variables investigated.

Pharmacokinetics of pipamperone from three different tablet formulations.

Twenty-four (24) Caucasian male subjects completed a single-blind, randomised, three-treatment, three-period, cross-over study. In each treatment phase, subjects received a single dose of 144 mg pipamperone dihydrochloride (CAS 2448-68-2) (equivalent to 120 mg pipamperone; CAS 1893-33-0) as either the reference product (3 x 40 mg tablets), test product A (3 x 40 mg tablets) or test product B (1 x 120 mg tablet). Each consecutive dosing was separated by a washout period of 14 days. Following each dosing, venous blood samples were collected over a period of 120 h for the determination of plasma pipamperone concentrations by high-performance liquid chromatography. The most common drug related adverse events, ranging from mild to moderate in intensity, were bloodshot eyes, nasal congestion, dry mouth, hypotension and dizziness. The geometric mean Cmax of pipamperone for both the reference product and test product A was 266 ng/ml and for test product B 263 ng/ml. The geometric mean AUC0-infinity was 3107 ng.h/ml for the reference product, 3229 ng.h/ml for test product A and 3108 ng.h/ml for test product B. The two test products were shown to be bioequivalent to the reference product with respect to all pharmacokinetic variables investigated.