Formulation Of Atenolol Research Articles

Effects of 100 mg of Controlled‐Release Metoprolol and 100 mg of Atenolol on Blood Pressure, Central Nervous System‐Related Symptoms, and General Well Being

Central nervous system (CNS)-related symptoms and quality of life during treatment with controlled-release (CR) metoprolol and a standard formulation of atenolol were compared in a double-blind crossover study in 60 patients with mild to moderate hypertension. After a 4-week placebo run-in period, each beta 1-adrenoceptor blocker was administered at a dosage of 100 mg once daily for 6 weeks. Quality of life was assessed regularly during the active treatment phases by use of two standardized self-administered questionnaires, the minor symptom evaluation (MSE) profile, and the psychologic general well-being (PGWB) index. Both questionnaires have previously been shown to be effective in detecting CNS symptoms and changes in well being produced by beta-blockers. Blood pressure and heart rate were monitored to assess the antihypertensive efficacy of the two drugs. Metoprolol CR and atenolol produced equivalent, clinically effective reductions in systolic and diastolic blood pressures measured 24 hours after administration. The drugs were found to exert similar effects on general well being, as assessed by the PGWB index, and there were no significant differences between the two treatments with regard to the three dimensions of the MSE profile, contentment, vitality, and sleep. Thus, at equivalent antihypertensive dosages, metoprolol CR and atenolol are clinically comparable with regard to the degree of CNS-related symptoms produced and effects on general well being. Because these agents differ markedly in lipophilicity, other factors, such as beta 1-selectivity/nonselectivity, may be more important determinants of whether these subjective symptoms occur during therapy with beta-blockers.

A study of the pharmacokinetics and pharmacodynamics of nifedipine in combination with atenolol

This double-blind randomized, crossover study was undertaken to determine the pharmacokinetic properties of nifedipine retard and atenolol when given separately, as a free or a fixed combination, compared with placebo in 15 healthy male volunteers. There was no difference between the three atenolol formulations in time to maximum blood concentration or elimination half-life. The fixed combination showed significant differences in both maximum observed blood concentrations (+16 per cent) and total area under the curve (+16 per cent) compared to atenolol alone. Urinary recovery of unchanged drug from the fixed combination was also slightly increased but the difference was not statistically significant. Furthermore, statistical evaluation of the plasma pharmacokinetics of nifedipine retard and urinary recovery of nifedipine metabolite showed that all three formulations were indistinguishable. Thus, it is concluded that the fixed combination of nifedipine and atenolol is bioequivalent to the free combination and that the bioavailability of both drugs in the fixed combination is equivalent to that of the single entities.

Bioequivalence of two atenolol formulations in healthy volunteers. Evaluation by ergometric exercise, gas liquid chromatography and radioreceptor assay

Bioequivalence of two atenolol formulations in healthy volunteers. Evaluation by ergometric exercise, gas liquid chromatography and radioreceptor assay

Compatibility Study Between Atenolol and Tablet Excipients Using Differential Scanning Calorimetry

AbstractIn order to improve the formulation of atenolol the physico-chemical compatibility between the drug and various excipients, commonly used in tablet manufacturing, was studied with the aid of Differential Scanning Calorimetry (DSC).Using this method, it was found that atenolol is compatible with starch, Sta-Rx®, Primojel®, Avicel PH®, Ac-Di-Sol®, cross-linked PVP, magnesium stearate, calcium sulphate dihydrate, dicalcium phosphate and icing sugar. Interactions of atenolol with PVP, lactose and the lubricant stearic acid were found, although it cannot be conlusively stated that interaction incompatibilities will occur during storage at room temperature.

Oral Bioavailability of Atenolol

The bioavailability of two formulations of atenolol was compared in an open, randomized crossover study. Each film-coated tablet contained 100 mg of active drug. The plasma concentrations of atenolol were determined using a newly developed and specific high-performance liquid chromatography procedure. The areas under the concentration-time curves (AUC) were calculated, as were pair differences and ratios for individual AUC values and for maximum plasma levels. The latter were determined (Cmax.(m] and calculated (Cmax.(c] at the corresponding time values (tmax.) for test and reference formulations, and were then tested for statistical significance. The 95% confidence limits for both test and reference preparations, taken according to Westlake or Wilcoxon, were found to be 80.0-114.7% for AUC, 80.2-119.9% for Cmax. and 74.5-132.8% for tmax. In terms of pharmacokinetic target criteria, therefore, it can be seen that there were no substantial differences between the two film-coated tablets. The two atenolol preparations, therefore, may be classified as bioequivalent.