Postmarketing pharmacokinetic and pharmacodynamic equivalence of generic and brand atenolol in Egypt

Concerns have been raised regarding the postmarketing quality of generic drugs. This study assessed the pharmacokinetic and pharmacodynamic equivalence of generic and brand atenolol tablets in 24 healthy male volunteers in a single-dose, open, randomized, two-period crossover study under fasting conditions. Blood samples were collected for 24 h post dosing and assayed for atenolol using HPLC. Blood pressure and heart rate were measured at baseline and throughout blood sampling. The mean plasma concentration-time curves for both products were similar. Pharmacokinetic and statistical analysis indicated bioequivalence based on the mean ratios of log-transformed Cmax and AUC values. Both products had similar time courses of pharmacodynamic activity with a significant fall in blood pressure and heart rate (maximum after ~5 h) followed by a gradual increase towards baseline. Both products were well tolerated. Both atenolol products were bioequivalent in the postmarketing setting and can be used interchangeably in clinical practice.

Solubilization of water by hydrotropic salts

The effect of some electrolytes, nonelectrolytes, surfactants, and hydrotropic salts on the solubility of water in 1-butanol and 1-hexanol was investigated. While sodium chloride and sodium acetate decrease the solubility of water in 1-butanol, urea has no significant effect. The ionic surfactants, sodium lauryl sulfate and cetrimide, cause an initial decrease in the solubility of water in 1-butanol followed by an increase at high surfactant concentrations. The nonionic surfactant, polysorbate 20, does not show the initial decrease in water solubility. On the other hand, the hydrotropic salts, sodium benzoate, sodium salicylate, and sodium gentisate, are shown to be the best water solubilizers in 1-butanol. Sodium salicylate showed the maximum solubilizing power. The effect of sodium benzoate, sodium salicylate, and sodium lauryl sulfate on the solubility of water in 1-hexanol was also investigated. Similar results were obtained.