Transdermal delivery of phénobarbital Preformulation studies

The aim of this paper was to develop a phénobarbital solution suitable for transdermal administration, and preformulation studies were carried out in order to obtain the solution with the desired phenobarbital content. The preconditions necessary for the permeation processes through the skin and the lipophilicity of the active molecule were investigated and characterized quantitatively with its octanol/water partition coefficient. It was determined how the apparent partition coefficient values changed (logPapp) in the function of changing the pH of the solvents. The amount of phenobarbital estimated for the successful treatment of grand mal epilepsy by the solution was ensured by using solvents of polar and semipolar character. An order based on the ability of the used solvents and cosolvents to increase the solubility of phenobarbital was established.