Effect of the wettability characteristics of polyethylene glycol derivatives on the drug release of wax matrices

The purpose of the present work was to study the relationship between the p hysicochemical characteristics of different polyethylene glycol aqueous sol utions and the kinetics of potassium chloride release from wax matrix sampl es containing polyethylene glycol derivatives. Potassium chloride was embed ded into thermosoftening matrix material to produce a sustained-release dos age form. Potassium chloride release was measured by the rotating paddle me thod of USP 23 and the dissolution process was characterized by a modified Nernst equation. Physicochemical characteristics - surface tension, dynamic contact angle, viscosity - of the polyethylene glycol aqueous solutions we re also determined. The results indicate that the adhesion tension of surfa ctant containing aqueous solutions has a decisive impact on the prediction of the potassium chloride release rate from wax matrices.