Sedatives physicochemical properties

The PIT (with water and a given oil phase, i.e., hexadecane) was first correlated with the cloud point, i.e., the temperature at which a surfactant phase separates from u low concentration, c.g., 3%. surfactant solution (48). It is worth noting that the cloud point indicates a property of the surfactant, somehow the HLB. while the PIT takes into account the interaction with both the aqueous and oil phase. Early experimental evidence indicated that the PIT increased as the nonionic surfactant polyethylene chain length increased, increased as the hydrocarbon oil chain length increa.sed, and decreased as the salt concentration increased in the aqucou.s phase. Since the PIT is actually the physicochemical situation in which Winsor = I, and since an increase in temperature tends to reduce the Aiw interaction, the interpretation of the previously mentioned trends is siraighiforward when the numerator and denominator of Winsor R are equated. 

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