Differential scanning calorimetry to study the possible ternary complex formation between chlorhexidine,...

The effect of chlorhexidine and its molecular complexes with some nonionic tenzides (Tween and Myrj series) on the phase transfer parameters of dipalmitoylphosphatidylcholine has been studied by differential scanning calorimetry. The application of principal component analysis facilitated the evaluation of the experimental data matrix. It was found that both the lipophilicity of the tenzide and the strength of interaction between chlorhexidine and nonionic tenzide had a considerable impact on some of the phase transition parameters of dipalmitoylphosphatidylcholine. These findings indicate the possible existence of ternary complexes. This ternary complex formation may cause a decrease of chlorhexidine activity in the presence of nonionic tenzides.