Alam Md Sayem, Ghosh Goutam
Department of Chemistry, Aligarh Muslim University, Aligarh-202 002, India.
J Phys Chem B. 2008 Oct 16;112(41):12962-7. doi: 10.1021/jp804238k. Epub 2008 Sep 20.
Two amphiphilic drugs, promethazine hydrochloride (PMT) and imipramine hydrochloride (IMP), have been studied using both static and dynamic light scattering techniques. Due to having rigid tricyclic hydrophobic moieties in their molecules, these drugs show interesting association behavior. The static light scattering (SLS) measurements show that the self-association commenced above a well-defined critical micellar concentration ( cmc), which decreases with increasing NaBr concentration. The Gibbs energy of micellization, DeltaG(0)M, in all cases, is negative. The colloidal stability of the system in terms of the interparticle interaction at different NaBr concentrations was studied using the dynamic light scattering (DLS) technique. The experimentally evaluated interparticle interaction parameter ( k D ) was compared with the Derjaguin-Landau-Verwey-Overbeek (DLVO) model. Interestingly, these two drugs with similar molecular structure show difference in their interparticle interactions, e.g., PMT showed complete agreement with the DLVO model whereas IMP showed clear deviation from this model at lower concentrations and agreement at higher concentrations of NaBr.
利用静态和动态光散射技术对两种两亲性药物盐酸异丙嗪（PMT）和盐酸丙咪嗪（IMP）进行了研究。由于其分子中具有刚性的三环疏水部分，这些药物表现出有趣的缔合行为。静态光散射（SLS）测量表明，自缔合在明确的临界胶束浓度（cmc）以上开始，该浓度随溴化钠浓度的增加而降低。在所有情况下，胶束化的吉布斯自由能ΔG(0)M均为负值。使用动态光散射（DLS）技术研究了在不同溴化钠浓度下系统在颗粒间相互作用方面的胶体稳定性。将实验评估的颗粒间相互作用参数（k D）与德亚金-朗道-韦弗-奥弗贝克（DLVO）模型进行了比较。有趣的是，这两种分子结构相似的药物在颗粒间相互作用方面存在差异，例如，PMT与DLVO模型完全吻合，而IMP在较低溴化钠浓度下与该模型有明显偏差，在较高浓度下则吻合。
