Determination of bile salt critical micellization concentration on the road to drug discovery

Spectroscopic investigation of interaction of Nile Blue A, a potent photosensitizer, with bile salts in aqueous medium

“…They are referred to as biosurfactants taking into account their capacity to solubilize and emulsify cholesterol, bilirubin, lecithin, lipids and fat soluble vitamins in living organisms [26][27][28][29][30][31]. Apart from their biological importance, bile salts also have got much recognition as delivery systems for medicines, cosmetics and several other chemicals and are also used as membrane penetration enhancers in drug formulations [31]. The structure of bile salt is very different from that of conventional surfactants.…”

“…Owing to the uniqueness of the aggregation patterns of bile salts, their micellization behavior has generated ample curiosity. Moreover the biocompatible and biodegradable nature of these makes them a very safe and efficacious vehicle for medical applications and because of which their interaction with drugs, model drugs and other biological macromolecules has been the subject of much interest [31].…”

Incorporating physiologically relevant mobile phases in micellar liquid chromatography for the prediction of human intestinal absorption

“…The mixed micellar system used in this method consisted of a mixture of six bile salts (NaDC, NaC, NaTDC, NaTC, NaGC and NaGDC) which included dihydroxy, trihydroxy, conjugated and unconjugated bile salts with lecithin phospholipid in 0.15 M NaCl with the pH controlled by HEPES buffer at 6.5. The CMC of the mixed micellar system was deemed to be 0.0046 M based on the average value of the CMCs of the bile salts included in the mixture in 0.15 M NaCl [NaTC CMC = 0.004 M (Natalini et al, 2014), NaDC CMC = 0.0024 M (Natalini et al, 2014), NaTDC CMC = 0.0024 M (Natalini et al, 2014), NaC CMC = 0.0075 M (Reis et al, 2004), NaGC CMC = 0.009 M (Natalini et al, 2014) and NaGDC CMC = 0.0022 M (Natalini et al, 2014)]. The bile salt–lecithin mixed micellar solution was used over a concentration range 0.005–0.017 M. The mixed micellar system was prepared in molar ratios similar to that present physiologically (Wiedmann et al, 2002).…”

Automated analysis of calorimetric demicellization titrations

“…Here, we show that a combination of both approaches provides an unbiased and reproducible data analysis strategy without the need for user input other than the calorimetric data proper. The approach is explained and exemplified using demicellization isotherms of the fluorinated surfactant F 6 OPC (3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluoro-n-octylphosphocholine) and the zwitterionic detergent CHAPSO (3-([3-cholamidopropyl]dimethylammonio)-2-hydroxy-1-propanesulfonate).…”

“…1 In aqueous solutions, surfactants form micelles when their concentration exceeds the CMC, which manifests as an abrupt change or discontinuity when various physical properties are plotted versus surfactant concentration [2]. Thus, the CMC can be experimentally determined using a variety of methods, including surface tension and conductivity measurements, dye binding experiments, and nuclear magnetic resonance spectroscopy [3]. However, isothermal titration calorimetry (ITC) is the method of choice [4] for the accurate and precise determination of CMC values because it is highly sensitive and noninvasive and offers superior resolution and reproducibility [5].…”