Kwan CC, Chu WH, Shimabayashi S. Effect of polyvinylpyrrolidone and sodium lauroyl isethionate on kaolinite suspension in an aqueous phase. Chem Pharm Bull (Tokyo). 2006 Aug;54(8):1082-7. doi: 10.1248/cpb.54.1082.

Abstract. Suspension of concentrated kaolinite (20 g/30 ml-medium) in the presence of polyvinylpyrrolidone (PVP) and sodium lauroyl isethionate (SLI) was allowed to evaluate its degree of dispersion based on their rheological studies. Flow curves at low shear rate, measured by means of cone-plate method, showed a non-Newtonian flow. Plastic viscosity and Bingham yield value were derived from the flow curves. Relative viscosity, effective volume fraction and void fraction of secondary particle were also obtained. Results of dispersity and fluidity of the suspension were explained. PVP acted as a flocculant at a concentration lower than 0.1% but as a dispersant at a higher concentration. The presence of SLI could decrease both the Bingham yield value and suspension viscosity. Cooperative and competitive effects of PVP and SLI were found. Results indicated that SLI enhanced the degree of dispersion of kaolinite when PVP was less than 0.1%. The suspension, however, showed a maximum flocculation (i.e., aggregation) at 4 mM SLI when the concentration of PVP was higher than 0.1%.

Gibson WT, Teall MR. Interactions of C12 surfactants with the skin: studies on enzyme release and percutaneous absorption in vitro. Food Chem Toxicol. 1983 Oct;21(5):581-6. doi: 10.1016/0278-6915(83)90144-8. 

Abstract. Using an in vitro penetration cell, it has been shown that enzymes (acid phosphatase, lactate dehydrogenase and N-acetylglucosaminidase) are released from rat-skin slices in response to contact with two irritant C12 surfactants, sodium laurate and sodium lauryl sulphate, but not with the non-irritant sodium lauroyl isethionate. About 3-5 hr contact of the stratum corneum with surfactant and a long incubation time (24 hr) were required for enzyme release. Adsorption and penetration of the two effective surfactants was also studied and the results for sodium lauryl sulphate suggested a relationship between enzyme release and adsorption of surfactant. However, no such simple relationship was observed for sodium laurate, emphasizing the complex nature of surfactant interactions with the skin.

Jeraal, M. I., Roberts, K. J., McRobbie, I., & Harbottle, D. (2018). Process-focused synthesis, crystallization, and physicochemical characterization of sodium lauroyl isethionate. ACS Sustainable Chemistry & Engineering, 6(2), 2667-2675.

Abstract. There is a notable lack of published data concerning sodium cocoyl isethionate despite widespread application in the personal care industry. A specific homologue, sodium lauroyl isethionate (SLI), was therefore synthesized, purified by recrystallization, and then subjected to a detailed physicochemical examination. A purity of 98% was achieved via repeat recrystallization in methanol. A turbidimetric solubility analysis was then executed to identify both its crystallizability and metastable zone width as a function of temperature. Thermogravimetric analysis yielded decomposition onsets of 330 °C for the purified SLI. A dynamic vapor sorption study also demonstrated reversibility in the 2.3% mass gained when it was exposed to sustained humidity of 87%. Surface tension measurements of purified SLI yielded a critical micellar concentration (CMC) of 5.4 mM and a plateau surface tension of 38 mN/m at 20 °C. Both values are lower than the previously reported values for SLI in water, thus indicating the performance benefits of purified isethionates in personal care formulations. The single step synthesis was chlorine-, catalyst-, and solvent-free, thus improving process efficiency, safety, and throughput over existing SLI syntheses. The succeeding physicochemical analysis crucially provides much needed insight into the purification, properties, and performance of isethionate ester surfactants, all of which are strongly applicable to their commercial manufacture from biorenewable sources.