Characterization of Oleic Acid and Propranolol Oleate Mesomorphism using 13C Solid‐State Nuclear Magnetic Resonance Spectroscopy (SSNMR)

Thermotropic phase behavior of triple-chained catanionic surfactants with varying headgroup chemistry

“…Besides the lyotropic behavior, catanionics also display fairly interesting thermotropic behavior, exhibiting a stepwise melting from the solid crystalline to the liquid phase [8,[23][24][25]. The formation of thermotropic liquid crystalline (lc) phases by certain classes of amphiphiles has been known and studied for some time, in particular for lipids [26][27][28][29][30][31][32][33][34] and metallic soaps [35,36]. Both the lyotropic and thermotropic behavior of amphiphiles are directly connected to molecular chemistry and geometric shape [31,37,38].…”

Solid-State Characterization of Amorphous and Mesomorphous Calcium Ketoprofen

“…However, this analytical technique could not differentiate between the mesomorphous and amorphous phases of CaKTN as these two phases showed almost identical spectra. The absence of changes in the chemical shifts in the spectra suggests that the changes in the nuclear environment of the major chemical groups of the salt were minimal 12…”

“…However, SSNMR has not been widely used to investigate liquid crystalline pharmaceuticals. Crowley et al,12 for example, studied the mesomorphous phases of oleic acid and propranolol oleate and showed that SSNMR was a powerful technique to characterize the phase properties of these two lipids and concluded that α‐oleic acid and propranolol oleate forms I and II were conformationally disordered crystalline phases (condis). Chemical shifts and peak broadening in SSNMR spectra were also used by Vadas et al13 along with other techniques to characterize the mesomorphic transition of L‐660,711, a leukotriene D4 receptor antagonist.…”

Thermotropic behavior of asymmetric chain length catanionic surfactants: The influence of the polar head group

“…Their rich thermotropic mesomorphism is thus comparable to that of other amphiphilic mesogens such as, inter alia, lipids [23][24][25][26][27][28][29][30][31][32][33] and metal soaps [34,35]. For the compounds studied in this work, there is a general tendency for the fusion process to follow this order: crystalline solid-soft crystal-SmB-SmA-liquid.…”