โ Scribed by Hiromu Satake; Hitoshi Matsuki; Shoji Kaneshina
No coin nor oath required. For personal study only.
The present study includes the colloidal solution properties of a local anesthetic, tetracaine hydrochloride (C15H,,N20,.HCI).
The CMC of C,,H,,N,O,,HCI was determined using a coated wire electrode that is selectively sensitive to a local anesthetic cation. The effects of added salt (NaCI) and temperature on the CMC were studied. A linear relationship between the logarithm of the CMC and the counterion concentration was confirmed at 25ยฐC. The CMC in the absence of added NaCl tends to increase as the temperature rises in the range IS-35ยฐC. The enthalpy change on micellization was estimated to be -3.7 kJ mol-' from the temperature dependence of the CMC. The Krafft phenomenon was observed from heating scans obtained by differential scanning calorimetry. The transition enthalpy from the hydrated solid to the micellar solution was 29.4 kJ mol-r.
Another transition associated with an enthalpy change of 1.7 kJ mol-' was observed just below the Krafft temperature, which was assigned to the transition between lyotropic liquid crystals.
๐ SIMILAR VOLUMES
Isonipecaine, an isonipecotic acid derivative (l-methyl-4-phenylpiperidine-4-carboxylic acid ethyl ester hydrochloride), was found to possess considerable local anesthetic properties. I n the discussion of the results, the structural relationships of isonipecaine are compared with those of atropine,
Silver from an aqueous solution of Ag' ions can be conveniently photodeposited on colloidal anthracene particles using sunlight. This method is advantageous when compared with photoextraction of silver with TiO,, and anthracene can be readily evaporated to obtain pure silver. The sensitivity of anth