DETERMINATION OF THE TONICITY OF LOCAL ANESTHETIC SOLUTIONS

¹ Research Laboratory of the College of Dentistry, Ohio State University, Columbus, Ohio

There was no tendency toward hypertonicity in any of the solutions used in this work.

Anesthetic 6 gave the poorest results. It was at its best, from the standpoint of hemolysis, when used immediately after storage for several weeks at 38°C. From this fact we conclude that the salts necessary to bring this solution to an isotonic state were dissolved more completely and uniformly after long periods of storage at body temperature (38°C.). The above results indicate that the common belief, that anesthetic solutions may be kept most satisfactorily at lower temperatures, does not apply to Anesthetic 6. This striking difference was not noted for any of the other anesthetic solutions.

The shaking of a tube of Anesthetic 6, after raising it more rapidly to 38°C. before using, apparently had no beneficial results.

Anesthetic 3 consistently gave a reduction, accompanied by a brown discoloration, making comparison with the color standard impossible.