of the agents; i. c., their rclativc ability to compress, their tendency to produce more or less “fines” per granulation, their relative hardness caused by the binding agent, and the type of granulation formed. Therefore, to obtain results of a comparative naturc, the disintegration times were extrapolated from individual hardnesses to a hardness of 7 Kg. by the rncthod previously discussed. The effect of aging the tablcts brought forth some data that influcnce the choice‘of disintegrating agent. The action of aging of tablets a t room temperature resulted in no appreciable effect over a period of 500 hours. Pectin was the only agent that IVAS in any way affected. IIardness may develop on storage of tablets in which gums such as acacia, pectin, etc., arc used for granulating or disintegrating (9). No other changes in hardness, color, odor, or disintcgration time wcre notcd. The exposure of the prepared tablcts to 4” for 500 hours showed that cold had no bad effect on disintegrating time or hardness. It will be noted that a slight decrease in disintcgration time resulted. No effect on color or appearance of the tablets was noted. The cold a.ging of tablets having odors seems to be indicated industrially. In these tests, tablets which had an odor on manufacture wcrc leached of that odor by subjection to 4’ for 500 hours in sealed containers. Heat aging, 45” for 500 hours, had a marked and deleterious effect. Color, odor, hardness, and disintegration time were affected. With rriany agents the color changed from white to brown duc to the rcaction of the ingredients with heat probably cansing decomposition, oxidation, and caramelization. Offcnsive odors developed in many of the tablets that changed color, and also in inany in which no color change was noted. A greater percentage of the allected agents were those that that were exposed to heat aging. In many cases the hardness of the tablets doubled. This is probably due to fusing of materials, cementation, hardening of the binder. loss of moisture and volatile
substances, and chemical dccorriposition of the disintegrating agent and other ingredients of the tablet, Since hardness is a primary variable factor of disintegration time, thc time rate of disintegration of the tablets was greatly affected by the heat aging. The time of disintegration increased.
4 Comparative study of 22 tablet disintegrating agents was carried out. New, as well as commonly used, agents were tested, and favorable results were shown by two of these new agents. Dried citrus pulp and powdrred dried sponge compare favorably as tablet dkintegrants with t h e best agents in use by pharmaceutical manufacturers. T h e effect of aging tests established a new critcria by which tablet disintegrators must be selected. Aging at room, elevated, and reduced temperatures for a mcasured time interval indicated t h a t tablets are markedly affected by heat. Cold had little effect on tablets. Aging at room temperature showed effect only with a certain type of agent which forms a harder tablet over a period of time. REFERENCES ( 1 ) Cook, 5. F,.; and La Wall, C . H., “Remington’s Practice of Pharmacy 8th ed., J. B. Lippincott Co., Philadelphia, 1936, p. 171’4. (2) Berry H. Pharm. J . 143 174(1939). (3) Hoyle, H.:Quarl. 1.P’haum! Phavmacol., 19,279(1916). (4) Berry, H . , ibid., 12, 5Ul(l939). ( 3 ) Beringer. G;“., A m . J. Phavm., 80, 387(1909). (6) Schroff E. Die Herstellung der Tahletten,” Sunderdruch a m Pharmdzeutische Zeitung, Nr. 35 and 36, 1033. (7) Sager, H., Phavm. Acta Helu., 24, 334(1949). ‘(8) Benton, B. E., and Granberg, C. B., Am. J . Phaum. 121 648(1940). i9) Husa U‘. J. Drug Mavkels, 20 317(1927). (10) Husa: W. J . , ’ A m .J. Phurm., 17: 38(1928).
Teachers’ Seminar on Pharmaceutical Chemistry Announced The Teachers’ Seminar on Pharmaceutical Chemistry will be held in Ann Arbor, Mich., July 7-12, 1%52. The College of Pharmacy of the Cniversity of Michigan was selected t o be the host institution by the Executive Committee of the American Association of Colleges of Pharmacy. This Seminar will be the fourth t o he sponsored by the A. A4.C. P. T h e funds for t h e previous seminars and for this one arc provided by the American Foundation for Pharmaceutical Education. Dr. Toni D. Rowe, chairman of the committee for planning the Seminar, has announced that preIiminary plans have hecn made for the program, which will include all branches of pharmaceutical chemistry. It is expected t h a t teachers from most of the Colleges of Pharmacy will be in attendance. The emphasis throughout the program will be on teaching methods, course contents, and new developments. Arrangements have hecn made t o provide accommodatiohs for those attending in one of t h e new dormitories at the University of Michigan.