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A Note on Tablet Disintegration with Starch*
16
JOURNAL OF
AMERICANPHARMACEUTICAL ASSOCIATION
Vol. XLIV, No. 1
CHART H
GROWTH CURVES OF 1953 COOPERATIVE A. Ph. A TEST MICE CONTROL
LARI
LAB.2.
LAB.3.
LAR4
LARS
LAR6
LAB.6 mw1 STaAII
3 s
. . . . . . I . . . . . . .
TIYE INTERVAL c( =ONE WLLK ROOKLAND DIET LAB. DIET
----
3. Differences in altitude or barometric pressure are apparently not responsible for the obvalues. served differences in LDKO 4. Differences in t h e strains of mice used are apparently not responsible for the observed differences in LDWvalues. This is worth rechecking later b u t should be postponed until it is demonstrated that different laboratories can obtain results that are statistically equivalent on mice from a single source. 5. Minor variations i n technique should b e examined, both within and between laboratories, in an attempt to account for the observed dif-
ferences i n results in t h e above test. 6. A comparative study of methods of estimation of LDsovalues is suggested in order better t o ascertain which methods are to be preferred for practical work.
REFERENCES (1) Allmark, M. G . . THISJOURNAL, 40, 27(1951). (2) Miller, L. C.. and Tainter, M. L., Proc. SOC.Exgfl. Riol. M c d . , 57, 261(1944). (3) Burn. J. H.. “Biological Standardization.” 2nd ed., Oxford University Press 1950. p. 11. (4). Finney, D. J.. “Statistical Method in Biological Assay Hafner, New York, 1952 p. 524. (b) Berkson, J., J . Am. Slot: Assoc., 48, 565U953).
A Note on Tablet Disintegration with Starch* By LEMUEL C. CURLINT
s
has been used as a disintegrant in tablets for decades. Its prompt action is well shown in the common aspirin tablet, which will break apart in seconds when dropped into water. This disintegrating action was thought to be due to starch granules swelling in water and breaking open the tablet. Other agents, which swell in water, as bentonite, gums, etc. have been used as disintegrants with poor results. We recently tried disintegrating aspirin tablets in hot water. They did not break u p but remained TARCH
*
Received December 4. 1953 from L. Perrigo Company, Allegan Mich. t Chief Chemist, L. Perrigo Company.
firm for a long period of time. Hot water should swell the starch granules quickly and brpak the tablets faster. We microscopically examined a thin slurry formed by dropping an aspirin tablet into a small amount of cold water. Although the tablet disintegrated iii 15 seconds, the starch granules were not swollen. We applied a drop of dye solution to an aspirin tablet. On cutting the tablet in half, we found the color had penetrated the tablet as though it were a blotter. We suggest that the disintegrating action of starch in tablets is due to capillary action rather than swelling. Possibly the spherical shape of the starch increases the porosity of the tablet.
JOURNAL OF
AMERICANPHARMACEUTICAL ASSOCIATION
Vol. XLIV, No. 1
CHART H
GROWTH CURVES OF 1953 COOPERATIVE A. Ph. A TEST MICE CONTROL
LARI
LAB.2.
LAB.3.
LAR4
LARS
LAR6
LAB.6 mw1 STaAII
3 s
. . . . . . I . . . . . . .
TIYE INTERVAL c( =ONE WLLK ROOKLAND DIET LAB. DIET
----
3. Differences in altitude or barometric pressure are apparently not responsible for the obvalues. served differences in LDKO 4. Differences in t h e strains of mice used are apparently not responsible for the observed differences in LDWvalues. This is worth rechecking later b u t should be postponed until it is demonstrated that different laboratories can obtain results that are statistically equivalent on mice from a single source. 5. Minor variations i n technique should b e examined, both within and between laboratories, in an attempt to account for the observed dif-
ferences i n results in t h e above test. 6. A comparative study of methods of estimation of LDsovalues is suggested in order better t o ascertain which methods are to be preferred for practical work.
REFERENCES (1) Allmark, M. G . . THISJOURNAL, 40, 27(1951). (2) Miller, L. C.. and Tainter, M. L., Proc. SOC.Exgfl. Riol. M c d . , 57, 261(1944). (3) Burn. J. H.. “Biological Standardization.” 2nd ed., Oxford University Press 1950. p. 11. (4). Finney, D. J.. “Statistical Method in Biological Assay Hafner, New York, 1952 p. 524. (b) Berkson, J., J . Am. Slot: Assoc., 48, 565U953).
A Note on Tablet Disintegration with Starch* By LEMUEL C. CURLINT
s
has been used as a disintegrant in tablets for decades. Its prompt action is well shown in the common aspirin tablet, which will break apart in seconds when dropped into water. This disintegrating action was thought to be due to starch granules swelling in water and breaking open the tablet. Other agents, which swell in water, as bentonite, gums, etc. have been used as disintegrants with poor results. We recently tried disintegrating aspirin tablets in hot water. They did not break u p but remained TARCH
*
Received December 4. 1953 from L. Perrigo Company, Allegan Mich. t Chief Chemist, L. Perrigo Company.
firm for a long period of time. Hot water should swell the starch granules quickly and brpak the tablets faster. We microscopically examined a thin slurry formed by dropping an aspirin tablet into a small amount of cold water. Although the tablet disintegrated iii 15 seconds, the starch granules were not swollen. We applied a drop of dye solution to an aspirin tablet. On cutting the tablet in half, we found the color had penetrated the tablet as though it were a blotter. We suggest that the disintegrating action of starch in tablets is due to capillary action rather than swelling. Possibly the spherical shape of the starch increases the porosity of the tablet.