Mechanism of cellulose derivative disintegrants
Two different types of carboxymethylcellulose were originally
It is necessary to consider the following three conditions to investigate the mechanism of cellulose derivative disintegrants.
EX-1: Disintegrative ability in the form of powders
Avicel PH101, L-HPC, and Ac-Di-Sol were supplied as samples to be
compared with ECG-505 and NS-300 for the purpose of examining the
mechanism of cellulose derivative disintegrants.
Fig-3 is the photographs of shape changes in water uptake of the
tablets made by compressing single disintegrant powders. ECG-505,
L-HPC, and Ac-Di-Sol swell with expansion, but NS-300 and Avicel PH101
volumetrically swell without expansion. The absorption and swelling
abilities of the former three samples are superior to those of the
later two samples in the form of powders as shown in Fig-2 and Fig-3.
Though NS-300 shows a low value of the max swelling force in the form of powder as shown in Fig-2, Fi-4 shows that the disintegration time of tablet including NS-300 is very short and accordingly the disintegrative ability of NS-300 in the form of tablet is very high.
Four types of disintegration mechanisms (swelling, deformation, wicking, and repulsion) are proposed in the review by Joseph (Pharmaceutical Technology April 1984). Judging from the review and the results from Fig-2~4, Ac-Di-Sol, L-PHC, and ECG-505 belong to the swelling type, while NS-300 is classified into the wicking type that exhibits the fast rate of water uptake.
From the foregoing study, it is supposed that the mechanism of cellulose
derivative disintegrants described above may be influenced by inter/intra
molecular hydrogen bonding of cellulose derivatives.
In conclusion, these examinations of the five disintegrants above-mentioned show that ECG-505 is a good disintegrant as a swelling type, while NS-300 is superior to the other disintegrants as a wicking type.
ECG-505 has been on sale as a disintegrant of swelling type and NS-300
also on sale as a disintegrant of wicking type by GOTOKU CHEMICAL
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