In Japan, ECG-505 has received the most favorable evaluation. Carboxymethylcellulose Calcium (ECG-505) and Carmellose Calcium (NS-300) have been produced under strict quality control, and have been widely used as agents for disintegration and dispersion of tablets and granules. This dispersion is one of the requirements for attaining the higher bioavailability of a drug. ECG-505 was published in JP in 1966. ECG-505 was published in USP-XXI, US-NF X VI in 1985 and in EP in 1994. NS-300 was also published in JP in 1986. In 1992, ECG-505 was chosen among the 25 most frequently used pharmaceutical excipients in International Harmonization Monographs and NS-300 was also chosen as an addendum item to those of ECG-505.
|Characteristics of ECG®-505 and NS-300®|
ECG-505 and NS-300 are made
up of cellulose modified by carboxymethylation.
|Advantages of ECG-505 and NS-300|
|1. Rapid Disintegration|
|ECG-505 and NS-300 are superior to starch in their disintegration abilities. ECG-505 has a higher ability to absorb water due to its chelate structure and calcium component.|
|2. Release and Dissolution|
|Higher drug release and dissolution properties are very important for promoting the bioavailability of tablets and granules. ECG-505 and NS-300 rapidly disintegrate tablets and granules, although they are insoluble in water.|
|Because of their fibrous shape, ECG-505 and NS-300 have a high compressibility as well as high disintegration properties. Tablets and granules formulated with ECG-505 and NS-300 show both a very short disintegration time and high mechanical strength based on their high compressibility.|
|ECG-505 and NS-300 show high long-term stability in various tablet and granule prescriptions. However, owing to its calcium, ECG-505 may interact with some substances containing phosphate and sulfate.|
|II. The Chemistry of ECG®-505 and NS-300®.|
|ECG-505 is composed of
the calcium salts Carboxymethylcellulose, while NS-300
is the free form of Carboxymethylcellulose, a cellulose
derivative formed by etherification with monochloroacetic
acid under the alkali catalyst.
Both products are, odorless, harmless fine powders.
Both are practically insoluble in ethanol and ether. They absorb and swell with water to form suspension.
The chemical structure formula of ECG-505 is shown in Fig-1-A; that of NS-300 is shown in Fig-1-B.
|Degree of Substitution||0.5-0.7/C6||0.4-0.6/C6|
|Particle Through 300mesh||more than 95%||more than 95%|
|Humidity||see Fig-2||see Fig-3|