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Carboxymethylcellulose Calcium
CMC-Ca Carmellose Calcium
Carmellose Calcium
CMC Carmellose
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.
| Product
Description |
| Characteristics
of ECG®-505 and NS-300® |
|
ECG-505 and NS-300 are made
up of cellulose modified by carboxymethylation.
ECG-505 is the only disintegrant, among many disintegrants
in the world, containing calcium as a component.
NS-300 is produced by lowering Carboxymethylcellulose
Sodium's pH by an acid treatment.
ECG-505 and NS-300 rapidly absorb the water needed
for swelling and consequently show a very short disintegration
time.
The process of dispersion to powder caused by the
disintegration of tablets and granules is very important
for promoting the solubility and thereby the bioavailability
of drugs.
ECG-505 is insoluble but shows hydrophilic property
in water due to its chemlate structure and calcium
component. NS-300 of carboxylic acid type shows poor
hydration but shows a sufficient disintegration function
by its electrostatic repulsive force.
Although in practice ECG-505 has been used favorably
more than has NS-300 for pharmaceutical formations,
one drawback is that the calcium component interacts
with some medicines which contain phosphate or sulfate.
In these cases, NS-300 is used instead of ECG-505.
|
| 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. |
| 3.
Compressibility |
| 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. |
| 4. Stability |
| 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. |
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|
|
| Properties |
|
|
ECG-505 |
NS-300 |
| Degree
of Substitution |
0.5-0.7/C6 |
0.4-0.6/C6 |
| Particle
Through 300mesh |
more
than 95% |
more
than 95% |
| Bulk
Density |
500-600gle |
300-400gle |
Solubility:
Distilled Water
0.1N NaOH |
Insoluble
Swellable
Gelation |
Insoluble
Swellable
Gelation |
| pH |
4.5-6.0 |
3.5-5.0 |
| Stability:
Sunlight |
Stable |
Stable |
| Humidity |
see Fig-2 |
see Fig-3 |
|
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