Disintegration performance
Primojel® takes up more than 20 times its own weight of water. Rapid water penetration into the tablets and powerful swelling results in rapid disintegration. The swelling actions makes Primojel® most effective in non-soluble matrices. Studies show that Primojel® takes up more water than comparative products on the market and develops a strong disintegrating force making it a highly effective product. The botanic source, degree of cross-linking and degree of substitution of Primojel® have been optimized in order to give rapid water uptake by the polymer without the formation of a viscous gel that may impede water penetration into the tablet.
In direct compression
The recommended starting point is 2%w/w to 4%w/w of Primojel®. The figure shows how the disintegration time of various placebo tablets (250 mg / 9 mm tablets containing 4%w/w Primojel® and 0.5%w/w magnesium stearate) is maintained after storage for 6 months at 40˚C / 75% RH in open containers. The disintegration of reference tablets stored for 6 months under ambient laboratory conditions is also shown. This data confirms that Primojel® remains an effective superdisintegrant.
In wet granulation
We recommend that Primojel® is incorporated at least partly (50% or more) during the granulation. This is especially important when a high proportion of insoluble diluent is employed. The intragranular components were wet granulated (high shear), dried, sieved and blended with the extragranular portion of Primojel® and magnesium stearate. Tablets were compressed at 250 mg and dissolution tested in 900ml of water using USP apparatus 2. Dissolution of Diclofenac Sodium is slower when Primojel® is used only in the extragranular phase. If lactose is used instead of dibasic calcium phosphate, then the effect of Primojel® location is greatly reduced.
