Effects of granule particle size and lubricant concentration on tablet hardness containing large concentration of polymers

ABSTRACT The objective of this research work is to demonstrate the impact of granule size and lubricant concentration on the hardness of tablets in formulations containing higher concentration of polymers and to resolve the hardness issue during compression process. The work involves optimization of a milling process for size reduction of granules and blending process to achieve tablets of good hardness on compression. To optimize the granule size, different sized co-mill screens were used. The different concentration of lubricant were studied on different sized granules to check the effect on hardness of tablets and to obtained the desired hardness of tablets. Compression of lubricated blend in various concentration was performed using the gravity feeder and force feeder separately to check the impact on the over lubrication effect. This ultimately leads to less hardness tablets. Lubricated blends were evaluated by performing the Bulk Density, Tapped Density, Hausner ratio and compressibility index tests. Tablets were evaluated for the physical characteristics like weight variation, hardness, thickness and dissolution. It has been conclude that on using the optimum granules size and lubricant concentration in formulation, all the downstream problems can be resolved and this in turn helps in compression of tablets and also provides the good hardness to the tablets.

Noveon AA1 as enhancer of HPMC as a direct compression matrix for controlled release.

This work aimed the assessment of the effect of different proportions of Noveon AA1 on performance of HPMC as a controlled release agent for direct compression tablets. The functionality of polymer blends was determined using dissolution profiles, compactibility profiles and the powders compressibility index. Ten percent HPMC allows a metronidazole release after 3 h of 85%, an exponent n=0.48 and a release constant K=6.9. The increasing polymer substitution by Noveon AA1 decreases drug dissolution up to 36%, increases the exponent to 1.0 and decreases the release constant to 0.2%. The metronidazole/HPMC blend shows a slower increasing and a lower potential of tablets compactibility (20 N) while its increasing substitution by Noveon AA1 attains faster increasing and higher potential compactibilities (39 N). The metronidazole/HPMC (90:10) blend shows a low compressibility index (14%) that increases up to 33.2% with increasing Noveon AA1 proportions. Noveon AA1 proportions ≤ 5% display good/passable powder flowabilities. Noveon AA1 enhances the overall controlled release performance of HPMC, inducing zero order release patterns without lag or burst effects and reducing drug release more efficiently. Noveon AA1 also improves the compactibility of metronidazole/HPMC blends, however, decreases their flowability; flowability is acceptable only at lesser polymer proportions.