General Overview on Diluents

meAll pharmaceutical necessity plays a very critical role in the stability of a formulation. Paxy Chem offers CALPAX a unique, inert and cost effective diluent. The ratio of diluent to active medicaments/ drugs in any solid dosage form is always a challenge to product development & design. The diluent to active drug ratio many times goes up to 90% to 95% of the gross weight.

It is to a large extent that formulation characteristics like Hardness, Dissolution Time, Disintegration Time etc. are dependent on the physical parameters of the selected excipient used in bulk. Particle size distribution & bulk density affect compression force & hardness in tablets. Related problems like capping and breaking of tablets could be caused by imbalance of these physical parameters. Likewise hygroscopic active ingredients would require low moisture content excipient.

Calpax improves hardness without affecting disintegration and friability, If in any tablet formulation large quantity of excipient portion is required, use of more than 60% Calpax in combination with starch produces much harder tablets than are produced with other conventional diluents e.g. DCP, Lactose, Starch etc., thus solving the problems of breaking of tablets. Use of Calpax also solves the problems of capping and chipping in tablets.

Calpax helps in clean disintegration of the tablets even when active ingredients are predominantly water soluble. Because degree of ionization of Calpax is more than other generally used diluents. With the use of Calpax the fracture of the tablets become gritty which helps in maintaining disintegration time even on long storage.

Due to start of evaporating of dihydrate molecule of Calpax at 1200 C, the free moisture content at process temperature is less than 1%, therefore Calpax is better choice for hygroscopic active ingredients like ethambutol etc.

When the active ingredients requiring direct compression are involved the Calpax aids formation of better slugs.


Calpax improves the look and finishing of the tablets. The tablets manufactured with the use of Calpax are free from dust, very smooth, evenly coloured or white and soft to touch yet very hard.