Development and evaluation of orodispersible tablets using a natural polysaccharide isolated from Cassia tora seeds

Orodispersible tablets or fast dissolving tablets dissolve or disintegrate immediately on the patients' tongue or buccal mucosa. This drug delivery system is suitable for drugs undergoing high first pass metabolism. It improves bioavailability, reduces dosing frequency, and thereby minimizes the side effects and also makes the dosage form more cost-effective. In this study, polysaccharide isolated from the seeds of Cassia tora was investigated as a superdisintegrant in the orodispersible tablets. The model drug chosen was valsartan, an antihypertensive drug.

Valsartan tablets were prepared separately using different concentrations (1%, 2.5%, 5%, and 7.5% w/w) of isolated C. tora seed polysaccharide (natural) and sodium starch glycolate (synthetic) as superdisintegrant by the direct compression method. Evaluation of tablets was done for various pre- and postcompression parameters. The stability studies were performed on optimized formulation F4. The disintegration time and in vitro drug release of the formulation F4 were compared with marketed formulations (conventional tablets).

The drug excipient interactions were characterized by Fourier transform infrared studies. The formulation F4 containing 7.5% polysaccharide showed good wetting time and disintegration time as compared to a formulation prepared using a synthetic superdisintegrant at the same concentration level. Hence, batch F4 was considered optimized formulation.

The present work revealed that C. tora seed polysaccharide has a good potential as a disintegrant in the formulation of orodispersible tablets. Because C. tora polysaccharide is inexpensive as compared to synthetic superdisintegrants, nontoxic, compatible, and easy to manufacture, it can be used in place of currently marketed superdisintegrants.