The stability and bioavailability of an herbal extract are crucial to its efficacy. The active substances in Phyllanthus niruri extract are corilagin, geraniin, brevifolin carboxylic acid , and Phyllanthus flavonoids.

These active substances contain many terminal hydroxyl groups that are easily oxidized. When the hydroxyl groups are oxidized to form keto groups, the efficacy of the extract is reduced.

Besides, Phyllanthus niruri extract is very hygroscopic and hence poses a major problem during processing and affects the quality of the capsule. When it absorbs moisture, the color of the powder extract darkens and forms a wet mass.