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.