Charak Samhita
द्रव्यप्रमाणं तु यदुक्तमस्मिन्मध्येषु तत् कोष्ठवयोबलेषु। तन्मूलमालम्ब्य भवेद्विकल्प्यं तेषां विकल्प्योऽभ्यधिकोनभावः॥८६॥
॥ Standard and personalized dose॥ The dose prescribed in the text are for the person with madhyama koshtha (normal bowel), vaya (middle age) & bala (strength). With reference to this one can alter the dose either higher or lesser.
english translation
dravyapramANaM tu yaduktamasminmadhyeSu tat koSThavayobaleSu। tanmUlamAlambya bhavedvikalpyaM teSAM vikalpyo'bhyadhikonabhAvaH॥86॥
hk transliteration by Sanscript