Astanga Hrudaya
दग्धोऽत ऊर्ध्वं निष्कार्यः स्यादामस्त्वग्निसादकृत् । मृदुर्नस्ये खरोऽभ्यङ्गे पाने वस्तौ च चिक्कणः ॥ २१ ॥
Heating beyond this stage results in a burnt product (dagdha) which is medically useless. On the other hand, an undercooked preparation (ama) diminishes the digestive fire. Mrudupaka sneha is useful as nasal drops, Khara stage of Sneha is useful in massage, for oral consumption and usage in Basti treatment, Chikkana stage of Snehapaka is ideal to use.
english translation
dagdho'ta UrdhvaM niSkAryaH syAdAmastvagnisAdakRt । mRdurnasye kharo'bhyaGge pAne vastau ca cikkaNaH ॥ 21 ॥
hk transliteration by Sanscript