The Compendium of Caraka 1.24.55

1.24.55

aṣṭāviṃśatyauṣadhasya tathā tiktasya sarpiṣaḥ/
prayogaḥ śasyate tadvanmahataḥ ṣaṭpalasya vā//

The use of the twenty-eight-ingredient medicine, and likewise of bitter ghee, / is commended, or likewise of the great ṣaṭpala ghee;