Charak Samhita
एतान् द्विपलिकान्भागांश्चूर्णं कुर्यात् पृथक् पृथक्। मण्डूरं द्विगुणं चूर्णाच्छुद्धमञ्जनसन्निभम्॥७४॥
Mandura bhasma which is dark in color like collyrium, should be cooked by adding eight times of cow’s urine and the powders of the above drugs should be mixed to this.
english translation
etAn dvipalikAnbhAgAMzcUrNaM kuryAt pRthak pRthak। maNDUraM dviguNaM cUrNAcchuddhamaJjanasannibham॥74॥
hk transliteration by Sanscript