Stable solutions of rebeccamycin analog and preparations thereof

Abstract From the Canadian patent

Stable solutions of rebeccamycin analog consist essentially of (a) water, (b) 8-N-(diethylaminoethyl)rebeccamycin in an effective dosage amount, and (c) pharmaceutically acceptable acid such that the presence of a molar equivalence thereof would solubilize (b), said acid being present in excess of said molar equivalence to provide a stabilizing pH ranging from 3 to 4 preferably from 3.0 to 3.6. A preferred solution contains 10 mg/ml of the free base and tartaric acid in equimolar amount with the free base to provide a pH of 3.5. Preferably the solution, is prepared by forming a suspension of 8-N-(diethylaminoethyl)rebeccamycin in water and adding acid to provide a pH ranging from 3 to 4.