abstract |
Polymorphic forms of 9-nitrocamptothecin (9NC) are provided. Distinct crysta l forms of 9NC are obtained from crystallization in different solvent systems and under various conditions, and are further charactherized using various analytical methods. For example, a particular crystal form of 9NC is provide d which is charactherizable as having, by differential scanning calorimetry, a n endotherm at between 175.5 and 177.2C, an exotherm at between 181.7 and 183.7C, and an IR spectrum with no absorption centered between 3625cm-1 and 3675cm-1. |