It is water soluble.

Yes, irinotecan is primarily indicated for advanced and metastatic colon cancer.

Irinotecan targets actively dividing cells in your body. In cases of cancer, this is a good thing because it stops rapidly dividing cancer cells from growing. However, it can also affect other tissues of your body that have high turnover rate, including the bone marrow and epithelial lining of the intestine. Hence, irinotecan increases the risk of diarrhea and neutropenia.

Irinotecan does not seem to increase toxicity but it improved response rates to 39%, added two to three months to disease-free survival, and prolonged overall survival by a little over two months.

pH can be measured in water and nano particles are not soluble (in general) though they can have acid or base properties