Nimustine hydrochloride is an active pharmaceutical ingredient used in the treatment of malignant brain tumors. Introduction of malignant brain tumors Malignant brain tumors can be divided into primary and secondary malignant brain tumors. Primary malignant brain tumors mean the cancer starts in the brain, while secondary malignant brain tumors mean the cancer starts somewhere else in the body and then metastasizes to the brain. The incidence of the latter is about 10 times that of the former. Meningioma brain tumors usually come with no symptoms, but as they grow gradually, patients may experience the following symptoms: Seizures Memory loss Speech problems Headache Loss of smell Hearing disability Numbness Blurred vision If left untreated, malignant brain tumors can rapidly grow and spread to other areas of the brain and spinal cord. The exact cause of malignant brain tumors remains unknown. However, possible risk factors include family history, skull injury or fracture, obesity, and radiation exposure. Since 1985, the treatment of malignant brain tumors was advanced by a combination of chemotherapy using nimustine hydrochloride and etoposide, which was particularly effective for malignant gliomas[1]. Mechanism of action Nimustine hydrochloride can alkylate and cross-link DNA, which induces DNA replication blockade and DNA double-strand breaks, leading to the failure of DNA synthesis. In this way, nimustine hydrochloride exerts an anti-tumor effect, especially on malignant brain tumors.