Ondansetron Hydrochloride (HCl) Base, as defined by the Indian Pharmacopoeia (IP), is a pharmaceutical substance categorized as a serotonin 5-HT3 receptor antagonist. It is primarily used to prevent nausea and vomiting induced by chemotherapy, radiotherapy, and surgery. The IP provides comprehensive specifications to ensure the quality, potency, and safety of Ondansetron HCl Base for medicinal use.