Abstract: A pharmaceutical composition for the sustained release of an effective amount of a selective 5-hydroxytryptamine 3 (5-HT3) receptor antagonist for the prevention, reduction or alleviation of acute and delayed chemotherapy-induced nausea and vomiting (CINV) following a course of emetogenic chemotherapy, wherein the composition is administered by subcutaneous injection, the composition comprising a 5-HT3 receptor antagonist, a semi-solid delivery vehicle and a pharmaceutically acceptable liquid excipient; wherein the composition, when administered in a single dosage, provides a controlled release of the 5-HT3 receptor antagonist and prolonging the release of the 5-HT3 receptor antagonist that tracks the profile of the incidence of vomiting.