intramuscular injection http://purl.bioontology.org/ontology/MEDDRA/10082261 http://purl.bioontology.org/ontology/MESH/D007273 http://purl.bioontology.org/ontology/SNOMEDCT/76601001 Forceful administration into a muscle of liquid medication, nutrient, or other fluid through a hollow needle piercing the muscle and any tissue covering it. Intramuscular injection is a route of drug administration via injection into muscle tissue. Aqueous or oleaginous solutions and emulsions or suspensions may be administered. Absorption rates, delay in availability of the drug to the systemic circulation, and duration of effect are perfusion-limited, depend on molecular size of the agent, volume, and osmolarity of the drug solution, fat content of the injection site, and patient physical activity. intramuscular injections intramuscular route of administration injection route of administration