'non-injectable' is formed from the prefix 'non-' (from Latin 'non', meaning 'not') combined with 'injectable' (from Latin 'injicere' via Late Latin/Modern Latin and English suffix '-able').

'injectable' comes from Latin 'injicere' ('in-' + 'jacere' meaning 'to throw'), through Late Latin/Medieval Latin forms into English as 'inject' + adjectival suffix '-able'; 'non-' was prefixed in English to negate the adjectival sense, producing 'non-injectable'.

Originally related to the physical sense of 'introducing (a substance) into' (from Latin 'to throw into'), the combined modern term 'non-injectable' has come to mean 'not suitable for injection' in medical and pharmaceutical usage.