Process for preparing compounds and prodrugs preparations containing them.

The invention relates to compounds PRO-DRUGS OF FORMULA A-CO (CH2) M (NHCO) NR, wherein A is a group of FARMACEUTICO COMPOUND HAVING THE GROUP = NH O NH 2 in the molecule, R IS A steroidal portion of a compound, M is an integer between 1 and 5 and n is zero or 1. ALSO REFERS TO THE SALES of said compounds, a process for their preparation and SUSTAINED RELEASE preparation containing them.