Is it permissible to take therapeutic compounds from a doctor who monopolizes them and withholds them from patients, in order to use them in the treatment of my mother and other patients, knowing that my intention is to help and not to profit?

If no other doctor is available to treat patients, then it becomes obligatory upon him. If he refuses, the ruler must compel him to treat them for a fair wage. This act is considered a communal obligation (fard kifaya), and if no one else performs it, it becomes an individual obligation (fard ayn) upon him. The original ruling for practicing medicine is permissibility, and it may become recommended with the intention of benefiting Muslims, and it becomes obligatory if an individual is designated due to the absence of anyone else. There is no sin in concealing worldly knowledge unless it leads to the non-fulfillment of communal obligations that people need, such as medicine; in that case, it must be offered.