What is the ruling on concealing the secrets of drug formulations and ingredients that a doctor learns from another source or person? And does a doctor's failure to inform or disclose the formulation of drugs he himself invents constitute concealment of knowledge?

On the Day of Resurrection, Allah will bridle with a bridle of fire whoever was asked about knowledge and concealed it. The principle is that this includes all beneficial knowledge, but many scholars have specified religious knowledge for this prohibition. It has been said that the prohibition is specific to one who is obligated to teach this knowledge and for whom it has become incumbent, such that people are in dire need of it and there is no one else. As for supererogatory knowledge, it is not included in this. A condition for the obligation of disclosure is that the questioner be deserving of it, not merely an intrusive person. Therefore, medical sciences and drug compositions are not included in the threat, unless their concealment results in harm to people and they cannot find anyone else but that particular doctor to explain the drug compositions to them.