Is the owner of a pharmacy sinful for refusing to sell medicines that are in short supply to those who are not his regular customers, and is the pharmacist sinful for following management's instructions in this regard?

The pharmacist is obligated to sell medication to whoever requests it, and it is not permissible to withhold it to save it for regular customers. This is because it is a religious and legal duty, and it is not permissible to obey the pharmacy owner if he orders the withholding of sales; by doing so, he incurs sin. The most a pharmacist can do is to ask regular customers to initiate the purchase of their needs, or inform them when the medication arrives so they can take their supply. However, if the medication is available and someone who needs it is denied, this is not permissible in any way, and it contradicts the law, ethics, and chivalry.