Does selling imported medications through unofficial channels, with the buyer's knowledge and the possibility of them being corrupted, cause the pharmacist to incur sin?

Both the seller and the buyer must be truthful and clear for their transaction to be blessed. If either of them lies and diminishes it, its blessing will be lost. The seller must inform the buyer of any defect, if one exists; otherwise, he is deceptive. If the buyer finds a defect in the merchandise, he is permitted to return it, and the seller must accept it. Most scholars have opted for the permissibility of the seller stipulating that he is not responsible for any defect in the merchandise, provided that he is not aware of the defect at the time of the stipulation. If he is aware of the defect, then he is deceptive, and the buyer has the right to return it in all cases.