Is the aforementioned transaction, which involves paying 200,000 Riyals to obtain 10 Riyals for each dozen of imported goods and 2 Riyals for each dozen of local goods, with no income after the goods arrive at the store, Islamically permissible?

This transaction is not valid for two reasons: First, it is not permissible to make the partner's share a fixed amount of money. Rather, it must be a percentage of the profit. Stipulating a known number of dirhams invalidates the partnership contract. Second, it is not permissible to guarantee the capital in a partnership. The loss is borne by the owner of the capital, and the questioner mentions that his brother guarantees the capital and the profit. The correct form is for them to agree on a percentage of the profit, and for the loss to be borne by the owners of the capital in proportion to their capital.