Is it permissible to count the amount paid to the husband—for the brother's debt—as part of Zakat al-Mal (obligatory charity on wealth)?

It is permissible to give Zakat to a needy brother. However, it is not permissible to pay off his debt with it unless he gives permission, because the Zakat must be given to the poor person as a possession, and then he has the choice to dispose of it as he wishes.