Is it permissible to give zakat to homes for the elderly, the poor, and orphans instead of the Zakat Bureau?

Zakat (definition) is not to be given to the elderly and orphans merely because of their old age or orphanhood, unless they fall under the eight categories eligible to receive zakat. If homes for the elderly and orphanages will disburse the zakat to the poor and needy among their residents, then it is permissible to give it to those homes. However, if they are wealthy, it is not permissible to give them zakat, nor is it permissible to give it to those homes if there are wealthy individuals among them, unless one is certain that they will disburse the zakat only to those who are eligible.