Zakaat

Distributing Vouchers as Zakaat

Q: Some organizations are issuing vouchers to the effect that the recipients of Zakaat can purchase groceries to the value of an x amount (e.g. R 200) from certain shops/supermarkets. Is it permissible for these organizations to sell these vouchers at par value (exact amount on the vouchers) to third parties who wish to distribute their own Zakaat to needy recipients themselves?