sometimes all you have to do is is call...
i called two farmacias in sosua for you: san gregorio and cereia. they do not have them at the moment but they can order for you.
Farmacia San Gregorio
J E Kunhardt 112, Sos?a
(809) 571-3478
Farmacia Cereia
Carr Cabarete Sosua 1, Sos?a
(809) 571-1085