1. Department of Pharmacy, University of Tirana, Street of Dibra, 371, Tirana, Albania, Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences (UIPS), Utrecht University, P.O. Box 80082, 3508 TB Utrecht, The Netherlands, and Department of Chemical Sciences, University of Camerino, Via S. Agostino, 1, 62032 Camerino, Italy