1. Institute of Polymers Bulgarian Academy of Sciences Akad. G. Bonchev St., Bl. 103A Sofia 1113 Bulgaria
2. Department of Pharmaceutical Technology and Biopharmaceutics Faculty of Pharmacy Medical University of Sofia 2 Dunav St. Sofia 1000 Bulgaria
3. Department of Pharmacology Pharmacotherapy and Toxicology Faculty of Pharmacy Medical University of Sofia 2 Dunav St. Sofia 1000 Bulgaria