Fariba Ganji - Biotechnology Group, Department of Chemical Engineering, Tarbiat Modares University, Tehran, Iran.
Elham Khodaverdi - Department of Pharmaceutics, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
Mohsen Tafaghodi - Department of Pharmaceutics, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
Maryam Sadoogh - Department of Pharmaceutics, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.

Chitosan/glycerol-phosphate solution is an injectable and thermosensitive in situ gel forming system, which undergoes sol-gel transition at physiological pH and temperature. Thishydrogel could be used as drug delivery systems for prolonged release of peptides and glycopeptides[1]. Although manystudies have been reported in the study of chitosan/GP solution properties during the past few years, little work has been done to investigate the effect of different excipients ontheir thermal properties. In this work, chitosan (DDA=85%) polymeric solutions (2% w/v) containing glycerolphosphatedisodium salt (Gp, 0.05% w/w) and different excipients in various concentrations were prepared, and pH, gelation time and irreversibility of gel-forming for final solution were evaluated