Hasan Mansouritorghabeh - Allergy Research Center, Ghaem Hospital, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
Mojtaba Sankian - Immunology Research Center, Buali Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
Abdol-Reza Varasteh - Allergy Research Center, Ghaem Hospital, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
Malihe Moghadam - Immunology Research Center, Buali Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
Bahman Khameneh - Department of Pharmaceutical Control, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
Reza Farid-Hosseini - Allergy Research Center, Ghaem Hospital, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
Farahzad Jabbari-Azad - Allergy Research Center, Ghaem Hospital, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.

Background: The quality of extracts used in the skin prick test directly influences the interpretation of the test. Accordingly, the outcomes and effectiveness of immunotherapy for the management of IgE-mediated allergies depend on the quality of the extracts used. Excipients, which are pharmacologically inert ingredients, are intentionally added to the active ingredients. The aim of this study was to address optimum excipients for stability Platanus (P.) orientalis extract. Methods: In this study the excipients examined were l-lysine (20 mM), l-cysteine (20 mM), albumin (0.5%), sorbitol (2%), sucrose (750 mM), trehalose (20 mM), D-mannitol (2% w/v), urea (100 mM) and Tween-20 (0.1%). Their effects on P. orientalis extract stability were analyzed using an inhibition enzyme linked immune assay at 37 ᵒC. Results: A mixture of lysine (20 mM), trehalose (20 mM), and D-mannitol (2% w/v) conferred the greatest stability on the P. orientalis extract. Conclusions: The P. orientalis extract stability was increased by a mixture of lysine (20 mM), trehalose (20 mM), and D-mannitol.  

Lysine, Mannitol, Platanus orientalis, Skin prick test, Trehalose.