Published in:
01-05-2007
Stability of Protease-Rich Periplaneta americana Allergen Extract During Storage: Formulating Preservatives to Enhance Shelf Life
Authors:
V. Thangam Sudha, Deepsikha Srivastava, Naveen Arora, Shailendra Nath Gaur, Bhanu Pratap Singh
Published in:
Journal of Clinical Immunology
|
Issue 3/2007
Login to get access
Abstract
Allergenic proteins in extracts degrade rapidly and lose potency on storage. Hence, formulation of optimum conditions is required to enhance shelf life of extracts for proper allergy diagnosis and immunotherapy. In the present study, allergenic potency of P. americana proteins was evaluated after storage with ε-aminocaproic acid (EACA), sucrose, glycerol, pepstatin A, and aprotinin, individually for 1, 3, 6, and 12 months at 4, 25, and 37°C. P. americana extract stored with EACA and sucrose individually retained potency comparable to proteins in standard extract (freeze-dried extract, stored at−70°C) upto 6 months at 4°C. The extracts without preservatives or with glycerol, pepstatin A, aprotinin, or stored at 37/25°C were severely degraded and lost potency by 3 months. A formulation containing a combination of EACA and sucrose enhanced the shelf life of P. americana proteins upto 12 months at 4°C. Hence, EACA and sucrose together show better potential for stabilization of protease-rich extracts.