Calcitonin intestin and dominant stimulus are the most

Calcitonin is a single
chain peptide composed of 32 amino acids with isoelectric pH of 8.86 which is
produced in parafollicular cells of the thyroid gland . Overally three classes
of calcitonin including teleost/avian, artyodactyl and primate have been identified
which have highest to lowest bone resorption inhibitory potency, respectively 1. The
basic stracture of non mamalian calcitonin is the resaon of its high biological
activity. Salmon calcitonin is belonged to teleost/avian calcitonin classes and
because of its high activity is used as a treatment of disease like
Osteoporosis and Paget’s disease in mammals. Hypercalcemia and bone
metastases are two other disease which are treated with exogenous calcitonin
adminstration. In the case of osteoporosis disease density of bone will
decrease and consequently the tissue within bone will deteriorated and lead to
bone fragility23. Just like many hormones injection is the primary adminstration of
calcitonin. Another more favorable way is the oral adminstration which resulted
in significant improvement in life quality of pationts4. The uses of hydrogel compounds in formulation of calcitonin hormone for
its oral delivery is an interesting issue for protecting hormon from harsh
condition of gut and intestin in combination with preparing a control release
method for locally admionstration of this peptide. It is demonstrated that the
upper small intestin and dominant stimulus are the most interesting parts for
oral peptide delivery5.Because of this acidic environment attacntions to the use of pH sensitive
hydrogels is increasing. In an study performed by Torres-Lugo et all salmon
calcitonin was sucseccfully incorporated in hydrogel of poly(methacrylic acid)
grafted with poly(ethylene glycol) (PMAA-g-EG) which is a pH sensitive hydrogel
and the constant release of calcitonin around 7 h and completely release
whithin 3 days was achived6. In another study the high loading efficiency of complexation hydrogels poly(methacrylic
acid-g-ethylene glycol) (henceforth designated as P(MAA-g-EG)) which was
previously used for insulin oral delivery was demonstrated. The polymer loaded
with calcitonin showed ph sensitive and complexation/decomplaxation release
behavior7