Stability of a transdermal salmon calcitonin formulation.

This study was designed to monitor the stability of salmon calcitonin during storage conditions, under the electric fields generated during iontophoresis and electroporation, in contact with transdermal glass diffusion cells, and during transport through skin. The formulation in a citrate buffer (pH 4.0) was stable in storage for short-term studies but degraded significantly on extended storage. Albumin was able to minimize adsorption in contact with glass surfaces, and aprotinin was able to minimize proteolytic degradation in contact with skin. The formulation was stable under electric field, but there was a loss due to adsorption if salt bridges were used.