Hollow polymer microneedles array resistance and insertion tests.

Microneedles are developed in order to become the transdermal administration method of the future. They however still face numerous challenges. This paper addresses the challenge to effectively insert the microneedle arrays into membranes. A recently proposed model membrane and test method for microneedles insertion, published in International Journal of Pharmaceutics, is used in this aim. A moulded 4 by 4 hollow polymer microneedle array developed at the Université Libre de Bruxelles is tested for insertion using this model. Results show that the array is extremely resistant to insertion, it can withstand very high forces and even multiple insertions without blunting. Different insertion tests were performed on a folded in eight Parafilm® film because it exhibits excellent similarity to porcine skin. The insertion force, the insertion speed and the holding time of the array against membranes must be optimised in order to get efficient reliable insertions at, at least, 500μm depth.