RESUMEN
BACKGROUND: There has been no research about the exact mechanism of transdermal drug delivery during mesotherapy. OBJECTIVE: We aimed to evaluate whether the commercial mesogun can be an appropriate technique for a transdermal drug delivery. MATERIALS AND METHODS: We injected blue ink into the polyurethane foam or pig skin with three types of mesotherapy using a commercial mesogun, or local made intradermal injector, or a manual injection of syringe. To assess the internal pressure of the cylinder and drug delivery time, we designed the evaluation setup using a needle tip pressure transducer. RESULT: All types of injectors induced adequate penetration of blue ink into the polyurethane foam without backflow. In the pig skin, blue ink leaked out rapidly with the backward movement of the needle in the commercial mesogun in contrast to the local made injector or the manual injection of syringe. When the time for backward movement of the syringe approaches 1000 ms, the cylinder pressure of the syringe is saturated at around 25 mmHg which can be translated into the dermal pressure of the pig skin. CONCLUSION: There should be sufficient time between the insertion and withdrawal of the needle of injector for the adequate transdermal drug delivery and it must be considered for mesotherapy.