Delivery of therapeutic and cosmetic agents into skin is hindered by the epidermal barriers. Many physical and chemical approaches have been developed to overcome the skin’s barriers. Chemical approaches often involve the complete disruption or removal of the epiderms resulting in irritation and inflammation, and physical approaches are restricted to the size of the delivery device – both limiting the delivery to focused areas of skin instead of much larger field delivery.
To overcome the skin’s barriers for the treatment of skin diseases, we have developed a novel cutaneous delivery method capable of field treatment using elongate microparticles.
We compared elongate microparticles with topical only and microneedle-enhanced delivery of sodium fluorescein, vitamins B3/E and 5-aminolevulinate. Elongate microparticle delivery results in a continuous delivery profile across the application area (field-delivery). Elongate microparticle-enhanced sodium fluorescein, Vitamins B3/E and 5-aminolevulinate delivery resulted in 7.1 (p=0.001), 8.8 (p=0.0001), 8.5 (p=0.0017) and 2.6 (p=0.0018) fold increase compared to topical alone. Furthermore, the passive and minimal invasive nature of elongate microparticle delivery results in a faster reduction in redness within the treated area compared to microneedles which require healing of the puncture sites. Finally, it was observed that the elongate microparticles are naturally removed through transepidermal elimination.