A Histological Study of a Novel Pneumatic-Mechanical Microneedle-Assisted Topical Cutaneous Delivery System.

[BACKGROUND] Device-assisted drug delivery (DADD) involves a device modality that facilitates the penetration of topical substances across the intact stratum corneum barrier.

[OBJECTIVE] This study analyzes the efficacy of a novel pneumatic-mechanical microneedle tip technology ("fusion tip") in assisting the transcutaneous delivery of fibroblast-stimulating substances including small particle hyaluronic acid (SPHA), large particle hyaluronic acid (LPHA), calcium hydroxylapatite (CaHA), and poly-L-lactic acid (PLLA).

[METHODS MATERIALS] The subject was a 34-year-old otherwise healthy woman. Subject abdominal skin preplanned for subsequent abdominoplasty was treated with pneumatic-mechanical and sham control tips in test spots to topically deliver liquid SPHA, LPHA, CaHA, and PLLA at 0.5 and 2.5 mm treatment depths. Immediately after and 1 week post-treatment, 3 mm punch biopsies were obtained for histological analysis.

[RESULTS] All substances showed demonstrable drug delivery with both tips except LPHA. Deeper needle depths improved delivery. The pneumatic-mechanical tip enhanced delivery of SPHA and PLLA both immediately postprocedure and at the 7-day follow-up. Calcium hydroxylapatite delivery was similar between the 2 tips, other than increased delivery at 0.5 mm depth immediately postprocedure with the pneumatic-mechanical tip.

[CONCLUSION] Microneedling is an effective method of DADD, with the pneumatic-mechanical tip improving delivery for most test substances.