Development of a Transdermal Microneedle Patch for Pediatric Conscious Sedation

Objectives: The goal of this research is to develop a transdermal microneedle patch system for the painless and anxiety-free administration of sedative-anxiolytic drugs for procedural sedation in children. Specific objectives included: Identification of drugs that can be used in such a device; Identification of a microneedle transdermal delivery system; Creation of a working prototype; and Surveying potential users regarding their acceptability of such a sedation modality.
Methods: A literature review was conducted on sedative agents that are being used in pediatric dentistry. The pharmacodynamics and clinical efficacy were reviewed for each agent and the most appropriate drug was chosen along with age- and weight- based dose estimations.
All types of microneedle systems were examined to identify one that met our desired clinical criteria which included pharmacokinetic profile of our chosen drug, ease of use, pain during administration, and appearance of the device.
Medical and dental professionals likely to use the sedation patch were surveyed regarding their likelihood for use of such a device, possible concerns and cost tolerance.
Results: Midazolam was identified as the most suitable agent. The clinically efficacious dose was calculated using pharmacokinetic of subcutaneous midazolam and correlation between sedation level and plasma concentration. The dose was estimated to be 0.3 mg/kg.
From an array of microneedle systems available, a hollow microneedle system was chosen. Ultimately, a 3D design of the patch was created, followed by fabrication of working prototypes for clinical trials. A working prototype suitable for use in an average 3 to 5-year-old child that is composed of a 12 stainless steel microneedle array with the penetration depth of 1000 µm and a drug volume of 1.2 ml was created for in vivo testing.
Results of the survey of clinicians revealed high acceptability for this concept.

Conclusions: The microneedle transdermal patch system will likely be a new, effective modality for administration of procedural sedation in children.