High-precision piezo-ejection ocular microdosing: Phase II study on local and systemic effects of topical...

Area of Science:

• Ophthalmology
• Pharmacology
• Biomedical Engineering

Background:

• Conventional eyedropper volumes (25-50 µl) surpass the eye's tear film capacity (7 µl), leading to overflow.
• Excessive drug volume can cause ocular and systemic complications.
• High-precision piezoelectric microdosing presents a potential solution to optimize ocular drug delivery.

Purpose of the Study:

• To compare the efficacy and safety of phenylephrine (PE) administered via electronic microdosing versus conventional eyedroppers.
• To evaluate pupil dilation, systemic absorption, and ocular side effects.

Main Methods:

• A masked, nonrandomized, cross-over study involving 12 subjects.
• Pupil dilation induced by 32-µl eyedropper (2.5% or 10% PE) and 8-µl electronic microdosing (10% PE).
• Peak dilation, plasma PE levels, vital signs, and eye irritation were assessed.

Main Results:

• Microdosing (PE-10%) achieved comparable peak dilation to the 10% eyedropper and superior dilation to the 2.5% eyedropper (p = 0.009 at 75 min).
• Microdosing significantly reduced 20-min plasma PE levels compared to the 10% eyedropper.
• Eye irritation was less frequent with microdosing than with the 10% eyedropper.

Conclusions:

• Piezo-ejection PE microdosing provides comparable biological effects to eyedropper dosing.
• Reduced systemic absorption with microdosing may lower the risk of systemic side effects.
• Microdosing represents a safer and potentially more effective method for ocular drug delivery.