title: Pharmacodynamic profile of mydriatic agents delivered by ocular piezo-ejection microdosing compared with conventional eyedropper.
abstract: Eyedroppers deliver medication volumes exceeding conjunctival absorptive capacity, causing spillage and risking ocular/systemic complications. We evaluated piezoelectric microdosing. Results/methodology: Subjects (n = 102) received precision microdroplet delivery of phenylephrine (2.5%) and tropicamide (1.0%): 1 × 1.5 μl, 1 × 6 μl or 2 × 3 μl of each (randomized 1:1:1), into one eye. Contralateral eyes received eyedropper doses of both drugs. Outcomes were pupil dilation (0-60 min) and patient satisfaction. Six-microliter microdosing achieved comparable, and 2 × 3 μl met/exceeded dilation speed and magnitude versus eyedropper. Separately, participants preferred piezoelectric saline self-delivery to eyedroppers, reporting better head-positioning comfort, reduced tearing/overflow and increased likelihood of adhering to ocular medication regimens.
  
  
  
  Piezoelectric microdosing achieves comparable effects as eyedroppers delivering 4-17-fold larger doses. Microdosing may enhance patient adherence to ocular medication regimens while minimizing side effects.
authors.affiliation: Department of Ophthalmology, University of California at San Francisco, 707 Oregon Ave, San Mateo, CA 94402, USA.
authors.forename: Tsontcho
authors.initials: T
authors.lastname: Ianchulev
authors.affiliation: CODET Vision Institute, Tijuana, Mexico.
authors.forename: Arturo
authors.initials: A
authors.lastname: Chayet
authors.affiliation: Department of Ophthalmology, University of Colorado, Aurora, CO, USA.
authors.forename: Malik
authors.initials: M
authors.lastname: Kahook
authors.affiliation: Mark Packer MD Consulting, Boulder, CO, USA.
authors.forename: Mark
authors.initials: M
authors.lastname: Packer
authors.affiliation: Massachusetts Eye & Harvard University, Cambridge, MA, USA.
authors.forename: Louis
authors.initials: L
authors.lastname: Pasquale
authors.affiliation: Department of Ophthalmology, Hamilton Glaucoma Center & Shiley Eye Institute, University of California at San Diego, CA, USA.
authors.forename: Robert N
authors.initials: RN
authors.lastname: Weinreb
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009184:Mydriatics / Q000008:administration & dosage*; D009883:Ophthalmic Solutions / Q000008:administration & dosage*; D010656:Phenylephrine / Q000008:administration & dosage*; D011680:Pupil; D014331:Tropicamide / Q000008:administration & dosage*; D055815:Young Adult
chemical_list: D009184:Mydriatics; D009883:Ophthalmic Solutions; D010656:Phenylephrine; D014331:Tropicamide
keywords: microdroplet ejection system; mydriasis; ocular drug delivery; ocular medication; piezoelectric; precision eye dosing