Introduction: Pilocarpine hydrochloride (pilo) ophthalmic solution has traditionally been used for the treatment of glaucoma, with opportunities to improve the tolerability profile experienced by patients. Pilocarpine hydrochloride ophthalmic solution 1.25% (Vuity TM , Allergan, an AbbVie company) was approved in late 2021 for the treatment of adults with presbyopia. This publication describes the properties of the optimized, proprietary vehicle of this new ophthalmic solution developed with the aim of improving tolerability upon instillation. Methods: An in vitro method determined the time required for the pH of pilo 1.25% in the proprietary vehicle (Optimized Formulation) and a commercially available 1% pilo ophthalmic solution (Generic Formulation) to equilibrate with the pH of simulated tear fluid (STF). In a pilot study, five of the six screened participants received one drop of the Optimized Formulation in one eye and Generic Formulation in the other. Ocular discomfort and vision blur were evaluated for each eye just prior to and at multiple times after drop instillation using visual analog scales (VAS), and adverse events were assessed. Results: The in vitro method showed that the Optimized Formulation achieved faster pH equilibration than the Generic Formulation. The pilot study revealed that the Optimized Formulation demonstrated less ocular discomfort, vision blur, and adverse events compared to the Generic.
Conclusion:The in vitro and pilot study of the Optimized Formulation indicated that it rapidly equilibrates to the physiologic pH of the tear film, providing greater comfort and tolerability while also minimizing vision blur. Overall, the proprietary vehicle is expected to improve comfort, result in less vision blur, and provide a well-tolerated alternative method to deliver pilo for the treatment of presbyopia when compared to what is commercially available.