METHODS: A stability study was conducted to help determine the feasibility of innovative formulations to meet an unmet clinical need for combination mydriatic ophthalmic eyedrops. An adult mydriatic ophthalmic solution containing phenylephrine hydrochloride 2.5% and tropicamide 1.0% and a pediatric formulation containing phenylephrine hydrochloride 2.5%, tropicamide 0.5%, and cyclopentolate hydrochloride 0.5% were prepared using proper aseptic techniques. Triplicate samples of each formulation were stored for 60 days at refrigeration temperatures (2-8 °C) and analyzed on day 0 and days 7, 14, 28, and 60. At each time point, the stability samples were assessed by visual inspection, pH measurement, and stability-indicating high-performance liquid chromatography (HPLC) analysis.
RESULTS: Over the 60-day storage period, there was no significant change in the visual appearance or pH level of any of the adult or pediatric solution samples. The results of HPLC analysis indicated that all samples retained 97-102% of the initial drug concentrations for up to 60 days.
CONCLUSIONS: Both adult and pediatric ophthalmic formulations containing combinations of phenylephrine, tropicamide, and cyclopentolate were stable physically and chemically for up to 60 days when stored at refrigeration temperatures (2-8 °C).