Abstract
Purpose :
Mydriatic Tropicamide (TR) eye drops available in the market are very painfull and burning due to the acidic formulations (pH=5.0). The objective of our study was to develop a new pH=7.0 hyaluronic acid-cyclodextrin based 0.5% TR formulation (MDV1221). Tolerability, Precorneal Residence Time and Mydriasis of MDV1221 were compared vs 1% TR solution (Visumidriatic, Visufarma Italy) in rabbits.
Methods :
Stability of MDV1221 was evaluated under ICH conditions. The assessment of the potential irritant and cytotoxic effects of MDV 1221 has been carried out through the model of the reconstituted human corneal epithelium (HCE) provided by SkinEthic Laboratories (Nice, France). The experiment was conducted as described by F. Van Goethem et al., 2006 Toxicol In Vitro, 20 (1), 1-17. Six male New Zealand albino rabbits were used and instilled with 30µl of MDV1221 (3 animals) and Visumidriatic (3 animals). Tear samples (1µl) were collected after 2, 5, 10, 20 and 40 min, diluted with water and TR concentrations evaluated by UHPLC-MS. Mean Precorneal Residence Time (MPRT min) of TR was defined as the ratio between Area Under Momentum Curve/Area Under Curve. Mydriatic activity tests were carried out on male not anaesthetized new Zealand albino rabbit, selected on the basis of the similar response to light intensity and to the mydriatic activity of TR. Peak time (Pt min), Duration (D min) and Maximal Mydriatic Response (Imax mm) of MDV1221 and Visumidriatic were compared.
Results :
MDV1221 was stable at 25°C for 24 months as well as at 40°C for 6 months. For what concern biocompatibility we had 95% of viability for MDV1221 (not irritant) while Visumidriatic resulted irritant with 58% viability; for citotoxicity we ha 89% of viability for MDV1221 (not citotoxic) while Visumidriatic resulted citotoxic with 54% viability. MPRT resulted similar 10.1min (MDV1221) vs 10.3min (Visumidriatic). Mydriatic parameters of both products were: Peak time 90min and Duration 360min for both MDV1221 and Visumidriatic, while Imax was 2.3mm for MDV1221 and 2.4mm for Visumidriatic.
Conclusions :
The hyaluronic acid-ciclodextrin vehicle guarantees stability at physiological pH as well better tolerability to TR in MDV1221 in comparison with Visumidriatic . Mydriatic parameters were similar. It can be hypothised that MDV1221 will represent a new effective burning – free formulation of Tropicamide.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.