Toxicity profiles of fixed-combination eye drops for glaucoma therapy using cultivated human corneal epithelial sheets

Frequency of Use of Fixed-Combination Eye Drops by Patients with Glaucoma at Multiple Private Practices in Japan

Purpose

To investigate the current use of fixed-combination eye drops by patients with glaucoma in Japan.

Patients and Methods

A total of 5303 outpatients (5303 eyes) with glaucoma or ocular hypertension were enrolled in the survey at 78 private practices from March 8 to 14, 2020. The medications they used were investigated. The use of fixed-combination medications was analyzed, stratified by the number of medications used. The results were compared to those of the survey performed in 2016 via χ 2 tests.

Results

Fixed-combination medications were used by 55.6%, 79.8%, 84.9%, 91.3%, and 94.1% of patients in the two-, three-, four-, five, and six-medications groups. The use of prostaglandin analog/β-blocker (PG/β), carbonic anhydrase inhibitor/β-blocker (CAI/β), and α-2-adrenergic agonist/β-blocker (α2/β) fixed-combination medications were 42.8%, 12.0%, and 0.8% in the two-medications group; 36.2%, 41.6%, and 2.0% in the three-medications group; and 23.5%, 60.1%, and 1.3% in the four-medications group, respectively. The most commonly used fixed-combination medications were PG/β in the two-medications group and CAI/β in the groups using three or more medications. Compared to those in the survey performed in 2016, there were increases (both P < 0.0001) in the use of PG/β fixed-combination medication in the two- (28.7% to 42.8%) and three-medications (21.7% to 36.2%) groups, and none in the use of CAI/β fixed-combination medication. There was little use of α2/β fixed-combination medication, probably because it was launched only three months before the survey.

Conclusion

The proportion of fixed-combination medications increased as the number of medications per patient increased.

In Vitro Toxicity Evaluation of New Generic Latanost® and Latacom® as an Ophthalmic Formulation

Aim and objective

To evaluate the safety of two new generic ophthalmic formulations, Latanost^® (latanoprost) and Latacom^® (latanoprost and timolol) by utilizing the three-dimensional reconstructed human cornea-like epithelium (RhCE) tissue constructs as an in vitro model in the assessment of ocular irritation.

Materials and methods

In vitro irritation test was conducted on Latanost^® (LTN) and Latacom^® (LTC) and their corresponding innovators, Xalatan^® (XLT) and Xalacom^® (XLC), respectively, by using RhCE. According to the OECD guidelines No. 492 on the testing of chemicals, the ophthalmic formulations were assessed via topical exposure of the formulations on in vitro RhCE tissue. Cell viability was measured by MTT assay.

Results

The mean cell viability percentage of LTN and XLT was 70.5 and 75.7%, respectively, whereas, for LTC and XLC, the percentage viability was 95.3 and 85.7%, respectively. The two new generic formulations (LTN and LTC) did not reduce the cell viability of the RhCE tissue to ≤60%. Thus, both can be considered as nonirritant.

Conclusion

Both newly developed generics are nonocular irritants.

Clinical significance

This study informs the safety assessment of new generic antiglaucoma ophthalmic solutions applicable for long-term glaucoma treatment. The formulations aim to keep eye irritation to a minimum level.

How to cite this article

Ng JSC, Tan YX, Alwi NAA, et al. In Vitro Toxicity Evaluation of New Generic Latanost^® and Latacom^® as an Ophthalmic Formulation. J Curr Glaucoma Pract 2021;15(3):139–143.