ABSTRACT
Objective: Glaucoma is the most frequent cause of blindness in Japan and is primarily treated using IOP-lowering ophthalmic solutions. Although the patients themselves frequently instill ophthalmic solutions, instillation by caregivers may be necessary for various reasons. Therefore, we evaluated pharmaceutical characteristics of antiglaucoma ophthalmic solutions and their usability from the caregivers' viewpoint.Methods: Five dorzolamide hydrochloride-timolol maleate ophthalmic solutions and 2 travoprost-timolol maleate ophthalmic solutions were evaluated concerning the pharmaceutical characteristics and subjective squeezability rated by adults aged 20 years or above.Results: Among the dorzolamide hydrochloride-timolol maleate compounding ophthalmic solutions, the squeeze force was the lowest in COSOPT® ophthalmic solution (11.8 N), and DORMOLOL® combination ophthalmic solution NITTEN was rated highest, with 68.2% of the subjects placing it within the top 3 levels of a 7-level scale. Of the travoprost-timolol maleate ophthalmic solutions, the squeeze force was 9.8 N, lower than the pioneer drug, in TraTimo® combination ophthalmic solution NITTO, which was also rated in the top 3 levels by 90.3% of the subjects. A strong negative correlation was observed between the squeeze force and squeezability.Conclusion: In instillation by caregivers, the squeeze force was shown to be correlated with subjective squeezability as in instillation by patients themselves. This study provided information concerning the usability of ophthalmic solutions from the caregivers' viewpoint. For the future, it is necessary to select ophthalmic solutions from the caregivers' as well as the patients' viewpoints by utilizing information obtained in this study.
ABSTRACT
<b>Objective: </b>The squeezing force and one-drop weight, suggested to directly influence adherence, were measured in 6 eye drop products containing a switch OTC drug, ketotifen fumarate, to investigate useful information for product selection.<br><b>Methods: </b>The squeeze force, one drop weight, and pH were measured using a digital force gauge, analytical balance, and pH meter, respectively. Information on additives contained in each product was collected from package inserts. For the total number of drops, the number per 10 mL was calculated from the obtained value.<br><b>Results: </b>The maximum squeeze force was 14.8 N of Irice AG Guard, and the one drop weight (33.2 mg) of Raferusa®AL was the minimum. The total number of drops per 10 mL was 215 in Sutto eyes Z, being the minimum. The pH was in the range of 5.2-5.7. On comparison of additives among the products, a cooling agent was contained in only 2 products.<br><b>Discussion: </b>Since the squeeze force was in the range of 5.3-14.8 N, it was less likely that the squeeze force reduces usability. Since the one-drop weights of 2 products were more than 10 mg lower than the weights of the other products, the dose may be insufficient and the effect may not be attained. The pH was within the acceptable range in all products. Two products contain a cooling agent as an additive, and this has to be explained beforehand. Information related to usability, actual feeling of the effect, and sense of the use of the products containing ketotifen fumarate was collected.