Force requirements in topical medicine use--the squeezability factor.

Area of Science:

• Ophthalmology
• Biomedical Engineering
• Patient Compliance Studies

Background:

• Patient compliance is critical for effective treatment, particularly with topical ocular medications.
• Difficulty in self-administering eye drops, often due to bottle aiming and squeezing issues, affects at least 50% of patients.
• Ease of topical drop delivery is a key factor in ensuring treatment efficacy.

Purpose of the Study:

• To quantify the force required to dispense a single drop from ophthalmic bottles (squeezability).
• To compare the ease of use across different ophthalmic bottle designs.
• To evaluate if compliance aids reduce the finger strength needed for eye drop administration.

Main Methods:

• Measured the force necessary to deliver a single drop from various common ophthalmic preparations.
• Applied force gradually to the midpoint of the bottle until drop release.
• Tested the efficacy of compliance aids using the same force measurement technique.

Main Results:

• Significant variability was observed in the force required to dispense drops from different ophthalmic preparations.
• Three out of four tested compliance aids increased the force needed for drop delivery.
• Compliance aids might offer other advantages, such as improving grip on the bottle.

Conclusions:

• There is a wide range in the force required to use topical ophthalmic medications and associated compliance aids.
• Findings are relevant for prescribing physicians and manufacturers of ophthalmic preparations and devices.
• Understanding bottle design and force requirements is crucial for improving patient adherence to eye drop therapy.