Eye drops

The COMOD airless system

From Mr J. J. Freyne, MRPharmS, and Ms D. Gross

In response to Lucy Titcomb’s Article “Are quality standards being reduced as eye drops are classified as devices?” (PJ, 26 June 2010, p633), Scope Ophthalmics would like to congratulate her on a thorough and well researched article, which has brought some clarity to an increasingly unclear area of ophthalmic pharmacy.

For the record, the patented COMOD system is the only airless system available on the UK market. This system prevents any retrograde action of environmental air or pathogens entering the bottle’s reservoir.

Mrs Titcomb’s article pays particular attention to the sterility of the tip of preservative free multidose bottles and some key features of the COMOD system should help reassure pharmacists of the safety and security of this bottle, particularly the tip.

There is a silver spiral directly behind the exterior opening of the bottle and silver has been shown to have a so-called oligodynamic (bactericidal) effect, which reduces the risk of contamination. It is commonly known that microbes need humidity to survive and proliferate, so there are a number of design features to keep the top of the bottle dry.

URSAPHARM, the manufacturer of all licensed and CE marked products filled into the COMOD bottle, can also confirm no case of reported infection for any products in this bottle since 1994. Mrs Titcomb’s concerns over the sterility of the tip of these preservative free multidose bottles must equally be extrapolated to preserved eye drop bottles because even a preservative would not be able to kill microbes during the application of the drop before it reaches the eye. Therefore, it is inappropriate to put higher requirements on the preservative free multidose containers compared with the preserved formulations.

The paper by Høvding and Sjursjen1 was published in 1982 and the COMOD bottle was not used in this study. Also, extensive tests challenging the COMOD system from external bacterial contamination have proved the security of this container.

In relation to the paper written by Stone et al,2 Scope Ophthalmics posits that our compliance aid, the ComplEye, can minimise the problem expressed in this paper for all patients. This aid allows elderly or arthritic patients to use the COMOD bottle with a two-handed technique. It is available to order through Scope Ophthalmics free of charge.

John Freyne

Commercial Director

Scope Ophthalmics

Manchester, UK

Dorothea Gross

Head of Medical Science Department

URSAPHARM Arzneimittel GmbH

Saarbrücken, Germany



1.    Høvding G, Sjursen H. Bacterial contamination of drops and dropper tips of in-use multidose eye drop bottles. Acta Ophthalmologica (Copenhagen) 1982;60:213–22.

2.    Stone JL, Robin AL, Novack GD, Covert DW, Cagle GD. An objective evaluation of eyedrop instillation in patients with glaucoma. Archives of Ophthalmology 2009;127:732–6.

Citation: The Salvadore URI: 11016333

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