Chemotactic and chemokinetic properties of topical ophthalmic preparations

Chronic ocular inflammation can be due to a disease process or to iatrogenic factors that attract inflammatory cells to the anterior chamber. This study was conducted to investigate the effect of commonly used ophthalmic preparations on leukocyte migration.

A modified multi-well Boyden chamber was used to study the chemotactic and chemokinetic effects of 33 commercial ophthalmic preparations. To determine whether the chemotactic effect was a property of the commercial ophthalmic preparation or other chemicals present in the products, experiments were also done with some common preservatives and excipients.

Of the drugs, 14 (42.4%) showed chemokinetic and/or chemotactic activity and 19 (57.6%) had either no effect or decreased neutrophil migration. Of the preservatives and excipients, 5 (62.5%) were found to be chemotactic. Eleven of 14 chemotactic drugs (78.6%) and 8 of 19 non-chemotactic drugs (42.1%) were positive for at least one chemotactic excipient. The correlation between chemotactic ophthalmic preparations and the presence of a chemotactic excipient in their composition was significant (p < 0.05).

Chemotactic activity was commonly found in commercial ophthalmic preparation. Furthermore, the presence of certain chemotactic preservatives and/or excipients was a contributing factor enhancing this property. Avoiding known chemotactic compounds or adjusting the intervals of the treatment may help to eliminate this iatrogenic component of the inflammatory process especially in patients with chronic ocular inflammation.