Magistraal bereide claritromycine oogpreparaten in vitro getest op groeiremming bij Moraxella catarrhalis

OBJECTIVE: To evaluate the in vitro efficacy of six novel ophthalmic clarithromycin formulations and to explore the pharmaceutical aspects of these formulations that may influence patient tolerability. Because clarithromycin ophthalmic formulations are not registered in Europe, we manufactured several extemporaneous ophthalmic formulations. DESIGN AND METHODS: Six clarithromycin ophthalmic formulations were prepared aseptically: three clear eye drops, two ophthalmic suspensions and one ophthalmic ointment. In vitro efficacy was tested by inoculating agar plates with Moraxella catarrhalis and determining growth inhibition. Bonferroni adjusted one-way ANOVA was used to statistically compare growth inhibition of the ophthalmic solutions. Formulations were tested for pH, presence of particles, and osmolarity. RESULTS: All six ophthalmic formulations resulted in significant growth inhibition of M. catarrhalis (P <0.001]. Clear eye drops based on clarithromycin powder for solution for injection performed best in terms of growth inhibition, followed by two suspension eye drops and preserved eye drops based on oral tablets (P <0.001). The preserved eye drop was the only ophthalmic formulation that met the ideal pharmaceutical criteria [pH 6.9, osmolarity 0.319 osmol/L]. The patient's ocular infection successfully resolved after intensive treatment with no significant residual ocular damage at two months. CONCLUSION: Clear clarithromycin eye drops based on oral tablets seem to be the most suitable ocular clarithromycin formulation: they showed excellent growth inhibition and met product specifications that are favourable for the prevention of ocular irritation. We therefore advocate the use of this extemporaneously prepared solution in absence of registered clarithromycin ophthalmic formulations or powder for solution for injection.