Background and importance Because of the absence of appropriate pharmaceutical forms, pharmaceutical compounding is necessary in paediatric patients.

Aim and objectives The aims of the study were to describe an eye drop formulation of levofloxacin 0.05% and to evaluate the effectiveness and safety of the eye drops in a premature infant.

Material and methods Case description: a premature infant (26 weeks’ gestation) was diagnosed with conjunctivitis due to Stenotrophomonas maltofilia multi-resistant, sensitive to levofloxacin. The neonatal intensive care unit requested the manufacture of levofloxacin based eye drops.

The pharmacy service initiated a bibliographic search to find out the indication, dosage, manufacture and stability of levofloxacin 0.05% based eye drops.

Results We decided to prepare it with injectable levofloxacin 500 mg/100 mL, taking into account the physical and chemical characteristics an ophthalmic drug should have:

• non–contraindicated excipients (injectable excipients: water, HCl and NaOH);

• acceptable pH (4.4–5.5) and osmotic concentration (300–310 mOsm/l).

We packaged the parenteral solution in a horizontal laminar flow cabin, filtering it with a 0.22 µm filter, in a light protected eye drops bottle. We checked whether it was clean and particle free. The validity period was established: 9 days inside a refrigerator, according to the risk matrix for sterile preparations included in the ‘Guía de Buenas Prácticas de Preparación de Medicamentes’.

The patient was started on treatment with levofloxacin 0.05% eye drops with the following dosage regimen: 1 drop every 6 hours. We recommended including the nasolacrimal canal for at least 2 min in order to avoid systemic absorption of the eye drops when administered via the eyes and to decrease any systemic adverse reactions. The patient showed good progress, so we decided to interrupt the treatment after 7 days due to symptomatic improvement with no conjunctivitis secretion. The eye drops were well tolerated.

Conclusion and relevance To manufacture eye drops it is necessary to know the physical and chemical characteristics of the active substance (pH, osmotic concentration and excipients), to ensure that it is effective, safe and stable.

The eye drops were effective and well tolerated in this premature infant, which means that it can be considered as a good option for other patients.

References and/or acknowledgements No conflict of interest.