DOI: 10.4103/odjo.odjo_23_26 ISSN: 2949-9607

Maintenance of sterility and antimicrobial activity of formulated cefazolin eye drops: Tested under real-time and simulated conditions

Himansu Sekhar Behera, Savitri Sharma, Aparajita Mallick, Sujata Das

Abstract

Purpose:

The study aimed to evaluate the safety, in terms of sterility, and the efficacy of in-house formulated cefazolin eye drops (in ocular lubricants) stored at two different temperatures.

Materials and Methods:

This was a prospective, comparative study with 10 formulated cefazolin (5%) eye drop bottles, which were divided into two groups (five in each group). Five bottles were kept at room temperature (25°C–37°C), while five bottles were kept at 2°C–4°C in the refrigerator for 4 weeks. Efficacy of the drug was checked by the agar diffusion method against a standard strain of Staphylococcus aureus . Simultaneously, the sterility of each drug was checked by inoculating one drop from each bottle on 5% sheep blood and chocolate agar plates. The plates were incubated at 37°C up to 4 days to check for any growth. We also collected used medication from patients and checked for efficacy and sterility by similar methods.

Results:

The zone of inhibition (ZOI) was comparable between the three groups (medication stored at room temperature, medication stored in refrigerator, and used medication from patients). The mean ZOI was 40 mm in the refrigerated condition, as well as the medication stored at room temperature on the 7 th day. The mean ZOI was 39.4, 39.8, and 39 mm for medication stored at room temperature, in the refrigerator, and used medication from patients, respectively, on the 28 th day. There was no contamination till the end of the study.

Conclusion:

Formulated cefazolin can be safely kept at room temperature for 4 weeks without losing its efficacy. There is no risk of contamination with proper maintenance of hygiene.

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