# Evaluating and Managing the Microbial Contamination of Eye Drops: A Two-Phase Hospital-Based Study
## Materials and Methods
### Study Design
The method used was membrane filtration or STERITEST(r) (Merck, Lyon, France), which retains microorganisms on a filter with a pore size of 0.45 \(\upmu\)m, and all inhibitory compounds are rinsed using the appropriate rinsing solution. Appropriate media (thioglycolate broth and Trypic Soy Broth--Merck, France), selected based on their ability to promote the growth of anaerobic or aerobic microorganisms, are then used for the transfer of the membrane filters [40]. Evidence of microbial growth is detected by visual observation of turbidity in the culture medium. 1.2 Phase 2: Evaluation of the Practical and Antimicrobial Properties of the Pylote SAS Antimicrobial Technology  
The second phase evaluated the practical and antimicrobial properties of the Pylote SAS antimicrobial technology applied to the tips and caps of the eye drops. Validation of the Practical Application of Activated Rispharm(tm)  
This phase focuses on validating the practical application of the eye drops activated by Pylote SAS technology. The process extends from manufacturing to the end-user experience and provides a comprehensive understanding of the effectiveness and applicability of implementing Pylote SAS technology in healthcare settings. Activated Rispharm(tm) Eye Drops: Practical Evaluation  
Integrating the new packaging for eye drops in the UPSO2 production process requires ensuring that it does not cause malfunctions during production or patient use. The packaging evaluation entails producing three fictitious batches of ten placebo eye drops with Activated Rispharm(tm) packaging by three operators following the applied procedures. Three pharmacists from the unit simulated the use of eye drops by a patient. At each stage, the professionals' feedback relied on using a form listing critical points. The Production of a Batch of Eye Drops in an Isolator: For the production of eye drops in the isolator, the operators had to evaluate the following:  
The adaptability of the bottleneck to the filling process. The attachment of the dropper tip to the eye drop container. The capping procedure. Inspection and Packaging: For the inspection and control of organoletic characteristics, operators were asked to verify that the bottles were transparent enough to allow the detection of any non-conformities (clarity, absence of particles, color, volume). Concerning labeling and packaging, they had to ensure the absence of significant malfunctions on the labeling lines and verify the suitability of the eye drop bottle size for the size of the eye drop boxes used by UPSO2 for secondary packaging. Practical Use: A drop was extracted from the eye drops every hour for several consecutive hours to replicate patient use. This administration pattern corresponds to enhanced antibiotic eye drop treatments that must be administered every hour for an average of 2 to 3 days or longer, depending on the severity of the infection. Other evaluated aspects included the flexibility of the bottle during manipulation, the consistency of delivered drops, and changes in or issues with the eye drops during use. Validation of the Antimicrobial Properties of Activated RispharmTM  
The dropper tip and inner cap surfaces of the standard packaging and ActivatedTM packaging types were inoculated with a determined number of the pre-selected microorganisms (initial validation step). At 24 h of contact, the tip and inner cap surfaces were cultured as previously described. The testing groups were as follows:  
* Group 1: 3 standard packaging vs. 3 Activated RispharmTM packaging contaminated with 105 CFU of _S. aureus_. * Group 2: 3 standard packaging vs. 3 Activated RispharmTM packaging contaminated with 105 CFU of _P. aeruginosa_. * Group 3: 3 standard packaging vs. 3 Activated RispharmTM packaging contaminated with 105 CFU of _C. albicans_.