Preclinical development of MGO Manuka Honey microemulsion for blepharitis management

• Published in: BMJ open ophthalmology 2017-08, Vol.1 (1), p.e000065
• Main Authors: Craig, Jennifer P, Rupenthal, Ilva D, Seyfoddin, Ali, Cheung, Isabella M Y, Uy, Benedict, Wang, Michael T M, Watters, Grant A, Swift, Simon
• Format: Article
• Language: English
• Subjects: Antibiotics; Bacteria; Drug resistance; Honey; Inflammation; Laboratories; Microemulsions; Original
• ISSN: 2397-3269; 2397-3269
• DOI: 10.1136/bmjophth-2016-000065

ObjectiveTo evaluate the in vitro antimicrobial effects of cyclodextrin-complexed and uncomplexed Manuka honey on bacteria commonly associated with blepharitis, and in vivo rabbit eye tolerability of a cyclodextrin-complexed methylglyoxal (MGO) Manuka Honey microemulsion (MHME).Methods and analysis In vitro phase: Bacterial growth inhibition was assessed by area under the growth curve (AUC) for Staphylococcus aureus, and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) for S. aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa with cyclodextrin-complexed and uncomplexed Manuka honey were determined. In vivo phase: Six rabbits were administered 20 µL of MHME (at 1:10 dilution) to the right eye (treated) and 20 µL of saline to the left eye (control) daily, for 5 days. Tear evaporation, production, osmolarity, lipid layer, conjunctival hyperaemia and fluorescein staining were assessed daily, before and 15 min after instillation.Results In vitro phase: The relative AUC for cyclodextrin-complexed Manuka honey was lower than that of uncomplexed honey at both 250 and 550 mg/kg of MGO (both p 0.05).ConclusionOverall, antimicrobial potency of cyclodextrin-complexed Manuka honey was greater than uncomplexed honey. No significant immediate or cumulative adverse effects were observed with MHME application on rabbit eyes, supporting future conduct of clinical safety and tolerability trials in human subjects.