Objectives: The aim of the current study was to minimize ocular irritation and prolong the pharmacological action of vancomycin via formulation into nanosized spherical niosomes loaded into pH-sensitive in-situ forming gel.
Methods: Stability and rheological behaviour of the various gelling systems were evaluated. The ability of the selected system to eradicate methicillin-resistant Staphylococcus aureus (MRSA) infections was examined in vitro and in vivo. Draize technique was also used to assess ocular irritation in rabbits.
Key findings: Nanosized spherical niosomes loaded with vancomycin at high entrapment efficiency were prepared and integrated into polymeric solution that forms gel in situ upon instillation into the eye, to allow for a further increase in the ocular residence time. In MRSA-infected rabbits, there were 180- and 2.5-fold increases in the antibacterial efficacy after treatment with the vancomycin niosomal gels in comparison with the untreated animals and the animals treated with the vancomycin free drug solution, respectively.
Conclusions: The developed formulations demonstrated promising in-vivo biocompatibility and antibacterial efficacy, signifying their potential application as ophthalmic preparation to overcome ocular infections induced by resistant bacterial strains while minimizing drug irritation and improving patient compliance.
Keywords: methicillin-resistant Staphylococcus aureus; in-situ forming gel; niosomes; ocular infections; vancomycin.
© 2019 Royal Pharmaceutical Society.