Tailoring moxifloxacin hydrochloride loaded oleic acid liposomes for the topical management of Methicillin-Resistant Staphylococcus aureus (MRSA)- Induced skin infection: In-vitro characterization and in-vivo assessment

Oleic acid liposomes (OALs) are novel vesicular carriers ofunsaturated fatty acids and their corresponding ionized species, arranged within an enclosed lipid bilayer. This study aimed to encapsulate moxifloxacin HCl (MOX), a broad-spectrum antibacterial drug into OALs for effective treatment of Methicillin-resistant Staphylococcus aureus (MRSA) infection through topical application. Various OALs were formulatedby combining varied quantities of phosphatidylcholine (PC), oleic acid (OA), and cholesterol (CH) with 50 mg of MOX. The OALs were produced utilizing varying sonication durations. MOX-loaded OALs were formulated using the thin film hydration method by applying (2⁴) a full factorial design utilizing the Design-Expert® software. The formula for MOX-loaded OALs was OAL13, which consisted of 200 mg of PC and 20 mg of OA. The mixture was sonicated for 5 min. The OAL13 exhibited spherical vesicles with a small diameter and a smooth outer surface. Additionally, the entrapment efficiency was measured to be 75.00 ± 1.41 %, the particle size was 234.65 ± 4.74 nm, the polydispersity index was 0.53 ± 0.01, and the zeta potential was -38.50 ± 0.42 mV. The OAL13 formula exhibited an extended release profile. Moreover, the antibiofilm activity of OAL13 gel and MOX-loaded liposomes gel against MRSA infection demonstrates greater activity than the MOX gel at the maximum concentration used (MIC/2). Furthermore, the in-vivo study showed that OAL13 improved MOX's antimicrobial and immunomodulatory effects against MRSA infection by increasing TLR-2 and IL-1β, as well as their downstream molecules NF-κB and TNF-α. Moreover, the histopathological examination conducted by a skin irritation test has verified the safety of OAL13. Overall, the results demonstrated the significant efficacy of MOX-loaded OALs in the treatment of MRSA infected wounds when applied topically.