Structural Insights into the Microemulsion‐Mediated Formation of Fluoroquinolone Nanoantibiotics

• Published in: ChemistrySelect (Weinheim) 2018-11, Vol.3 (41), p.11616-11621
• Main Authors: Saleem, Muhammad A., Nazar, Muhammad F., Yameen, Basit, Khan, Asad M., Hussain, Syed Z., Khalid, Muhammad R.
• Format: Article
• Language: English
• Subjects: Fluoroquinolone; Formulation, Interfacial film, Microemulsion; Nanoparticles
• ISSN: 2365-6549; 2365-6549
• DOI: 10.1002/slct.201801925

Microemulsions (μEs) are being exploited as a potential route for yielding an extensive range of nanoparticles of different chemical nature, shapes and sizes. Nanodrugs offer new avenues for structuring better “drug delivery systems”. In this study, an oil‐in‐water (o/w) μE formulation comprising N‐butyl acetate/polysorbate 80/ethanol/water was developed for the preparation of nanoparticles of fluoroquinolone antibiotics (FLQ‐NPs). A pseudoternary phase diagram was mapped at constant surfactant/cosurfactant (1:2), revealing improved and high loading of FLQs in an optimum μE formulation. The as‐formulated μE showed high loading of FLQs as; levofloxacin (4.20 wt.%), ciprofloxacin (3.16 wt.%), moxifloxacin (2.53 wt.%), gatifloxacin (1.36 wt.%), ofloxacin (0.70 wt.%). Fourier transform IR analysis indicated good compatibility of each FLQ drug with μE excipients. However, dynamic light scattering showed an increase in the average particle size of the μE on drug loading, indicating the accumulation of FLQ at interface layer of the micelle. Additionally, lyophilized levofloxacin (a selected antibiotic) showed long‐term stability, amorphous morphology and improved dissolution rate, inspected by scanning transmission electron microscopy, X‐ray diffraction and electronic spectroscopy, respectively. Moreover, fluorescence measurements suggested the interfacial vicinity of levofloxacin within the μE domain, which may support controlled release of drug during systemic circulation. A biocompatible and optimized o/w microemulsion formulation was developed and quantified through pseudoternary phase diagram. Complementary characterization techniques were employed to insight the as‐formulated microemulsion composition. Optimized microemulsion formulation was successfully utilized to prepare nanoparticles of fluoroquinolone antibiotics.  loading, suggesting the interfacial vicinity of antibiotics within the microemulsion domain.