Date of Award
1-1-2024
Document Type
Dissertation
Degree Name
Ph.D. in Pharmaceutical Sciences
First Advisor
Soumyajit Majumdar
Second Advisor
Mahmoud A. ElSohly
Third Advisor
Eman Ashour
School
University of Mississippi
Relational Format
dissertation/thesis
Abstract
This work investigates the formulation and characterization of stable and effective drug delivery systems for ocular infections using moxifloxacin (MOX) in combination with mucoadhesive polymers and cannabidiol (CBD). The work is divided into three interconnected studies, addressing the physicochemical interactions between MOX and polymers, the development of nanoemulsion gels, and the stability of dual-acting formulations.
The first project studies the interactions between fluoroquinolones (MOX, levofloxacin, and ciprofloxacin) and acidic mucoadhesive polymers (Carbopol®940 and Carbopol®934). Using varied drug-to-polymer ratios, high-performance liquid chromatography (HPLC), and Fourier-transform infrared (FTIR) spectroscopy, the study demonstrates that electrostatic interactions between the amine group of fluoroquinolones and the carboxylic groups of Carbopol® result in complexation. pH adjustments and the addition of basic salts such as sodium bicarbonate (NaHCO₃) and disodium hydrogen phosphate (Na₂HPO₄.2H₂O) effectively disrupt these complexes, enabling the development of clear solutions with drug retention between 97% and 103%.
The second project focuses on formulating a stable nanoemulsion gel eye drop combining MOX as an antibacterial agent with Carbopol® polymer as a mucoadhesive agent to enhance bioavailability and patient compliance. The addition of 2% basic salts successfully overcame physical incompatibilities between MOX and Carbopol®, resulting in clear nanoemulsions. Stability studies of formulations F1 and F3 showed consistent physicochemical properties under accelerated conditions, with F1 demonstrating optimal viscosity (54 cP) for eye drop applications. The formulation's enhanced bio-adhesive properties highlight its potential as a leading ocular therapeutic delivery system.
The third study explores a nanoemulsion (NE) formulation incorporating MOX and CBD for managing bacterial keratitis. Formulations using oleic acid and Capmul® PG-8 as lipid phases were characterized for particle size (PS), polydispersity index (PDI), zeta potential (ZP), pH, and osmolality. Stability studies revealed that formulations containing both MOX and CBD exhibited significantly higher CBD stability under accelerated conditions compared to CBD-only formulations. MOX was found to interfere with CBD degradation pathways, further enhancing formulation stability.
In conclusion, this thesis establishes innovative approaches for combining MOX with polymers and CBD to overcome formulation challenges, improve stability, and optimize therapeutic efficacy in ocular drug delivery systems. These findings contribute to advancing treatments for ocular infections and inflammation, with significant implications for future pharmaceutical applications.
Recommended Citation
Geweda, Mona M., "Moxifloxacin-Loaded Ophthalmic Nanoemulsions" (2024). Electronic Theses and Dissertations. 3013.
https://egrove.olemiss.edu/etd/3013
