Background: Rheumatoid arthritis (RA) is a debilitating disease
which results in joint destruction, mainly due to chronic inflammation and
oxidative stress. Meloxicam (MLX) is a preferential cyclooxygenase-2
(COX-2) inhibitor with potential free radical scavenging activity. Mixed
nanomicelles (NMs) of MLX can augment its antioxidant effects.
Objective: The present study aims to prepare, characterize, and evaluate the
in vitro antioxidant effects of MLX-loaded mixed nanomicelles (MLXNMs).
Method: Conventional thin-film hydration method was employed to fabricate
MLX-NMs. The formulations were characterized for particle size, zeta potential, entrapment
efficiency (EE), and drug loading (DL). Additionally, the optimized formulation
was characterized for small-angle neutron scattering (SANS), in vitro drug release, and morphology.
MLX encapsulation in NMs was confirmed by Fourier Transform Infrared spectroscopy
(FTIR), differential scanning calorimetry (DSC), 1H nuclear magnetic resonance
(NMR), and X-ray diffraction (XRD), studies. The cell uptake of sulforhodamine B (SRB)-
labeled NMs was studied in RAW 264.7 cells. The in vitro antioxidant activity of optimized
MLX-NMs was studied by different antioxidant assays.
Results: The optimized MLX-NMs exhibited average size and zeta potential of 88 ± 42 nm
and -47.4 ± 16.2 mV, respectively. The EE and DL of MLX were 94.13 ± 1.01 % and 4.20 ±
0.05 %, respectively. Morphology studies confirmed the oblate ellipsoidal shape of MLXNMs.
The in vitro release study exhibited a biphasic release pattern. MLX encapsulation into
the micelle core was confirmed by FTIR, DSC, 1H NMR, and XRD studies. Additionally,
SRB-labeled NMs demonstrated efficient in vitro cell uptake in RAW 264.7 cells. Furthermore,
in vitro antioxidant studies exhibited superior free radical scavenging activity of MLXNMs
as compared to free MLX.
Conclusion: The NMs potentiate the in vitro antioxidant effects of MLX.