SYNTHESIS AND CHARACTERIZATION OF NANO NSAIDS, BIOMEDICAL APPLICATION AND POTENTIAL TOXIC EFFECTS

Abstract

The therapeutic use of non-steroidal anti-inflammatory agents is associated with several tissue toxicities or organ failure. While these agents offer excellent anti-inflammatory, analgesic, and antipyretic effects, their therapeutic use is linked to tissue toxicities and organ failure. Reducing drug doses or discontinuing their use entirely is not practical, as alternate effective medications are lacking, and low dosages may not achieve the required therapeutic plasma concentration. Nano-drug delivery offers rational solutions to the challenges associated with high-dose drug formulations by decreasing the effective drug doses through conjugation to nanocarrier without compromising its therapeutic efficacy. Among nanocarriers, magnesium oxide nanoparticles can be used as an excellent drug delivery tool due to their mechanical strength, small particle size, wide surface area, and superior drug adsorption capabilities. In this investigation, we synthesized MgO nanoparticles (NPs) as carriers for naproxen sodium, creating two nanoformulations: "coated nanoformulation" (CNF) with naproxen sodium conjugated to MgO NPs and polyvinyl alcohol (PVA) as a capping agent, and "uncoated nanoformulation" (UNF) without PVA coating. Various analytical techniques, including UV-visible spectroscopy, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and laser-induced breakdown spectroscopy (LIBS), were used to analyze and compare all compounds. In vitro, the drug loading efficiency of MgO NPs and the drug release profile of CNF were also studied. Thorough acute and sub-acute toxicity experiments were conducted on male and female mice to assess the potential adverse effects and determine the lethal dose and no observed-adverse-effect level (NOAEL) of the CNF. Ultimately, a comprehensive investigation aimed to gain an understanding of any potential differences in organ specific responses between the conventional naproxen and its nanoformulations (CNF, UNF) at human therapeutic doses was conducted on target organs, specifically the heart, liver, stomach, and kidneys. To ensure unbiased results, bare MgO nanoparticles underwent separate and thorough evaluations to mitigate potential biases and provide a reliable assessment of the safety profile. At present, CNF with a hydrodynamic size of 161 nm and surface charge of ̶ 8.85 mV, showed maximal and sustained release of naproxen (>95%) at pH 6.8 within 24 h. XV Investigation of thermal attributes showed that the CNF was more stable at a higher temperature than free NPRS and UNF. In vivo anti-inflammatory, analgesic, and antipyretic activities revealed that in all cases, the potency and efficacy of CNF were found to be higher (p<0.05- p<0.001) than conventional NPRS and UNF. The ratio between the minimum effective dose (1 mg/kg) and LD50 indicated a broader therapeutic window. Since the concentration of NPRS in CNF was only 43.2 ± 2%, our results indicated that conjugation to MgO nanocarrier boosts the biological activity of NPRS by approximately 2.3 times. In addition, CNF is found to be biocompatible and hemocompatible. Data from the acute toxicity study of CNF indicated that it was well tolerated up to 2000 mg/kg b.w with an LD50 of 2574.77 mg/kg. While a 14-day subacute toxicity testing revealed that low dose (30 mg/kg) administration of CNF for 14 days did not produce any adverse effect on male and female Balb/c mice blood profile, serum ALT, AST, ALP, creatinine, bilirubin (total and direct), triglyceride, cholesterol, and LDH. Additionally, tissue oxidative stress markers (ROS and MDA) and antioxidant enzymes (CAT, SOD POD, and GSH) were found near normal levels. Histological assessment of brain, heart, stomach, spleen, liver, kidney, seminal vesicles, and testicular tissue obtained from male and female mice showed no evidence of toxicity. Mice when administrated a medium dose of naproxen nanoformulation (300 mg/kg) showed mild to moderated toxic effects (p<0.05) specifically on the brain, stomach, and heart in male and female mice. while, in the liver, kidney, spleen, testis, and seminal vehicles, the levels of ROS, LPO, CAT, SOD, POD, and GSH remained unaffected. Histological assessment revealed that administration of medium-dose has caused mild toxicity to brain, kidneys, and stomach tissues in male and female mice. Serum biochemical parameters, however, remained unaffected. At present some aspects of the toxicity were observed associated with the minimum dose (300 mg/kg) and in comparison, with the existing detecting indexes to determine the no-observed-adverse-effect level (NOAEL), the NOAEL of CNF was regarded as higher than 300 mg/kg in this study. The administration of a high dose (1000 mg/kg) altered all hematological, serum, and tissue biochemical and morphological parameters in both male and female mice significantly, therefore regarded as toxic. In the comparative study, compared to NPRS-treated mice data revealed that XVI all administration of the therapeutic dose of CNF and UNF to the experimental mice at a human therapeutic dose succeeded in preventing tissue damage through the restoration of hematological, serum, and tissue biochemical, histological, and immunohistochemical alterations to near control levels. However this effect was more pronounced in CNF treated mice as compared to UNF treated mice. on the other, the administration of NPRS alone had elevated MDA and ROS levels, and deceased CAT, POD, SOD, and GSH levels, significantly increased expression of IL-1β, IL-6, and TNF-α mRNA, COX-2, i-NOS, and caspase-3 expression in mice heart, liver, kidney, and stomach tissues. The present study demonstrates that CNF has a tissue-protective action and in the clinical setup can be a better alternative to conventional naproxen. In conclusion, the nanosizing of a drug offer much promise as a better alternative to standard anti-inflammatory drugs for the treatment of various diseases. In addition, synthesized nanoformulation “CNF” has potent anti-inflammatory activity, low toxicity, and a better safety profile than naproxen sodium alone, so it is recommended that the potential of this drug delivery system should be explored for the treatment of other inflammatory diseases for example chronic peptic ulcer, asthma, arthritis, tuberculosis, sinusitis, and active hepatitis.