Preparation of α-Tocopherol based nanoemulsion for efficacious delivery of Methotrexate

Development of bio-nano-herbicide using Eucalyptus citriodora essential oil against a notorious weed Echinochloa crus-galli

BACKGROUND

Weeds are a menace in agriculture causing crop yield reductions to the tune of 40-50%. To overcome the problems of weeds, herbicides have been used excessively to the extent that they have caused resistance in weeds, in addition to the environmental hazards. Nano-herbicides are intended to exploit botanicals to develop novel bio-nano-herbicide formulations. Bio-nano herbicide was developed using Eucalyptus citriodora essential oil combined high-energy approaches such as ultra-sonication and high-pressure homogenization. The formulation has hydrodynamic and physical sizes of 95.5 and 32.3-57.7 nm, respectively. The product was tested for their pre-emergence and post-emergence herbicidal activity against Echinochloa crus-galli.

RESULTS

Increased concentration of bio-nano-herbicide inhibited the pre-emergence of weed seeds. Treated weed seeds registered lower dehydrogenase (0.80 to 0.32), alpha-amylase (1.349 to 0.101 mg maltose), catalase (3.87 to 3.52 μmol H₂O₂ min-1 g-1 protein), peroxidase (3.96 to 3.61 U mg-1 protein min-1) and super oxide dismutase (0.94 to 0.56 U mg-1 protein min-1) activities than control. Further, foliar spray of 1% nanoemulsion recorded significantly lower total chlorophyll content (1.62 mg g-1 fresh weight), than the crude oil (2.58 mg g-1). The antioxidant enzyme activities increased immediately after the first spray and the weeds wilted after the second spray.

CONCLUSION

This study is a maiden attempt to clearly demonstrate that bio-nano-herbicide can be developed using Eucalyptus citriodora essential oil which has both pre-emergence and post-emergence inhibitory activities against the notorious weed Echinochloa crus-galli. Field studies are to be taken up in the near future to validate the herbicidal efficacy of the novel nano herbicide formulation. © 2025 Society of Chemical Industry.

Innovations in Nanoemulsion Technology: Enhancing Drug Delivery for Oral, Parenteral, and Ophthalmic Applications

Nanoemulsions (NEs) are submicron-sized heterogeneous biphasic liquid systems stabilized by surfactants. They are physically transparent or translucent, optically isotropic, and kinetically stable, with droplet sizes ranging from 20 to 500 nm. Their unique properties, such as high surface area, small droplet size, enhanced bioavailability, excellent physical stability, and rapid digestibility, make them ideal for encapsulating various active substances. This review focuses on recent advancements, future prospects, and challenges in the field of NEs, particularly in oral, parenteral, and ophthalmic delivery. It also discusses recent clinical trials and patents. Different types of in vitro and in vivo NE characterization techniques are summarized. High-energy and low-energy preparation methods are briefly described with diagrams. Formulation considerations and commonly used excipients for oral, ocular, and ophthalmic drug delivery are presented. The review emphasizes the need for new functional excipients to improve the permeation of large molecular weight unstable proteins, oligonucleotides, and hydrophilic drugs to advance drug delivery rapidly.

Development of a Novel Methotrexate-Loaded Nanoemulsion for Rheumatoid Arthritis Treatment with Site-Specific Targeting Subcutaneous Delivery

Rheumatoid arthritis (RA) is a systemic, chronic autoimmune disease that causes disability due to progressive inflammation and destruction of the tissues around the joints. Methotrexate is mainly used to prevent the progression of joint destruction and reduce the deformity. The major challenge in treating RA with methotrexate is the systemic side effects that limit dose escalation. Hence, a novel formulation of a methotrexate-loaded nanoemulsion for subcutaneous administration was developed that aims to deliver methotrexate into the system via the lymph. The methotrexate-loaded nanoemulsion was prepared by using the aqueous-titration method. The prepared nanoemulsion was investigated for particle size, surface charge, surface morphology, entrapment efficiency, DSC (differential scanning colorimetry), drug release, hemocompatibility assay, and cytotoxicity, as well as anti-arthritic and stability studies. The vesicle size, zeta potential, PDI (polydispersity index), and entrapment efficiency of the optimized nanoemulsion were 87.89 ± 2.86 nm, 35.9 ± 0.73 mV, 0.27, and 87 ± 0.25%, respectively. The DSC study showed that the crystalline methotrexate was converted to an amorphous form and the drug was fully incorporated into the vesicles. After 72 h, the optimized nanoemulsion showed a drug release of 96.77 ± 0.63%, indicating a sustained-release dosage form. Cytocompatibility testing by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide) assay on macrophage cell lines showed that the nanoemulsion was non-toxic. The formulation showed significant anti-arthritic activity compared to the marketed drug solution. In addition, the nanoemulsion containing methotrexate remained stable for three months when stored at a low temperature. Since the nanoemulsion containing methotrexate has excellent physicochemical properties and lowers systemic side effects by targeted delivery, it is a desirable technology for subcutaneous drug delivery.