METHODS: 5-fluorouracil-loaded ethosomes were prepared and subjected to size, zeta potential, morphology, drug content, drug release and skin permeation tests. The molecular characteristics of untreated, microwave and/or ethosome-treated skins were examined by Fourier transform infrared and raman spectroscopy, thermal and electron microscopy techniques.
RESULTS: The skin drug retention was promoted using larger ethosomes with negative zeta potentials that repelled anionic lipids of skin and hindered vesicle permeation into deep layers. These ethosomes had low ethanol content. They were less able to fluidize the lipid and defluidize the protein domains at epidermis to enlarge aqueous pores for drug permeation. Pre-treatment of skin by 2450 MHz microwave for 2.5 min further increased skin drug penetration and retention of low ethanol ethosomes and provided lower drug permeation than cases treated for 1.15 min and 5 min. A 2.5 min treatment might be accompanied by specific dermal protein fluidization via C=O moiety which translated to macromolecular swelling, narrowing of intercellular spaces at lower skin layers, increased drug retention and reduced drug permeation.
CONCLUSION: Ethosomes and microwave synergized to promote skin drug retention.
AREAS COVERED: This review examines the state of the art in passive (processing and formulation) and active (targeting ligand and receptor binding) technologies in association with the use of nanocarrier to combat lung cancer. It highlights routes to equip nanocarrier with targeting ligands as a function of the chemistry of participating biomolecules and challenges in inhalational nanoproduct development and clinical applications. Both research and review articles were examined using the Scopus, Elsevier, Web of Science, Chemical Abstracts, Medline, CASREACT, CHEMCATS, and CHEMLIST database with the majority of information retrieved between those of 2000-2018.
EXPERT COMMENTARY: The therapeutic efficacy of targeting ligand-decorated nanocarriers needs to be demonstrated in vivo in the form of finished inhalational products. Their inhalation efficiency and medical responses require further examination. Clinical application of inhaled nanocancer chemotherapeutics is premature.
AREAS COVERED: This comprehensive review deals with the survey, performed through different electronic databases, regarding various challenges and their solutions attained by fabricating delivery systems like nanoparticles, micelle, nanocapsules, nanochannels, and liposomes. It also covers the synthesis of novel LAPA-conjugates for diagnostic purpose.
EXPERT OPINION: Unfortunately, clinical use of LAPA is restricted because of its extensive albumin binding capacity, poor oral bioavailability, and poor aqueous solubility. LAPA is marketed as the oral tablet only. Therefore, it becomes imperative to formulate alternate efficient multiparticulate or nano-delivery systems for administration through non-oral routes, for active/passive targeting, and to scale-up by pharmaceutical scientists followed by their clinical trials by clinical experts. LAPA combinations with capecitabine and letrozole should also be tried for breast cancer treatment.
METHODS: This work reports the application of an X-ray microbeam via synchrotron SAXS/WAXS analysis to monitor drug crystallization in the skin, especially in the deeper skin layers. Confocal Raman spectroscopy (CRS) was employed to examine drug distribution in the skin to complement the detection of drug crystallization using SAXS/WAXS analysis.
RESULTS: Following application of saturated drug solutions (ibuprofen, diclofenac acid, and salts), CRS depth profiles confirmed that the drugs generally were delivered to a depth of ~15 - 20 µm in the skin. This was compared with the WAXS profiles that measured drug crystal diffraction at a depth of up to ~25 µm of the skin.
CONCLUSION: This study demonstrates the potential of synchrotron SAXS/WAXS analysis for profiling of drug crystallization in situ in the deeper skin layers without pre-treatment for the skin samples. [Figure: see text].