Oils and lipids help make water-insoluble drugs soluble by dispersing them in an aqueous medium with the help of a surfactant and enabling their absorption across the gut barrier. The emergence of microemulsions (thermodynamically stable), nanoemulsions (kinetically stable), and self-emulsifying drug delivery systems added unique characteristics that make them suitable for prolonged storage and controlled release. In the 1990s, solid-phase lipids were introduced to reduce drug leakage from nanoparticles and prolong drug release. Manipulating the structure of emulsions and solid lipid nanoparticles has enabled multifunctional nanoparticles and the loading of therapeutic macromolecules such as proteins, nucleic acid, vaccines, etc. Phospholipids and surfactants with a well-defined polar head and carbon chain have been used to prepare bilayer vesicles known as liposomes and niosomes, respectively. The increasing knowledge of targeting ligands and external factors to gain control over pharmacokinetics and the ever-increasing number of synthetic lipids are expected to make lipid nanoparticles and vesicular systems a preferred choice for the encapsulation and targeted delivery of therapeutic agents. This review discusses different lipids and oil-based nanoparticulate systems for the delivery of water-insoluble drugs. The salient features of each system are highlighted, and special emphasis is given to studies that compare them.

Post-operative surgical site infections (SSI) present a serious threat and may lead to complications. Currently available dressings for SSI lack mucoadhesion, safety, efficacy and most importantly patient compliance. We aimed to address these concerns by developing a bioactive thiolated chitosan-alginate bandage embedded with zinc oxide nanoparticles (ZnO-NPs) for localized topical treatment of SSI. The FTIR, XRD, DSC and TGA of bandage confirmed the compatibility of ingredients and modifications made. The porosity, swelling index and lysozyme degradation showed good properties for wound healing and biodegradation. Moreover, in-vitro antibacterial activity showed higher bactericidal effect as compared to ZnO-NPs free bandage. In-vivo wound healing in murine model showed significant improved tissue generation and speedy wound healing as compared to positive and negative controls. Over all, thiolated bandage showed potential as an advanced therapeutic agent for treating surgical site infections, meeting the required features of an ideal surgical dressing.

Microneedle patches are promising transdermal drug delivery platforms with minimal invasiveness in a painless manner. Microneedle patch could be a promising alternate route for delivery of drugs having poor solubility and low bioavailability. This research work therefore, aimed to develop and characterize microneedle patch of thiolated chitosan (TCS) and polyvinyl acetate (PVA) for the systemic delivery of dydrogesterone (DYD). TCS-PVA-based microneedle patch was fabricated with 225 needles having a length of 575 µm with the sharp pointed end. Different ratios of TCS-PVA-based patch were employed to investigate the effects of mechanical tensile strength and percentage elongation. The scanning electron microscopy (SEM) revealed intact sharp-pointed needles. In vitro dissolution studies of microneedle patch (MN-P) were carried out by modified Franz-diffusion cell revealing the sustained release of DYD 81.45 ± 2.768 % at 48 hrs as compared to pure drug that showed 96.7 ± 1.75 % at 12 hrs. The transport of DYD (81%) across skin reaching the systemic circulation was evaluated through ex vivo permeation studies of MN-P. The skin penetration study through the parafilm M method showed good penetration with no deformation and breakage of needles along with no visible signs of skin irritation. Histological study of mice skins clearly showed the deeper penetration of needles into the skin. In summary, as-prepared MN-P show potential in developing an effective transdermal delivery system for DYD.

A facile, green synthesis of selenium doped zinc oxide nano-antibiotic (Se-ZnO-NAB) using the Curcuma longa extract is reported to combat the increased emergence of methicillin-resistant Staphylococcus aureus (MRSA). The developed Se-ZnO-NAB were characterized for their physicochemical parameters and extensively evaluated for their toxicological potential in an animal model. The prepared Se-ZnO-NABs were characterized via Fourier transformed infrared spectroscopy to get functional insight into their surface chemistry, scanning electron microscopy revealing the polyhedral morphology with a size range of 36 ± 16 nm, having −28.9 ± 6.42 mV zeta potential, and inductively coupled plasma optical emission spectrometry confirming the amount of Se and Zn to be 14.43 and 71.70 mg L⁻¹ respectively. Moreover, the antibacterial activity against MRSA showed significantly low minimum inhibitory concentration at 6.2 μg mL⁻¹ when compared against antibiotics. Also, total protein content and reactive oxygen species production in MRSA, under the stressed environment of Se-ZnO-NAB, significantly (p < 0.05) decreased compared to the negative control. Moreover, the results of acute oral toxicity in rats showed moderate variations in blood biochemistry and histopathology of vital organs. The teratogenicity and fetal evaluations also revealed some signs of toxicity along with changes in biochemical parameters. The overall outcomes suggest that Se-ZnO-NAB can be of significant importance for combating multi-drug resistance but must be used with extreme caution, particularly in pregnancy, as moderate toxicity was observed at a toxic dose of 2000 mg kg⁻¹.