Analytical Method for Quantifying Monoterpenoids (p-Cymene and Myrcene) in Nanoemulsions Using High-Performance Liquid Chromatography.

BACKGROUND: Myrcene and cymene, aromatic monoterpenes found in plants and essential oils, possess distinctive aromatic qualities. However, their volatility and limited solubility pose challenges in precise handling and formulation. Meanwhile, nanoemulsions emerge as promising drug delivery systems, improving the bioavailability and stability of these active ingredients. OBJECTIVE: This article aimed to develop an HPLC method for the quantification of two monoterpenoids, p-cymene and myrcene, in nanoemulsions. METHOD: The method used a Phenomenex® Synergi™ Fusion-RP column (150 mm × 4.6 mm id, 4 µm particle size) on an HPLC system with isocratic elution. The mobile phase was composed of acetonitrile and water (60:40, v/v) and was validated in terms of specificity, linearity, accuracy, precision, robustness, and selectivity. RESULTS: The method provided accurate and precise results with a correlation coefficient of 0.999 and RSD values of less than 2%. The method can be used for quality control of nanoemulsions containing these monoterpenoids and as a reference for future studies on their efficacy and stability. CONCLUSIONS: The study demonstrates the feasibility of using HPLC for the quantification of monoterpenoids in nanoemulsions and its potential as a quality control tool for nanoemulsion-based drug delivery systems. HIGHLIGHTS: The method's accuracy, precision, and reliability, as evidenced by high correlation coefficients and low RSD values, underscore its suitability for ensuring the consistent formulation of these monoterpenoid-containing nanoemulsions, while also serving as a reference point for future research endeavors in this field.

Liposome-siderophore conjugates loaded with moxifloxacin serve as a model for drug delivery against Mycobacterium tuberculosis.

Tuberculosis (TB) is an infectious disease that annually affects millions of people, and resistance to available antibiotics has exacerbated this situation. Another notable characteristic of Mycobacterium tuberculosis, the primary causative agent of TB, is its ability to survive inside macrophages, a key component of the immune system. In our quest for an effective and safe treatment that facilitates the targeted delivery of antibiotics to the site of infection, we have proposed a nanotechnology approach based on an iron chelator. Iron chelators are the primary mechanism by which bacteria acquire iron, a metal essential for their metabolism. Four liposomes were synthesized and characterized using the dynamic light scattering technique (DLS), nanoparticle tracking analysis (NTA), and transmission electron microscopy (TEM). All of these methods revealed the presence of spherical particles, approximately 200 nm in size. NTA indicated a concentration of around 1011 particles/mL. We also developed and validated a high-performance liquid chromatography method for quantifying Moxifloxacin to determine encapsulation efficiency (EE) and release profiles (RF). The EE was 51.31 % for LipMox and 45.76 % for LipIchMox. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) confirmed the phagocytosis of liposomal vesicles by macrophages. Functionalizing liposomes with iron chelators can offer significant benefits for TB treatment, such as targeted drug delivery to intracellular bacilli through the phagocytosis of liposomal particles by cells like macrophages.