Lemongrass (Cymbopogon citratus) is an aromatic plant of great significance in industries due to its essential oil characteristic aroma. Essential oils are concentrated plant extracts that evaporate when in contact with air and have low chemical stability, which can improve encapsulation techniques. This study aimed to evaluate the seasonal influence in the concentration of the predominant component citral of the essential oil of C. citratus and develop microparticles by spray drying containing this vegetal matrix. The lemongrass leaves were collected in the four seasons, and the essential oil was extracted by hydrodistillation. The chemical composition was determined by gas chromatography coupled with the mass spectrometry technique (GC-MS). Different proportions of arabic and guar gums were evaluated as encapsulating agents. Physicochemical analyses characterized the microparticle powder. GC-MS showed higher citral in the spring and summer (84.89% and 79.39%, respectively), and it was possible to identify a high amount of citral in the microparticles. Field-emission scanning electron microscopy showed agglomerate and collapsed microparticles. Fourier transform infrared spectroscopy suggested the essential oil encapsulation due to a band at 1675 cm^-1 used as a reference, related to the acyclic monoterpenes of citral. X-ray diffraction showed the amorphous structure of the microparticles. Thermogravimetric curves of microparticles showed higher T_onset in microparticles than those observed for pure lemongrass essential oil, inferring that microencapsulation improved the thermal stability. This result confirms the lemongrass essential oil microencapsulation and its potential application in food products, drugs, or cosmetics.

Essential oils (EOs) are recognized for their multiple health benefits. However, their high volatility, low stability, and limited water solubility limit their effective application. This systematic review aims to assess the use of nanoemulsions as delivery systems for the topical administration of EOs, highlighting their efficacy, safety, and limitations. A literature search was conducted in the PubMed, Scopus, and Web of Science databases for studies published in English before February 2025, following the PRISMA 2020 guidelines. Studies limited to in vitro or ex vivo assays, using isolated EO components, or involving non‐topical applications were excluded. Twenty‐two articles were included in this review, comprising EOs from 18 plant species, and applied in animal or human in vivo models for wound healing ( n = 6), anti‐inflammatory/analgesic effects ( n = 5), cosmetic ( n = 6), and transdermal delivery/permeation enhancer ( n = 5). Nanoemulsions improved EOs' bioactivities, particularly their anti‐inflammatory, antioxidant, and antimicrobial effects, by enhancing skin permeation, bioavailability, and skin barrier function, reducing skin irritation, and allowing a controlled release. However, the overall risk of bias, assessed using the SYRCLE and RoB 2 tools, was considered high, and the studies' heterogeneity limited direct comparisons. Therefore, further well‐designed preclinical and clinical trials are needed to validate these findings and assess the potential of the EOs nanoemulsions for topical use.

This study aimed to develop and analyze nystatin:β-cyclodextrin and chlorhexidine:β-cyclodextrin mucoadhesive hydrogels. Hydrogels were characterized by in vitro and ex vivo analyses, and antifungal activity against Candida albicans. The hydrogel showed high adhesiveness and retention (83.37 ± 2.05%) to the porcine oral mucosa. The drug release from complexed nystatin and chlorhexidine hydrogels was 1.5 (95 µg/cm²) and 4.0 times higher (800 µg/cm²) than non-complexed drugs. Rheological studies indicated the prevalence of elastic behavior of the formulations. Ex vivo permeation using porcine mucosa showed retention on the oral mucosa. Hydrogels with nystatin and chlorhexidine inclusion complex showed inhibition percentages of 88.87% and 91.57%, respectively, and median inhibition zones of 8 mm. Mucoadhesive hydrogels with inclusion complex are promising for oral lesions with greater retention at the treatment site.

Striae distensae are common dermal lesions that negatively affect skin appearance, and topical management remains limited by challenges related to skin deposition and residence time. Here, we developed transparent surfactant‐based isotropic systems for the topical co‐delivery of ascorbic acid (AA), retinoic acid (RA), and lavender essential oil (LEO) as a multifunctional system for striae distensae management. Ternary phase‐diagram screening identified transparent single‐phase regions, and polarized light microscopy, pH, thermal profiling, texture profile analysis, and rheology were used to characterize three shortlisted formulations (ME28, ME29, and ME32). ME28 showed the most favorable mechanical profile, combining high adhesiveness and hardness with shear‐thinning behavior that supports skin residence while maintaining spreadability. Phase‐continuity studies (dye diffusion, low conductivity, and selective dilution) indicated an oil‐continuous (W/O‐like) structured isotropic system. Upon 1:100 aqueous dilution, ME28 formed a visually transparent dispersion with a hydrodynamic diameter of ~359 nm, PDI ~0.25, and zeta potential of −22 mV. ME28 also maintained macroscopic homogeneity, resisted centrifugation, and preserved an isotropic pattern under polarized light microscopy over 90 days, with better visual preservation under refrigeration. Preliminary cytocompatibility testing showed high fibroblast viability up to 0.25 mg/mL. Overall, ME28 represents a promising structured isotropic system for topical co‐delivery, combining mechanical performance, physical stability, defined phase‐continuity behavior, and preliminary cytocompatibility.

This study reports the experimental design-based optimization of ionic self-assembled lecithin (LC)–chitosan (CS) hybrid nanoparticles using progesterone (PG), a poorly water-soluble lipophilic model drug, to investigate the design-driven development of these nanoparticles. Nanoparticles were prepared by ethanol injection and optimized using a 3² factorial design to establish structure–property relationships between formulation variables and nanoparticle physicochemical performance. The optimized formulation exhibited a nanometric diameter (~ 230 nm), a narrow size distribution, a positive surface charge ( ~ + 20 mV), and a high encapsulation efficiency (~ 97%). Structural analyses (XRD and FTIR) suggested reduced PG crystallinity and interactions among the formulation components, supporting PG incorporation into the hybrid nanoparticles, while field-emission scanning electron microscopy (FESEM) revealed a uniform spherical morphology. Surface charge played a key role in mucin interactions by promoting electrostatic interactions, as evidenced by increased particle size, surface charge reversal, and a binding efficiency of approximately 28%. The hybrid nanoparticles exhibited pH-responsive drug release, with greater release under acidic conditions (73.9% at pH 4.0) than at neutral pH conditions (48.6% at pH 7.4) over 12 h. Release kinetics were compatible with diffusion-controlled behavior (n < 0.45), indicating transport through the ionically stabilized hybrid lipid–polymer matrix. This study provides a design-driven system for understanding how LC and CS composition modulates the colloidal organization, drug incorporation, surface charge, mucin interaction, and pH-dependent release of PG-loaded hybrid nanoparticles. These findings contribute to PG nanoparticle vaginal mucosal drug delivery by supporting the rational design of lipid–polymer nanocarriers for poorly water-soluble steroidal drugs and by identifying formulation attributes that may guide future mucosal-oriented delivery studies. Graphical abstract