Predicting nanoemulsion formulation and studying the synergism mechanism between surfactant and cosurfactant: a combined computational and experimental approach

Development and Characterization of Silibinin-Loaded Nanoemulsions: A Promising Mucoadhesive Platform for Enhanced Mucosal Drug Delivery

Background: Silibinin (SLB), a flavonoid derived from milk thistle, exhibits promising therapeutic properties but faces significant clinical limitations due to poor solubility and bioavailability. Objectives: This study focuses on the development and characterization of SLB-loaded nanoemulsions designed for mucosal delivery. Methods: Nanoemulsions were prepared using the spontaneous emulsification method, guided by pseudoternary phase diagrams to determine selected component ratios. Comprehensive characterization included particle size, polydispersity index (PDI), zeta potential, encapsulation efficiency, rheological properties, and surface tension. Mucoadhesive properties were evaluated using quartz crystal microbalance with dissipation (QCM-D) to quantify interactions with mucin layers. Results: The combination of Capryol 90, Tween 80, and Transcutol in selected proportions yielded nanoemulsions with excellent stability and solubilization capacity, enhancing the solubility of silibinin by 625 times compared to its intrinsic solubility in water. The ternary phase diagram indicated that achieving nanoemulsions with particle sizes between 100 and 300 nm required higher concentrations of surfactants (60%), relative to oil (20%) and water (20%), with formulations predominantly composed of Smix (surfactant and cosurfactant mixture in a 1:1 ratio). Rheological analysis revealed Newtonian behavior, characterized by constant viscosity across varying shear rates and a linear torque response, ensuring ease of application and mechanical stability. QCM-D analysis confirmed strong mucoadhesive interactions, with significant frequency and dissipation shifts, indicative of prolonged retention and enhanced mucosal drug delivery. Furthermore, contact angle measurements showed a marked reduction in surface tension upon interaction with mucin, with the SLB-loaded nanoemulsion demonstrating superior wettability and strong mucoadhesive potential. Conclusions: These findings underscore the suitability of SLB-loaded nanoemulsions as a robust platform for effective mucosal drug delivery, addressing solubility and bioavailability challenges while enabling prolonged retention and controlled therapeutic release.

Alopecia Management Potential of Rosemary-Based Nanoemulgel Loaded with Metformin: Approach Combining Active Essential Oil and Repurposed Drug

Introduction

Androgenetic alopecia (AGA) is a multifactorial and age-related dermatological disease that affects both males and females, usually at older ages. Traditional hair repair drugs exemplified by minoxidil have limitations such as skin irritation and hypertrichosis. Thus, attention has been shifted to the use of repurposing drugs. Metformin is an anti-diabetic drug, that can promote hair follicle regeneration via upregulation of the hair-inductive capability. Hence, the current study aims to fabricate a safe and effective nanoemulsion to improve metformin efficacy in targeting AGA.

Methods

Rosemary oil was selected as the oily phase due to its ability to increase blood flow and hair growth. Rosemary-based nanoemulsions were statistically optimized by Box-Behnken experimental design, loaded with metformin, and incorporated into a hydrogel to form a nanoemulgel. Metformin-loaded nanoemulsions were assessed for their diametric size, uniformity, zeta potential, and metformin characteristics within the formulated nanosystem. The nanoemulgel was then evaluated in terms of its pH, percentage drug content, and in-vitro release performance. In-vivo study assessed the nanoemulgel's ability to augment hair growth in rats.

Results

The experimental design displayed that using 50%w/w, 20%w/w, and 10%w/w of Cremophor®, Labrafil®, and deionized water, respectively, resulted in nanoemulsion formulation with the smallest globule size (125.01 ± 0.534 nm), unimodal size distribution (PDI=0.103), negative surface charge (-19.9 ± 2.01 mV) with a spherical morphological structure. Rosemary-based nanoemulgel displayed acceptable physicochemical characterizations namely; a neutral pH value of 6.7±0.15, high drug content (92.9± 2.3%), and controlled metformin in-vitro release. Besides, the formulated nanoemulgel significantly increased the number of hair follicles in the animal model compared with other controls and tested groups.

Conclusion

The designed nanoemulgel is a promising approach for treating androgenic alopecia.

Lipid-Based Nanoparticles for Drug/Gene Delivery: An Overview of the Production Techniques and Difficulties Encountered in Their Industrial Development

Over the past decade, the therapeutic potential of nanomaterials as novel drug delivery systems complementing conventional pharmacology has been widely acknowledged. Among these nanomaterials, lipid-based nanoparticles (LNPs) have shown remarkable pharmacological performance and promising therapeutic outcomes, thus gaining substantial interest in preclinical and clinical research. In this review, we introduce the main types of LNPs used in drug formulations such as liposomes, nanoemulsions, solid lipid nanoparticles, nanostructured lipid carriers, and lipid polymer hybrid nanoparticles, focusing on their main physicochemical properties and therapeutic potential. We discuss computational studies and modeling techniques to enhance the understanding of how LNPs interact with therapeutic cargo and to predict the potential effectiveness of such interactions in therapeutic applications. We also analyze the benefits and drawbacks of various LNP production techniques such as nanoprecipitation, emulsification, evaporation, thin film hydration, microfluidic-based methods, and an impingement jet mixer. Additionally, we discuss the major challenges associated with industrial development, including stability and sterilization, storage, regulatory compliance, reproducibility, and quality control. Overcoming these challenges and facilitating regulatory compliance represent the key steps toward LNP's successful commercialization and translation into clinical settings.