Microemulsions as nanocarriers for oral and transdermal administration of enoxaparin

Preparation, in vitro and in vivo evaluation of a novel mitiglinide microemulsions

This study aimed to prepare an o/w mitiglinide microemulsion (MTGME) to improve the drug solubility and bioavailability. The formulation of o/w MTGME was optimized by the solubility study of drug, pseudo-ternary phase diagram and Box-Behnken design successively. MTGME was characterized by dynamic laser light scattering (DLS), zeta potential and transmission electron microscopy (TEM), moreover, the storage stability, pharmacodynamics and pharmacokinetics were investigated. The optimal prescription for MTGME consisted of Maisine 35-1 (oil), Cremophor EL (surfactant) and propylene glycol (PG, cosurfactant). MTGME with a spherical dimension of 58.1 ± 5.86 nm was stable when stored at 4 °C for 3 months. The blood glucose levers (BGL) of diabetic mice were uniformly and significantly decreased by intragastric (i.g.) administration of 1-4 mg/kg MTGME, in which BGL (i.g. 4 mg/kg MTGME) was reduced by 69% during 24 h. The pharmacokinetics study of MTGME (i.g., 20 mg/kg) in Wistar rats showed higher plasma drug concentration (Cmax, 2.9 folds), larger area under curve (AUC, 4.6 folds) and oral bioavailability than those of MTG suspensions. Generally, the MTGME (o/w) showed good effect on controlling hyperglycemia. Therefore, microemulsion can be used as an effective oral drug delivery system to improve the bioavailability of MTG.

The Application of Nanogels as Efficient Drug Delivery Platforms for Dermal/Transdermal Delivery

The delivery of active molecules via the skin seems to be an efficient technology, given the various disadvantages of oral drug administration. Skin, which is the largest human organ of the body, has the important role of acting as a barrier for pathogens and other molecules including drugs; in fact, it serves as a primary defense system blocking any particle from entering the body. Therefore, to overcome the skin barriers and poor skin permeability, researchers implement novel carriers which can effectively carry out transdermal delivery of the molecules. Another significant issue which medical society tries to solve is the effective dermal delivery of molecules especially for topical wound delivery. The application of nanogels is only one of the available approaches offering promising results for both dermal and transdermal administration routes. Nanogels are polymer-based networks in nanoscale dimensions which have been explored as potent carriers of poorly soluble drugs, genes and vaccines. The nanogels present unique physicochemical properties, i.e., high surface area, biocompatibility, etc., and, importantly, can improve solubility. In this review, authors aimed to summarize the available applications of nanogels as possible vehicles for dermal and transdermal delivery of active pharmaceutical ingredients and discuss their future in the pharmaceutical manufacturing field.

Preparation and in vitro characterization studies of astaxanthin-loaded nanostructured lipid carriers with antioxidant properties

The purpose of this study was to evaluate the astaxanthin-loaded nanostructured lipid carriers (ASX-NLC) prepared using a high-pressure homogenization transport system for local application of astaxanthin. Dynamic light scattering (DLS) and X-ray diffraction (XRD) were used to study the effect of microencapsulation on the properties of ASX-NLC. The mean size of ASX-NLC was about 108.43 ± 0.26 nm and PdI was 0.176 ± 0.002. The ASX-NLC had high encapsulation efficiency which was 95.69 ± 0.13%. Good light stability and temperature stability were shown at the ASX-NLC, indicating that the preparation process was feasible. The 2,2-diphenyl-1-pyridylohydrazinyl (DPPH) scavenging test showed that ASX-NLC could still play an antioxidant role. In vitro release studies showed that compared with an astaxanthin ethanol solution, an ASX-NLC could maintain astaxanthin release more effectively. In vitro permeation studies showed that ASX-NLC could increase astaxanthin retention in the skin. In conclusion, ASX-NLC could significantly enhance astaxanthin accumulation during dermal applications. The research results have important reference significance for local skin applications and provide a basis for the development of nanostructured lipid carriers. ASX-NLC might be suitable carriers for the local application of astaxanthin.

Exploring the Versatility of Microemulsions in Cutaneous Drug Delivery: Opportunities and Challenges

Microemulsions are novel drug delivery systems that have garnered significant attention in the pharmaceutical research field. These systems possess several desirable characteristics, such as transparency and thermodynamic stability, which make them suitable for delivering both hydrophilic and hydrophobic drugs. In this comprehensive review, we aim to explore different aspects related to the formulation, characterization, and applications of microemulsions, with a particular emphasis on their potential for cutaneous drug delivery. Microemulsions have shown great promise in overcoming bioavailability concerns and enabling sustained drug delivery. Thus, it is crucial to have a thorough understanding of their formulation and characterization in order to optimize their effectiveness and safety. This review will delve into the different types of microemulsions, their composition, and the factors that affect their stability. Furthermore, the potential of microemulsions as drug delivery systems for skin applications will be discussed. Overall, this review will provide valuable insights into the advantages of microemulsions as drug delivery systems and their potential for improving cutaneous drug delivery.

Transdermal delivery of celecoxib and α-linolenic acid from microemulsion-incorporated dissolving microneedles for enhanced osteoarthritis therapy

Dissolving microneedles, the promising vehicles for transdermal delivery, are incapable of directly loading hydrophobic components that limit the application of transdermal drug delivery. Microemulsion holds great potential in the solubilisation of water-insoluble drugs but is limited by the high epidermal retention. In this study, we fabricated microemulsion-incorporated dissolving microneedles co-loading celecoxib and α-linolenic acid (Cel-MEs@MNs) for enhancing osteoarthritis (OA) therapy via synergistic anti-inflammation and potent transdermal delivery. Cel-MEs@MNs composed of celecoxib & α-linolenic acid-coloaded microemulsion (Cel-MEs) and hyaluronic acid-based microneedles (MNs) can be completely dissolved in 90 s with a particle size of ∼30 nm. Each microneedle array with a hardness exceeding 30 N contained 57.9 ± 2.5 μg of celecoxib and 442.5 ± 24.2 μg of α-linolenic acid. The 8 h-cumulative transdermal of celecoxib from Cel-MEs@MNs was 89.2 ± 5.1 μg celecoxib/cm², which is 2.98-fold higher than that from Cel-MEs. Combinational celecoxib and α-linolenic acid with a weight ratio of 1/5 can synergistically induce M1-like macrophage to M2 repolarization, reduce M1-like macrophages-resulted chondrocytes apoptosis, and lower serum prostaglandin E-2 (PGE-2). Notably, Cel-MEs@MNs amplified such collaborated anti-inflammatory effects. More importantly, in the treatment of OA-bearing rat models, Cel-MEs@MNs with a half-dose of celecoxib and α-linolenic acid significantly shrunk the paw swelling, reduced inflammatory cytokines, and improved cartilage damage compared with the oral administration of celecoxib and α-linolenic acid, as well as transdermal administration of Cel-MEs. Such an integrational strategy of microemulsion-incorporated dissolving MNs offers the feasibility of combinational celecoxib and α-linolenic acid in transdermal permeation and boosted OA therapy.