Preparation of Compound Salvia miltiorrhiza-Blumea balsamifera Nanoemulsion Gel and Its Effect on Hypertrophic Scars in the Rabbit Ear Model

Hypertrophic scars (HS) still remain an urgent challenge in the medical community. Traditional Chinese medicine (TCM) has unique advantages in the treatment of HS. However, due to the natural barrier of the skin, it is difficult for the natural active components of TCM to more effectively penetrate the skin and exert therapeutic effects. Therefore, the development of an efficient drug delivery system to facilitate enhanced transdermal absorption of TCM becomes imperative for its clinical application. In this study, we designed a compound Salvia miltiorrhiza-Blumea balsamifera nanoemulsion gel (CSB-NEG) and investigated its therapeutic effects on rabbit HS models. The prescription of CSB-NEG was optimized by single-factor, pseudoternary phase diagram, and central composite design experiments. The results showed that the average particle size and PDI of the optimized CSB-NE were 46.0 ± 0.2 nm and 0.222 ± 0.004, respectively, and the encapsulation efficiency of total phenolic acid was 93.37 ± 2.56%. CSB-NEG demonstrated excellent stability and skin permeation in vitro and displayed a significantly enhanced ability to inhibit scar formation compared to the CSB physical mixture in vivo. After 3 weeks of CSB-NEG treatment, the scar appeared to be flat, pink, and flexible. Furthermore, this treatment also resulted in a decrease in the levels of the collagen I/III ratio and TGF-β1 and Smad2 proteins while simultaneously promoting the growth and remodeling of microvessels. These findings suggest that CSB-NEG has the potential to effectively address the barrier properties of the skin and provide therapeutic benefits for HS, offering a new perspective for the prevention and treatment of HS.

Triptolide nanoemulsion gel as a transdermal drug delivery system: preparation, pharmacokinetics, and rheumatoid arthritis evaluation

PURPOSE

This study aimed to develop and evaluate triptolide nanoemulsion gels (TP-NE gels) as a transdermal drug delivery system.

METHODS

TP-NE was prepared and optimized via emulsification and the central composite design response surface method. The optimized TP-NE gel was evaluated in vitro and in vivo. TP-NE gel microstructure, in vitro and in vivo pharmacokinetics, and anti-rheumatoid arthritis effects were studied to evaluate the feasibility of its percutaneous administration.

RESULTS

The Optimized TP-NE was observed using a Malvern Autosizer Nano ZS 90 inspection system and a transmission electron microscope (TEM). The nanoemulsion had an average size of 162.9 ± 0.281 nm, a polydispersity index of 0.272 ± 0.024, a zeta potential of -30.03 ± 2.01 mV, and mostly spherical and uniform morphology. In addition, the TP-NE gel pharmacokinetics, assessed via a skin-blood two-site synchronous microdialysis, revealed that TP was higher in the skin than in the blood. TP-NE gel is crucial in reducing knee edema, inhibiting inflammation, and treating rheumatoid arthritis by regulating tumor necrosis factor-alpha, interleukin-1β, and -6 levels.

CONCLUSION

The TP-NE gel is a promising local delivery method for rheumatoid arthritis (RA)-associated edema and inflammation and can serve as a prospective platform for percutaneous TP administration.

In Vitro and In Vivo Investigation of a Dual-Targeted Nanoemulsion Gel for the Amelioration of Psoriasis

Psoriasis, due to its unique pathological manifestations and the limited success of existing therapeutic modalities, demands dedicated domain research. Our group has developed nanotherapeutics consisting of bioactives such as Thymoquinone (TQ) and Fulvic acid (FA), which have been successfully incorporated into a Nanoemulsion gel (NEG), taking kalonji oil as oil phase. The composition is aimed at ameliorating psoriasis with better therapeutic outcomes. TQ is a natural bio-active that has been linked to anti-psoriatic actions. FA has anti-inflammatory actions due to its free radical and oxidant-scavenging activity. Our previous publication reports the formulation development of the NEG, where we overcame the pharmaco-technical limitations of combining the above two natural bioactives. In vitro evaluation of the optimized NEG was carried out, which showed an enhanced dissolution rate and skin permeation of TQ. This work furthers the pharmaceutical progression of dual-targeted synergistic NEG to treat psoriasis. A suitable animal model, BALB/c mice, has been used to conduct the in vivo studies, which revealed the effective anti-psoriatic action of TQ. Molecular docking studies corroborated the results and revealed a good binding affinity for both the targets of TNF-α (Tumor necrosis factor) and IL-6 (Interlukin-6). Tissue uptake by Confocal laser scanning microscopy (CLSM), a skin interaction study of the gel formulation, and an antioxidant free radical scavenging assay (1-1 Diphenyl-2-picrylhydrazyl DPPH) were also carried out. It was concluded that the NEG may be effective in treating psoriasis with minimal side effects.

Pharmacokinetic Study of Triptolide Nanocarrier in Transdermal Drug Delivery System-Combination of Experiment and Mathematical Modeling

Compared with traditional oral and injection administration, the transdermal administration of traditional Chinese medicine has distinctive characteristics and advantages, which can avoid the "first pass effect" of the liver and the destruction of the gastrointestinal tract, maintain a stable blood concentration, and prolong drug action time. However, the basic theory and technology research in transdermal drug delivery are relatively limited at present, especially regarding research on new carriers of transdermal drug delivery and pharmacokinetic studies of the skin, which has become a bottleneck of transdermal drug delivery development. Triptolide is one of the main active components of Tripterygium wilfordii, which displays activities against mouse models of polycystic kidney disease and pancreatic cancer but its physical properties and severe toxicity limit its therapeutic potential. Due to the previously mentioned advantages of transdermal administration, in this study, we performed a detail analysis of the pharmacokinetics of a new transdermal triptolide delivery system. Triptolide nanoemulsion gels were prepared and served as new delivery systems, and the ex vivo characteristics were described. The metabolic characteristics of the different triptolide transdermal drug delivery formulations were investigated via skin-blood synchronous microdialysis combined with LC/MS. A multiscale modeling framework, molecular dynamics and finite element modeling were adopted to simulate the transport process of triptolide in the skin and to explore the pharmacokinetics and mathematical patterns. This study shows that the three-layer model can be used for transdermal drug delivery system drug diffusion research. Therefore, it is profitable for transdermal drug delivery system design and the optimization of the dosage form. Based on the drug concentration of the in vivo microdialysis measurement technology, the diffusion coefficient of drugs in the skin can be more accurately measured, and the numerical results can be verified. Therefore, the microdialysis technique combined with mathematical modeling provides a very good platform for the further study of transdermal delivery systems. This research will provide a new technology and method for the study of the pharmacokinetics of traditional Chinese medicine transdermal drug delivery. It has important theoretical and practical significance in clarifying the metabolic transformation of percutaneous drug absorption and screening for appropriate drugs and dosage forms of transdermal drug delivery.

Formulation Development and In Vitro/In Vivo Characterization of Methotrexate-Loaded Nanoemulsion Gel Formulations for Enhanced Topical Delivery

Methotrexate-loaded oil-in-water nanoemulsion formulations were prepared using the high shear homogenization technique. A drug excipient study (ATR-FTIR) was carried out to investigate the compatibility between the drug, the polymers, and its admixtures. The thermal stability of the nanoemulsion formulations was evaluated by subjecting them to a heating and cooling cycle. The prepared nanoemulsion formulations (FNE1 to FNE6) were evaluated for particle size, PDI value, and entrapment efficiency (EE). They were analyzed for morphological information using transmission electron microscopy. The drug (methotrexate)-loaded nanoemulsion formulations (FNE2, FNE4, and FNE6) were then converted into nanoemulsion gel formulations by adding 1% chitosan (polymer) as a gelling agent. The nanoemulsion gel formulations (FNEG2, FNEG4, and FNEG6) were investigated for physicochemical parameters, viscosity, spreadability, extrudability, drug content, and skin irritation. Various penetration enhancers (olive oil, clove, and almond oil) were employed to examine the potency of the prepared nanoemulsion gel formulations. In vitro drug release, ex vivo permeation, skin drug retention, and stability tests were carried out for evaluation of the prepared nanoemulsion gel formulations (FNEG2, FNEG4, and FNEG6). The data obtained from the in vitro study were subjected to the kinetic model, and the Korsemeyer-Peppas model was best fitted to the data. The nanoemulsion gel formulation FNEG6 showed the maximum controlled drug release and followed an anomalous, non-Fickian release mechanism. The use of almond oil in the preparation of the nanoemulsion gel formulation FNEG6 helped the penetration of the drug across stratum corneum and the restructuring of the properties of skin and resulted in a higher penetration and retention of methotrexate in a deeper layer of the skin. The current study concluded that the methotrexate-loaded nanoemulsion gel formulation FNEG6 showed the best optimum release, permeation, and retention results as compared to the available oral tablets' formulations, followed by a low serum concentration and the maximum drug retention, which is beneficial in treating skin infections and reducing systemic toxicity.

Development of Chitosan-Based Nanoemulsion Gel Containing Microbial Secondary Metabolite with Effective Antifungal Activity: In vitro and in vivo Characterizations

Purpose

Microbial resistance to antibiotics is one of the most important public health concerns of the 21^st century. We isolated, purified, and structurally elucidated antifungal secondary metabolites from red soil microbes and encapsulated them into chitosan (CS)-based nanoemulsion (NE) gel (NEG).

Methods

Three compounds were isolated and purified of which only one compound (Pure 2) showed potent antifungal activity (MFC: 8–132 µg/mL), which was also significantly (P<0.05) more efficient than fluconazole (MFC: 32–132 µg/mL). Pure 2 was structurally elucidated using 1D- and 2D-NMR before its incorporation into NEG. The formulations were prepared by high-speed homogenization technique. Physicochemical and pharmacological characterizations of formulations (ie, droplet size, PDI, zeta potential, drug content, viscosity, SEM, FTIR, spreadability, in vitro drug release, ex vivo permeation, in vitro antifungal and in vivo antifungal activities) were assessed.

Results

NMR analyses identified the compound as a derivative of phthalic acid ester (PAE). The optimized formulations displayed a droplet size <100 nm, -ve zeta potential, and PDI <0.45. The drug content was within the official limit of pharmacopeia (ie, 100±10%). Insignificant changes (P>0.05) in the viscosity of the formulations stored were observed. The morphology of the formulations indicated mesh-like structure. The FTIR study indicated that there were no interactions between the drug and other ingredients of the formulations. Optimum spreadability was observed in all formulations. NEG released 75.3±1.12% of Pure 2 after 12 hrs while NE released 85.33±1.88% of the compound. The skin permeation of F2 (71.15±1.28%) was significantly different (P<0.05) from F3 (81.80±1.91%) in rabbits. Complete and apparently safe recovery from the fungal infection was achieved in rabbits treated topically with Pure 2-loaded NEGs.

Conclusion

Hence, the NEG-loaded PAE isolated from Pseudomonas fluorescens represents a possible alternative for the treatment of fungal infections as compared to available therapies.

Development and Optimization of Cinnamon Oil Nanoemulgel for Enhancement of Solubility and Evaluation of Antibacterial, Antifungal and Analgesic Effects against Oral Microbiota

Oral health is a key contributor to a person’s overall health and well-being. Oral microbiota can pose a serious threat to oral health. Thus, the present study aimed to develop a cinnamon oil (CO)-loaded nanoemulsion gel (NEG1) to enhance the solubilization of oil within the oral cavity, which will enhance its antibacterial, antifungal, and analgesic actions against oral microbiota. For this purpose, the CO-loaded nanoemulsion (CO-NE) was optimized using I-optimal response surface design. A mixture of Pluracare L44 and PlurolOleique CC 497 was used as the surfactant and Capryol was used as the co-surfactant. The optimized CO-NE had a globule size of 92 ± 3 nm, stability index of 95% ± 2%, and a zone of inhibition of 23 ± 1.5 mm. This optimized CO-NE formulation was converted into NEG1 using 2.5% hydroxypropyl cellulose as the gelling agent. The rheological characterizations revealed that the NEG1 formulation exhibited pseudoplastic behavior. The in vitro release of eugenol (the marker molecule for CO) from NEG1 showed an enhanced release compared with that of pure CO. The ex vivo mucosal permeation was found to be highest for NEG1 compared to the aqueous dispersion of CO-NE and pure cinnamon oil. The latency reaction time during the hot-plate test in rats was highest (45 min) for the NEG1 sample at all-time points compared with those of the other tested formulations. The results showed that the CO-NEG formulation could be beneficial in enhancing the actions of CO against oral microbiota, as well as relieving pain and improving overall oral health.

Novel Approach for Transdermal Delivery of Rifampicin to Induce Synergistic Antimycobacterial Effects Against Cutaneous and Systemic Tuberculosis Using a Cationic Nanoemulsion Gel

Purpose

This study demonstrated improved transdermal delivery of rifampicin-loaded cationic nanoemulsion gel to treat systemic and cutaneous tuberculosis using capmul, labrasol, and acconon, which exert anti-Mycobacterium activities. This approach enhanced drug permeation across the skin, increased therapeutic efficacy, and reduced dose-related side effects.

Methods

Design Expert^® was used to optimize formulations (S_mix ratio and capmul as independent factors), which were prepared using a slow spontaneous titration method. The optimized nanoemulsion was incorporated into carbopol gel to allow for topical application and comparative assessments. Nanoemulsions and gels were evaluated for size, size distribution, shape, zeta potential, percent spread, viscosity, in vitro hemolysis, in vitro release, and ex vivo skin permeation and deposition. A mechanistic evaluation was performed using scanning electron microscopy. Furthermore, in vivo pharmacokinetic and irritation studies were performed.

Results

The optimized cationic nanoemulsion (OCNE-1) was characterized by small particle size (≤100 nm), had optimal viscosity, percent spread, zeta potential, and percent drug release, and was hemocompatible. The OCNE-1T gel exhibited higher permeation flux (51.32 ± 0.5 µg/cm² hr), permeation coefficient (2.566 ± 0.08 cm/hr), drug deposition (994.404 µg/cm²), and enhancement ratio (7.16) than those of the OCNE-1 nanoemulsion or drug solution. Scanning electron microscopy was used to characterize the mechanism of enhanced permeation. An In vivo study showed that the C_max and area under the curve following transdermal application were 4.34- and 4.74-fold higher than those following oral administration.

Conclusion

Transdermal delivery of rifampicin could be a promising alternative to conventional approaches to treat systemic and local tuberculosis, and other bacterial infections.

Development and optimization of nanoemulsion based gel for enhanced transdermal delivery of nitrendipine using box-behnken statistical design

Objective: The purpose of present research was to develop and statistically optimize nitrendipine nanoemulsion gel for transdermal delivery using box-behnken statistical design.Method: The nanoemulsion formulations bearing nitrendipine were prepared by application of ternary phase diagram and spontaneous emulsification method. Box-behnken design was employed for the optimization of nitrendipine loaded nanoemulsion. The independent variables were oil, surfactant and co-surfactant while globule size, drug content and zeta potential were dependent variables. The optimized nanoemulsion formulation was incorporated into gel and evaluated for in-vitro release, ex-vivo permeation studies, confocal laser scanning microscopy, skin irritation and histopathological studies.Results: The optimized formulation through box-behnken statistical design showed globule size of 20.43 ± 1.50 nm, drug content of 97.05 ± 1.77% and zeta potential of -15.45 ± 0.35 mV. The ex-vivo study confirmed the enhanced delivery of nitrendipine from nanoemulsion gel than compare to drug solution by virtue of better permeation and solubility. Nanoemulsion gel was proved significantly superior by confocal laser scanning microscopy for satisfactory permeation and distribution of gel, deep into the rat skin. The optimized gel was found with no allergic dermal effects and was proved safe by histopathological studies for transdermal application.Conclusions: Results reveals that developed nitrendipine nanoemulsion gel overcomes the limitation of low penetration and accentuate permeation through albino Wistar rat skin. It was concluded that nanoemulsion gel could be utilized as a potential carrier for transdermal delivery of nitrendipine.

Bromocriptine Nanoemulsion-Loaded Transdermal Gel: Optimization Using Factorial Design, In Vitro and In Vivo Evaluation

Bromocriptine mesylate (BCM), a dopaminergic agonist administered orally, exhibits retarded bioavailability owing to poor absorption and extreme first-pass metabolism. The objective of the current study was to develop, characterize, and statistically optimize BCM nanoemulsion (BCM-NE) loaded into a gel (BCM-NE gel) to evaluate its potential for improved permeation of BCM through the transdermal route, thereby improving its pharmacokinetic profile. BCM-NE was prepared by o/w spontaneous emulsification method and the effects of different formulation variables on the critical attributes of NE like globule size were investigated by implementing factorial design. The optimized formulation exhibited a mean globule size of 160 ± 6.5 nm, zeta potential of - 20.4 ± 1.23 mV, and drug content of 99.45 ± 1.9%. Ex vivo permeation studies across rat skin exhibited a significant enhancement in permeation, i.e., enhancement ratio (ER) of ~ 7.4 and 5.86 for BCM-NE and BCM-NE gel, respectively, when compared with aqueous BCM suspension gel. In vivo pharmacokinetic studies performed in rats demonstrated a higher and prolonged drug release of BCM from BCM-NE gel when compared to oral aqueous BCM suspension. The AUC_0-t for BCM-NE gel and BCM suspension was found to be 562.54 ± 77.55 and 204.96 ± 51.93 ng/ml h, respectively. The relative bioavailability (%F) of BCM was shown to be enhanced 274% by BCM-NE gel. Histopathological studies demonstrated the safety and biocompatibility of the developed system. All the above results proved that the BCM-NE gel could be a superior and patient-compliant alternative to oral delivery in the management of PD.

Appraisal of Transdermal Water-in-Oil Nanoemulgel of Selegiline HCl for the Effective Management of Parkinson's Disease: Pharmacodynamic, Pharmacokinetic, and Biochemical Investigations

In the present study, the potential of transdermal nanoemulsion gel of selegiline hydrochloride for the treatment of Parkinson's disease was investigated. Water-in-oil nanoemulsions were developed by comparing low- and high-energy methods and were subjected to thermodynamic stability tests, in vitro permeation, and characterization studies. In vitro studies indicated that components of nanoemulsion acted as permeation enhancers with highest flux of 3.531 ± 1.94 μg/cm²/h from nanoemulsion SB6 containing 0.5 mg selegiline hydrochloride, 3% distilled water, 21% S _mix (Span 85, Tween 80, PEG 400), and 76% isopropyl myristate by weight. SB6 with the least droplet size of 183.4 ± 0.35 nm, polydispersity index of 0.42 ± 0.06 with pH of 5.9 ± 0.32 and viscosity of 22.42 ± 0.14 cps was converted to nanoemulsion gel NEGS4 (viscosity = 22,200 ± 400 cps) by addition of Viscup160® for ease of application and evaluated for permeation, safety, and pharmacokinetic profile in Wistar rats. It provided enhancement ratio 3.69 times greater than conventional gel. NEGS4 showed 6.56 and 5.53 times increase in bioavailability in comparison to tablet and conventional gel, respectively, along with sustained effect. Therefore, the developed water-in-oil nanoemulsion gel promises to be an effective vehicle for transdermal delivery of selegiline hydrochloride.

Effects of Carbopol® 934 proportion on nanoemulsion gel for topical and transdermal drug delivery: a skin permeation study

Nanoemulsions (NEs) are used as transdermal drug delivery systems for systematic therapeutic purposes. We hypothesized that the skin permeation profile of an NE could be modulated by incorporating it into a hydrogel containing differing proportions of thickening agent. The objectives of this study were as follows: 1) to determine the stability and skin irritability of NE gels (NGs) containing 1%, 2%, and 3% (w/w) Carbopol^® 934 (CP934) (termed NG1, NG2, and NG3, respectively); 2) to compare the skin permeation profiles and drug deposition patterns of the NGs; and 3) to visualize the drug delivery routes of the NGs. Terbinafine and citral were incorporated into the NGs as model drugs. Ex vivo skin permeation tests indicated that the percutaneous flux rates of terbinafine decreased in the order NE (215 μg/cm²) > NG1 (213 μg/cm²) > NG2 (123 μg/cm²) > NG3 (74.3 μg/cm²). The flux rates of citral decreased in the order NE (1,026 μg/cm²) > NG1 (1,021 μg/cm²) > NG2 (541 μg/cm²) > NG3 (353 μg/cm²). The NGs accumulated greater amounts of the drugs in the stratum corneum and less in the epidermis/dermis than did the NE (P<0.05) over a period of 12 h. Laser scanning confocal microscopy indicated that the NGs altered the main drug delivery routes from skin appendages to intercellular paths. Histological images suggested that perturbations to the skin structure, specifically the size of the epidermal intercellular spaces and the separation distance of dermal collagen bundles, could be significantly minimized by increasing the proportion of CP934. These results suggest that adjustments of the CP934 proportions can be used to modulate the skin permeation profiles of NGs for specific therapeutic purposes.