Development of Nanoemulsion-based Hydrogel Containing Andrographolide: Physical Properties and Stability Evaluation

Effective Mosquito Repellents: Myrcene- and Cymene-Loaded Nanohydrogels against Aedes aegypti

Aedes mosquito-borne diseases remain a significant global health threat, necessitating effective control strategies. This study introduces monoterpenes-based nanohydrogels for potential use as repellents against Aedes aegypti, the primary dengue vector worldwide. We formulated hydrogels using cymene- and myrcene-based nanoemulsions with different polymers: chitosan, carboxymethylcellulose (CMC), and carbopol®. Our evaluations of rheological, texture, and bioadhesive properties identified CMC hydrogel as the most promising gelling agent for topical application, exhibiting sustained monoterpene release over 12 h with low skin permeation and high retention in the stratum corneum. Myrcene-loaded CMC hydrogel achieved a 57% feeding deterrence compared to 47% with cymene hydrogel in the mosquito membrane-feeding model. Molecular docking studies revealed interactions between myrcene and an essential amino acid (Ile116) in the Ae. aegypti odorant-binding protein 22 (AeOBP22), corroborating its higher repellent efficacy. These findings suggest that myrcene-loaded CMC hydrogels offer a promising, minimally invasive strategy for personal protection against Ae. aegypti and warrant further investigation to optimize monoterpene concentrations for vector control.

Statistical modeling, optimization and characterization of andrographolide loaded emulgel for its therapeutic application on skin cancer through enhancing its skin permeability

Andrographolide is a natural diterpene lactone with multiple biological effects. In the present study, a total of 11 andrographolide-loaded emulgels (ANG 1- ANG 11) were prepared by emulsification and solvent evaporation method using flaxseed oil and xanthan gum in different ratios, as suggested by the Design-Expert software. A 2-factor-5-level design was employed with different responses including spreadability, extrudability, viscosity, and drug release after 1 h (h) and 24 h. Based on the Design-Expert software response, the optimized emulgel ANG 12 was formulated and evaluated. The 24 h In-vitro drug release was found to be 95.7 % following Higuchi kinetics. Ex-vivo skin retention of 784.78 ug/cm2 was observed during the study. MTT assay performed on Human epidermoid carcinoma (A-431) cells demonstrated cell growth arrest at G0/G1 and G2/M phase after 24 h of ANG 12 treatment (IC50: 11.5 µg/ml). The cellular permeability of ANG-12 was assessed by Fluorescein isothiocyanate (FITC) assay. Compared to untreated cells (0.54 % uptake) the ANG-12 treated cells had shown 87.17 % FITC permeation. The biocompatibility study performed on non-cancerous human dermal fibroblast cells (HDF cells) shows 91.54 % viability after 24 h of the treatment showing the non-toxic nature of ANG-12. Confocal imaging had shown a significant time-dependent increase in in-vivo cellular uptake with enhanced, progressive penetration of the emulgel into the skin. An in-vivo skin irritation study conducted on Swiss albino mice confirmed the safety aspects of the ANG 12. Hence, it can be concluded that nanoemulgel of andrographolide (ANG 12) could be a novel approach to treating skin cancer.

A Wound-Healing Effect of Nanoemulgel of Kangkung (Ipomoea Reptans, Poir) Leaf Extract in STZ Diabetic Rats

Context

The chronic diabetes mellitus (DM) condition may lead to diabetic wounds that increase morbidity in patients. Ipomoea reptans Poir leaves have been widely reported to possess anti-diabetic activity due to their flavonoid contents. To enhance drug penetration, a nanoemulgel preparation was formulated.

Aims

This study aimed to evaluate the activity of nanoemulgel preparations of Ipomoea reptans Poir leaf extract on diabetic and non-diabetic wound-healing using male Wistar rats.

Settings and Design

This research was an experimental study with a post-test only control group design.

Materials and Methods

The rats (n = 32) were randomly divided into two groups: diabetic (induced by 40 mg/kg BW STZ) and non-diabetic model. Each model consisted of four groups: normal, positive control, I. reptans leaf extract (IRLE), and nanoemulgel of I. reptans leaf extract (NIRLE). All the animals studied were shaved from the back, and a 2.5 × 0.5 cm full-thickness excision wound was made. IRLE and NIRLE were administered daily and observed for the wound-healing process.

Statistical Analysis Used

The one-way analysis of variance with the Tukey post-hoc test was used for the statistical analysis.

Results

A NIRLE formulation has been developed to produce a preparation that meets the physical requirements. IRLE and NIRLE possessed wound-healing activity in normal and diabetic rat models. However, the wound-healing process in diabetic rats treated with NIRLE was faster than those with IRLE.

Conclusions

NIRLE increased the activity of wound-healing effect of I. reptans leaves on diabetic rats in comparison with the extract form.

Drug permeation enhancement, efficacy, and safety assessment of azelaic acid loaded SNEDDS hydrogel to overcome the treatment barriers of atopic dermatitis

Atopic dermatitis is one of the most widespread chronic inflammatory skin conditions that can occur at any age, though the prevalence is highest in children. The purpose of the current study was to prepare and optimize the azelaic acid (AzA) loaded SNEDDS using Pseudo ternary phase diagram, which was subsequently incorporated into the Carbopol 940 hydrogel for the treatment of atopic dermatitis. The composition was evaluated for size, entrapment efficiency, in vitro, ex vivo, and in vivo studies. The polydispersity index of the optimized preparation was found to be less than 0.5, and the size of the distributed globules was found to be 151.20 ± 3.67 nm. The SNEDDS hydrogel was characterized for pH, viscosity, spreadability, and texture analysis. When compared to the marketed formulation, SNEDDS hydrogel was found to have a higher rate of permeation through the rat skin. In addition, a skin irritation test carried out on experimental animals showed that the SNEDDS formulation did not exhibit any erythematous symptoms after a 24-h exposure. In conclusion, the topical delivery of AzA through the skin using SNEDDS hydrogel could prove to be an effective approach for the treatment of atopic dermatitis.

Design and Development of a Topical Nanogel Formulation Comprising of a Unani Medicinal Agent for the Management of Pain

The oil of the Unani medicinal herb Baboona (Matricaria chamomilla) has shown potential in the management of pain. However, predicaments such as poor skin penetration, skin sensitization, liable to degradation, and volatile nature restrict its use. Therefore, our group for the first time has developed a carrier-based delivery system to facilitate the direct application of chamomile oil to the forehead. The developed nanogel was characterized for physical parameters such as compatibility, TEM, and stability studies. Further, it was also evaluated for pH, viscosity, spread ability, and extrudability, as well as through texture analyses, in vitro studies, and skin irritation tests. The formulation was successfully developed with all the necessary attributes. The in vitro studies revealed the enhanced skin penetration of chamomile oil nanogel. The in vivo studies were also performed in chemically induced pain models, mimicking migraine. The studies show significant improvement of the pain threshold for chamomile nanogel when compared to the positive control group and the results were comparable to marketed diclofenac formulations. Finally, the encapsulation into nanogel reduced the skin irritation property. The nanogel formulation showed promising effects in the pain management of migraine.

Recent Update on Nanoemulsion Impregnated Hydrogel: a Gleam into the Revolutionary Strategy for Diffusion-Controlled Delivery of Therapeutics

Since earlier times, dermatological remedies have been utilized to treat diseases associated with pain, irritation, and skin conditions. Compared to other routes of drug delivery, topical delivery of drugs offers several benefits. Scientists are investigating different alterations in dosage forms in addition to existing topical formulations such as ointments, gels, creams, lotions, and ointments to significantly improve the permeation of drugs and enhance the pharmacological efficacy of medications that are poorly absorbed via the skin. Conventional formulations have a plethora of problems viz. poor absorption, no target specificity, low spreadability, and inadequate bioavailability which leads the researchers toward developing novel formulations like nanoemulsions. The nanoemulsion can enhance the gradient in concentration and thermodynamic movement toward the epidermis and enhance the penetration of its constituents. However, due to its difficult application, nanoemulsion's lower viscosity limited its use in transdermal delivery. Thus, the development of nanoemulsion-based hydrogels has shown to be a successful strategy for removing obstacles from existing drug formulations. The simple application, expedient spreadability, non-stickiness, safety, and effectiveness of nanoemulsion-based hydrogel have led to substantial growth in their research in recent years. This review gives a brief idea about the prevalence of skin diseases, skin as an obstacle for drug delivery, and recent research insights to combat these obstacles. The work highlights the mechanism of drug release via nanoemulsion, hydrogels, and nanoemulsion-based hydrogels with reference to recent research on hydrophobic and hydrophilic drugs.

Novel wine in an old bottle: Preventive and therapeutic potentials of andrographolide in atherosclerotic cardiovascular diseases

Atherosclerotic cardiovascular disease (ASCVD) frequently results in sudden death and poses a serious threat to public health worldwide. The drugs approved for the prevention and treatment of ASCVD are usually used in combination but are inefficient owing to their side effects and single therapeutic targets. Therefore, the use of natural products in developing drugs for the prevention and treatment of ASCVD has received great scholarly attention. Andrographolide (AG) is a diterpenoid lactone compound extracted from Andrographis paniculata. In addition to its use in conditions such as sore throat, AG can be used to prevent and treat ASCVD. It is different from drugs that are commonly used in the prevention and treatment of ASCVD and can not only treat obesity, diabetes, hyperlipidaemia and ASCVD but also inhibit the pathological process of atherosclerosis (AS) including lipid accumulation, inflammation, oxidative stress and cellular abnormalities by regulating various targets and pathways. However, the pharmacological mechanisms of AG underlying the prevention and treatment of ASCVD have not been corroborated, which may hinder its clinical development and application. Therefore, this review summarizes the physiological and pathological mechanisms underlying the development of ASCVD and the in vivo and in vitro pharmacological effects of AG on the relative risk factors of AS and ASCVD. The findings support the use of the old pharmacological compound ('old bottle') as a novel drug ('novel wine') for the prevention and treatment of ASCVD. Additionally, this review summarizes studies on the availability as well as pharmaceutical and pharmacokinetic properties of AG, aiming to provide more information regarding the clinical application and further research and development of AG.

An Overview of Nanoemulgels for Bioavailability Enhancement in Inflammatory Conditions via Topical Delivery

The anti-inflammatory drugs that are generally available possess the disadvantage of hydrophobicity, which leads to poor permeability and erratic bioavailability. Nanoemulgels (NEGs) are novel drug delivery systems that aim to improve the solubility and permeability of drugs across the biological membrane. The nano-sized droplets in the nanoemulsion enhance the permeation of the formulation, along with surfactants and co-surfactants that act as permeation enhancers and can further improve permeability. The hydrogel component of NEG helps to increase the viscosity and spreadability of the formulation, making it ideal for topical application. Moreover, oils that have anti-inflammatory properties, such as eucalyptus oil, emu oil and clove oil, are used as oil phases in the preparation of the nanoemulsion, which shows a synergistic effect with active moiety and enhances its overall therapeutic profile. This leads to the creation of hydrophobic drugs that possess enhanced pharmacokinetic and pharmacodynamic properties, and simultaneously avoid systemic side effects in individuals with external inflammatory disorders. The nanoemulsion's effective spreadability, ease of application, non-invasive administration, and subsequent ability to achieve patient compliance make it more suitable for topical application in the combat of many inflammatory disorders, such as dermatitis, psoriasis, rheumatoid arthritis, osteoarthritis and so on. Although the large-scale practical application of NEG is limited due to problems regarding its scalability and thermodynamic instability, which arise from the use of high-energy approaches during the production of the nanoemulsion, these can be resolved by the advancement of an alternative nanoemulsification technique. Considering the potential advantages and long-term benefits of NEGs, the authors of this paper have compiled a review that elaborates the potential significance of utilizing nanoemulgels in a topical delivery system for anti-inflammatory drugs.

Cellulose nanofibrils reinforced chitosan-gelatin based hydrogel loaded with nanoemulsion of oregano essential oil for diabetic wound healing assisted by low level laser therapy

Diabetic foot ulcers are imperfections in the process of wound healing due to hyperglycemic conditions. Here, a nanoemulgel fabricated with oregano essential oil nanoemulsion, assisted by low-level laser therapy, was investigated for its efficacy in diabetic wound healing. A hydrogel- based healing patch, fabricated using biological polymers namely chitosan and gelatin and, polyvinyl pyrollidone. The hydrogel was reinforced with cellulose nanofibrils for enhanced stability and barrier properties. Nanoemulsion of oregano essential oil, with an average particle size of 293.7 ± 8.3 nm, was prepared via homogenization with chitosan as the coating agent. Nanoemulsion impregnated hydrogel, termed as the nanoemulgel, was assessed for its physio-mechanical properties and healing efficiency. The strong linkages in nanoemulgel demonstrated its large swelling capacity, high mechanical strength, and maximum thermal stability. The optimized conditions for low-level laser therapy using 808 nm were 1 W. cm^-2 and 5 min. The optimized drug concentration of 128 μg. mL^-1 exhibited viability of NIH/3 T3 fibroblasts as 75.5 ± 1.2 % after 24 h. Cell migration assay demonstrated that dual therapy facilitated wound healing, with a maximum closure rate of 100 % at 48 h. In vivo results revealed the rapid healing effects of the dual therapy in diabetic rat models with foot ulcers: a maximum healing rate of 97.5 %, minimum scar formation, increased granulation, enhanced reepithelialization, and a drastic decrease in inflammation and neutrophil infiltration within the treatment period compared to monotherapy and control. In summary, the combinatorial therapy of nanoemulgel and low-level laser therapy is a promising regimen for managing diabetic foot ulcers with a rapid healing effect.

Andrographis paniculata Dosage Forms and Advances in Nanoparticulate Delivery Systems: An Overview

Andrographis paniculata is a well-known Asian medicinal plant with a major phytoconstituent of diterpene lactones, such as andrographolide, 14-deoxyandrographolide, and neoandrographolide. A World Health Organization (WHO) monograph on selected medicinal plants showed that A. paniculata extracts and its major diterpene lactones have promising anti-inflammatory, antidiabetic, antimalarial, anticancer, antifungal, antibacterial, antioxidant, and hypoglycemic activities. However, these active phytochemicals have poor water solubility and bioavailability when delivered in a conventional dosage form. These biological barriers can be mitigated if the extract or isolated compound are delivered as nanoparticles. This review discusses existing studies and marketed products of A. paniculata in solid, liquid, semi-solid, and gaseous dosage forms, either as an extract or isolated pure compounds, as well as their deficits in reaching maximum bioavailability. The pharmaceutics and pharmacological activity of A. paniculata as a nano-delivery system are also discussed.