Nanoemulsion-based gel formulations of COX-2 inhibitors for enhanced efficacy in inflammatory conditions

Development and preclinical assessment of nanoemulgel loaded with phytoconstituents for the management of rheumatoid arthritis

In recent years, natural ingredients have gained importance for therapeutic treatment due to their minimal toxicity. However, the delivery of these phytoconstituents poses a challenge to provide better efficacy. Current research reports the development of nanoemulgel (NEG) loaded with ginger oleoresin (GOR) and lipid guggul extract (LGE) for the management of rheumatoid arthritis (RA). The nanoemulsion (NE) was developed using the spontaneous emulsification technique by the pseudo-ternary method. The optimized nanoemulsion exhibited globule size of 16.08 ± 2.55 nm, PDI of 0.187 ± 0.06, and zeta potential of - 22.4 ± 0.31 mV. The cumulative release from in vitro diffusion studies at pH 7.4 was about 99.72 ± 3.47%, 57.98 ± 2.11%, and 86.42 ± 5.13% of 6-gingerol, E-guggulsterone, and Z-guggulsterone respectively at the end of 24 h. The ex vivo studies on porcine ear skin showed sustained release with 92.8 ± 3.21% for 6-gingerol, 55.61 ± 0.91% for E-guggulsterone, and 84.2 ± 4.22% for Z-guggulsterone released at the end of 24 h. The cell culture studies on RAW 264.7 cells indicated a robust inhibition of LPS-induced IL-6 and TNF-α production indicating its efficacy in the management of RA. The preclinical studies on male Wistar rats suggest that the developed NEG exhibited a comparable decrease in paw edema inflammation as compared to the marketed diclofenac sodium gel. These encouraging results demonstrate the potential of the developed nanoemulgel containing combination of GOR and LGE for the management of RA.

Nanoemulsions: summary of a decade of research and recent advances

Nanoemulsions consist of a combination of several components such as oil, water, emulsifiers, surfactants and cosurfactants. Various techniques for producing nanoemulsions include high-energy and low-energy approaches such as high-pressure homogenization, microfluidization, jet disperser and phase inversion methods. The properties of a formulation can be influenced by elements such as the composition, concentration, size and charge of droplets, which in turn can affect the technique of manufacture. Characterization is conducted by the assessment of several factors such as physical properties, pH analysis, viscosity measurement and refractive index determination. This article offers a thorough examination of the latest developments in nanoemulsion technology, with a focus on their wide-ranging applications and promising future possibilities. It also discusses the administration of nanoemulsions through several methods.

Nanoemulsion: An Emerging Novel Technology for Improving the Bioavailability of Drugs

The pharmaceutical sector has made considerable strides recently, emphasizing improving drug delivery methods to increase the bioavailability of various drugs. When used as a medication delivery method, nanoemulsions have multiple benefits. Their small droplet size, which is generally between 20 and 200 nanometers, creates a significant interfacial area for drug dissolution, improving the solubility and bioavailability of drugs that are weakly water-soluble. Additionally, nanoemulsions are a flexible platform for drug administration across various therapeutic areas since they can encapsulate hydrophilic and hydrophobic medicines. Nanoemulsion can be formulated in multiple dosage forms, for example, gels, creams, foams, aerosols, and sprays by using low-cost standard operative processes and also be taken orally, topically, topically, intravenously, intrapulmonary, intranasally, and intraocularly. The article explores nanoemulsion formulation and production methods, emphasizing the role of surfactants and cosurfactants in creating stable formulations. In order to customize nanoemulsions to particular medication delivery requirements, the choice of components and production techniques is crucial in assuring the stability and efficacy of the finished product. Nanoemulsions are a cutting-edge technology with a lot of potential for improving medication bioavailability in a variety of therapeutic contexts. They are a useful tool in the creation of innovative pharmaceutical formulations due to their capacity to enhance drug solubility, stability, and delivery. Nanoemulsions are positioned to play a crucial role in boosting medication delivery and enhancing patient outcomes as this field of study continues to advance.

Design and dermatokinetic appraisal of lornoxicam-loaded ultrafine self-nanoemulsion hydrogel for the management of inflammation: In vitro and in vivo studies

The present study aimed to evaluate the impact of ultrafine nanoemulsions on the transdermal delivery of lornoxicam (LOR) for management of the inflammation. The transdermal administration of LORNE could increase the efficacy of LOR with a reduction in side effects. Merging the beneficial properties of ultrafine nanoemulsions and their components (penetration enhancers) can lead to good solubilization, a small droplet size, and more effective LOR carriers. Therefore, this study aims to develop and evaluate the potential use of ultrafine nanoemulsions of LOR (LORNE) to elucidate their skin targeting for the treatment of inflammation. Based on solubility and pseudo ternary phase diagram tests, ultrafine LORNE composed of Labrafil M 2125 CS, Cremophor RH40, and Transcutol HP to deliver LOR was developed and characterized for its physicochemical properties, emulsification, and in vitro release. The selected LORNE was incorporated into carbopol gel (LORNE-Gel) and examined for ex vivo skin permeation, retention, dermatokinetics, anti-inflammatory efficacy, and skin irritation. The selected LORNE12-Gel could improve skin permeation, retention, and dermatokinetic results significantly (p < 0.05) with enhanced C_{Skin max} and AUC_0-48h compared to LOR-Gel. Moreover, LORNE12-Gel showed a remarkable anti-inflammatory effect compared to LOR-Gel after topical application. No signs of skin irritation were observed following treatment, indicating the safety of LORNE12-Gel. Thus, this study demonstrated that LOR-loaded LORNE12-Gel could be promising as an efficient transdermal nanocarrier for an anti-inflammatory alternative.

Current Advances in Lipid Nanosystems Intended for Topical and Transdermal Drug Delivery Applications

Skin delivery is an exciting and challenging field. It is a promising approach for effective drug delivery due to its ease of administration, ease of handling, high flexibility, controlled release, prolonged therapeutic effect, adaptability, and many other advantages. The main associated challenge, however, is low skin permeability. The skin is a healthy barrier that serves as the body's primary defence mechanism against foreign particles. New advances in skin delivery (both topical and transdermal) depend on overcoming the challenges associated with drug molecule permeation and skin irritation. These limitations can be overcome by employing new approaches such as lipid nanosystems. Due to their advantages (such as easy scaling, low cost, and remarkable stability) these systems have attracted interest from the scientific community. However, for a successful formulation, several factors including particle size, surface charge, components, etc. have to be understood and controlled. This review provided a brief overview of the structure of the skin as well as the different pathways of nanoparticle penetration. In addition, the main factors influencing the penetration of nanoparticles have been highlighted. Applications of lipid nanosystems for dermal and transdermal delivery, as well as regulatory aspects, were critically discussed.

Microemulsions and Nanoemulsions in Skin Drug Delivery

Microemulsions and nanoemulsions are lipid-based pharmaceutical systems with a high potential to increase the permeation of drugs through the skin. Although being isotropic dispersions of two nonmiscible liquids (oil and water), significant differences are encountered between microemulsions and nanoemulsions. Microemulsions are thermodynamically stable o/w emulsions of mean droplet size approximately 100–400 nm, whereas nanoemulsions are thermodynamically unstable o/w emulsions of mean droplet size approximately 1 to 100 nm. Their inner oil phase allows the solubilization of lipophilic drugs, achieving high encapsulation rates, which are instrumental for drug delivery. In this review, the importance of these systems, the key differences regarding their composition and production processes are discussed. While most of the micro/nanoemulsions on the market are held by the cosmetic industry to enhance the activity of drugs used in skincare products, the development of novel pharmaceutical formulations designed for the topical, dermal and transdermal administration of therapeutic drugs is being considered. The delivery of poorly water-soluble molecules through the skin has shown some advantages over the oral route, since drugs escape from first-pass metabolism; particularly for the treatment of cutaneous diseases, topical delivery should be the preferential route in order to reduce the number of drugs used and potential side-effects, while directing the drugs to the site of action. Thus, nanoemulsions and microemulsions represent versatile options for the delivery of drugs through lipophilic barriers, and many synthetic and natural compounds have been formulated using these delivery systems, aiming to improve stability, delivery and bioactivity. Detailed information is provided concerning the most relevant recent scientific publications reporting the potential of these delivery systems to increase the skin permeability of drugs with anti-inflammatory, sun-protection, anticarcinogenic and/or wound-healing activities. The main marketed skincare products using emulsion-based systems are also presented and discussed.

Nanoemulsion-based dosage forms for the transdermal drug delivery applications: A review of recent advances

INTRODUCTION

Nanoemulsion-based drug delivery approaches have witnessed massive acceptance over the years and acquired a significant foothold owing to their tremendous benefits over the others. It has widely been used for transdermal delivery of hydrophobic and hydrophilic drugs with solubility, lipophilicity, and bioavailability issues.

AREAS COVERED

The review highlights the recent advancements and applications of transdermal nanoemulsions. Their utilities and characteristics, clinical pertinence showcasing intellectual properties and advancements, potential in treating disorders accompanying liquid, semisolid, and solid dosage forms, the ability to modulate a drug's physicochemical properties, and regulatory status are thoroughly summarized.

EXPERT OPINION

Despite tremendous therapeutic utilities and extensive investigations, this field of transdermal nanoemulsion-based technologies yet tackles several challenges such as optimum use of surfactant mixtures, economic burden due to high energy consumption during production, lack of concrete regulatory requirement, etc. Provided with the concrete guidelines on the safe use of surfactants, stability, use of scalable and economical methods, and the use of NE as a transdermal system would solve the purpose best as nanoemulsion shows remarkable improvement in drug release profiles and bioavailability of many drugs. Nevertheless, a better understanding of nanoemulsion technology holds a promising outlook and would land more opportunities and better delivery outcomes.

A Review of Biopolymers' Utility as Emulsion Stabilizers

Polysaccharides, polynucleotides, and polypeptides are basic natural polymers. They have various applications based on their properties. This review mostly discusses the application of natural polymers as emulsion stabilizers. Natural emulsion stabilizers are polymers of amino acid, nucleic acid, carbohydrate, etc., which are derived from microorganisms, bacteria, and other organic materials. Plant and animal proteins are basic sources of natural emulsion stabilizers. Pea protein-maltodextrin and lentil protein feature entrapment capacity up to 88%, (1-10% concentrated), zein proteins feature 74-89% entrapment efficiency, soy proteins in various concentrations increase dissolution, retention, and stability to the emulsion and whey proteins, egg proteins, and proteins from all other animals are applicable in membrane formation and encapsulation to stabilize emulsion/nanoemulsion. In pharmaceutical industries, phospholipids, phosphatidyl choline (PC), phosphatidyl ethanol-amine (PE), and phosphatidyl glycerol (PG)-based stabilizers are very effective as emulsion stabilizers. Lecithin (a combination of phospholipids) is used in the cosmetics and food industries. Various factors such as temperature, pH, droplets size, etc. destabilize the emulsion. Therefore, the emulsion stabilizers are used to stabilize, preserve and safely deliver the formulated drugs, also as a preservative in food and stabilizer in cosmetic products. Natural emulsion stabilizers offer great advantages because they are naturally degradable, ecologically effective, non-toxic, easily available in nature, non-carcinogenic, and not harmful to health.

Recent exploration of nanoemulsions for drugs and cosmeceuticals delivery

BACKGROUND

Nanoemulsions (NEs) have been explored as nanocarriers for the delivery of many drugs and cosmeceuticals. The extraordinary expansion of using NEs is due to their capability to conquer the main challenges of conventional delivery systems such as short residence time with low patient acceptance, poor stability, low aqueous solubility, permeability, and hence bioavailability.

METHODS

This review recapitulated the most recent pharmaceutical and cosmeceutical applications of NEs as effective delivery nanocarriers. The outputs of our research studies and the literature review on the latest NEs applications were assessed to highlight the NEs components, preparations, applications, and the improved quality and elegance of the used product.

RESULTS

NEs are stable submicronic translucent dispersions with narrow droplet size distribution. They exhibited excellent ability to efficiently encapsulate therapeutics of diverse nature of drugs and cosmeceuticals. NE formulations showed superiority over conventional delivery approaches with overabundances of advantages through different routes of administration. This novel technology exhibited better aesthetic appeal, higher bioavailability, and a longer duration compared to the conventional delivery systems.

CONCLUSION

This novel technology holds promise for different therapeutics fields. However, the success of NEs use advocated the development of robust formulations, proper choice of equipment, ample process characterization, and assurance of their efficacy, stability, safety and cosmetic appeal.

Development of Propolis (Apis trigona)-loaded Nanoemulgel for Improved Skin Penetration of Caffeic Acid: The Effect of Variation of Oleic Acid Concentration

BACKGROUND: Propolis contains caffeic acid compounds, which are proven to have pharmacological effects as an anti-inflammatory. However, its effectiveness is hampered by the poor solubility of caffeic acid. Here, we report developing the nanoemulgel approach containing propolis extract as an active ingredient and oleic acid as a permeation enhancer for transdermal delivery of caffeic acid. AIM: This study aims to determine the effect of oleic acid concentration on increasing caffeic acid permeation in the skin and obtain a nanoemulgel formula with desired physical characteristics and stability. MATERIALS AND METHODS: Propolis was macerated with 70% ethanol; the total phenolic content was measured by ultraviolet–visible spectrophotometer, and the levels of caffeic acid in the extracts and nanoemulgel preparations were finally determined using ultra-fast liquid chromatography. Formulas were made using various concentrations of oleic acid, namely, 1.25%w/w (Formula F1); 2.5%w/w (Formula F2); 5%w/w (Formula F3), respectively; and 1.25%w/w without propolis extract (Formula F4) as a comparison. RESULTS: The results obtained from analysis of variance statistical exhibited that the difference in oleic acid concentrations in four formulas significantly affected (p < 0.05) particle size, polydispersity index, spreadability, adhesion, freeze-thaw, permeation, and retention test. However, there was no significant difference (p > 0.05) on pH and viscosity before and after 4 weeks of storage and zeta potential test. The highest amount of permeation and retention was found in F3 and F2, respectively, and all formulas tended to follow zero-order drug release kinetics. Furthermore, the results showed that the number of percent’s permeated in a row was 3.74% (F1); 5.58% (F2); 11.67% (F3), and F2 was the formula with the most optimal retention amount with a percentage of 43.13% at 24 h. CONCLUSION: This study shows a promising delivery system for increasing the effectiveness of natural lipophilic compounds to treat inflammation in the skin.

Glimepiride-Loaded Nanoemulgel; Development, In Vitro Characterization, Ex Vivo Permeation and In Vivo Antidiabetic Evaluation

Glimepiride (GMP), an oral hypoglycemic agent is extensively employed in the treatment of type 2 diabetes. Transdermal delivery of GMP has been widely investigated as a promising alternative to an oral approach but the delivery of GMP is hindered owing to its low solubility and permeation. The present study was designed to formulate topical nanoemulgel GMP system and previously reported solubility enhanced glimepiride (GMP/βCD/GEL-44/16) in combination with anti-diabetic oil to enhance the hypoglycemic effect. Nanoemulsions were developed using clove oil, Tween-80, and PEG-400 and were gelled using xanthan gum (3%, w/w) to achieve the final nanoemulgel formulations. All of the formulations were evaluated in terms of particle size, zeta potential, pH, conductivity, viscosity, and in vitro skin permeation studies. In vivo hypoglycemic activity of the optimized nanoemulgel formulations was evaluated using a streptozocin-induced diabetes model. It was found that a synergistic combination of GMP with clove oil improved the overall drug permeation across the skin membrane and the hypoglycemic activity of GMP. The results showed that GMP/βCD/GEL-44/16-loaded nanoemulgel enhanced the in vitro skin permeation and improved the hypoglycemic activity in comparison with pure and marketed GMP. It is suggested that topical nano emulsion-based GMP gel and GMP/βCD/GEL-44/16 could be an effective alternative for oral therapy in the treatment of diabetes.

Topical nanocarriers for management of Rheumatoid Arthritis: A review

Rheumatoid arthritis (RA) is a systemic autoimmune disease manifested by chronic joint inflammation leading to severe disability and premature mortality. With a global prevalence of about 0.3%-1% RA is 3-5 times more prevalent in women than in men. There is no known cure for RA; the ultimate goal for treatment of RA is to provide symptomatic relief. The treatment regimen for RA involves frequent drug administration and high doses of NSAIDs such as indomethacin, diclofenac, ibuprofen, celecoxib, etorcoxib. These potent drugs often have off target effects which drastically decreases patient compliance. Moreover, conventional non-steroidal anti-inflammatory have many formulation challenges like low solubility and permeability, poor bioavailability, degradation by gastrointestinal enzymes, food interactions and toxicity. To overcome these barriers, researchers have turned to topical route of drug administration, which has superior patience compliance and they also bypass the first past effect experienced with conventional oral administration. Furthermore, to enhance the permeation of drug through the layers of the skin and reach the site of inflammation, nanosized carriers have been designed such as liposomes, nanoemulsions, niosomes, ethosomes, solid lipid nanoparticles and transferosomes. These drug delivery systems are non-toxic and have high drug encapsulation efficiency and they also provide sustained release of drug. This review discusses the effect of formulation composition on the physiochemical properties of these nanocarriers in terms of particle size, surface charge, drug entrapment and also drug release profile thus providing a landscape of topically used nanoformulations for symptomatic treatment of RA.

Improving in vitro bioaccessibility and bioactivity of carnosic acid using a lecithin-based nanoemulsion system

As a phenolic terpenoid, carnosic acid (CA) mainly exists in rosemary, which can be effectively used for the treatment of degenerative and chronic diseases by taking advantage of its health-promoting bioactivities. However, the low solubility and dissolution of CA in aqueous solutions at ambient and body temperatures result in low stability and bioaccessibility during the digestion process, which limits its application scope in the functional foods industry. In this regard, a lecithin based nanoemulsion system (CA-NE) is employed in the present work to enhance the bioaccessibility and bioactivities of CA. It is revealed that the CA-NE under investigation exhibits high loading capacity (2.80 ± 0.15%), small particle size (172.0 ± 3.5 nm) with homogeneous particle distribution (polydispersity index (PDI) of 0.231± 0.025) and high repulsive force (zeta potential = -57.2 ± 0.24 mV). More importantly, the bioaccessibility of CA-NE is improved by 2.8-fold compared to that of CA in MCT oil. In addition, the cellular antioxidant assay (CAA) and cellular uptake study of the CA-NE in HepG2 cell models demonstrate a longer endocytosis process, suggesting the well-controlled release of CA from CA-NE. Furthermore, an improved anti-inflammatory activity was evaluated via the inhibition of the pro-inflammatory cytokines, nitric oxide (NO) and TNF-α production in LPS-stimulated RAW 264.7 macrophage cells. The results clearly demonstrated a promising application of CA-NE as a functional food.

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.

Design and optimization of film-forming gel of etoricoxib using research surface methodology

The present investigation is focused on the development of transdermal film-forming gel (FFG) loaded with etoricoxib employing research surface methodology (RSM). Box-Behnken surface design method was used to develop experimental run using different concentrations of etoricoxib, hydroxypropyl methylcellulose (HPMC K100M), and eudragit RL100 as independent variables, and Derringer's optimization tool was employed to optimize best possible formulation. The dependent variables considered in this study were viscosity and drug permeation at 24 h (Q24, μg/cm²). Anti-inflammatory study was performed on Wistar albino rats for 8 h. Skin irritation studies and accelerated stability studies were performed for validated FFG formulations. Quadratic model was found to be best fit model (p < 0.0001) for both the responses. The influence of HPMC concentration on the viscosity was found to be highest whereas concentration of etoricoxib was maximum for Q24. The optimum composition of the FFG was observed to be 4% of etoricoxib, 1.1246% of HPMC, and 0.4% of eudragit. Above composition resulted in viscosity of 1549.5 mPa.s and maximum Q24 of 4639.11 μg/cm² with desirability 0.918. The in vivo anti-inflammatory study demonstrated better sustained release effect (for 8 h) of optimized FFG compared to orally administered drug suspension. An average irritation score of 0.555 was observed on Draize scoring system. The validated FFG formulation was found to be stable for the 3 months in accelerated conditions. It can be concluded from the above investigations that the validated FFG formulation of etoricoxib is well tolerated and could provide sustained drug release for 8 h. Graphical abstract.

Nanocarriers for Topical Drug Delivery: Approaches and Advancements

Background:

Delivery of drugs through the skin has been an attractive as well as a challenging area for research. Topical drug delivery has provided enormous advantages over the systemic route for various drugs and one of the important amongst them is reduced toxicity due to a minimum or zero exposure to non-target organs.

Methods:

Various nanocarrier loaded topical preparations including organogels, emulgels, niosomal gel, lyotropic liquid crystal based gels, etc have been investigated for their topical application. Nanocarriers loaded topical preparation have been proven for improved permeation through the cutaneous barrier and delivering the drug at the target site. The objective of this review is to study the recent updates regarding newer topical gel formulations and highlighting their current potential and future scope of the same.

Results:

The present work has summarized different studies related to nanotechnology derived topical gel formulations and also enlisted few drugs which have been successfully formulated as novel topical gels. Advancement in nanocarriers loaded topical preparations have also been reviewed with their permeation and efficacy compared to conventional formulations.

Conclusion:

The present review will provide an overview of nanotechnology based topical preparation to the readers and will create curiosity for further development.

Transdermal Delivery of Snakehead Fish (Ophiocephalus striatus) Nanoemulgel Containing Hydrophobic Powder for Burn Wound

Background: The aim of the present study was to characterize and evaluate the nanoemulgel (NEG) of snakehead fish powder (SFP), as a transdermal delivery system for poorly water soluble drug, in order to conquer the inconveniences related to its oral conveyance. Methods: Diverse nanoemulsion components (oil, surfactant, and co-surfactant) were chosen based on solvency and emulsification capacity. SFP loaded nanoemulsion which tested by stress-stability testing was carried out for all formulations and those that passed these tests were characterized for mean droplet size, polydispersity index (PDI), zeta potential, pH, viscosity, and transmittance. After that, this was continued by permeation studies using snake skin in vitro and rabbit skin in vivo studies i.e. skin irritation study and the effectiveness test. Results: Mean droplet size and zeta potential of the optimized nanoemulsion (NE4) were found to be 98.6 ± 0.93 nm (polydispersity index, PDI = 0.1 ± 0.20) and -57.5 ± 0.3 mV respectively. Optimized nanoemulsion was converted into nanoemulgel with 1.5% w/v of gelling agent (HPMC) and evaluated for pH, viscosity, spreadability, and extrudability measurement. Ex vivo transdermal permeation value for SFP through snake skin as membrane from NEG1, NEG2, NEG3 and marketed SFP cream showed results of 55.65 ± 0.93%, 56.14 ± 0.70%, 66.75 ± 1.03% and 49.80 ± 3.42% respectively in 3 hours. Moreover, all the treatment group did not show skin irritation of each group. The effect of burn wound healing of NEG3 showed a significant (P<0.05) on the measurement of wound area compared to marketed cream. Conclusion: The novel NEG of SFP was successfully formulated for transdermal application based on the results of evaluations and stability tests on accelerating burn wound healing.

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.

Nanoemulsion as pharmaceutical carrier for dermal and transdermal drug delivery: Formulation development, stability issues, basic considerations and applications

The use of nanoemulsion in augmenting dermal and transdermal effectiveness of drugs has now well established. The development of nanoemulsion based semisolid dosage forms is an active area of present research. However, thickening or liquid-to-semisolid conversion of the nanoemulsions provides opportunities to the formulation scientist to explore novel means of solving instability issues during transformation. Extending knowledge about the explicit role of nature/magnitude of zeta potential, types of emulsifiers and selection of appropriate semisolid bases could place these versatile carriers from laboratory to industrial scale. This article reviews the progressive advancement in the delivery of medicament via nanoemulsion with special reference to the dermal and transdermal administration. It is attempted to explore the most suitable semi solid dosage form for the particular type of nanoemulsion (o/w, w/o and others) and effect of particle size and zeta potential on the delivery of drugs through dermal or transdermal route. Finally, this review also highlights the basic principles and fundamental considerations of nanoemulsion manufacture, application of nanoemulsion based semisolid dosage forms in the dermal/transdermal administration and basic considerations during the nanoemulsion absorption into and through skin.

Topical Nano and Microemulsions for Skin Delivery

Nanosystems such as microemulsions (ME) and nanoemulsions (NE) offer considerable opportunities for targeted drug delivery to and via the skin. ME and NE are stable colloidal systems composed of oil and water, stabilised by a mixture of surfactants and cosurfactants, that have received particular interest as topical skin delivery systems. There is considerable scope to manipulate the formulation components and characteristics to achieve optimal bioavailability and minimal skin irritancy. This includes the incorporation of established chemical penetration enhancers to fluidize the stratum corneum lipid bilayers, thus reducing the primary skin barrier and increasing permeation. This review discusses nanosystems with utility in skin delivery and focuses on the composition and characterization of ME and NE for topical and transdermal delivery. The mechanism of skin delivery across the stratum corneum and via hair follicles is reviewed with particular focus on the influence of formulation.

Nanoemulsion: Concepts, development and applications in drug delivery

Nanoemulsions are biphasic dispersion of two immiscible liquids: either water in oil (W/O) or oil in water (O/W) droplets stabilized by an amphiphilic surfactant. These come across as ultrafine dispersions whose differential drug loading; viscoelastic as well as visual properties can cater to a wide range of functionalities including drug delivery. However there is still relatively narrow insight regarding development, manufacturing, fabrication and manipulation of nanoemulsions which primarily stems from the fact that conventional aspects of emulsion formation and stabilization only partially apply to nanoemulsions. This general deficiency sets up the premise for current review. We attempt to explore varying intricacies, excipients, manufacturing techniques and their underlying principles, production conditions, structural dynamics, prevalent destabilization mechanisms, and drug delivery applications of nanoemulsions to spike interest of those contemplating a foray in this field.

Transungual Delivery of Ketoconazole Nanoemulgel for the Effective Management of Onychomycosis

Ketoconazole (KCZ) nanoemulgel containing permeation enhancer was formulated as a vehicle for transungual drug delivery, and its efficacy to inhibit the growth of onychomycotic dermatophytes was investigated in vitro. Different components of oil-in-water nanoemulsions were moderately agitated by classical titration method and passed through a high-pressure homogenizer to formulate various nanoemulsions, which were further identified by constructing pseudo-ternary phase diagrams. Stress-stability testing was carried out for the nanoemulsions, and those that passed these tests were characterized for mean droplet size, zeta potential, morphology, pH, refractive index, viscosity and transmittance. Mean droplet size and zeta potential of the optimized nanoemulsion (NE3) were found to be 77.52 ± 0.92 nm (polydispersity index (PDI) = 0.128 ± 0.035) and -5.44 ± 0.67 mV, respectively. Optimized nanoemulsion was converted into nanoemulgel (NEG₁) with 1% (w/w) of gelling agent (Carbopol® Ultrez 21) and 1%-2% (v/v) thioglycolic acid as permeation enhancer, and evaluated for pH, viscosity, spreadability, extrudability, tensile strength and bio-adhesion measurement. In vitro cumulative drug released at the end of 24 h from NE3, NEG₁ and drug suspension were found to be 98.87 ± 1.29, 84.42 ± 2.78% and 54.86 ± 2.19%, respectively. Ex vivo transungual permeation values for KCZ through goat hooves from NE3, NEG₁ and drug suspension were found to be 62.49 ± 2.98, 77.54 ± 2.88% and 38.54 ± 2.54%, respectively, in 24 h. The antifungal effect of NEG₁ on Trichophyton rubrum and Candida albicans showed a significant (p < 0.05) zone of inhibition as compared to drug solution. Skin irritation and histopathology studies on rat skin showed the safe topical use and enhanced permeation of formulated nanoemulgel.

Enhanced permeability of ferulic acid loaded nanoemulsion based gel through skin against UVA mediated oxidative stress

AIMS

The study was aimed to develop a ferulic acid (FA) loaded nanoemulsion based gel in order to ensure the enhanced permeability and maximum antioxidant activity against UVA induced oxidative stress in rat.

MAIN METHODS

The optimized ferulic acid loaded nanoemulsion 3 (FA-NE3) was prepared by spontaneous nano-emulsification method with an appropriate ratio (20:30:50% w/w) of the oil (isostearyl isostearate), aqueous system and Smix [surfactant (labrasol) and co-surfactant (plurol isostearique)] respectively. FA-NE3 was characterized by measuring their droplet size, zeta potential, refractive index, transmission electron microscopy (TEM), ultraviolet (UV), fourier transform infrared spectroscopy (FTIR) and rheological characteristics. Ex vivo skin permeation and in vivo UVA protection activity of FA-NE3 based nano-gels (FA-NG3) along with placebo were studied through the rat skin.

KEY FINDINGS

FA-NE3 exhibited sustained-release profile, better permeability and ultraviolet A (UVA) protection activity as compared to conventional dosage form. This phenomenon may be attributed towards increased solubility of the drug and enhanced permeability from nanoemulsion. FA-NE3 based nanogel (FA-NG3) could elevate the level of skin marker enzymes against oxidative stress mediated by UVA.

SIGNIFICANCE

The gel formulation exhibited significant (P<0.01) skin permeability and antioxidant activity in the current investigations. The nanogel could be promising nanocarriers for topical delivery of FA in response to better skin protection activity against UVA rays in a sustained manner.