Enhanced transdermal bioavailability of testosterone propionate via surfactant-modified ethosomes

Review on novel targeted enzyme drug delivery systems: enzymosomes

The goal of this review is to present enzymosomes as an innovative means for site-specific drug delivery. Enzymosomes make use of an enzyme's special characteristics, such as its capacity to accelerate the reaction rate and bind to a particular substrate at a regulated rate. Enzymosomes are created when an enzyme forms a covalent linkage with a liposome or lipid vesicle surface. To construct enzymosomes with specialized activities, enzymes are linked using acylation, direct conjugation, physical adsorption, and encapsulation techniques. By reducing the negative side effects of earlier treatment techniques and exhibiting efficient medication release, these cutting-edge drug delivery systems improve long-term sickness treatments. They could be a good substitute for antiplatelet medication, gout treatment, and other traditional medicines. Recently developed supramolecular vesicular delivery systems called enzymosomes have the potential to improve drug targeting, physicochemical characteristics, and ultimately bioavailability in the pharmaceutical industry. Enzymosomes have advantages over narrow-therapeutic index pharmaceuticals as focusing on their site of action enhances both their pharmacodynamic and pharmacokinetic profiles. Additionally, it reduces changes in normal enzymatic activity, which enhances the half-life of an enzyme and accomplishes enzyme activity on specific locations.

Development of erlotinib-loaded nanotransferosomal gel for the topical treatment of ductal carcinoma in situ

Aims: This study was aimed to formulate erlotinib (ERL)-loaded transferosomal gel (ERL@TG) intended for topical application for the treatment of ductal carcinoma in situ. Materials & methods: The optimized process involved a thin-film hydration method to generate ERL-loaded transferosomes (ERL@TFS), which was incorporated into a carbopol gel matrix to generate ERL@TG. The optimized formulation was characterized in vitro followed by cytotoxicity evaluation on MCF-7 breast cancer cell lines and acute toxicity and skin irritation studies was performed in vivo. Results: In a comparative assessment against plain ERL, ERL@TG displayed enhanced efficacy against MCF-7 cell lines, reflected in considerably lower IC50 values with an enhanced safety profile. Conclusion: Optimized ERL@TG was identified as a promising avenue for addressing ductal carcinoma in situ breast cancer.

Unlocking the potential of cosmetic dermal delivery with ethosomes: A comprehensive review

BACKGROUND

In a world where hair loss, acne, and skin whitening are common concerns, ethosomes emerge as a captivating breakthrough in cosmetic drug delivery.

METHOD

This review provides a comprehensive overview of the ethosomal system and assesses its potential as an effective nanocarrier for delivering active ingredients to the skin. The focus is on exploring their applications in various pathologies, particularly skin disorders such as acne, hair loss, and skin pigmentation.

RESULTS

Ethosomes are a novel type of vesicular nanocarrier composed of high concentrations of ethanol (20-45%) and phospholipids. Their unique structure and composition make them an ideal choice for transporting active ingredients through the skin, offering targeted and effective treatment. The inclusion of ethanol in ethosomes' composition gives them distinctive properties, including flexibility, deformability, and stability, facilitating deep penetration into the skin and enhancing medication deposition. Moreover, ethosomes improved theoverall drug-loading capacity, and specificity of target treatment CONCLUSION: Ethosomes represent a unique and suitable approach for delivering active cosmetic ingredients in the treatment of hair loss, acne, and skin whitening, presenting a versatile alternative to traditional dermal delivery systems. Despite the challenges associated with their complex preparation and sensitivity to temperature and humidity, the remarkable potential benefits of ethosomes cannot be ignored. Further research is crucial to unlock their full potential, understand their limitations, and refine their formulations and administration methods. Ethosomes hold the promise of transforming the way we address these cosmetic concerns, offering an exciting glimpse into the future of advanced skincare solutions.

Transethosome: An ultra-deformable ethanolic vesicle for enhanced transdermal drug delivery

Drug delivery through the skin improves solubility, bioavailability, and unwanted systemic side effects of the drug. The selection of a suitable carrier is a challenging process. The conventional lipid vesicles have some limitations. They deliver the drug in the stratum corneum and have poor colloidal stability. Here comes the need for ultra-deformable lipid vesicles to provide the drug beyond the stratum corneum. Transethosomes are novel ultra-deformable vesicles that can deliver drugs into deeper tissues. The composition of transethosomes includes phospholipid, ethanol and surfactants. Each ingredient has a pivotal role in the properties of the carrier. This review covers the design, preparation method, characterisation, and characteristics of the novel vesicle. Also, we cover the impact of surfactants on vesicular properties and the skin permeation behaviour of novel vesicles.

Wound Healing Efficacy of Rosuvastatin Transethosomal Gel, I Optimal Optimization, Histological and In Vivo Evaluation

This study aimed to make a formulation and statistical optimization of transethosomal formulations of rosuvastatin (ROS) to enhance its topical wound healing efficiency. Design-Expert^® software was used to employ I optimal design. The formulation variables in the study were surfactant concentration (%w/v), ethanol concentration (%w/v) and surfactant type (span 60 or tween 80), while the dependent responses were entrapment efficiency percent (EE%), vesicle size (VS) and zeta potential (ZP). The numerical optimization process employed by the design expert software resulted in an optimum formula composed of 0.819439 (%w/v) span 60, 40 (%w/v) ethanol and 100 mg lecithin with a desirability of 0.745. It showed a predicted EE% value of 66.5517 vs. 277.703 nm and a ZP of -33. When it was prepared and validated, it showed less than a 5% deviation from the predicted values. The optimum formula was subjected to further characterizations, such as DSC, XRD, TEM, in vitro release, the effect of aging and wound healing efficiency. The DSC thermogram made a confirmation of the compatibility of ROS with the ingredients used in the formulation. XRD showed the encapsulation of ROS in the transethosomal vesicles. The TEM image pointed out the spherical nature of the nanovesicles with the absence of aggregation. Additionally, the optimum formula revealed an enhancement of drug release in comparison with the drug suspension. It also showed good stability for one month. Furthermore, it revealed good wound healing efficiency when compared with the standard silver sulphadiazine (1% w/w) ointment or the drug-loaded gel, which could be related to the enhanced penetration of the nanosized vesicles of TESMs into the skin, which enhances the wound healing process. So, it could be regarded as a promising carrier of ROS for the treatment of chronic wounds.

Ethosomes as dermal/transdermal drug delivery systems: applications, preparation and characterization

Transdermal drug delivery systems (TDDSs) have gained substantial attention during the last decade. TDDS are versatile delivery systems in which active components are delivered to skin for local effects or systemic delivery of active pharmaceutical through the skin. Overcoming stratum corneum is the most challenging step of delivering drugs through the skin. Lipid-based vesicular delivery systems due to the capability of the delivery of both hydrophilic and hydrophobic drugs are becoming more popular during the recent years. Ethosomes are innovative, biocompatible, biodegradable and non-toxic form of lipid-based vesicles that efficiently enable to entrap drugs of various physicochemical properties. These are other forms of liposome which contain high amounts of ethanol in their structure that enabling ethosomes to efficiently penetrate through deeper layers of skin. Ethosomes have various compositions based on their type but are mainly composed of phospholipids, ethanol, water and the active components. Ethosomes are easily manufactured and they are superior compared to liposomes in terms of different aspects due to the presence of ethanol. The purpose of this review is to thoroughly focus on various aspects of ethosomes, including mechanism of penetration, advantages and disadvantages, characterisation and applications.

Transcutaneous tumor vaccination combined with anti-programmed death-1 monoclonal antibody treatment produces a synergistic antitumor effect

Transcutaneous immunization (TCI) has the advantages of safety, high efficiency, non-invasiveness and convenient use. The key for a TCI system is transdermal targeted delivery of antigen to dendritic cells (DCs), the most powerful antigen presenting cells. DCs also play an important role in tumor immunotherapy, which provides a huge imagination for the application of TCI to tumor treatment. In this study, a transcutaneous tumor vaccine (TTV) delivery system was developed using the electrospun silk fibroin (SF) and polyvinyl alcohol (PVA) composite nanofibrous patch loaded with mannosylated polyethyleneimine (PEI^man)-modified ethosome (Eth) (termed Eth-PEI^man). Eth-PEI^man showed a good performance in targeting DCs, and the carriers loaded with antigen (encapsulated in Eths) and adjuvant (absorbed in PEI^man) were observed effectively induce DCs maturation in vitro. With the tyrosinase-related protein-2 (TRP2) peptide as antigen and oligodeoxynucleotides containing unmethylated CpG motifs as adjuvant, the TTV-loaded patches (TTVP) significantly inhibited the growth of melanoma in a syngeneic mouse model for melanoma by subcutaneous injection of B16F10 cell lines. Moreover, the combined application of the TTVP and anti-programmed death-1 monoclonal antibody (aPD-1) produced a synergistic antitumor effect, which could be related to the infiltration of more CD4⁺ and CD8⁺ T cells in the tumor tissues. The application of TTVP also increased the expression of IL-12, which may be part of the mechanism of synergistic antitumor effect between the TTVP and aPD-1. These results suggest that the combination of the TTVP and immune checkpoint blockers could be an effective strategy for tumor treatment. STATEMENT OF SIGNIFICANCE: Transcutaneous immunization has the advantages of safety, high efficiency, non-invasiveness and convenient use. In this study, a novel transcutaneous tumor vaccine patch (TTVP) was developed using tumor antigens-loaded ethosomes that can target dendritic cells percutaneously. Our data demonstrated that the TTVP can significantly inhibit tumor growth. Furthermore, the combination of TTVP and aPD-1 produced a synergistic anti-melanoma effect. Considering its convenience and non-invasiveness, this TTVP system could find good application prospects in immunotherapy. The combination of TTVP and aPD-1 could be a useful strategy for the prevention and treatment of tumors.

Tailoring of Retinyl Palmitate-Based Ethosomal Hydrogel as a Novel Nanoplatform for Acne Vulgaris Management: Fabrication, Optimization, and Clinical Evaluation Employing a Split-Face Comparative Study

AIM

Retinyl palmitate (RP), the most stable vitamin A derivative, is used to treat photoaging and other skin disorders. The need to minimize the adverse effects of topical drug administration has led to an enhanced interest in loading RP on ethosomes for topical drug delivery. The aim of the current study was to prepare and compare the performance of RP decorated ethosomal hydrogel with tretinoin cream in the treatment of acne vulgaris as an approach to improve drug efficacy and decrease its side effects.

METHODS

RP-loaded ethosomes were prepared using the injection sonication technique. A Box-Behnken design using Design Expert® software was used for the optimization of formulation variables. Particle size, zeta potential (ZP), entrapment efficiency percent (EE%), % drug release, and permeation over 24 h of different formulations were determined. The optimal formulation was incorporated into a hydrogel. Finally, the efficacy and tolerability of the optimized RP ethosomal hydrogel were clinically evaluated for acne treatment using a split-face comparative clinical study.

RESULTS

The optimized ethosomal RP showed particle size of 195.8±5.45 nm, ZP of -62.1±2.85 mV, EE% of 92.63±4.33%, drug release % of 96.63±6.81%, and drug permeation % of 85.98 ±4.79%. Both the optimized RP ethosomal hydrogel and tretinoin effectively reduced all types of acne lesions (inflammatory, non-inflammatory, and total lesions). However, RP resulted in significantly lower non-inflammatory and total acne lesion count than the marketed tretinoin formulation. Besides, RP-loaded ethosomes showed significantly improved tolerability compared to marketed tretinoin with no or minimal skin irritation symptoms.

CONCLUSION

RP ethosomal hydrogel is considerably effective in controlling acne vulgaris with excellent skin tolerability. Therefore, it represents an interesting alternative to conventional marketed tretinoin formulation for topical acne treatment.

Ethosomes as Nanocarriers for the Development of Skin Delivery Formulations

The use of nanotechnology has been extensively explored for developing efficient drug delivery systems towards topical and transdermal applications. Ethosomes constitute a vesicular nanocarrier containing a relatively high concentration of ethanol (20-45%). Ethanol is a well-known permeation enhancer, which confers ethosomes unique features, including high elasticity and deformability, allowing them to penetrate deeply across the skin and enhance drug permeation and deposition. The improved composition of ethosomes offer, thereby, significant advantages in the delivery of therapeutic agents over particularly the conventional liposomes regarding different pathologies, including acne, psoriasis, alopecia, skin infections, hormonal deficiencies, among others. This review provides a comprehensive overview of the ethosomal system and an assessment of its potential as an efficient nanocarrier towards the skin delivery of active ingredients. Special attention is given to the composition of ethosomes and the mechanism of skin permeation, as well as their potential applications in different pathologies, particularly skin pathologies (acne, psoriasis, atopic dermatitis, skin cancer and skin infections). Some examples of ethosome-based formulations for the management of skin disorders are also highlighted. Besides the need for further studies, particularly in humans, ethosomal-based formulations hold great promise in the skin delivery of active ingredients, which increasingly asserts oneself as a viable alternative to the oral route.

Soft Malleable Vesicles: versatile carriers for efficient topical delivery of fungal therapeutics

Fungal infections have become a subject of great concern and the incidence of fungal infections is increasing, presenting an enormous challenge to healthcare professionals. Since most of the fungal infections are occurring over the skin, the treatment option of these infections always involves topical application. However, in topical delivery drug reaches into systemic circulation through different barriers of skin. Nevertheless, due to the low permeability, skin restricts the movement of many drugs. Hence, a delivery system is required, which deliver the medicament into the skin layers or through the skin and into the systemic circulation. Ethosomes or Soft malleable vesicles are the novel lipid vesicular carrier that offer improved skin permeability and efficient delivery due to their structure and composition. They contain high concentration of ethanol, which increases the fluidity of the skin. Therefore, in the present paper, we have explored the utility of ethosomal systems in the topical treatment of fungal infections. Structure, compositions types, mechanism and techniques of preparation of ethosome also discussed in the paper.

Mitigation of Rheumatic Arthritis in a Rat Model via Transdermal Delivery of Dapoxetine HCl Amalgamated as a Nanoplatform: In vitro and in vivo Assessment

Purpose

Dapoxetine HCl (DH), a selective serotonin reuptake inhibitor, may be useful for the treatment of rheumatic arthritis (RA). The purpose of this study was to investigate the therapeutic efficacy of transdermal delivery of DH in transethosome nanovesicles (TENVs). This novel delivery of DH may overcome the drawbacks associated with orally administered DH and improve patient compliance.

Methods

DH-TENV formulations were prepared using an injection- sonication method and optimized using a 3³ Box-Behnken-design with Design Expert^® software. The TENV formulations were assessed for entrapment efficiency (EE-%), vesicle size, zeta potential, in vitro DH release, and skin permeation. The tolerability of the optimized DH-TENV gel was investigated using a rat skin irritation test. A pharmacokinetic analysis of the optimized DH-TENV gel was also conducted in rats. Moreover, the anti-RA activity of the optimized DH-TENV gel was assessed based on the RA-specific marker anti-cyclic cirtullinated peptide antibody (anti-CCP), the cartilage destruction marker cartilage oligomeric matrix protein (COMP) and the inflammatory marker interleukin-6 (IL-6). Level of tissue receptor activator of nuclear factor kappa-Β ligand (RANKL) were also assessed.

Results

The optimized DH-TENV formulation involved spherical nanovesicles that had an appropriate EE- % and skin permeation characteristic. The DH-TENV gel was well tolerated by rats. The pharmacokinetics analysis showed that the optimized DH-TENV gel boosted the bioavailability of the DH by 2.42- and 4.16-fold compared to the oral DH solution and the control DH gel, respectively. Moreover, it significantly reduced the serum anti-CCP, COMP and IL-6 levels and decreased the RANKL levels. Furthermore, the DH-TENV gel attenuated histopathological changes by almost normalizing the articular surface and synovial fluid.

Conclusion

The results indicate that DH-TENVs can improve transdermal delivery of DH and thereby alleviate RA.

Design and Development of Novel Transdermal Nanoemulgel for Alzheimer’s Disease: Pharmacokinetic, Pharmacodynamic and Biochemical Investigations

Background:

Alzheimer’s disease is a chronic progressive neurodegenerative disorder associated with depletion of acetylcholine. Oral treatment with tacrine hydrochloride; a reversible inhibitor of acetylcholinesterase, finds limited use in Alzheimer’s disease due to frequent dosing, hepatotoxicity and extensive pre-systemic metabolism.

Objectives:

The objective of the study was to evaluate pharmacokinetic, pharmacodynamic, safety and stability profile of transdermal w/o nanoemulsion gel of tacrine hydrochloride and determine its relative bioavailability from transdermal nanogel in contrast to marketed capsule and conventional hydrogel.

Methods:

The optimized nanoemulsion gel NEGT4 (droplet size 156.4 ±0.48 nm, with poly dispersity index 0.36 ±0.4, permeation flux 6.172±2.94 µg/cm2/h across rat skin) was prepared by spontaneous emulsification followed by sonication. NEGT4 contained 7 mg of drug in 10% w/w distilled water, 30% w/w surfactant (Labrafil M) and cosurfactant (Transcutol P) mixture in ratio 1:4 and 60 % Capryol 90 as oily phase thickened with 98.9 mg ethyl cellulose (20 cps). In vivo studies were carried out on male Wistar rats following standard guidelines. Scopolamine was used to induce amnesia in rats which is a characteristic of Alzheimer’s disease. Various formulations were compared by performing pharmacokinetic, histopathological, behavioural and biochemical studies on rats. Stability studies on nanoemulsion gels were carried out in accordance with The International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) guidelines.

Results:

Pharmacokinetic studies exhibited significantly greater extent of absorption from NEGT4 in comparison to capsule and hydrogel with a 2.18 and 5.26-fold increase respectively. Significant improvement in neurobehavioral parameters was observed with NEGT4 in scopolamine-induced amnesic rats. Biochemical assessment showed superior anti-amnesic activity of NEGT4 through augmentation of antioxidant enzymes, decreased lipid peroxidation and acetylcholinesterase activity. Low value of serum aminotransferase in rats treated with NEGT4 indicated the absence of hepatotoxicity. NEGT4 was found to be non-irritant and possessed a shelf life of 4.11 years.

Conclusion:

Developed nanoemulsion gel of tacrine hydrochloride was found to be safe, stable, and efficacious and has immense potential to be used in the therapy of Alzheimer’s disease.

Recent Advancements in Non-Invasive Formulations for Protein Drug Delivery

Advancements in biotechnology and protein engineering expand the availability of various therapeutic proteins including vaccines, antibodies, hormones, and growth factors. In addition, protein drugs hold many therapeutic advantages over small synthetic drugs in terms of high specificity and activity. This has led to further R&D investment in protein-based drug products and an increased number of drug approvals for therapeutic proteins. However, there are many biological and biopharmaceutical obstacles inherent to protein drugs including physicochemical and enzymatic destabilization, which limit their development and clinical application. Therefore, effective formulations of therapeutic proteins are needed to overcome the various physicochemical and biological barriers. In current medical practice, protein drugs are predominantly available in injectable formulations, which have disadvantages including pain, the possibility of infection, high cost, and low patient compliance. Consequently, non-invasive drug delivery systems for therapeutic proteins have gained great attention in the research and development of biomedicines. Therefore, this review covers the various formulation approaches to optimizing the delivery properties of protein drugs with an emphasis on improving bioavailability and patient compliance. It provides a comprehensive update on recent advancements in nanotechnologies with regard to non-invasive protein drug delivery systems, which is also categorized by the route of administrations including oral, nasal, transdermal, pulmonary, ocular, and rectal delivery systems.

Skin delivery of hyaluronic acid by the combined use of sponge spicules and flexible liposomes

We demonstrated that the topical combined use of sponge Haliclona sp. spicules (SHS) and flexible liposomes (FL), referred to as SFLS (SHS-Flexible Liposomes combined System), can result in synergy to improve the skin absorption and deposition of hyaluronic acid (HA), especially in deep skin layers, both in vitro and in vivo. SHS treatment can result in skin micro-channels which are continuous, deep enough (48.6 ± 13.5 μm) and available in large quantities (850 ± 125 micro-channels per mm2). These micro-channels gradually closed up in 120 h and also allowed the intact vesicles of flexible liposomes and vesicle-bound or vesicle-encapsulated HA to penetrate into the skin-deep layers under the driving force of transdermal osmotic gradients. Specifically, SFLS topical application enhanced the penetration of FITC-HA (MW: 250 kDa) into porcine skin in vitro up to 23.2 ± 3.7%, which is 19.4 ± 3.1-fold (p < 0.001) that of a Phosphate Buffered Saline (PBS) group, 3.4 ± 0.5-fold (p < 0.01) that of an SHS group and 3.6 ± 0.6-fold (p < 0.01) that from the combined use of a Dermaroller and flexible liposomes. Moreover, SFLS can lead to significantly enhanced skin deposition of HA in all skin layers, especially in deep skin layers: up to 86.8 ± 4.1% of HA absorbed by skin was accumulated in deep skin layers. The effectiveness of SFLS topical application was also confirmed in vivo by using BALB/c mice. In addition, a skin irritation and toxicity study showed that the SFLS treatment may cause very minimal redness and the skin can recover in a short time. In sum, the combined use of SHS and FL (SFLS) offers a promising strategy to safely and effectively improve the skin delivery of hydrophilic biomacromolecules such as HA.

Liposomes for delivery of antioxidants in cosmeceuticals: Challenges and development strategies

Antioxidants (AOs) play a crucial role in the protection and maintenance of health and are also integral ingredients in beauty products. Unfortunately, most of them are sensitive due to their instability and insolubility. The use of liposomes to protect AOs and expand their applicability to cosmeceuticals, thereby, is one of the most effective solutions. Notwithstanding their offered advantages for the delivery of AOs, liposomes, in their production and application, present many challenges. Here, we provide a critical review of the major problems complicating the development of liposomes for AO delivery. Along with issues related to preparation techniques and encapsulation efficiency, the loss of protective function and inefficiency of skin permeability are the main disadvantages of liposomes. Corresponding development strategies for resolving these problems, with their respective advantages and drawbacks, are introduced, discussed in some depth, and summarized in these pages as well. Advanced liposomes have a vital role to play in the development and delivery of AOs in practical cosmeceutical product applications.

Factorial design based curcumin ethosomal nanocarriers for the skin cancer delivery: in vitro evaluation

Melanoma is the most deadly and life-threatening form of skin cancer with progressively higher rates of incidence worldwide. The objective of the present investigation is to develop and to statistically optimize and characterize curcumin (CUR) loaded ethosomes for treatment of melanoma. A two factor, three level (3²) factorial design approach was employed for the optimization of ethosomes. The prepared ethosomes were evaluated for size, zeta potential, entrapment efficiency, in vitro skin permeation and deposition ability. The optimized ethosomal formulation was evaluated for in vitro cytotoxicity and cellular uptake studies using A375 human melanoma cells. The optimized formulation has imperfect round shaped unilamellar structures with a mean vesicle size of 247 ± 5.25 nm and an entrapment efficiency of 92.24 ± 0.20%. The in vitro skin permeation studies proved the superiority of ethosomes over the traditional liposomes in terms of the amount of drug permeated and deposited in skin layers. Fluorescence microscopy showed the enhanced penetration of ethosomes into the deeper layers of the skin. In vitro cytotoxicity and cellular uptake studies revealed that curcumin ethosomes have significantly improved cytotoxicity and cellular uptake in A375 human melanoma cell lines. The colony formation assay results showed that curcumin ethosomes have a superior antiproliferative effect as they effectively inhibit the clonogenic ability of A375 cells. The flow cytometry results indicate that curcumin ethosomes induce cell death in A375 cells by apoptosis mechanism. The present study provides a strong rationale and motivation for further investigation of newly developed curcumin ethosomes as a potential therapeutic strategy for melanoma treatment.

Paeonol-Loaded Ethosomes as Transdermal Delivery Carriers: Design, Preparation and Evaluation

Paeonol exhibits a wide range of pharmacological activities, such as anti-inflammatory, antidiabetic as well as pain-relieving activities. However, its intrinsic properties, such as low water solubility, poor stability and low oral bioavailability, restrict its clinical application. The current study aimed to optimize paeonol-loaded ethosomal formulation and characterize it in terms of encapsulation efficiency (EE), vesicle size (VS), zeta potential (ZP) and polydispersity index (PDI), in addition to differential scanning calorimetry (DSC), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR) studies. Here, paeonol-loaded ethosomes were prepared by the injection method and optimized by the single-factor test and central composite design-response surface methodology. The optimized paeonol-loaded ethosomes had an EE of 84.33 ± 1.34%, VS of 120.2 ± 1.3 nm, negative charge of −16.8 ± 0.36 mV, and PDI of 0.131 ± 0.006. Ethosomes showed a spherical morphology under the transmission electron microscope (TEM). DSC, XRD and FT-IR results indicated that paeonol was successfully incorporated into the ethosomes. In-vitro transdermal absorption and skin retention of paeonol from paeonol-loaded ethosomes were 138.58 ± 9.60 µg/cm² and 52.60 ± 7.90 µg/cm², respectively. With reasonable skin tolerance, ethosomes could be a promising vehicle for transdermal delivery of paeonol.

Transethosomal gels as carriers for the transdermal delivery of colchicine: statistical optimization, characterization, and ex vivo evaluation

Introduction

Colchicine is used for the treatment of gout, pseudo-gout, familial Mediterranean fever, and many other illnesses. Its oral administration is associated with poor bioavailability and severe gastrointestinal side effects. The drug is also known to have a low therapeutic index. Thus to overcome these drawbacks, the transdermal delivery of colchicine was investigated using transethosomal gels as potential carriers.

Methods

Colchicine-loaded transethosomes (TEs) were prepared by the cold method and statistically optimized using three sets of 24 factorial design experiments. The optimized formulations were incorporated into Carbopol 940^® gel base. The prepared colchicine-loaded transethosomal gels were further characterized for vesicular size, dispersity, zeta potential, drug content, pH, viscosity, yield, rheological behavior, and ex vivo skin permeation through Sprague Dawley rats’ back skin.

Results

The results showed that the colchicine-loaded TEs had aspherical irregular shape, nanometric size range, and high entrapment efficiency. All the formulated gels exhibited non-Newtonian plastic flow without thixotropy. Colchicine-loaded transethosomal gels were able to significantly enhance the skin permeation parameters of the drug in comparison to the non-ethosomal gel.

Conclusion

These findings suggested that the transethosomal gels are promising carriers for the transdermal delivery of colchicine, providing an alternative route for drug administration.

Rutin-phospholipid complex in polymer matrix for long-term delivery of rutin via skin for the treatment of inflammatory diseases

The drug with poor oral bioavailability necessitates the development of novel carrier for efficient drug delivery. This paper reports the rutin-phospholipid complex in polymer matrix for sustained delivery of rutin via the skin for the treatment of acute and chronic inflammatory diseases. Rutin in phospholipid complex (RNPs) are better soluble and permeable than the free rutin. The RNPs-loaded polymeric matrix patch with moderate adhesiveness was developed for convenient means of long term drug application on the skin. The patch was analysed for physicochemical properties, ex vivo skin permeability and in vivo efficacy in rat paw oedema model. The skin targeting efficacy was analysed by CLSM study. Optimized formulation (F2) showed 31 ± 2.32% and 26.56 ± 5.52% skin permeation at 24 h across excised rat skin and human cadaver skin, respectively. The sustained anti-inflammatory effect of the patch formulation in rat paw oedema model confirmed its unique in vivo efficacy over the conventional diclofenac gel. The CLSM study confirmed the localization of RNPs in the dermis for sustained anti-inflammatory effect. Our results suggest that the developed patch has a potential for long term site specific delivery of rutin in arthritic patients.

Ibuprofen loaded nano-ethanolic liposomes carbopol gel system: in vitro characterization and anti-inflammatory efficacy assessment in Wistar rats

The objective of the present study was to develop and characterize nano-ethanolic liposomes (NEL) for transdermal delivery of ibuprofen (IBU). The NEL for transdermal delivery of IBU were prepared by thin film hydration technique and evaluated for vesicle size, shape, entrapment efficiency, transdermal flux, and in vivo anti-inflammatory activity in Wistar rats. The NEL optimized formulation (NEL-Opt) presented vesicle sizes of 32.85±1.98 nm and entrapment efficiency of 86.40±0.55% with improved transdermal flux. The presence of ethanol and flexibility of NEL could be the reasons for better permeation enhancement of IBU via rat’s skin. In vivo anti-inflammatory study of IBU-loaded NEL-Opt gel showed significant reduction (41.18%) of edema in carrageenan-induced rat paw edema as compared to conventional gel of IBU, where reduction of edema was found to be 12.50%. Our results suggest that developed NEL formulations are efficient systems for transdermal IBU delivery against inflammation. The stability study confirmed that the NEL-Opt gel formulation was considerably stable at refrigerator temperature. Our results concluded that NEL are an efficient carrier for transdermal delivery of IBU.

Sustained Anti-inflammatory Effect of Resveratrol-Phospholipid Complex Embedded Polymeric Patch

Resveratrol-phospholipid complex (Phytosome®) (RSVP) was found better aqueous soluble and permeable than free resveratrol (RSV). RSVPs were incorporated in polymeric patch prepared by solvent casting method using Eudragit RL 100, PVP K30, and PEG 400 for application on dermal sites for sustained treating of inflammation. Prepared patches were evaluated for various physicochemical properties, surface morphology by SEM, TEM, and compatibility of patch components by FT-IR and DSC studies. Optimized formulation (F9) gave 95.79 ± 3.02% drug release and 51.36% (4.28 ± 0.48 mg/cm²) skin permeation after 24 h. Skin extract when examined for drug accumulation showed 38.31 ± 2.42% drug content. FE-SEM images of the patch taken after drug release and skin permeation studies showed that RSVPs in polymeric patch are stable and retain their structure after 24 h long exposure to physiologic environment. Sustained anti-inflammatory effect was established in carrageenan-induced paw edema model in which test formulation gave 84.10% inhibition of inflammation at 24 h as compared to 39.58% for standard diclofenac sodium gel. The CLSM study confirmed the localization of RSVPs for a longer period, thus enabling drug targeting to the dermis for sustained effect. Skin irritation test on rabbit revealed that the patches are safe for skin application. Histological observations suggested that after exposure to the permeants, the SC integrity had not altered and no evidence of presence of inflammatory cells found. RSVP (Phytosome®) containing patches abled to give sustained therapeutic effect that may be useful in treating acute and chronic inflammation.

Formulation and characterization of novel soft nanovesicles for enhanced transdermal delivery of eprosartan mesylate

The objective of the present work was to formulate, optimize and evaluate the potential of novel soft nanovesicles i.e. nano-transfersomes, containing eprosartan mesylate (EM) for transdermal delivery. Nano-transfersomes of EM were developed using Phospholipon 90G, Span 80 (SP) and sodium deoxycholate (SDC) and characterized for vesicle size, shape, entrapment efficiency, in vitro skin permeation study and confocal laser scanning microscopy. The optimized nano-transfersomes formulation showed vesicles size of 108.53 ± 0.06 nm and entrapment efficiency of 63.00 ± 2.76%. The optimized nano-transfersomes provided an improved transdermal flux of 27.22 ± 0.29 µg/cm²/h with an enhancement ratio of 16.80 over traditional liposomes through Wistar rat skin. Confocal laser microscopy of rat skin treated with the optimized formulation showed that the formulation was eventually distributed and permeated deep into the rat skin. The present investigation has shown that the nature and concentration of surfactants (edge activators) influence immense control on the characteristics of nano-transfersomes. It was concluded that the developed nano-transfersomes surmount the limitation of low penetration ability of the traditional liposomes across the rat skin. Improved drug delivery presented by nano-transfersomes establishes this system as an encouraging dosage form for the delivery of EM via skin route.

Evaluation of paeonol-loaded transethosomes as transdermal delivery carriers

Paeonol shows effective anti-allergic, anti-inflammatory and analgesic activities. However, because of its poor solubility in water and high volatility at room temperature, the application of this drug is restricted in the clinic. The objective of this research was to develop a biocompatible paeonol formulation with improved stability, skin delivery and pharmacokinetic efficiency. In this paper, paeonol-loaded vesicles were prepared using an ethanol injection method. Nano-vesicles were characterized for their physical properties and encapsulation efficiency (EE). Drug permeation behavior in vitro and deposition quantity in porcine ear skin were measured with a Valia-Chien (V-C) diffusion device. Additionally, a validated and sensitive high performance liquid chromatography (HPLC) method was developed to analyze paeonol concentrations in rat plasma after transdermal administration. The results showed that the particle-size order of the nano-vesicles was the following: transethosomes (122.5±7.5nm)<transfersomes (256.5±8.9nm). Compared to the paeonol transfersomes, the transethosomes had a higher EE (85.5±5.2%), and they showed a spherical morphology with a smooth surface when viewed under a transmission electron microscope (TEM). In an in vitro permeation study, the paeonol transethosomes showed an enhanced transdermal flux of 95.7±8.8μg/cm²/h and a higher deposition quantity in porcine ear skin compared to the transfersomes. A one-compartment first-order absorption model could be used to describe the pharmacokinetics of paeonol in rats after transdermal administration. The AUC of the paeonol transethosomes was approximately 1.57- and 3.52-fold higher than those of the transfersomes and a saturated solution of paeonol in 35% ethanol, respectively. The results demonstrated that the paeonol transethosomes had a narrow size distribution, high encapsulation efficiency, and long residence in the plasma. This formulation remarkably enhanced the bioavailability of paeonol.

Ethosomal nanocarriers: the impact of constituents and formulation techniques on ethosomal properties, in vivo studies, and clinical trials

Ethosomal systems are novel lipid vesicular carriers containing a relatively high percentage of ethanol. These nanocarriers are especially designed for the efficient delivery of therapeutic agents with different physicochemical properties into deep skin layers and across the skin. Ethosomes have undergone extensive research since they were invented in 1996; new compounds were added to their initial formula, which led to the production of new types of ethosomal systems. Different preparation techniques are used in the preparation of these novel carriers. For ease of application and stability, ethosomal dispersions are incorporated into gels, patches, and creams. Highly diverse in vivo models are used to evaluate their efficacy in dermal/transdermal delivery, in addition to clinical trials. This article provides a detailed review of the ethosomal systems and categorizes them on the basis of their constituents to classical ethosomes, binary ethosomes, and transethosomes. The differences among these systems are discussed from several perspectives, including the formulation, size, ζ-potential (zeta potential), entrapment efficiency, skin-permeation properties, and stability. This paper gives a detailed review on the effects of ethosomal system constituents, preparation methods, and their significant roles in determining the final properties of these nanocarriers. Furthermore, the novel pharmaceutical dosage forms of ethosomal gels, patches, and creams are highlighted. The article also provides detailed information regarding the in vivo studies and clinical trials conducted for the evaluation of these vesicular systems.

Pharmaceutical liposomal drug delivery: a review of new delivery systems and a look at the regulatory landscape

Liposomes were the first nanoscale drug to be approved for clinical use in 1995. Since then, the technology has grown considerably, and pioneering recent work in liposome-based delivery systems has brought about remarkable developments with significant clinical implications. This includes long-circulating liposomes, stimuli-responsive liposomes, nebulized liposomes, elastic liposomes for topical, oral and transdermal delivery and covalent lipid-drug complexes for improved drug plasma membrane crossing and targeting to specific organelles. While the regulatory bodies' opinion on liposomes is well-documented, current guidance that address new delivery systems are not. This review describes, in depth, the current state-of-the-art of these new liposomal delivery systems and provides a critical overview of the current regulatory landscape surrounding commercialization efforts of higher-level complexity systems, the expected requirements and the hurdles faced by companies seeking to bring novel liposome-based systems for clinical use to market.

Design, formulation and optimization of novel soft nano-carriers for transdermal olmesartan medoxomil delivery: In vitro characterization and in vivo pharmacokinetic assessment

Olmesartan is a hydrophobic antihypertensive drug with a short biological half-life, and low bioavailability, presents a challenge with respect to its oral administration. The objective of the work was to formulate, optimize and evaluate the transdermal potential of novel vesicular nano-invasomes, containing above anti-hypertensive agent. To achieve the above purpose, soft carriers (viz. nano-invasomes) of olmesartan with β-citronellene as potential permeation enhancer were developed and optimized using Box-Behnken design. The physicochemical characteristics e.g., vesicle size, shape, entrapment efficiency and skin permeability of the nano-invasomes formulations were evaluated. The optimized formulation was further evaluated for in vitro drug release, confocal microscopy and in vivo pharmacokinetic study. The optimum nano-invasomes formulation showed vesicles size of 83.35±3.25nm, entrapment efficiency of 65.21±2.25% and transdermal flux of 32.78±0.703 (μg/cm(2)/h) which were found in agreement with the predicted value generated by Box-Behnken design. Confocal laser microscopy of rat skin showed that optimized formulation was eventually distributed and permeated deep into the skin. The pharmacokinetic study presented that transdermal nano-invasomes formulation showed 1.15 times improvement in bioavailability of olmesartan with respect to the control formulation in Wistar rats. It was concluded that the response surfaces estimated by Design Expert(®) illustrated obvious relationship between formulation factors and response variables and nano-invasomes were found to be a proficient carrier system for transdermal delivery of olmesartan.

Current and emerging lipid-based systems for transdermal drug delivery

Developing a transdermal drug delivery system is a challenging task considering the selective permeability of the skin and the physicochemical properties the drug must possess to permeate through the skin. Lipid-based drug delivery systems have contributed a great deal in this direction in the last few decades, and thereby have helped to expand the range of therapeutic molecules that can be delivered through the skin in a safe and effective manner. Additionally, vesicular delivery systems such as nanoparticles and emulsions have also played important roles in providing alternative novel approaches for drug delivery. In this article, we will discuss some of the current and future lipid-based systems for transdermal drug delivery along with the associated challenges.

Compound antimalarial ethosomal cataplasm: preparation, evaluation, and mechanism of penetration enhancement

Malaria is still a serious public health problem in some parts of the world. The problems of recurrence and drug resistance are increasingly more serious. Thus, it is necessary to develop a novel antimalarial agent. The objectives of this study were to construct a novel compound antimalarial transdermal nanosystem–ethosomal cataplasm, to investigate its characteristics and efficiency, and to systematically explore the penetration-enhancing mechanisms of ethosomal cataplasm. Artesunate-loaded ethosomes and febrifugine-loaded ethosomes were prepared, and their characteristics were evaluated. Drug-loaded ethosomes were incorporated in the matrix of cataplasm to form the compound antimalarial ethosomal cataplasm. With the help of ethosomal technology, the accumulated permeation quantity of artesunate significantly increased at 8 hours after administration, which was 1.57 times as much as that of conventional cataplasm. Soon after administration, the ethosomal cataplasm could make a large quantity of antimalarial drug quickly penetrate through skin, then the remaining drug in the ethosomal cataplasm could be steadily released. These characteristics of ethosomal cataplasm are favorable for antimalarial drugs to kill Plasmodium spp. quickly and prevent the resurgence of Plasmodium spp. As expected, the ethosomal cataplasm showed good antimalarial efficiency in this experiment. The negative conversion rates were 100% and the recurrence rates were 0% at all dosages. The mechanism of penetration enhancement of the ethosomal cataplasm was systematically explored using an optics microscope, polarization microscope, and transmission electron microscopy. The microstructure, ultrastructure, and birefringent structure in skin were observed. Data obtained in this study showed that the application of ethosomal technology to antimalarial cataplasm could improve the transdermal delivery of drug, enhance the efficacy, and facilitate practical application in clinic.

In vitro skin models as a tool in optimization of drug formulation

(Trans)dermal drug therapy is gaining increasing importance in the modern drug development. To fully utilize the potential of this route, it is important to optimize the delivery of active ingredient/drug into/through the skin. The optimal carrier/vehicle can enhance the desired outcome of the therapy therefore the optimization of skin formulations is often included in the early stages of the product development. A rational approach in designing and optimizing skin formulations requires well-defined skin models, able to identify and evaluate the intrinsic properties of the formulation. Most of the current optimization relies on the use of suitable ex vivo animal/human models. However, increasing restrictions in use and handling of animals and human skin stimulated the search for suitable artificial skin models. This review attempts to provide an unbiased overview of the most commonly used models, with emphasis on their limitations and advantages. The choice of the most applicable in vitro model for the particular purpose should be based on the interplay between the availability, easiness of the use, cost and the respective limitations.

Enhanced anti-inflammatory activity of carbopol loaded meloxicam nanoethosomes gel

The aim of the current investigation is to develop nanoethosomes for transdermal meloxicam delivery. The ethosomes were prepared by varying the variables such as concentrations of phospholipids 90G, ethanol, and sonication time while entrapment efficiency, vesicle size and transdermal flux were the chosen responses. Results indicate that the nanoethosomes of meloxicam provides lesser vesicles size, better entrapment efficiency and improved flux for transdermal delivery as compared to rigid liposomes. The optimized formulation (MCEF-OPT) obtained was further evaluated for an in vivo anti-inflammatory activity in rats. Optimized nanoethosomal formulation with vesicles size of 142.3nm showed 78.25% entrapment efficiency and achieved transdermal flux of 10.42μg/cm(2)/h. Nanoethosomes proved to be significantly superior in terms of, amount of drug permeated into the skin, with an enhancement ratio of 3.77 when compared to rigid liposomes. In vivo pharmacodynamic study of carbopol(®) loaded nanoethosomal gel showed significant higher percent inhibition of rat paw edema compared with oral administration of meloxicam. Our results suggest that nanoethosomes are an efficient carrier for transdermal delivery of meloxicam.