Novel carbopol-based transfersomal gel of 5-fluorouracil for skin cancer treatment:in vitrocharacterization andin vivostudy

Progress in novel ultradeformable vesicular drug carrier in the topical and transdermal treatment of psoriasis

Psoriasis is a chronic autoimmune condition that is described by infected skin patches. Ultradeformable vesicles have been a novel carrier for the treatment of psoriasis in topical and transdermal therapy. The systemic route may induce adverse effects and the drug concentration may not be localized when applied topically to the psoriasis skin due to their physicochemical properties. These limitations can be overcome by a vesicular delivery system such as transferosomes. Research on transferosomes is ongoing. Transferosomes are flexible deformable vesicular structures, which consist of a bilayer softening agent such as an edge activator, which allows it to penetrate deeper dermal layers. This review outlines the use of transferosomes in the treatment of deeply rooted dermal disorders like psoriasis.

Transfersomes: A Promising Nanoencapsulation Technique for Transdermal Drug Delivery

Transdermal delivery systems have gained much interest in recent years owing to their advantages compared to conventional oral and parenteral delivery systems. They are noninvasive and self-administered delivery systems that can improve patient compliance and provide a controlled release of the therapeutic agents. The greatest challenge of transdermal delivery systems is the barrier function of the skin's outermost layer. Molecules with molecular weights greater than 500 Da and ionized compounds generally do not pass through the skin. Therefore, only a limited number of drugs are capable of being administered by this route. Encapsulating the drugs in transfersomes are one of the potential approaches to overcome this problem. They have a bilayered structure that facilitates the encapsulation of lipophilic and hydrophilic, as well as amphiphilic, drug with higher permeation efficiencies compared to conventional liposomes. Transfersomes are elastic in nature, which can deform and squeeze themselves as an intact vesicle through narrow pores that are significantly smaller than its size. This review aims to describe the concept of transfersomes, the mechanism of action, different methods of preparation and characterization and factors affecting the properties of transfersomes, along with their recent applications in the transdermal administration of drugs.

Nano-elastic liposomes as multidrug carrier of sodium stibogluconate and ketoconazole: A potential new approach for the topical treatment of cutaneous Leishmaniasis

The present study evaluates the efficacy of sodium stibogluconate (SSG) co-loaded with ketoconazole (KTZ) in nano-elastic liposomes (NELs) for the topical treatment of cutaneous leishmaniasis (CL). SSG-KTZ co-loaded NELs were developed and assessed for various physicochemical properties and anti-leishmanial potential. The optimized nano-vesicles have an average size of 212.8 ± 3.1 nm and entrapment efficiency of 61.2 ± 2.9%. SSG-KTZ co-loaded NELs displayed 5.37-fold higher skin permeation of SSG as compared to drug solution. SSG and KTZ displayed a synergistic interaction and flow cytometry revealed enhanced killing of DsRed Leishmania mexicana in infected macrophages. In-vitro and in-vivo anti-leishmanial studies indicated a 10.67-fold lower IC₅₀ value and a 35.33-fold reduced parasitic burden as compared with plain SSG solution, respectively. SSG-KTZ co-loaded NELs were found to be a promising approach for the topical treatment of CL.

Ultra-deformable Liposomes as Flexible Nanovesicular Carrier to Penetrate Versatile Drugs Transdermally

Introduction:

Transferosomes also known as ultra-deformable liposomes were introduced by Gregor Cevc in 1990. These are deformable vesicles that transport drug across the skin, which is the best route of drug delivery because skin is the largest human organ with 3 kg total weight and a surface area of 1.5-2.0 m2.

Methods:

Transferosomes are able to efficiently deliver low as well as high molecular weight drug across the skin in terms of quantity and depth. Various methods used for the preparation of transferosomes such as thin film hydration method, reverse phase evaporation method, vortex/sonication method, ethanol injection method and freeze thaw method.

Results:

The prepared transferosomal preparation will be evaluated for particle shape and size, entrapment efficiency, stability study, penetration ability and skin permeation study. In vitro release studies are to be performed using a specific dissolution medium.

Conclusion:

Ultra deformable liposomes can be used for delivery of different drugs e.g. analgesic, anesthetic, corticosteroids, anticancer, sex hormone, insulin, gap junction protein, and albumin.

Transferosomes as nanocarriers for drugs across the skin: Quality by design from lab to industrial scale

Transferosomes, also known as transfersomes, are ultradeformable vesicles for transdermal applications consisting of a lipid bilayer with phospholipids and an edge activator and an ethanol/aqueous core. Depending on the lipophilicity of the active substance, it can be encapsulated within the core or amongst the lipid bilayer. Compared to liposomes, transferosomes are able to reach intact deeper regions of the skin after topical administration delivering higher concentrations of active substances making them a successful drug delivery carrier for transdermal applications. Most transferosomes contain phosphatidylcholine (C18) as it is the most abundant lipid component of the cell membrane, and hence, it is highly tolerated for the skin, decreasing the risk of undesirable effects, such as hypersensitive reactions. The most common edge activators are surfactants such as sodium deoxycholate, Tween® 80 and Span® 80. Their chain length is optimal for intercalation within the C18 phospholipid bilayer. A wide variety of drugs has been successfully encapsulated within transferosomes such as phytocompounds like sinomenine or apigenin for rheumatoid arthritis and leukaemia respectively, small hydrophobic drugs but also macromolecules like insulin. The main factors to develop optimal transferosomal formulations (with high drug loading and nanometric size) are the optimal ratio between the main components as well as the critical process parameters for their manufacture. Application of quality by design (QbD), specifically design of experiments (DoE), is crucial to understand the interplay among all these factors not only during the preparation at lab scale but also in the scale-up process. Clinical trials of a licensed topical ketoprofen transferosomal gel have shown promising results in the alleviation of symptons in orthreothritis with non-severe skin and subcutaneous tissue disorders. However, the product was withdrawn from the market which probably was related to the higher cost of the medicine linked to the expensive manufacturing process required in the production of transferosomes compared to other conventional gel formulations. This example brings out the need for a careful formulation design to exploit the best properties of this drug delivery system as well as the development of manufacturing processes easily scalable at industrial level.

Combined use of nanocarriers and physical methods for percutaneous penetration enhancement

Dermal and transdermal drug delivery (due to its non-invasiveness, avoidance of the first-pass metabolism, controlling the rate of drug input over a prolonged time, etc.) have gained significant acceptance. Several methods are employed to overcome the permeability barrier of the skin, improving drug penetration into/through skin. Among chemical penetration enhancement methods, nanocarriers have been extensively studied. When applied alone, nanocarriers mostly deliver drugs to skin and can be used to treat skin diseases. To achieve effective transdermal drug delivery, nanocarriers should be applied with physical methods, as they act synergistically in enhancing drug penetration. This review describes combined use of frequently used nanocarriers (liposomes, novel elastic vesicles, lipid-based and polymer-based nanoparticles and dendrimers) with the most efficient physical methods (microneedles, iontophoresis, ultrasound and electroporation) and demonstrates superiority of the combined use of nanocarriers and physical methods in drug penetration enhancement compared to their single use.

Fabrication, in-vitro characterization, and enhanced in-vivo evaluation of carbopol-based nanoemulsion gel of apigenin for UV-induced skin carcinoma

The aim of this study was to develop a potential novel formulation of carbopol-based nanoemulsion gel containing apigenin using tamarind gum emulsifier which was having the smallest droplet size, the highest drug content, and a good physical stability for Skin delivery. Apigenin loaded nanoemulsion was prepared by high speed homogenization method and they were characterized with respect to morphology, zeta potential, differential scanning calorimeter study, and penetration studies. In-vitro release studies and skin permeation of apigenin loaded nanoemulsion by goat abdominal skin was determined using Franz diffusion cell and confocal laser scanning microscope (CLSM). The cytotoxicity of the reported formulation was evaluated in HaCaT Cells (A) and A431 cells (B) by MTT assay. The nanoemulsion formulation showed droplet size, polydispersity index, and zeta potential of 183.31 nm, 0.532, and 31.9 mV, respectively. The nanoemulsions were characterized by TEM demonstrated spherical droplets and FTIR to ensure the compatibility among its ingredients. CLSM showed uniform fluorescence intensity across the entire depth of skin in nanocarriers treatment, indicating high penetrability of nanoemulsion gel through goatskin. The nanoemulsion gel showed toxicity on melanoma (A341) in a concentration range of 0.4-2.0 mg/ml, but less toxicity toward HaCaT cells. The carbopol-based nanoemulsion gel formulation of apigenin possesses better penetrability across goatskin as compared to marketed formulation. Hence, the study postulates that the novel nanoemulsion gel of apigenin can be proved fruitful for the treatment of skin cancer in near future.

Trans-resveratrol-loaded nonionic lamellar liquid-crystalline systems: structural, rheological, mechanical, textural, and bioadhesive characterization and evaluation of in vivo anti-inflammatory activity

Resveratrol (Res) is a common phytoalexin present in a few edible materials, such as grape skin, peanuts, and red wine. Evidence has shown the beneficial effects of Res on human health, which may be attributed to its anti-inflammatory activity. However, the poor aqueous solubility of Res limits its therapeutic effectiveness. Therefore, the use of nanostructured delivery systems for Res, such as liquid-crystalline systems, could be beneficial. In this study, we aimed to develop, characterize, and determine the in vivo effectiveness of Res-loaded liquid-crystalline systems. Systems containing copaiba balsam oil, polyethylene glycol-40 hydrogenated castor oil, and water were designed. Results of polarized light microscopy, small-angle X-ray scattering, texture-profile analysis, and flow-rheology analysis showed that the Res-loaded liquid-crystalline system had a lamellar structure, textural and mechanical (hardness, compressibility, and adhesiveness) properties, and behaved as a non-Newtonian fluid, showing pseudoplastic behavior upon skin application. Furthermore, all liquid-crystalline systems presented bioadhesive properties that may have assisted in maintaining the anti-inflammatory activity of Res, since the topical application of the Res-loaded lamellar mesophase liquid crystals resulted in edema inhibition in a carrageenan-induced paw-inflammation mouse model. Therefore, Res-loaded lamellar mesophases represent a promising new therapeutic approach for inhibition of skin inflammation.

Stratum corneum modulation by chemical enhancers and lipid nanostructures: implications for transdermal drug delivery

Skin is the outermost and largest protective covering of the body. The uppermost layer of the skin, stratum corneum also called the horny layer is composed of keratin-filled cells covered by a lipid matrix which shields the skin from physical and chemical entrants. The lipid lamellar structure comprises of ceramides, cholesterol, fatty acids and proteins. Chemical enhancers that mimic the lamellar chemistry, reversibly fluidize the latter can be utilized for enhancing transport of cargo across the epidermis into the dermis. This review deals with the stratum corneum chemistry, mechanisms to modulate its packing with the aid of chemical enhancers, biophysical techniques for characterization and applications in the design of nature-inspired biocompatible lipid nanostructures for transdermal delivery of drugs and bioactive agents.

Transfersomes as versatile and flexible nano-vesicular carriers in skin cancer therapy: the state of the art

Introduction: The skin acts as a barrier and prevents transcutaneous delivery of therapeutic agents. Transfersomes are novel vesicular systems that are several times more elastic than other vesicular systems. These are composed of edge activator, phospholipids, ethanol, and sodium cholate and are applied in a non-occlusive manner. Areas covered: This article covers information such as merits/demerits of transfersomes, regulatory aspects of materials used in preparation, different methods of preparation, mechanism of action, review of clinical investigations performed, marketed preparations available, research reports, and patent reports related to transfersomes. Expert opinion: Research over the past few years has provided a better understanding of transfersomal permeation of therapeutic agents across stratum corneum barrier. Transfersomes provides an essential feature of their application to variety of compositions in order to optimize the permeability of a range of therapeutic molecules. This is evidenced by the fact that there are several Transfersome products being processed in advanced clinical trials. It is noteworthy that a number of Transfersome products for dermal and transdermal delivery will gain a global market success in near future.

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.

Optimizing novel penetration enhancing hybridized vesicles for augmenting the in-vivo effect of an anti-glaucoma drug

Usually the topical delivery of ocular drugs poses a great challenge. Accordingly, the work in this study comprised the use of different hybrids of generally regarded as safe (GRAS) oils and surfactants in order to develop and optimize novel acetazolamide (AZD) entrapped-vesicular systems aiming at improving its ocular delivery and reaching better therapeutic outcomes in the treatment of glaucoma. The phospholipid/cholesterol bilayer of the vesicles was enriched with hybrids of Tween 80, Labrasol, Transcutol and Labrafac lipophile WL in different masses and proportions according to a mixture design viz. D-optimal mixture design. Three models were generated comprising three responses: particles size, percentage of entrapment efficiency and amount of drug released after 24 hours (Q24h). The results demonstrated the ability of the penetration enhancing hybrids in modulating the three responses compared to the conventional liposomes. Transmission electron microscope was used to characterize the selected formulations. Sterilization of selected formulations was carried out using gamma radiation and the effect of gamma radiations on entrapment, particle size and in vitro release were studied. The selected sterilized formulations were tested in-vivo on the eyes of albino rabbits in order to evaluate the efficiency of the novel delivery systems on the intra-ocular pressure reduction (IOP) compared to drug solution and the conventional liposomes. The novel formulations proved their efficiency in reducing the IOP to lower values compared to the conventional liposomes, which pose new successful platform for ocular delivery of AZD and other anti-glaucoma drug analogs.

Transdermal delivery of atorvastatin calcium from novel nanovesicular systems using polyethylene glycol fatty acid esters: Ameliorated effect without liver toxicity in poloxamer 407-induced hyperlipidemic rats

CONTEXT

Atorvastatin calcium (ATV), a cholesterol-lowering agent, suffers from poor systemic availability (14%) after oral administration in addition to other side effects on the gastrointestinal tract, liver and muscle.

OBJECTIVE

The goal of the present investigation was to improve ATV bioavailability and overcome complications attendant with peroral administration by developing a new nanovesicular system encapsulating ATV for its delivery via the transdermal route.

METHODS

The vesicular systems were prepared by incorporating different polyethylene glycol fatty acid esters such as Labrasol, Cremophor EL, Gelucire 44/14 and Tween 80 as edge activators (EAs) in the lipid bilayer. The effect of the phosphatidylcholine (PC):EA molar ratio on the physicochemical properties of the vesicles was investigated. The pharmacokinetic studies of the optimized formulation were evaluated in rats. The optimized formulation was tested in poloxamer 407-induced hyperlipidemic rats. The plasma lipid profile, activity of liver enzymes, and oxidative stress parameters were measured using commercially available kits.

RESULTS

The results revealed high ATV entrapment efficiency (EE%) ranging from 55.62 to 83.91%. The formulations that contained Labrasol showed the highest EE%. The mean diameter of the vesicles was in the range of 186-583nm. T8 containing Gelucire 44/14 as an EA in the molar ratio of 15:1 (PC:EA) gave the smallest size and exhibited the best permeation parameters across the skin. The pharmacokinetic studies revealed that about three times statistically significant (p<0.05) improvement in bioavailability, after transdermal administration of nanotransfersomal ATV gel compared to oral ATV suspension. The transdermal vesicular system exhibited a significant decrease in plasma total cholesterol, triglycerides and LDL cholesterol comparable to oral ATV. Additionally, it lowered the malondialdehyde levels in plasma and abolished the increase in liver enzyme activity.

CONCLUSION

The results obtained suggest that the proposed transdermal vesicular system can serve as a promising alternative means for delivery of ATV.

Nanotransfersomes-loaded thermosensitive in situ gel as a rectal delivery system of tizanidine HCl: preparation, in vitro and in vivo performance

The purpose of the current study was to develop tizanidine HCl (TIZ; a myotonolytic agent used for treatment of spasticity) loaded nanotransfersomes intended for rectal administration, aiming to bypass the hepatic first-pass metabolism. TIZ-loaded nanotransfersomes were prepared by thin-film hydration method followed by characterization for various parameters including entrapment efficiency, vesicle diameter, in vitro release and ex vivo permeation studies. Transfersomal formulation composed of phosphatidylcholine and Tween 80 at a weight ratio of (85:15) gave a satisfactory results. It exhibited encapsulation efficiency of 52.39%, mean diameter of 150.33 nm, controlled drug release over 8 h and good permeation characteristics. Optimum formula was then incorporated into Pluronic-based thermoreversible gel using hydroxypropyl methylcellulose (HPMC) as a mucoadhesive polymer. Pharmacokinetic study was performed by rectal administration of transfersomes-loaded in situ gel to rabbits and compared with oral drug solution and rectal TIZ in situ gel. The pharmacokinetic study revealed that the transfersomal formulation successively enhanced the bioavailability of TIZ by about 2.18-fold and increased t_1/2 to about 10 h as compared to oral solution. It can be concluded that encapsulation of TIZ into nanotransfersomes can achieve a dual purpose of prolonged TIZ release and enhanced bioavailability and so may be considered as a promising drug delivery system for the treatment of spasticity.

Development and evaluation of nanostructured lipid carrier-based hydrogel for topical delivery of 5-fluorouracil

The aim of this study was to develop a nanostructured lipid carrier (NLC)-based hydrogel and study its potential for the topical delivery of 5-fluorouracil (5-FU). Precirol® ATO 5 (glyceryl palmitostearate) and Labrasol® were selected as the solid and liquid lipid phases, respectively. Poloxamer 188 and Solutol® HS15 (polyoxyl-15-hydroxystearate) were selected as surfactants. The developed lipid formulations were dispersed in 1% Carbopol® 934 (poly[acrylic acid]) gel medium in order to maintain the topical application consistency. The average size, zeta potential, and polydispersity index for the 5-FU-NLC were found to be 208.32±8.21 nm, -21.82±0.40 mV, and 0.352±0.060, respectively. Transmission electron microscopy study revealed that 5-FU-NLC was <200 nm in size, with a spherical shape. In vitro drug permeation studies showed a release pattern with initial burst followed by sustained release, and the rate of 5-FU permeation was significantly improved for 5-FU-NLC gel (10.27±1.82 μg/cm2/h) as compared with plain 5-FU gel (2.85±1.12 μg/cm2/h). Further, skin retention studies showed a significant retention of 5-FU from the NLC gel (91.256±4.56 μg/cm2) as compared with that from the 5-FU plain gel (12.23±3.86 μg/cm2) in the rat skin. Skin irritation was also significantly reduced with 5-FU-NLC gel as compared with 5-FU plain gel. These results show that the prepared 5-FU-loaded NLC has high potential to improve the penetration of 5-FU through the stratum corneum, with enormous retention and with minimal skin irritation, which is the prerequisite for topically applied formulations.

Lipid-based nanovesicles for nanomedicine

Multifunctional lipid-based nanovesicles (L-NVs) prepared by molecular self-assembly of membrane components together with (bio)-active molecules, by means of compressed CO₂-media or other non-conventional methods lead to highly homogeneous, tailor-made nanovesicles that are used for advanced nanomedicine. Confocal microscopy image of siRNA transfection using L-NVs, reprinted with permission from de Jonge,et al.,Gene Therapy, 2006,13, 400–411.

Self-emulsifying drug delivery system developed by the HLB-RSM approach: Characterization by transmission electron microscopy and pharmacokinetic study

Recently, we developed a new approach to rationalize an optimized design for self-emulsifying drug delivery system (SEDDS) by introducing the HLB and the response surface as determinant factors in SEDDS development. The aim of this current paper is to assess the suitability of this HLB-RSM approach to enhance the oral bioavailability of BCS class II compounds using fenofibrate as drug model. Eight SEDDS formulations (I→VIII) were pre-selected regarding their self-emulsification capacity and their effect on increasing in vitro drug release. They were firstly evaluated for their thermodynamic stability and zeta potential. Unstable SEDDS were discarded meanwhile the structural morphology of the stable ones (I, VI and VIII) was characterized using transmission electron microscopy (TEM). A pharmacokinetic study was then undertaken on male BALB/cJRj mices. The in vivo results showed a significant increase of fenofibrate absorption for all the three stable SEDDS formulations compared to the commercialized form, (LIPANTHYL micronized(®) (p<0.05)). The highest enhancement was recorded for SEDDS I, where AUC and Cmax values respectively increased by 2 and 4.4 folds. This justifies the fact that HLB-RSM approach could be considered as a promising method for the development of efficient and highly stable SEDDS aiming to increase the poor bioavailability of BCS class II molecules.