New ultradeformable drug carriers for potential transdermal application of interleukin-2 and interferon-alpha: theoretic and practical aspects

Development and In Vitro/Ex Vivo Evaluation of Lecithin-Based Deformable Transfersomes and Transfersome-Based Gels for Combined Dermal Delivery of Meloxicam and Dexamethasone

Transfersomes (TFS) are the promising carriers for transdermal delivery of various low and high molecular weight drugs, owing to their self-regulating and self-optimizing nature. Herein, we report synthesis and characterization of TFS loaded with meloxicam (MLX), an NSAID, and dexamethasone (DEX), a steroid, for simultaneous transdermal delivery. The different formulations of TFS containing varying amounts of lecithin, Span 80, and Tween 80 (TFS-1 to TFS-6) were successfully prepared by thin-film hydration method. The size of ranged between 248 and 273 nm, zeta potential values covering from -62.6 to -69.5 mV, polydispersity index (PDI) values in between 0.329 and 0.526, and entrapment efficiency of MLX and DEX ranged between 63-96% and 48-81%, respectively. Release experiments at pH 7.4 demonstrated higher cumulative drug release attained with Tween 80 compared to Span 80-based TFS. The scanning electron microscopy (SEM) of selected formulations -1 and TFS-3 revealed spherical shape of vesicles. Furthermore, three optimized transfersomal formulations (based on entrapment efficiency, TFS-1, TFS-3, and TFS-5) were incorporated into carbopol-940 gels coded as TF-G1, TF-G3, and TF-G5. These transfersomal gels were subjected to pH, spreadability, viscosity, homogeneity, skin irritation, in vitro drug release, and ex vivo skin permeation studies, and the results were compared with plain (nontransfersomal) gel having MLX and DEX. TFS released 71.72% to 81.87% MLX in 12 h; whereas, DEX release was quantified as 74.72% to 83.72% in same time. Nevertheless, TF-based gels showed slower drug release; 51.54% to 59.60% for MLX and 48.98% to 61.23% for DEX. The TF-G systems showed 85.87% permeation of MLX (TF-G1), 68.15% (TF-G3), and 68.94% (TF-G5); whereas, 78.59%, 70.54%, and 75.97% of DEX was permeated by TF-G1, TF-G3, and TF-G5, respectively. Kinetic modeling of release and permeation data indicated to follow Korsmeyer-Peppas model showing diffusion diffusion-based drug moment. Conversely, plain gel influx was found mere 26.18% and 22.94% for MLX and DEX, respectively. These results suggest that TF-G loaded with MLX and DEX can be proposed as an alternate drug carriers for improved transdermal flux that will certainly increase therapeutic outcomes.

Advanced nanomedicine approaches applied for treatment of skin carcinoma

Skin-cancer is the commonest malignancy affecting huge proportion of the population, reaching heights in terms of morbidity. The treatment strategies are presently focusing on surgery, radiation and chemotherapy, which eventually cause destruction to unaffected cells. To overcome this limitation, wide range of nanoscaled materials have been recognized as potential carriers for delivering selective response to cancerous cells and neoplasms. Nanotechnological approach has been tremendously exploited in several areas, owing to their functional nanometric dimensions. The alarming incidence of skin cancer engenders burdensome effects worldwide, which is further awakening innovational medicinal approaches, accompanying target specific drug delivery tools for coveted benefits to provide reduced toxicity and tackle proliferative episodes of skin cancer. The developed nanosystems for anti-cancer agents include liposomes, ethosomes, nanofibers, solid lipid nanoparticles and metallic nanoparticles, which exhibit pronounced outcomes for skin carcinoma. In this review, skin cancer with its sub-types is explained in nutshell, followed by compendium of specific nanotechnological tools presented, in addition to therapeutic applications of drug-loaded nano systems for skin cancer.

Lecithin soybean phospholipid nano-transfersomes as potential carriers for transdermal delivery of the human growth hormone

Pharmaceutical molecules such as peptides and proteins are usually injected into the body. Numerous efforts have been made to find new noninvasive ways to administer these peptides. In this study, highly flexible vesicles (transfersomes [TFs]) were designed as a new modern transdermal drug delivery system for systemic drug administration through the skin, which had also been evaluated in vitro. In this study, two growth hormone-loaded TF formulations were prepared, using soybean lecithin and two different surfactants; F1 _sodium deoxycholate and F 2 _sodium lauryl sulfate. Thereafter, the amount of skin penetration by the two formulas was assessed using the Franz diffusion cell system. TF formulations were evaluated for size, zeta potential and in vitro skin penetration across the rat skin. Results indicated that vesicle formulations were stable for 4 weeks and their mean sizes were 241.33 ± 17 and 171 ± 12.12 nm in the F 1 and F 2 formulation, respectively. After application to rat skin, transport of the human growth hormone (hGH) released from the TF formulations was found to be higher than that of the hGH alone. Maximum amounts of transdermal hormone delivery were estimated to be 489.54 ± 8.301  and 248.46 ± 4.019 ng·cm-2 , for F 1 and F 2 , respectively. The results demonstrate the capability of the TF-containing growth hormone in transdermal delivery and superiority of the F 1 to F 2 TFs.

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.

Anti-inflammatory activity of niosomes entrapped with Plai oil (Zingiber cassumunar Roxb.) by therapeutic ultrasound in a rat model

OBJECTIVE

The aim of this study was to evaluate the antioxidant and anti-inflammatory activities of Plai oil-encapsulated niosomes (Zingiber cassumunar Roxb.) on inflamed subcutaneous Wistar rat skin by therapeutic ultrasound.

METHODS

Pure oil from Plai rhizomes was extracted by steam distillation, and antioxidant activities were determined by 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay. Bioactive compounds were analyzed by gas chromatography-mass spectrometry. Niosome particles containing Plai oil were prepared by chloroform film method with sonication before testing for anti-inflammatory activity on locally inflamed subcutaneous rat skin after inducement from lipopolysaccharide with ultrasound once a day for 3 days. Skin temperatures and blood flow were evaluated.

RESULTS

Plai oil presented antioxidant activity that inhibited 2,2-diphenyl-1-picrylhydrazyl radicals. Four active compounds found in the essential oil were sabinene, γ-terpinene, terpinene-4-ol, and (E)-1-(3,4-dimethyoxy phenyl) butadiene. Application of ultrasound (0.2 W/cm2, 20%, 3 min) with gel containing Plai oil-encapsulated niosomes decreased skin temperature and blood flow to the lowest level compared to the application of neurofen drug or gel-based control.

CONCLUSION

Plai oil, which consists of four main bioactive compounds and possesses antioxidant and anti-inflammatory activities, can be applied against local subcutaneous inflammation when used with therapeutic ultrasound via entrapped niosomes.

Deformability properties of timolol-loaded transfersomes based on the extrusion mechanism. Statistical optimization of the process

The purpose of this work was to analyze the deformability properties of different timolol maleate (TM)-loaded transfersomes by extrusion. This was performed because elastic liposomes may contribute to the elevation of amount and rate of drug permeation through the corneal membrane. This paper describes the optimization of a transfersome formulation by use of Taguchi orthogonal experimental design and two different statistical analysis approaches were utilized. The amount of cholesterol (F1), the amount of edge-activator (F2), the distribution of the drug into the vesicle (F3), the addition of stearylamine (F4) and the type of edge-activator (F5) were selected as causal factors. The deformability index, the phosphorous recovery, the vesicle size, the polydispersity index, the zeta potential and percentage of drug entrapped were fixed as the dependent variables and these responses were evaluated for each formulation. Two different statistical analysis approaches were applied. The better statistical approach was determined by comparing their prediction errors, where regression analysis provided better optimized responses than marginal means. From the study, an optimized formulation of TM-loaded transfersomes was prepared and obtained for the proposed ophthalmic delivery for the treatment of open angle glaucoma. It was found that the lipid to surfactant ratio and type of surfactant are the main key factors for determining the flexibility of the bilayer of transfersomes. From in vitro permeation studies, we can conclude that TM-loaded transfersomes may enhance the corneal transmittance and improve the bioavailability of conventional TM delivery.

Preparation of transfersomes encapsulating sildenafil aimed for transdermal drug delivery: Plackett-Burman design and characterization

The aim of this work was to study the effect of different processing and formulation parameters on the preparation of sildenafil (SD) transfersomes utilizing the Plackett-Burman design. The drug to phospholipid molar ratio (X1), phospholipid to surfactant ratio (X2), hydrophilic-lipophilic balance of the surfactant (X3), hydration medium pH (X4), hydration time (X5) and the temperature of hydration (X6) were investigated to study their effect on the vesicle size (Y1) and entrapment efficiency (EE) of the drug (Y2). The preparation conditions were optimized to minimize the vesicle size and maximize the EE. The prepared transfersomes were also subjected to zeta potential measurements, morphological and physicochemical characterization. The combinations of factors that achieve the optimum desirability were identified. An optimized formulation was prepared and characterized once more for its vesicle size, EE, in vitro permeation and deformability index. The results revealed that both X3 and X6 had a pronounced effect on Y1, while X1 and X4 showed a significant effect on Y2. Morphological and physicochemical study confirmed the transfersomes spherical shape and compatibility of the formulation ingredients. The formulation with optimum desirability showed EE and vesicle size of 97.21% and 610 nm, respectively. In vitro permeation of the drug-loaded transfersome showed more than 5-fold higher permeation rate compared with drug suspension. Deformability index verified elasticity of the preparation. The significant variables could be optimized again to produce smaller vesicle size that could increase SD permeation from transdermal delivery systems loaded drug optimized transfersomes.

Miconazole nitrate bearing ultraflexible liposomes for the treatment of fungal infection

Miconazole nitrate is a widely used antifungal agent, but its use in topical formulations is not efficacious because deep seated fungal infections are difficult to treat with conventional topical formulation. Miconazole nitrate loaded ultraflexible liposomes have been prepared and their topical performance has been compared with conventional liposomes containing miconazole nitrate. Various ultraflexible liposomal formulations were prepared and extensively characterized for vesicular shape, size, entrapment efficiency, degree of deformability and in-vitro skin permeation through rat skin. Higher rate of drug transfer across the skin with ultraflexible liposomal formulations of miconazole nitrate suggests that the drug in its lipo-solubilized state might have gained facilitated entry into the tough barrier consisting of subcutaneous. In-vivo study showed better antifungal activity as compared to traditional liposomes and plain drug solution. This was confirmed through fluoroscence microscopy. It is concluded that prepared ultraflexible liposomes can facilitate improved and localized drug action in the skin, thus providing a better option to deal with deep seated skin problems.

Low cytotoxic elastic niosomes loaded with salmon calcitonin on human skin fibroblasts

A low cytotoxic elastic niosomal formulation loaded with salmon calcitonin was developed. The elastic niosomes were prepared from Tween 61 mixed with cholesterol at various concentrations of the edge activators (sodium cholate (NaC) and sodium deoxycholate (NaDC); 0.25, 0.5, 2.5, 5 and 10% mole) or ethanol (10–30% v/v). The effects of the niosomal concentrations (5, 10 and 20 mM) and phosphate buffer at pH 7.0 (5, 10, 20 and 30 mM) on the physical characteristics of niosomes were investigated. The 5 mM elastic niosomes in 5 mM phosphate buffer containing calcitonin 0.22 mg/mL gave the highest elasticity (deformability index (DI)) at 6.79 ± 2.03 determined by the extrusion method. The blank elastic niosomes comprised 2.5% mole NaDC, 5% mole NaC or 20% v/v ethanol showed the highest elasticity. The 5% mole NaC elastic niosomes loaded with calcitonin gave the highest DI (21.59 ± 0.91) and percentages of calcitonin entrapment efficiency (60.11 ± 4.98). This study has demonstrated that this NaC elastic niosome did not only reduce the cytotoxicity of the loaded calcitonin but also gave superior cell viability to the ethanolic elastic niosome as well.

Colloidal, in vitro and in vivo anti-leishmanial properties of transfersomes containing paromomycin sulfate in susceptible BALB/c mice

The aim of this study was to develop transfersomal formulation with respect to dermal delivery of paromomycin sulfate (PM) for possible topical therapy of cutaneous leishmaniasis (CL). PM transfersomal formulations (PMTFs) with different percent of soy phosphatidylcholine, sodium cholate (Na-Ch) and ethanol were prepared and characterized for the size, zeta potential and encapsulation efficiency. The results showed that the most stable formulations with suitable colloidal properties were obtained by 2% Na-Ch which had average size of around 200 nm. The in vitro permeation study using Franz diffusion cells fitted with mouse skin at 37°C for 24h showed that almost 23% of the PMTFs applied penetrated the mouse skin, and the amount retained in the skin was about 67% for both formulations; however, the percent of penetration and retention for PM conventional cream was 49 and 13, respectively. The 50% effective doses of PMTFs against Leishmania major promastigotes and amastigotes in culture were significantly less than cream and/or solution of PM. Selected PMTFs and empty transfersomes showed no cytotoxicity in J774 A.1 mouse macrophage cell line. Selected PMTFs was used topically twice a day for 4 weeks to treat L. major lesions on BALB/c mice, and the results showed a significantly (P<0.05) smaller lesion size in the mice in the treated groups than in the mice in the control groups, which received either empty transfersomes or phosphate-buffered saline (PBS) and also PM cream. The spleen parasite burden was significantly (P<0.01) lower in mice treated with selected PMTFs than in mice treated with PBS or control transfersomes, and PM cream. The results of this study showed that PMTFs prepared with 2% of Na-Ch with and without 5% ethanol might be useful as a candidate for the topical treatment of CL.

Skin permeation of retinol in Tween 20-based deformable liposomes: in-vitro evaluation in human skin and keratinocyte models

To develop a more effective transdermal delivery method for lipophilic functional cosmetic compounds such as retinol, we formulated various deformable liposomes and compared their transdermal delivery efficiency with those of neutral or negatively-charged conventional liposomes. We tested the deformability of liposomes containing edge activators such as bile salts, polyoxyethylene esters and polyoxyethylene ethers. As indicators of deformability, we used the passed volume and phospholipid ratios during extrusion, as well as the deformability index. We found that the type of edge activator significantly affected the extent of deformability, and that Tween 20 provided the highest level of deformability. Accordingly, we used Tween 20 to formulate deformable liposomes containing retinol in the membrane bilayers, and conducted a skin permeation study in Franz diffusion cells, using dermatomed human skin and three-dimensional human keratinocyte layers. As compared with the use of conventional neutral or negatively-charged liposomes, the use of Tween 20-based deformable liposomes significantly increased the skin permeation of retinol. These results suggested that deformable liposomes might be of potential use for the formulation of retinol and other lipophilic functional cosmetic compounds.

Novel Delivery Systems for Interferons

Interferons, IFNs, are among the most widely studied and clinically used biopharmaceuticals. Despite their invaluable therapeutic roles, the widespread use of IFNs suffers from some inherent limitations, mainly their relatively short circulation lifespan and their unwanted effects on some non-target tissues. Therefore, both these constraints have become the central focus points for the research efforts on the development of a variety of novel delivery systems for these therapeutic agents with the ultimate goal of improving their therapeutic end-points. Generally, the delivery systems currently under investigation for IFNs can be classified as particulate delivery systems, including micro- and nano-particles, liposomes, minipellets, cellular carriers, and non-particulate delivery systems, including PEGylated IFNs, other chemically conjugated IFNs, immunoconjugated IFNs, and genetically conjugated IFNs. All these strategies and techniques have their own possibilities and limitations, which should be taken into account when considering their clinical application. In this article, currently studied delivery systems/techniques for IFN delivery have been reviewed extensively, with the main focus on the pharmacokinetic consequences of each procedure.

Elastic liposomes mediated transdermal delivery of an anti-hypertensive agent: propranolol hydrochloride

One major problem encountered in transdermal drug delivery is the low permeability of drugs through the skin barrier. In the present investigation ultradeformable lipid vesicles, that is, elastic liposomes were prepared incorporating propranolol hydrochloride for enhanced transdermal delivery. Elastic liposomes bearing propranolol hydrochloride were prepared by conventional rotary evaporation method and characterized for various parameters including vesicles shape and surface morphology, size and size distribution, entrapment efficiency, elasticity, turbidity, and in vitro drug release. In vitro flux, enhancement ratio (ER), and release pattern of propranolol hydrochloride were calculated for transdermal delivery. In vivo study conducted on male albino rats (Sprague Dawley) was also taken as a measure of performance of elastic liposomal, liposomal, and plain drug solution. The better permeation through the skin was confirmed by confocal laser scanning microscopy (CLSM). Results indicate that the elastic liposomal formulation for transdermal delivery of propranolol hydrochloride provides better transdermal flux, higher entrapment efficiency, ability as a self-penetration enhancer and effectiveness for transdermal delivery as compared to liposomes.

Pharmacology of bile acids and their derivatives: Absorption promoters and therapeutic agents

The role of bile acids in pharmacotherapy is reviewed in this article. The therapeutic use of bile has been recognized since ancient times. Previously bile acids were the standard treatment for gallstones where chenodeoxycholic acid and ursodeoxycholic acid were effective in promoting the dissolution of cholesterol gallstones. Today their therapeutic role looks set to expand enormously. Bile acids as absorption promoters have the potential to aid intestinal, buccal, transdermal, ocular, nasal, rectal and pulmonary absorption of various drugs at concentrations that are non-toxic. Keto derivatives of cholic acid, such as 3a,7a,dihydroxy-12-keto-5alpha-cholic acid (sodium salt and methyl ester) are potential modifiers of blood-brain barrier transport and have been shown to promote quinine uptake, enhance the analgesic effect of morphine and prolong the sleeping time induced by pentobarbital. They have also been shown to be hypoglycaemic. Bile acids as therapeutic agents have the potential to produce beneficial effects in sexually transmitted diseases, primary biliary cirrhosis, primary sclerosing cholangitis, gallstones, digestive tract diseases, cystic fibrosis, cancer and diabetes.

Novel ultra-deformable vesicles entrapped with bleomycin and enhanced to penetrate rat skin

Beta-sitosterol 3-beta-D-glucoside (Sit-G), an absorption enhancer, was incorporated into ultra-deformable vesicles containing bleomycin to attenuate drug toxicity in human keratinocytes. The presence of Sit-G increased drug entrapment and improved in vitro stability of ultra-deformable vesicles. Confocal laser scanning microscopy revealed the extent to which Sit-G facilitated the penetration of ultra-deformable vesicles containing fluorescent probes into rat skin upon non-occlusive topical application. Furthermore, treatment with preparations incorporating Sit-G resulted in elevated epidermal and dermal concentrations of bleomycin. Ultra-deformable formulation contained Sit-G maintained flexibility for penetration through the skin, increased entrapment efficiency of bleomycin and stability in vitro, and significantly increased distribution of bleomycin in epidermis and dermis compared with those without Sit-G.

Transcutaneous IL-2 uptake mediated by Transfersomes depends on concentration and fractionated application

INTRODUCTION

Transfersomes (TF) are new, ultradeformable carriers with characteristics that enable them to penetrate the skin spontaneously. TFs are able to transport noninvasively both low- and high-molecular-weight molecules into the body.

MATERIALS AND METHODS

TFs contain phosphatidylcholine and sodium cholate. Recombinant human interleukin-2 (Proleukin, Chiron) was added to the TFs and incubated for 24 h at 4 degrees C. The immunotransfersomes (ITF) were isolated from free interleukin-2 (IL-2) by filtration (Centrisart, Sartorius). Twenty-five thousand, 50,000 and 150,000 IU pure IL-2 and ITFs, which had been incubated with the same concentrations of IL-2, were applied subcutaneously (s.c.) (n = 8) and epicutaneously (e.c.) (n = 8) to mice. The IL-2 serum concentrations in the mice were then measured by ELISA after 2, 4, 6, 8, 10 and 24 h. Fractionation of the transdermal IL-2 application was also examined as a means of improving uptake.

RESULTS

In concentrations of 25,000 and 50,000 IU IL-2, the subcutaneous application of ITFs resulted in a longer lasting IL-2 serum concentration than did the subcutaneous application of pure IL-2. While at 25,000 IU, the epicutaneous application of ITFs resulted in serum concentrations comparable to those resulting from s.c. application, at 50,000 and 150,000 IU, only 50% and 22.6% of the maximum serum concentration resulting from the s.c. application of pure IL-2 was obtained. Fractionating the transdermal IL-2 application improved uptake.

CONCLUSION

We were able to show that biologically active IL-2 can be bonded to TFs up to 75%. It is possible to transport IL-2 through the skin using TFs. Both the concentration-dependent saturation of the TFs with IL-2 and fractionation of the application resulted in differing degrees of transcutaneous IL-2 uptake.

Tetanus toxoid-loaded transfersomes for topical immunization

Topical immunization is a novel immunization strategy by which antigens and adjuvants are applied topically to intact skin to induce potent antibody and cell-mediated responses. Among various approaches for topical immunization, the vesicular approach is gaining wide attention. Proteineous antigen alone or in combination with conventional bioactive carriers could not penetrate through the intact skin. Hence, specially designed, deformable lipid vesicles called transfersomes were used in this study for the non-invasive delivery of tetanus toxoid (TT). Transfersomes were prepared and characterized for shape, size, entrapment efficiency and deformability index. Fluorescence microscopy was used to investigate the mechanism of vesicle penetration through the skin. The immune stimulating activity of these vesicles was studied by measuring the serum anti-tetanus toxoid IgG titre following topical immunization. The immune response was compared with the same dose of alum adsorbed tetanus toxoid (AATT) given intramuscularly, topically administered plain tetanus toxoid solution, and a physical mixture of tetanus toxoid and transfersomes again given topically. The results indicated that the optimal transfersomal formulation had a soya phosphatidylcholine and sodium deoxycholate ratio of 85:15%, w/w. This formulation showed maximum entrapment efficiency (87.34 +/- 3.81%) and deformability index (121.5 +/- 4.21). An in-vivo study revealed that topically administered tetanus toxoid-loaded transfersomes, after secondary immunization, elicited an immune response (anti-TT-IgG) comparable with that produced by intramuscular AATT. Fluorescence microscopy revealed the penetration of transfersomes through the skin to deliver the antigen to the immunocompetent Langerhans cells.

Non-invasive vaccine delivery in transfersomes, niosomes and liposomes: a comparative study

Non-invasive vaccine delivery is a top priority for public health agencies because conventional immunization practices are unsafe and associated with numerous limitations. Recently, the skin has emerged as a potential alternative route for non-invasive delivery of vaccine. Topical immunization (TI), introduction of antigen through topical application onto the intact skin, has many practical merits compared to injectable routes of administration. One of the possibilities for increasing the penetration of bioactives through the skin is the use of vesicular systems. Specially designed lipid vesicles are attracting intense attention and can be used for non-invasive antigen delivery. In the present study, elastic vesicle transfersomes, non-ionic surfactant vesicles (niosomes) and liposomes were used to study their relative potential in non-invasive delivery of tetanus toxoid (TT). Transfersomes, niosomes and liposomes were prepared and characterized for shape, size and entrapment efficiency. These vesicles were extruded through polycarbonate filter (50-nm pore size) to assess the elasticity of the vesicles. The immune stimulating activity of transfersomes, niosomes and liposomes were studied by measuring the serum anti-TT IgG titre following topical immunization. The immune response elicited by topical immunization was compared with that elicited by same dose of alum-adsorbed tetanus toxoid (AATT) given intramuscularly. The results indicate that optimal formulations of transfersomes, niosomes and liposomes could entrap 72.7+/-3.4, 42.5+/-2.4 and 41.3+/-2.2% of antigen and their elasticity values were 124.4+/-4.2, 29.3+/-2.4 and 21.7+/-1.9, respectively. In vivo study revealed that topically given TT containing transfersomes, after secondary immunization, could elicit immune response (anti-TT-IgG) that was equivalent to one that produced following intramuscularly alum-adsorbed TT-based immunization. In comparison to transfersomes, niosomes and liposomes elicited weaker immune response. Thus transfersomes hold promise for effective non-invasive topical delivery of antigen(s).

In vitro and in vivo transfection efficiency of a novel ultradeformable cationic liposome

Cationic lipids have been often used as one of the major components in making most promising non-viral gene delivery systems, whereas sodium cholate, a surfactant so-called edge activator has been used in preparing ultradeformable and ultraflexible liposomes called Transfersomes. Using both a cationic lipid, DOTAP and sodium cholate, a novel formulation of ultradeformable cationic liposome (UCL) has been prepared. The average particle size of this formulation was approximately 80 nm. The physical and chemical stabilities at two different temperatures (4 degrees C and 20 degrees C) were also evaluated for 60 days. The ultradeformability of new formulation was also assessed, and it has been proved that the formulation is deformable. In vitro transfection efficiency of plasmid DNA/UCL was assessed by the expression of green fluorescent protein (GFP) in four cell lines, OVCAR-3 (human ovarian carcinoma cells), HepG2 (human hepatoma cells), H-1299 (human lung carcinoma cells) and T98G (human brain carcinoma cells). The optimal ratio of DNA to liposome for maximal transfection efficiency was 1:14 (w/w) in all the cell lines except for the human brain carcinoma cells. The same formulation was tested for in vivo transfection efficiency and its retention time within the organs by applying the DNA/UCL complexes on hair-removed dorsal skin of mice non-invasively. It was found that genes were transported into several organs for 6 days once applied on intact skin.

Transfersomes—A Novel Vesicular Carrier for Enhanced Transdermal Delivery: Development, Characterization, and Performance Evaluation

This work describes the use of a novel vesicular drug carrier system called transfersomes, which is composed of phospholipid, surfactant, and water for enhanced transdermal delivery. The transfersomal system was much more efficient at delivering a low and high molecular weight drug to the skin in terms of quantity and depth. In the present study transfersomes and liposomes were prepared by using dexamethasone as a model drug. The system was evaluated in vitro for vesicle shape and size, entrapment efficiency, degree of deformability, number of vesicles per cubic mm, and drug diffusion across the artificial membrane and rat skin. The effects of surfactant type, composition, charge, and concentration of surfactant were studied. The in vivo performance of selected formulation was evaluated by using a carrageenan-induced rat paw edema model. Fluorescence microscopy by using rhodamine-123 and 6-carboxyfluorescein as fluorescence probe was performed. The stability study was performed at 4 degrees C and 37 degrees C. An in vitro drug release study has shown a nearly zero order release of drug and no lag phase. The absence of lag phase in comparison to liposomes and ointment is attributed to the greater deformability, which may account for better skin permeability of transfersomes. In vivo studies of transfersomes showed better antiedema activity in comparison to liposomes and ointment, indicating better permeation through the penetration barrier of the skin. This was further confirmed through a fluorescence microscopy study. Finally, it may be concluded from the study that complex lipid molecules, transfersomes, can increase the transdermal flux, prolong the release, and improve the site specificity of bioactive molecules.