Vesicular Formulations Research Articles

Provesicular elastic carriers of Simvastatin for enhanced wound healing activity: An in-vitro/in-vivo study.

The aim of this study was to prepare and evaluate simvastatin (SIM) loaded elastic provesicular systems for effective topical wound management. SIM provesicles were prepared using the non-ionic surfactant Span 40, cholesterol and three edge activators i.e. Span 80, Tween 80 and sodium cholate. The vesicles revealed high SIM encapsulation efficiency ranging from 87.25 to 98.15%, whereas vesicle sizes ranged from 462.3 to 801.5nm. Vesicle sizes decreased with increasing the concentration of the edge activator. High negative zeta potential values were observed, revealing good stability of the vesicular formulations. The release of SIM from hydrated provesicular carriers was biphasic in nature. The selected SIM provesicular elastic carrier exerted approximately two-fold increase in the amount of SIM permeated through rat skin, compared to the free drug. Evaluation of wound healing activity of the selected provesicular formulation revealed significant reduction in wound size in rats, fourteen days post-wounding. These results were further confirmed by a significant increase in expression of vascular endothelial growth factor and collagen type I compared to the free drug. These results indicate that provesicular carriers could be a promising drug delivery system for encapsulating SIM and enhancing its wound healing efficacy.

Advanced strategy to exploit wine-making waste by manufacturing antioxidant and prebiotic fibre-enriched vesicles for intestinal health

Grape extract-loaded fibre-enriched vesicles, nutriosomes, were prepared by combining antioxidant extracts obtained from grape pomaces and a prebiotic, soluble fibre (Nutriose®FM06). The nutriosomes were small in size (from ∼140 to 260 nm), homogeneous (polydispersity index < 0.2) and highly negative (∼ −79 mV). The vesicles were highly stable during 12 months of storage at 25 °C. When diluted with warmed (37 °C) acidic medium (pH 1.2) of high ionic strength, the vesicles only displayed an increase of the mean diameter and a low release of the extract, which were dependent on Nutriose concentration. The formulations were highly biocompatible and able to protect intestinal cells (Caco-2) from oxidative stress damage. In vivo results underlined that the composition of mouse microbiota was not affected by the vesicular formulations. Overall results support the potential application of grape nutriosomes as an alternative strategy for the protection of the intestinal tract.

DoE directed optimization, development and evaluation of resveratrol loaded ultradeformable vesicular cream for topical antioxidant benefits

Objective: Aim of the present work was to optimize and formulate resveratrol loaded vesicular cream intended for dermal delivery of resveratrol with high skin deposition potential.Methods: Formulation was developed and optimized using Central Composite Design. Amount of phospholipid and sodium cholate were selected as critical material attributes and vesicle size and entrapment efficiency of resveratrol were taken as critical quality attributes. To increase the skin applicability and patient compliance, vesicles were further developed as vesicular cream which was then thoroughly characterized for physicochemical parameters, ex vivo skin permeation/deposition profile and antioxidant potential.Results: Vesicle size and entrapment efficiency of the optimized batch were found to be 178.9 ± 12.87 nm with 72.32 ± 3.45% respectively. Physicochemical properties and viscosity of cream formulation were also found to be favorable for skin applicability. Permeation flux at the end of 24 h was found to be 2.70 ± 0.73, 4.45 ± 0.56 and 4.95 ± 0.69 µg cm−2 h−1 for conventional cream, vesicular dispersion, and vesicular cream formulation respectively. Higher drug deposition in the skin via vesicular cream formulation was observed i.e. 335.2 ± 4.12 µg cm−2 (70.16 ± 0.87%) as compared to conventional cream i.e. 67.12 ± 19.63 µg cm−2 (14.05 ± 4.11%). Resveratrol encapsulated in vesicular cream has retained its inherent antioxidant activity suggesting the stability of resveratrol in vesicular cream.Conclusion: Thus, it can be concluded that deformable vesicular cream is capable of delivering encapsulated bioactive in deeper layers of skin, where it can be retained for achieving higher dermatological benefits.

FORMULATION AND EVALUATION OF ELASTIC LIPOSOMES OF DECITABINE PREPARED BY ROTARY EVAPORATION METHOD

Decitabine is a cytidine deoxynucleoside analog, which acts by inhibiting DNA methyltransferase, and is used for the treatment of acute myeloid leukemia. Decitabine has a short half-life (25 minutes), and is sensitive to harsh conditions. Elastic liposomes are an effective tool that can be used to overcome this disadvantage. Elastic liposomes also known as transfersomes are modified lipid carriers that enable drug to reach deeper skin layers and/or the systemic circulation. These vesicular formulations are several orders of magnitudes, more deformable than the standard liposomes and thus well suited for skin penetration. The objective of present study is to develop and evaluate the elastic liposomes of Decitabine so as to provide the sustained release and improve its bioavailability. Elastic liposomes were prepared by rotary evaporation method using Span 80 and Span 60 as a surfactants. The prepared Elastic liposomes were evaluated for entrapment efficiency, vesicle size, in vitro drug release. The drug release profiles from different elastic liposomes-in-vehicle formulations were in agreement with the physicochemical properties of the formulations. Based on different parameters formulations of batch ELS1 was found to be the best formulations. Stability study was performed on the selected formulation ELS1. Study concludes that Decitabine can also be formulated in the liposomal carrier which finds its best way for the topical administration.

Antioxidant activity of quercetin in Eudragit-coated liposomes for intestinal delivery.

Quercetin, a natural polyphenol with strong antioxidant activity, was loaded in Eudragit-coated liposomes conceived for intestinal delivery. Eudragit was used to form a protective shell on the surface of liposomes to resist gastric environment and allow the delivery of quercetin to the intestine. The physico-chemical properties of the liposomes were assessed by light scattering and cryogenic transmission electron microscopy. Small, spherical, uni- and bilamellar liposomes were produced, with the presence of multilamellar structures in Eudragit-coated liposomes. The Eudragit coating increased the physical stability of the vesicular system in fluids mimicking the gastrointestinal environment. Further, the incorporation of quercetin in the vesicular system did not affect its intrinsic antioxidant activity, as DPPH radical was almost completely inhibited, and the vesicles were also capable of ensuring optimal protection against oxidative stress in human intestinal cells by reducing reactive oxygen species (ROS) production. The proposed approach based on quercetin vesicular formulations may be of value in the treatment of pathological conditions associated with intestinal oxidative stress.

Enhanced stability of phenylethyl resorcinol in elastic vesicular formulations

Purpose: To enhance the stability and reduce photo-degradation of phenylethyl resorcinol (PR) by elastic vesicle formation.Methods: PR solution was stored at different temperatures, pH conditions, and under protected and unprotected natural light. The color of the solution and total active content were investigated. Three types of elastic vesicles, viz, ethosomes, transfersomes and invasomes, were prepared and their sedimentation in formulations and total active content were investigated before and after storage under various conditions for 4 months. The stability of the solutions and vesicular formulations were assessed.Results: PR solution was unstable at pH 9, higher temperature (70 ± 1 oC) and under natural light. The color of PR solution changed from colorless to orange tone and the PR content decreased. On the other hand, PR entrapped within ethosome, tranfersome and invasome vesicles showed better stability, color change was not observed in the formulations, and PR content remained &gt; 90 %.Conclusion: All the vesicles display reduced degradation of PR under thermal and natural light. Thus, PR vesicular formulation enhances stability and improves the quality of the product for use in topical administration.Keywords: Phenylethyl resorcinol, Degradation, Ethosomes, Transfersomes, Invasomes, Topical administration

Co-Loading of Ascorbic Acid and Tocopherol in Eudragit-Nutriosomes to Counteract Intestinal Oxidative Stress.

The present study aimed at developing a new vesicular formulation capable of promoting the protective effect of ascorbic acid and tocopherol against intestinal oxidative stress damage, and their efficacy in intestinal wound healing upon oral administration. A pH-dependent copolymer (Eudragit® L100), a water-soluble prebiotic fibre (Nutriose® FM06), a phospholipid mixture (Lipoid S75), and two natural antioxidants (ascorbic acid and tocopherol) were combined to fabricate eudragit-nutriosomes by a simple, solvent-free procedure. The vesicles were spherical and oligolamellar, with some multicompartment structures in Eudragit-nutriosomes, small in size (~100 nm), with highly negative zeta potential. The effect of Eudragit® and Nutriose® on the stability on storage and in simulated gastrointestinal fluids were confirmed by the Turbiscan® technology and in vitro studies, respectively. Eudragit-nutriosomes exhibited a protective effect against H2O2-induced oxidative stress, and a proliferative effect in Caco-2 cells, as they provided the closure of the scratched area after 96 h of incubation.

Sorbitol-penetration enhancer containing vesicles loaded with baicalin for the protection and regeneration of skin injured by oxidative stress and UV radiation

Aiming at improving the protective effects of baicalin on the skin, new highly-biocompatible penetration enhancer containing vesicles (PEVs) were developed by modifying the base formulation of transfersomes with sorbitol, thus obtaining sorbitol-PEVs. An extensive evaluation of the physico-chemical features of both transfersomes and sorbitol-PEVs was carried out. Transfersomes were mainly close-packed, multi-compartment vesicles, while sorbitol-PEVs appeared mostly as single, spherical, unilamellar vesicles. All the vesicles were small in size (∼128 nm) and negatively charged (∼−67 mV), without significant differences between the formulations. The in vitro delivery of baicalin to intact skin showed an improved ability of sorbitol-PEVs to favour the deposition of the flavonoid into the whole skin. In addition, the vesicular formulations protected keratinocytes and fibroblasts from oxidative stress and UV radiation, and promoted cell proliferation and migration, which favoured the closure of skin wound. Cell uptake was promoted as well, especially when sorbitol-PEVs were used.

Flexible nano-sized lipid vesicles for the transdermal delivery of colchicine; in vitro/in vivo investigation

Colchicine (CL) is the most effective treatment of acute gout, however, it is associated with side effects in 80% of the patients at therapeutic doses, in addition, it's a water-soluble strong base (pKa ∼12.8) which ionizes at physiological gastrointestinal pH resulting in low oral bioavailability of 44%. This work employed enhancing the bioavailability and reducing the side effects of CL through combining the benefits of the transdermal route together with those of elastic lipid nano-vesicles. Transfersomes (TRs) have been studied as vehicles for transdermal drug delivery, however, poor encapsulation of drugs and drug leaking of the vesicles required complexation of CL with β-cyclodextrin (β-CD) before formulation. The composition of the designed CL-β-CD-TR was studied to balance the flexibility of the vesicles to their entrapment ability. CL-β-CD-TR were characterized for their shape, size, entrapment efficiency, elasticity, release profile, ex vivo skin permeation, pharmacological efficacy, and histopathological effect. Encapsulation efficiency of CL-β-CD complex in the vesicular formulations ranged from 42.3% to 93.8%. Particle size ranged from 70.6 nm to 138.5 nm and zeta potential ranged from 16.1 mV to 23.4 mV. The in vitro release of CL from the selected CL-β-CD-TR formulation (F3) showed a controlled, biphasic profile. Ex vivo study reported the great potential of F3 (CL-β-CD-TR) for skin permeation. In vivo experiment demonstrated that F3 (CL-β-CD-TR) possessed high biological efficacy with reduced skin irritation.

FORMULATION DEVELOPMENT AND EVALUATION OF TRANSFEROSOMAL GEL

Transfersomes are particularly optimized, ultradeformable (ultraflexible) lipid supramolecular aggregates, which are able to penetrate the mammalian skin intact. Transfersome is a type of carrier system which is capable of transdermal delivery of low as well as high molecular weight drugs. Transfersomes penetrate through the pores of stratum corneum which are smaller than its size and get into the underlying viable skin in intact form. Acne vulgaris is a disease of the pilosebaceous follicle characterized by non-inflammatory (open and closed comedones) and inflammatory lesions (papules, pustules, and nodules). In such situation transdermal drug delivery remains the most preferential mode of administration. But, stratum corneum forms the most formidable barrier for the penetration of drug through skin. To overcome the stratum corneum barrier, the use of lipid vesicles like transfersomes in delivery systems has involved increasing attention in recent years. The aim of the present study was to statistically optimize the vesicular formulations (Transfersomes) for enhanced skin delivery of a model drug Clindamycin Phosphate.&#x0D; Keywords: Transfersomes, Acne vulgaris, Clindamycin Phosphate

FORMULATION, SYSTEMATIC OPTIMIZATION, IN VITRO, EX VIVO, AND STABILITY ASSESSMENT OF TRANSETHOSOME BASED GEL OF CURCUMIN

Objectives: The current work presents a formulation of curcumin-loaded transethosome (CRM-TE) in the form of a gel and its characterization.Methods: Thirteen formulations were prepared by varying the concentration of Phospholipon 90G as lipid, ethanol, and ratio of lipid: Span using Box- Behnken Design. The optimized formulation was characterized by vesicle size, entrapment efficiency, drug retention, drug permeation through skin, and morphology. Parameters of CRM-TE were compared to other vesicular systems that include liposomes, ethosomes, and transfersomes. Optimized CRM-TE was incorporated into gels, and comparative evaluation was performed. CRM-TE gel was kept at 5±3°C, 25±3°C, and 40±3°C for 180 days, further evaluated for entrapment efficacy and vesicle size.Results: CRM-TE showed 286.4 nm vesicle size, 61.2% entrapment efficiency, 19.8% drug retention, and 71.3% drug permeation at 24 h in the skin. It was found superior in terms of all the parameters as compared to other vesicular formulations. CRM-TE gel also exhibited best characteristics in terms of entrapment efficiency, drug retention, and drug permeation. CRM-TE gel exhibited better stability at 5±3°C in terms of vesicle size and entrapment efficiency as compared to other storage conditions.Conclusion: CRM-TE gel could offer efficient delivery of curcumin through topical route.

In vitro stabilization and in vivo improvement of ocular pharmacokinetics of the multi-therapeutic agent baicalin: Delineating the most suitable vesicular systems

Baicalin is a multi-purpose flavonoid used in the treatment of different ocular diseases. Owing to its poor stability in basic pH and its poor solubility, a suitable carrier system is needed to enhance its ocular therapeutic potential. Therefore, the objective of this work was to prepare and contrast different baicalin vesicular systems; namely liposomes, penetration enhancer vesicles PEVs and transfersomes. Results revealed that baicalin vesicles exhibited suitable particle size and zeta potential, high entrapment efficiency and controlled release. Depending on the vesicular composition, selected formulations were able to resist physical changes of particle size, zeta potential, entrapment efficiency and in vitro release after storage for 3 months, while retarding the degradation of baicalin. Selected vesicular formulations displayed equivalent or superior antioxidant potential compared to baicalin solution, with absolute superiority over ascorbic acid reference, while demonstrating sterilization endurance and safety on ocular tissues. Pharmacokinetic studies revealed that transfersomes displayed the fastest onset of action, while liposomes displayed the highest extent of absorption as concluded from the Tmax, Cmax, and AUC0-∞ values with 4–5 folds increase in bioavailability compared to baicalin control solution. This delineates baicalin vesicular systems as a promising platform for treatment of ocular diseases such as inflammation, cataract and diabetic retinopathy.

Improvement of dermal delivery of tetracycline using vesicular nanostructures.

The objective of this investigation was to study the potential use of nanoliposomes and nanotransfersomes in dermal delivery of tetracycline hydrochloride (TC) for acne treatment. Vesicular nanostructures were prepared by thin film hydration method and evaluated for their size, zeta potential, morphology, and entrapment efficiency. Minimal inhibitory concentration values of TC-loaded vesicles were evaluated and compared with TC aqueous solution against Staphylococcus epidermis. In vitro drug release and ex vivo drug permeation through the excised rat skin were performed to assess drug delivery efficiency. Particle size, zeta potential, and entrapment efficiency of prepared nanoliposomes and nanotransfersomes were found to be 75 and 78 nm, 17 and 7 mV, and 45 and 55%, respectively. Antimicrobial analysis indicated that there was no difference between vesicular formulations and aqueous solution of TC. In vitro drug release study indicated that nanoliposomes could release TC 2.6 folds more than nanotransfersomes, and skin permeation study showed that the permeability of TC-loaded nanotransfersomes was 1.6 times higher than nanoliposomes which was also confirmed by fluorescence microscope imaging. These findings concluded that nanoliposomal and especially nanotransfersomal formulations could be proposed as the potential approach for better therapeutic performance of TC against acne.

Formulation and in vitro stability evaluation of ethosomal carbomer hydrogel for transdermal vaccine delivery

The primary objective of this study was to develop, evaluate and compare the effectiveness and stability of ethosomal carbomer gels in different solvents. The optimal ethosomal formulation was isolated to create ethosomal gels using carbomer in either pure water (water gel) or PBS containing 30% ethanol (PBS gel). In vitro release of the ethosomal gels were tested using Franz apparatus on hydrophilic and hydrophobic artificial membranes. In vitro stability of two ethosomal gels was systematically evaluated. Transdermal antigen delivery of ethosomal gel was finally performed on the skin of hair removal mice. Both solvent and concentration effects on the in vitro release performance of ethosomal gel of carbomer have been confirmed. Penetration depth has been found to be dependent on the nature of the membranes such that penetration rate is higher in the hydrophobic membrane than the hydrophilic ones. Furthermore, in vitro stability test indicated that ethosomal PBS gel was more stable than ethosomal water gel. In vivo immunoassay confirmed that the ethosomal PBS gel could deliver the antigenic molecules into the skin of mice and stimulate specific IgG secretion. Using the same solvent for lipid vesicular formulation when making polymeric hydrogel may help to provide a more conducive environment for lipid vesicles and hence enhance their roles in transdermal antigen delivery.

"Preparation and Physicochemical Characterization of Topical Niosomal Formulation of Minoxidil and Tretinoin"

Hair loss is a worldwide problem and minoxidil is one of FDA-approved drugs for this stressing condition. Use of topical vesicular formulations containing minoxidil and tretinoin likely increase permeability, efficacy, and release time and decrease the drug toxicity. One of the vesicular systems is the niosome formulation which prepared and investigated about physiochemical properties in this study.

Tumor regression after intravenous administration of targeted vesicles entrapping the vitamin E α-tocotrienol

The therapeutic potential of tocotrienol, a member of the vitamin E family of compounds with potent in vitro anti-cancer properties, is limited by its inability to specifically reach tumors following intravenous administration. The purpose of this study is to determine whether a novel tumor-targeted vesicular formulation of tocotrienol would suppress the growth of A431 epidermoid carcinoma and B16-F10 melanoma in vitro and in vivo.In this work, we demonstrated that novel transferrin-bearing multilamellar vesicles entrapping α-T3 resulted in a dramatically improved (by at least 52-fold) therapeutic efficacy in vitro on A431 cell line, compared to the free drug. In addition, the intravenous administration of tocotrienol entrapped in transferrin-bearing vesicles resulted in tumor suppression for 30% of A431 and 60% of B16-F10 tumors, without visible toxicity. Mouse survival was enhanced by >13days compared to controls administered with the drug solution only.This tumor-targeted, tocotrienol-based nanomedicine therefore significantly improved the therapeutic response in cancer treatment.

Physico-chemical characterization of succinyl chitosan-stabilized liposomes for the oral co-delivery of quercetin and resveratrol

In the present work, quercetin and resveratrol, natural polyphenols with strong antioxidant and anti-inflammatory properties, were co-loaded in polymer-associated liposomes conceived for oral delivery, by exploiting the potential of pH-sensitive succinyl-chitosan. Chitosan was succinylated, characterized by Nuclear Magnetic Resonance spectroscopy and Gel Permeation Chromatography, and used to form a protective shell on the surface of liposomes. The physico-chemical properties of the succinyl-chitosan liposomes were assessed by light scattering, zeta potential, cryogenic transmission electron microscopy, and small angle X-ray scattering. Small, spherical, uni- and bilamellar vesicles were produced. The succinyl-chitosan shell increased not only the physical stability of the vesicular system, as demonstrated by accelerated stability tests, but also the release of the polyphenols to a greater extent at pH 7.0, mimicking the intestinal environment.The proposed approach based on polyphenol vesicular formulations may be of value in the treatment of pre-cancerous/cancerous intestinal conditions associated with inflammation and oxidative stress.

Lipid vesicular nanocarrier: Quick encapsulation efficiency determination and transcutaneous application

Nanoscale delivery systems have been widely investigated to overcome the penetration barrier of stratum corneum for effective transcutaneous application. The aim of this study is the development of effective vesicular formulations of ovalbumin and saponin which are able to promote penetration through the skin layers. Three kinds of vesicular formulations have been investigated as carriers, including liposomes, transfersomes and ethosomes, in which cholesterol and/or cationic lipid stearylamine are incorporated. The impact of membrane composition variations on the protein entrapment has been evaluated for each vesicle type. Formulations were characterized for particle size, polydispersity and encapsulation efficiency. The best formulations for each type of vesicle were subjected to in vivo transdermal immunization in mice. Among the three kinds of vesicular carrier, ethosomal nano carrier not only showed the best stability over a two months’ storage, but also enabled the highest increase in the titer of serum antibody. In this regard, cationic nano-ethosomes can be considered as a promising vesicular carrier for transdermal vaccines. Meanwhile, we have developed a simple method to determine encapsulation efficiency of vesicular systems, which has potential application as a high throughput screening for vesicular formulations.

Composite chitosan-transfersomal vesicles for improved transnasal permeation and bioavailability of verapamil

The creation of composite systems has become an emerging field in drug delivery. Chitosan has demonstrated several pharmaceutical advantages, especially in intranasal delivery. In this manuscript, a comparative study was conducted between regular vesicles (transfersomes and penetration enhancer vesicles) and composite vesicles (chitosan containing transfersomes and penetration enhancer vesicles) loaded with a model antihypertensive drug; verapamil hydrochloride VRP. Composite vesicles displayed larger particle size than regular vesicles owing to the coating potential of chitosan on the vesicular bilayer as displayed by transmission electron microscopy, with an increased viscosity of composite vesicles and a shift in the zeta potential values from negative to positive. The entrapment efficiency of VRP in the vesicles ranged from 24 to 64%, with best physical stability displayed with transfersomal vesicles prepared using sodium deoxycholate. Chitosan slowed the in vitro release of VRP from the selected formulation but managed to achieve high penetrability across sheep nasal mucosa as displayed by confocal laser microscopy. The chitosan composite transfersomal formulation exhibited absolute bioavailability of 81.83% compared to the oral solution which displayed only 13.04%. Findings of this manuscript highly recommend chitosan as a promising functional additive in vesicular formulations to improve the intranasal delivery of drugs with low oral bioavailability.

Effect of quercetin and resveratrol co-incorporated in liposomes against inflammatory/oxidative response associated with skin cancer

The present investigation reports the development of liposomes for the co-delivery of naturally occurring polyphenols, namely quercetin and resveratrol. Small, spherical, uni/bilamellar vesicles were produced, as demonstrated by light scattering, cryo-TEM, SAXS. The incorporation of quercetin and resveratrol in liposomes did not affect their intrinsic antioxidant activity, as DPPH radical was almost completely inhibited. The cellular uptake of the polyphenols was higher when they were formulated in liposomes, and especially when co-loaded rather than as single agents, which resulted in a superior ability to scavenge ROS in fibroblasts. The in vivo efficacy of the polyphenols in liposomes was assessed in a mouse model of skin lesion. The topical administration of liposomes led to a remarkable amelioration of the tissue damage, with a significant reduction of oedema and leukocyte infiltration. Therefore, the proposed approach based on polyphenol vesicular formulation may be of value in the treatment of inflammation/oxidative stress associated with pre-cancerous/cancerous skin lesions.