Diacerein niosomal gel for topical delivery: development,in vitro and in vivo assessment

The purpose of this study was to load diacerein (DCR) in niosomes by applying response surface methodology and incorporate these niosomes in gel base for topical delivery. Box–Behnken design was used to investigate the effect of charge-inducing agent (X₁), surfactant HLB (X₂) and sonication time (X₃) on the vesicle size (Y₁), entrapment efficiency (Y₂) and cumulative drug released (Y₃). DCR niosomal formulations were prepared by thin film hydration method. The optimized formula was incorporated in different gel bases. DCR niosomal gels were evaluated for homogeneity, rheological behavior; in vitro release and pharmacodynamic activity by carrageenan-induced hind paw edema method in the rat compared with DCR commercial gel. The results revealed that the mean vesicle sizes of the prepared niosomes ranged from 7.33 to 23.72?µm and the entrapment efficiency ranged from 9.52% to 58.43% with controlled release pattern over 8?h. DCR niosomal gels exhibited pseudoplastic flow with thixotropic behavior. The pharmacodynamic activity of DCR niosomal gel in 3% HPMC showed significant, 37.66%, maximum inhibition of edema size in comparison with 20.83% for the commercial gel (p?相似文献   

Enhanced Oral Bioavailability of Griseofulvin via Niosomes

The aim of the present report was to develop nonionic surfactant vesicles (niosomes) to improve poor and variable oral bioavailability of griseofulvin. Niosomes were prepared by using different nonionic surfactants span 20, span 40, and span 60. The lipid mixture consisted of surfactant, cholesterol, and dicetyl phosphate in the molar ratio of 125:25:1.5, 100:50:1.5, and 75:75:1.5, respectively. The niosomal formulations were prepared by thin film method and ether injection method. The influence of different formulation variables such as surfactant type, surfactant concentration, and cholesterol concentration was optimized for size distribution and entrapment efficiency for both methods. Result indicated that the niosomes prepared by thin film method with span 60 provided higher entrapment efficiency. The niosomal formulation exhibited significantly retarded in vitro release as compared with free drug. The in vivo study revealed that the niosomal dispersion significantly improved the oral bioavailability of griseofulvin in albino rats after a single oral dose. The maximum concentration (C _max) achieved in case of niosomal formulation was approximately double (2.98 μg/ml) as compared to free drug (1.54 μg/ml). Plasma drug profile also suggested that the developed niosomal system also has the potential of maintaining therapeutic level of griseofulvin for a longer period of time as compared to free griseofulvin. The niosomal formulation showed significant increase in area under the curve_0-24 (AUC; 41.56 μg/ml h) as compared to free griseofulvin (22.36 μg/ml h) reflecting sustained release characteristics. In conclusion, the niosomal formulation could be one of the promising delivery system for griseofulvin with improved oral bioavailability and prolonged drug release profiles.     

Investigating superiority of novel bilosomes over niosomes in the transdermal delivery of diacerein: in vitro characterization,ex vivo permeation and in vivo skin deposition study

Skin is considered the most accessible organ of the body because of its underlying capillary network. However, stratum corneum (SC), the upper most layer of skin, represents major diffusional barrier for most drugs. Hence, the use of edge activators (EAs) in designing novel elastic vesicles is hypothesized to impart their lipid bilayer with ultra-flexibility to trespass SC by high self-optimizing deformability. To confirm this hypothesis, this work aimed at developing novel bilosomes by modulating conventional niosomal composition using different bile salts as EAs and investigating their superiority over niosomes for transdermal delivery of diacerein (DCN), as model drug. Bilosomes were prepared by thin film hydration (TFH) technique according to full 3¹.2² factorial design to select the optimal formulation using Design-Expert^® software. The optimal bilosomes (B6) showed nanosized vesicles (301.65?±?17.32?nm) and 100.00?±?0.00 % entrapment efficiency. Ex vivo permeation studies and in vivo evaluation revealed that B6 exhibited superior permeation and drug retention capacity compared to the conventional niosomal formulation and drug suspension. Furthermore, B6 was subjected to in vivo histopathological study using male Wistar rats which ensured its safety for topical application. Overall, the results confirmed the hypothesized superiority of bilosomes over niosomes for enhancing DCN flux across the skin.     

Enhancement of lomefloxacin Hcl ocular efficacy via niosomal encapsulation: in vitro characterization and in vivo evaluation

The aim of this study is to develop and evaluate niosomal dispersions loaded with the hydrophilic drug; lomefloxacin Hcl (LXN) for the management of ocular bacterial conjunctivitis. LXN-loaded niosomes were prepared by the thin film hydration method following a full factorial formulation design. Two independent variables were evaluated: the type of surfactant (X1) and the surfactant:cholesterol ratio (X2). The dependent variables comprised entrapment efficiency (EE%: Y1), particle size (PS: Y2) and zeta potential (ZP: Y3). The optimum formulation, N-LXN14 (Tw60: CH, 1:1), was spherical in shape and exhibited EE% of 68.41?±?0.07, PS of 176.0?±?0.98 and ZP of -40.70?±?2.20 with a sustained release profile over 8?hours following the Higuchi model. N-LXN14 proved good physicochemical stability under refrigeration up to 3 months. Ocular irritancy test showed no signs of ocular toxicity, confirming the safety and suitability for ocular application. Microbiological evaluation of the antibacterial effect of N-LXN14 was conducted using the susceptibility test and through the induction of topical conjunctivitis by Staphylococcus aureus (S. aureus) followed by topical therapy. Susceptibility test manifested significantly higher percent inhibition of S. aureus and higher AUC_0–12?h of N-LXN14 (604.59?±?0.05) compared to the commercial product (126.25?±?0.049). Both clinical observation and colony count of the infected eyes after eight days of treatment demonstrated significant improvement in therapeutic response. The infected eyes were completely healed with eradication of S. aureus. In conclusion, the results showed that LXN niosomal dispersions may serve as a promising superior ocular delivery system in the treatment of bacterial conjunctivitis.     

Niosomes for oral delivery of nateglinide: in situ–in vivo correlation

Niosomes have been claimed to enhance intestinal absorption and to widen the absorption window of acidic drugs. This was reported after monitoring the intestinal absorption in situ. Accordingly, the aim of this work was to investigate the effect of niosomal encapsulation on intestinal absorption and oral bioavailability of nateglinide. This was conducted with the goal of correlation between in situ intestinal absorption and in vivo availability. The drug was encapsulated into proniosomes. The niosomes resulting after hydration of proniosomes were characterized with respect to vesicle size and drug entrapment efficiency. The in situ rabbit intestinal absorption of nateglinide was monitored from its aqueous solution and niosomes. Streptozotocin was used to induce diabetes in albino rats which were then used to assess the hypoglycemic effect of nateglinide after oral administration of aqueous dispersion and niosomal systems. The prepared vesicles were in the nanoscale with the recorded size being 283?nm. The entrapment efficiency depended on the pH of the formulation. The in situ intestinal absorption reflected non-significant alteration in the membrane transport parameters of the drug after niosomal encapsulation compared with the free drug solution. In contrast, niosomes showed significant improvement in the rate and extent of the hypoglycemic effect compared with the unprocessed drug. This discrepancy can be attributed to different transport pathway for the drug after niosomal inclusion with the vesicles undergoing translymphatic transport which can minimize presystemic metabolism. However, this requires confirmatory investigations. In conclusion niosomes can enhance oral bioavailability of nateglinide with the absorption being through nontraditional pathway.     

Formulation of Niosomal Gel for Enhanced Transdermal Lopinavir Delivery and Its Comparative Evaluation with Ethosomal Gel

The aim was to develop niosomal gel as a transdermal nanocarrier for improved systemic availability of lopinavir. Niosomes were prepared using thin-film hydration method and optimized for molar quantities of Span 40 and cholesterol to impart desirable characteristics. Comparative evaluation with ethosomes was performed using ex vivo skin permeation, fluorescence microscopy, and histopathology studies. Clinical utility via transdermal route was acknowledged using in vivo bioavailability study in male Wistar rats. The niosomal formulation containing lopinavir, Span 40, and cholesterol in a molar ratio of 1:0.9:0.6 possessed optimally high percentage of drug entrapment with minimum mean vesicular diameter. Ex vivo skin permeation studies of lopinavir as well as fluorescent probe coumarin revealed a better deposition of ethosomal carriers but a better release with niosomal carriers. Histopathological studies indicated the better safety profile of niosomes over ethosomes. In vivo bioavailability study in male Wistar rats showed a significantly higher extent of absorption (AUC_0→∞, 72.87 h × μg/ml) of lopinavir via transdermally applied niosomal gel as compared with its oral suspension. Taken together, these findings suggested that niosomal gel holds a great potential of being utilized as novel, nanosized drug delivery vehicle for transdermal lopinavir delivery.KEY WORDS: ethosomes, lopinavir, niosomes, transdermal     

Development and Characterization of Mixed Niosomes for Oral Delivery Using Candesartan Cilexetil as a Model Poorly Water-Soluble Drug

The aim of this study was to prepare candesartan cilexetil-loaded niosomes and mixed niosomes to enhance the aqueous solubility of the drug, thus improving its oral bioavailability. The formulations were prepared using various types and combinations of surfactants, copolymers, and charge-inducing agents. The candesartan cilexetil entrapment efficiency, particle size, and zeta potential of these niosomes varied within the range of 99.06 ± 1.74 to 36.26 ± 2.78, 157.3 ± 3.3 to 658.3 ± 12.7 nm, and −14.7 ± 2.8 to −44.5 ± 1.5 mV, respectively. The in vitro drug release from niosomes was improved after niosomal entrapment compared to pure candesartan cilexetil. The sedimentation behavior study and formulation stability tests against bile salt revealed that mixed niosomes prepared by combining Span 60 and Pluronic P85 demonstrated better stability. The differential scanning calorimetry analysis showed the conversion of crystal structure of candesartan cilexetil to the soluble amorphous form after niosomal encapsulation which induced the drug release. Consequently, oral drug delivery by Span 60/Pluronic P85-mixed niosomes seems feasible due to enhanced drug release and stability.KEY WORDS: in vitro drug release, niosomes, oral drug delivery, stability, surfactants     

Preparation of Artemisia Turcomanic Encapsulated Niosomal Nanocarriers and Evaluation of Anticancer Activities and Apoptosis Gene Expression Analysis in HeLa Cells

Artemisia turcomanic as a natural antibacterial agent, exhibited significant antibacterial effect in the treatment against cancer. This study is the first to investigate size, encapsulation efficiencies, release behavior of Artemisia turcomanic loaded niosomal nanocarriers, and the anticancer effect of niosomal nanocarriers by MTT assay, flow cytometry, and real time (on HeLa cell lines). When the molar ratio of cholesterol: surfactant was 1 : 2 and the liquid content was 300 μmol, the highest percentage of entrapment efficiency was 83.25 %. Moreover, niosomal formulation showed a pH-dependent release; a slow-release profile in physiological pH (7.4), and a more significant release rate at acidic conditions (pH=5.4). In addition, The apoptotic rate of Artemisia loaded niosomes on HeLa cell lines was higher than free extract and pristine niosome. Also, reduction in the expression levels of Bcl2, caspase-3, and p53 genes and increase in the expression level of BAX after treatment with Artemisia turcomanic-loaded niosomes were more significant than those after treatment with free Artemisia turcomanic and blank niosome. The cytotoxicity results of samples presented that Artemisia turcomanic loaded niosomes are more beneficial in the death of HeLa cell lines.     

Preparation and evaluation of niosome gel containing acyclovir for enhanced dermal deposition

Niosomes suggest a versatile vesicle delivery system with possible transport of drugs via topical route for skin delivery. The aim of the present research was to optimize niosome gel formulation of acyclovir and to evaluate in both in vitro and in vivo rabbit model. Niosome formulations were formulated by coacervation phase separation technique with different ratios of nonionic surfactants, phospholipids and cholesterol using 3² factorial design. Altering the surfactant concentration has influenced the drug entrapment, but not vesicle size. At high surfactant combinations, the acyclovir release from niosomes was strongly influenced by cholesterol:lecithin ratio. Ex vivo drug permeation data indicate substantial difference in flux values and was influenced by the niosome composition. Ex vivo studies using formulation (B₈) for drug deposition indicate greater amount of niosome being diffused into the skin layers and formed a depot, compared to commercial acyclovir cream (control). Two distinct dermatopharmacokinetic profiles were observed, in vivo, for niosome gel formulation (B₈) and control, which were analog to the profiles observed with ex vivo deposition studies. In vivo plasma drug level suggests low systemic exposure of acyclovir (C_max: 9.44?±?2.27?ng/mL and 14.54?±?3.11?ng/mL for niosome formulation and control, respectively). Comparison of kinetic data of acyclovir in the stratum corneum and plasma signifies that the niosome formulation forms a depot in the epidermis or dermis region. This study concludes that the niosome gel formulation (B₈) could be a viable vesicular system for an impressive transdermal delivery of acyclovir by topical application.     

Niosome-Encapsulated Gentamicin for Ophthalmic Controlled Delivery

The objective of the present research was to investigate the feasibility of using non-ionic surfactant vesicles (niosomes) as carriers for the ophthalmic controlled delivery of a water soluble local antibiotic; gentamicin sulphate. Niosomal formulations were prepared using various surfactants (Tween 60, Tween 80 or Brij 35), in the presence of cholesterol and a negative charge inducer dicetyl phosphate (DCP) in different molar ratios and by employing a thin film hydration technique. The ability of these vesicles to entrap the studied drug was evaluated by determining the entrapment efficiency %EE after centrifugation and separation of the formed vesicles. Photomicroscopy and transmission electron microscopy as well as particle size analysis were used to study the formation, morphology and size of the drug loaded niosomes. Results showed a substantial change in the release rate and an alteration in the %EE of gentamicin sulphate from niosomal formulations upon varying type of surfactant, cholesterol content and presence or absence of DCP. In-vitro drug release results confirmed that niosomal formulations have exhibited a high retention of gentamicin sulphate inside the vesicles such that their in vitro release was slower compared to the drug solution. A preparation with 1:1:0.1 molar ratio of Tween 60, cholesterol and DCP gave the most advantageous entrapment (92.02% ± 1.43) and release results (Q_8h = 66.29% ± 1.33) as compared to other compositions. Ocular irritancy test performed on albino rabbits, showed no sign of irritation for all tested niosomal formulations.     

Influence of a niosomal formulation on the oral bioavailability of acyclovir in rabbits

The purpose of this research was to prepare acyclovir niosomes in a trial to improve its poor and variable oral bioavailability. The nonionic surfactant vesicles were prepared by the conventional thin film hydration method. The lipid mixture consisted of cholesterol, span 60, and dicetyl phosphate in the molar ratio of 65:60:5, respectively. The percentage entrapment was approximately 11% of acyclovir used in the hydration process. The vesicles have an average size of 0.95 microm, a most probable size of 0.8 microm, and a size range of 0.4 to 2.2 microm. Most of the niosomes have unilamellar spherical shape. In vitro drug release profile was found to follow Higuchi's equation for free and niosomal drug. The niosomal formulation exhibited significantly retarded release compared with free drug. The in vivo study revealed that the niosomal dispersion significantly improved the oral bioavailability of acyclovir in rabbits after a single oral dose of 40 mg kg(-1). The average relative bioavailability of the drug from the niosomal dispersion in relation to the free solution was 2.55 indicating more than 2-fold increase in drug bioavailability. The niosomal dispersion showed significant increase in the mean residence time (MRT) of acyclovir reflecting sustained release characteristics. In conclusion, the niosomal formulation could be a promising delivery system for acyclovir with improved oral bioavailability and prolonged drug release profiles.     

Metformin hydrochloride and wound healing: from nanoformulation to pharmacological evaluation

Abstract

Niosomes as drug delivery systems have the ability to decrease drugs' side effects and increase their therapeutic effectiveness. Metformin HCl is an oral antihyperglycemic agent belonging to biguanides. It is the most commonly chosen drug as a startup therapy for patients newly diagnosed with type 2 diabetes. This study aims to encapsulate metformin HCl inside niosomes to be used as a transdermal formulation helping to prolong its antidiabetic effect and investigate its ability to enhance wound healing in diabetic patients. Thin film hydration method was used to prepare metformin HCl niosomes using different proportions of Span 60, Span 40, Tween 80, and cholesterol. All formulations were characterized using transmission electron microscope, zeta potential, and vesicle size. In vitro release studies, stability studies and in vivo evaluation were conducted on selected niosomal formulations. The results of entrapment efficiency ranged from 13% to 32%. Vesicle sizes were determined in nano-range. The in vitro release profile of metformin HCl from niosomes occurred in two consecutive phases. Biological evaluation on diabetic rats revealed that metformin HCl niosomal gel given every 2 days showed a better sustained antidiabetic effect than oral doses given daily. It also showed an improvement in wound healing for diabetic rats given metformin formulations compared to nontreated ones.     

Sorbitan ester niosomes for topical delivery of rofecoxib

The aim of the present investigation is to encapsulate rofecoxib in niosomes and incorporate the prepared niosomes into dermal gel base for sustained therapeutic action. Niosomes were prepared by lipid film hydration technique and were analyzed for size, entrapment efficiency and drug retention capacity. Niosomal vesicles were then incorporated into blank carbopol gel to form niosomal gel. The in vitro permeation study across pig skin was performed using Keshary-Chien glass diffusion cell. The size and entrapment efficiency of the niosomal vesicles increased with gradual increase in HLB value of nonionic surfactants used. Maximum drug entrapment was observed with Span 20 with HLB value of 8.6 and drug leakage from vesicles was less at refrigerated condition than at the room temperature. Higher proportion of cholesterol made the niosomal formulation more stable with high drug retention properties. The niosomal gel showed a prolong drug release behavior compared to plain drug gel. Differential scanning calorimetric study of drug loaded gel and pig skin after permeation study confirmed inertness of carbopol gel base toward rofecoxib and absence of drug metabolism in the skin during permeation study, respectively. The niosomal formulations were successfully prepared by lipid film hydration technique using cholesterol and Span as nonionic surfactant. Presence of cholesterol made niosomes more stable with high drug entrapment efficiency and retention properties. The lower flux value of niosomal gel as compared to plain drug gel across pig skin assured the prolong drug release behavior with sustained action.     

Stability of niosomes with encapsulated vitamin D3 and ferrous sulfate generated using a novel supercritical carbon dioxide method

Niosomes were prepared using a novel supercritical carbon dioxide based method to simultaneously encapsulate ferrous sulfate and vitamin D₃ as hydrophilic and hydrophobic cargo, respectively. Vesicle particle size was determined to be bimodal with peak diameters of 1.44?±?0.16?μm and 7.21?±?0.64?μm, with the smaller peak comprising 98.8% of the total niosomal volume. Encapsulation efficiency of ferrous sulfate was 25.1?±?0.2% and encapsulation efficiency of vitamin D₃ was 95.9?±?1.47%. Physical stability of the produced niosomes was assessed throughout a storage period of 21 days. Niosomes showed good physical stability at 20?°C, but storage at 4?°C showed an initial burst release, indicating possible rupture of the niosomal membrane. The Korsmeyer–Peppas equation was used to model the release of ferrous sulfate over time at both storage temperatures.     

Lung delivery of nanoliposomal salbutamol sulfate dry powder inhalation for facilitated asthma therapy

Abstract

The motive behind present work was to discover a solution for overcoming the problems allied with a deprived oral bioavailability of salbutamol sulfate (SS) due to its first pass hepatic metabolism, shorter half-life, and systemic toxicity at high doses. Pulmonary delivery provides an alternative route of administration to avoid hepatic metabolism of SS, moreover facilitated diffusion and prolonged retention can be achieved by incorporation into liposomes. Liposomes were prepared by thin film hydration technique using 3² full factorial design and formulation was optimized based on the vesicle size and percent drug entrapment (PDE) of liposomes. Optimized liposomal formulation exhibited an average size of about 167.2?±?0.170?nm, with 80.68?±?0.74% drug entrapment, and 9.74?±?1.10?mV zeta potential. The liposomal dispersion was then spray dried and further characterized for in-vitro aerosol performance using Andersen Cascade Impactor. Optimized liposomal formulation revealed prolonged in-vitro drug release of more than 90% up to 14?h following Higuchi’s controlled release model. Thus, the proposed new-fangled liposomal formulation would be a propitious alternative to conventional therapy for efficient and methodical treatment of asthma and alike respiratory ailments.     

Dextrose modified bilosomes for peroral delivery: improved therapeutic potential and stability of silymarin in diethylnitrosamine-induced hepatic carcinoma in rats

Abstract

Hepatic carcinoma (HC) is one of the most prevalent cancers, ranked as the second most common cause of cancer-related deaths worldwide. Silymarin (SYL) has been reported for its anticarcinogenic activity against various types of cancer such as prostate, breast, ovary, colon, lung, bladder and liver. Due to poor solubility and low bioavailability SYL lacks satisfactory therapeutic value thus designing a suitable and effective delivery system of SYL can led to improved therapeutic potential. The present study was aimed to develop SYL-loaded dextrose (DEX) modified bilosomes for targeted delivery to HC cells. The DEX-modified bilosomes were prepared through thin-film hydration method and optimized employing Box Behnken design. The bilosomes were evaluated for percent entrapment, drug loading, in vitro release and cytotoxicity on Hep-G2 cells. The optimized DEX-SYL-BL exhibited a particle size of 219.3?±?2.99?nm, percent entrapment of 62.32?±?4.23%, drug loading of 34.56?±?1.23% and 84.96?±?2.76% drug release respectively over a period of 24?hr. The stability of bilosomes was ascertained in simulated gastric and intestinal fluids. Cytotoxicity studies revealed greater performance of DEX-SYL-BL in terms of reduced viability in Hep-G2 cell lines when compared with pure SYL and SYL-BL. Further DEX-modified bilosomes were evaluated in vivo for their therapeutic efficacy in DEN-induced (Diethylnitrosamine) hepatic carcinoma in animal model. The DEX-SYL-BL displayed higher therapeutic potential as revealed from enhanced survival and reduced tumour burden in animals. DEX-SYL-BL also displayed significant restoration of altered oxidative markers and SGOT, SGPT levels towards normal value when compared with pure SYL.     

Investigation of Formulation Variables and Excipient Interaction on the Production of Niosomes

The aim of this study was to investigate the effects of formulation and process variables on the properties of niosomes formed from Span 40 as nonionic surfactant. A variety of formulations encapsulating Paclitaxel, a hydrophobic model drug, were prepared using different dicetyl phosphate (DCP) and Span 40-cholesterol (1:1) amounts. Formulations were optimized by multiple regression analysis to evaluate the changes on niosome characteristics such as entrapment efficiency, particle size, polydispersity index, zeta potential and in vitro drug release. Multiple regression analysis revealed that as Span 40-cholesterol amounts in the formulations were increased, zeta potential and percent of drug released at 24th hour were decreased. Besides, DCP was found to be effective on increasing niosome size. As a process variable, the effect of sonication was observed and findings revealed an irreversible size reduction on Span 40 niosomes after probe sonication. Monodisperse small sized (133 ± 6.01 nm) Span 40 niosomes entrapping 98.2% of Paclitaxel with a weight percentage of 3.64% were successfully prepared. The drug–excipient interactions in niosomes were observed by differential scanning calorimetry and X-ray powder diffraction analysis. Both techniques suggest the conversion of PCTs’ crystal structure to amorphous form. The thermal analyses demonstrate the high interaction between drug and surfactant that explains high entrapment efficiency. After 3-month storage, niosomes preserved their stability in terms of drug amount and particle size. Overall, this study showed that Span 40 niosomes with desired properties can be prepared by changing the content and production variables.Key words: drug delivery systems, drug release, multiple regression, niosomes, paclitaxel     

Vancomycin-Eluting Niosomes: A New Approach to the Inhibition of Staphylococcal Biofilm on Abiotic Surfaces

A new vancomycin (VCM)-eluting mixed bilayer niosome formulation was evaluated for the control of staphylococcal colonization and biofilm formation on abiotic surfaces, a niosome application not explored to date. Cosurfactant niosomes were prepared using a Span 60/Tween 40/cholesterol blend (1: 1: 2). Tween 40, a polyethoxylated amphiphile, was included to enhance VCM entrapment and confer niosomal surface properties precluding bacterial adhesion. VCM-eluting niosomes showed good quality attributes including relatively high entrapment efficiency (～50%), association of Tween 40 with vesicles in a constant proportion (～87%), biphasic release profile suitable for inhibiting early bacterial colonization, and long-term stability at 4°C for a 12-month study period. Niosomes significantly enhanced VCM activity against planktonic bacteria of nine staphylococcal strains. Using microtiter plates as abiotic surface, VCM-eluting niosomes proved superior to VCM in inhibiting biofilm formation, eradicating surface-borne biofilms, inhibiting biofilm growth, and interfering with biofilm induction by VCM subminimal inhibitory concentrations. Data suggest dual functionality of cosurfactant VCM-eluting niosomes as passive colonization inhibiting barrier and active antimicrobial-controlled delivery system, two functions recognized in infection control of abiotic surfaces and medical devices.     

Nano-transfersomal formulations for transdermal delivery of asenapine maleate: in vitro and in vivo performance evaluations

Context: Asenapine maleate (ASPM) is an antipsychotic drug for the treatment of schizophrenia and bipolar disorder. Extensive metabolism makes the oral route inconvenient for ASPM.

Objective: The objective of this study is to increase ASPM bioavailability via transdermal route by improving the skin permeation using combined strategy of chemical and nano-carrier (transfersomal) based approaches.

Materials and methods: Transfersomes were prepared by the thin film hydration method using soy-phosphatidylcholine (SPC) and sodium deoxycholate (SDC). Transfersomes were characterized for particle size, polydispersity index (PDI), zeta potential (ZP), entrapment efficiency, surface morphology, and in vitro skin permeation studies. Various chemical enhancers were screened for skin permeation enhancement of ASPM. Optimized transfersomes were incorporated into a gel base containing suitable chemical enhancer for efficient transdermal delivery. In vivo pharmacokinetic study was performed in rats to assess bioavailability by transdermal route against oral administration.

Results and discussion: Optimized transfersomes with drug:SPC:SDC weight ratio of 5:75:10 were spherical with an average size of 126.0?nm, PDI of 0.232, ZP of??43.7?mV, and entrapment efficiency of 54.96%. Ethanol (20% v/v) showed greater skin permeation enhancement. The cumulative amount of ASPM permeated after 24?h (Q₂₄) by individual effect of ethanol and transfersome, and in combination was found to be 160.0, 132.9, and 309.3?μg, respectively, indicating beneficial synergistic effect of combined approach. In vivo pharmacokinetic study revealed significant (p?Conclusion: Dual strategy of permeation enhancement was successful in increasing the transdermal permeation and bioavailability of ASPM.     

Preparation and anti-inflammatory activity of triptolide ethosomes in an erythema model

Context: The aim of this work was to evaluate the suitability of ethosomes as carriers for the topical application of triptolide in a rat model of erythema.

Objective: We determined the optimal conditions for preparing ethosomes, and we measured their vesicle size by a laser particle-size analyzer and the efficiency of entrapment of triptolide by ultracentrifugation.

Methods: The in vitro percutaneous permeation of triptolide-loaded ethosomes was investigated by measuring diffusion across a sample of rat skin. To explore the transdermal delivery in vivo, we used a model in which erythema was induced in rats by methyl nicotinate and determined the change in erythema index caused by the anti-inflammatory activity of triptolide by a reflection spectrophotometer.

Results: The optimal conditions for preparing triptolide ethosomes consisted of ultrasonication of 45% (v/v) ethanol and 2% (w/v) DPPC for 5 minutes, which produced an average vesicle size of 51.4?nm and an entrapment efficiency of 98%. This ethosomal formulation of triptolide caused the greatest in vitro 24-hour accumulation of triptolide (83.7%) with no permeation time delay, and it reduced erythema in vivo more rapidly and more completely than other formulations.

Conclusions: Ethosomes might be a promising carrier that would enable the beneficial properties of triptolide to be safely delivered in a topical formulation.