Nonionic surfactant vesicles (niosomes) of cytarabine hydrochloride for effective treatment of leukemias: encapsulation, storage, and in vitro release

Desosomes and desimicelles - a novel vesicular and micellar system for enhanced oral delivery of poorly soluble drug: Optimization of in vitro characteristics and in vivo performance

This study introduces two innovative nanocarrier systems to improve oral drug delivery. Desosomes and desimicelles combine Deep eutectic solvent (DES) with vesicular or micellar nanosystems, respectively. These novel nanosystems integrate the DES solubilization potency for administering drugs with low aqueous solubility and the vesicular and micellar systems to bypass physiological barriers and improve poor drug bioavailability. Lornoxicam (LRX) is a BCS class II anti-inflammatory with limited aqueous solubility and rapid clearance. Desosomes and desimicelles were prepared and successfully optimized. The optimization depended on particle size, zetapotential, entrapment efficiency, and solubility. The optimized desosomes (LRX-DES-V) and desimicelles (LRX-DES-M) were pictured by transmission electron microscope. Differential scanning calorimetry (DSC) and FTIR analysis indicated the successful inclusion of LRX inside each system. Invitro LRX release profiles revealed controlled release of LRX-DES-V and LRX-DES-M, with more sustained release by the later one. In-vivo study, inflammation was induced using a carrageenan rat model, and the anti-inflammatory effect of LRX-pure, marketed product, traditional niosomes, LRX-DES-V & LRX-DES-M were determined using inhibition %, serum inflammatory cytokines, and histopathology. After 4 h of induction, LRX-DES-M (68.05%) showed a significant inhibition compared to LRX-DES-V (63.57%). LRX-DES-M also showed a better reduction in COX2, PGE2, and TNF-α (1.25-fold, 1.24-fold, and 1.36-fold inhibition), respectively, compared to LRX-DES-V. We can conclude that LRX-DES-V and LRX-DES-M showed better effects than all other groups and that LRX-DES-M might be more effective than LRX-DES-V.

Formulation of novel niosomal repaglinide chewable tablets using coprocessed excipients: in vitro characterization, optimization and enhanced hypoglycemic activity in rats

Repaglinide (RPG), a monotherapy insulin secretagogue used to treat diabetes mellitus-type II yet, it suffers from poor water solubility and variable bioavailability (∼ 50%) due to hepatic first pass metabolism. In this study, 2FI I-Optimal statistical design was employed to encapsulate RPG into niosomal formulations using cholesterol,span 60 and peceol^TM. The optimized niosomal formulation (ONF) showed particle size 306.60 ± 84.00 nm, zeta potential -38.60 ± 1.20 mV, polydispersity index 0.48 ± 0.05 and entrapment efficiency 92.00 ± 2.60%. ONF showed > 65% RPG release that lasted for 3.5 h, and significantly higher sustained release compared to Novonorm® tablets after 6 h (p < 0.0001). TEM for ONF showed spherical vesicles with dark core and light-colored lipid bilayer membrane. RPG peaks disappeared in FTIR confirming successful RPG entrapment. To eliminate dysphagia associating conventional oral tablets, chewable tablets loaded with ONF were prepared using coprocessed excipients; Pharmaburst^® 500, F-melt^® and Prosolv^® ODT. Tablets showed friability <1%, hardness 3.9 ± 0.423-4.7 ± 0.410 Kg, thickness 4.1 ± 0.045-4.4 ± 0.017 mm and acceptable weight.All tablets showed robust RPG release at 30 min compared to Novonorm^® tablets. At 6h, chewable tablets containing only Pharmaburst^® 500 and F-melt^® showed sustained and significantly increased RPG release compared to Novonorm^® tablets (p < 0.05). Pharmaburst^® 500 and F-melt^® tablets showed rapid in vivo hypoglycemic effect with 5 and 3.5 fold significant reduction in blood glucose compared to Novonorm^® tablets (p < 0.05) at 30 min. Also, at 6h the same tablets showed 1.5 and 1.3 fold significant extended reduction in blood glucose compared to the same market product (p < 0.05). It could be concluded that chewable tablets loaded with RPG ONF represent promising novel oral drug delivery systems for diabetic patients suffering from dysphagia.

Improving the Bioavailability and Efficacy of Coenzyme Q10 on Alzheimer's Disease Through the Arginine Based Proniosomes

Coenzyme Q10 (CoQ10) is a fat-soluble vitamin-with a benzoquinone-like structure. CoQ10 plays a role in membrane stability, energy conversion, and ATP production. It is also one of the important antioxidants in the body. The bioavailability of exogenous CoQ10 is extremely low due to its poor aqueous solubility and large molecular mass. In this study, mixed proniosomal drug delivery systems have been used to increase solubility and bioavailability of CoQ10. Arginine (semi-essential amino acid) was incorporated in the formulation composition to achieve higher efficacy by boosting nitric oxide presence, endothelial dysfunction, and cellular uptake. Proniosomes were investigated in terms of particle size, polydispersity index, zeta potential, encapsulation efficiency, and process yield, and optimization studies were carried on by utilizing STATISTICA 8.0 software considering dependent factors (carrier amount, drug amount, and surfactant ratio). Optimum proniosome formulation (particle size 187.5 ± 16.35 nm, zeta potential: -44.7 ± 12.8 mV, encapsulation efficiency 99.05±0.30%, and product yield: 90.55%) was evaluated for thermal analysis, in-vitro drug release using microcentrifuge method. In-vitro cytotoxicity studies of proniosomes were performed on intestinal Epithelial Cells (Cellartis®, ChiPSC18) and no cytotoxic effects was seen during the 72 h. Besides, anti Alzheimer effect was investigated on APPSL-GFP lentivirus-infected human neural cells (APPSL-GFP-l-HNC) and Alzheimer biomarkers (p-tau181 and p-tau217). While CoQ10's relative bioavailability was statistically increased by proniosome compared to CoQ10 suspension (p<0.01, Grubb test). PK parameters of proniosome formulation, obtained with non-compartmental modeling, were fitting to the data (R2=0.956±0.026). The study results proved that proniosomal formulation has a high potential drug delivery system for both increasing bioavailability and anti-Alzheimer effect of CoQ10.

Application of Box-Behnken Design in the Preparation, Optimization, and In-Vivo Pharmacokinetic Evaluation of Oral Tadalafil-Loaded Niosomal Film

Benign prostatic hyperplasia (BPH) affects about 90% of men whose ages are over 65. Tadalafil, a selective PDE-5 inhibitor, was approved by FDA for BPH, however, its poor aqueous solubility and bioavailability are considered major drawbacks. This work intended to develop and evaluate oral fast dissolving film containing tadalafil-loaded niosomes for those who cannot receive the oral dosage form. Niosomes were statistically optimized by Box-Behnken experimental design and loaded into a polymeric oral film. Niosomes were assessed for their vesicular size, uniformity, and zeta potential. The thickness, content uniformity, folding endurance, tensile strength, disintegration time, and surface morphology were evaluated for the prepared polymeric film. The optimized niosomes revealed high entrapment efficiency (99.78 ± 2.132%) and the film was smooth with good flexibility and convenient thickness (110 ± 10 µm). A fast release of tadalafil was achieved within 5 min significantly faster than the niosomes-free drug film. The in-vivo bioavailability in rats established that the optimized niosomal film enhanced tadalafil systemic absorption, with higher peak concentration (Cmax = 0.63 ± 0.03 µg/mL), shorter Tmax value (0.66-fold), and relative bioavailability of 118.4% compared to the marketed tablet. These results propose that the oral film of tadalafil-loaded niosomes is a suitable therapeutic application that can be passed with ease to geriatric patients who suffer from BPH.

Ion-Triggered In Situ Gelling Intranasal Spray of Dronedarone Hydrochloride Nanocarriers: In Vitro Optimization and In Vivo Pharmacokinetic Appraisal

The current study aims to develop niosomal nanocarriers for intranasal delivery of dronedarone hydrochloride to ameliorate its limited bioavailability. Niosomes were prepared by ethanol injection method and optimized using 3² full factorial experimental design. Both Span® type (X1) and Span®: cholesterol ratio (X2) were set as independent variables. Vesicle size (Y1), polydispersity index (Y2), zeta potential (Y3), and entrapment efficiency (Y4) were set as responses. The optimal formula was further incorporated into an ion-sensitive in situ gelling polymer for intranasal delivery. Optimal formula (N7), which is composed of Span® 80: cholesterol (1:1), was of the least vesicle size (121.27 ± 13.31 nm), least polydispersity index (0.43 ± 0.073), highest zeta potential (-22.23 ± 2.84 mV) and highest entrapment efficiency (73.44 ± 2.8%). About 75.86% and 60.29% of dronedarone hydrochloride were released from N7 dispersion and in situ gel, respectively, within 12 h, compared to only 13.3% released from a drug-free suspension. In vivo pharmacokinetic study on male New Zealand rabbits resulted in significantly higher Cmax, AUC0-72, and AUC0-∞ of intranasal niosomal in situ gel compared to oral suspension. Almost twofold amplification of relative bioavailability was obtained after intranasal administration of niosomal in situ gel (195.7%) compared to oral suspension.

Physicochemical and Stability Evaluation of Topical Niosomal Encapsulating Fosinopril/γ-Cyclodextrin Complex for Ocular Delivery

This study aimed to develop a chemically stable niosomal eye drop containing fosinopril (FOS) for lowering intraocular pressure. The effects of cyclodextrin (CD), surfactant types and membrane stabilizer/charged inducers on physiochemical and chemical properties of niosome were evaluated. The pH value, average particle size, size distribution and zeta potentials were within the acceptable range. All niosomal formulations were shown to be slightly hypertonic with low viscosity. Span® 60/dicetyl phosphate niosomes in the presence and absence of γCD were selected as the optimum formulations according to their high %entrapment efficiency and negative zeta potential values as well as controlled release profile. According to ex vivo permeation study, the obtained lowest flux and apparent permeability coefficient values confirmed that FOS/γCD complex was encapsulated within the inner aqueous core of niosome and could be able to protect FOS from its hydrolytic degradation. The in vitro cytotoxicity revealed that niosome entrapped FOS or FOS/γCD formulations were moderate irritation to the eyes. Furthermore, FOS-loaded niosomal preparations exhibited good physical and chemical stabilities especially of those in the presence of γCD, for at least three months under the storage condition of 2–8 °C.

Niosome-encapsulated Doxycycline hyclate for Potentiation of Acne Therapy: Formulation and Characterization

BACKGROUND

Acne is the pilosebaceous units' disorder. The most important cause of acne is the colonization of bacteria in the follicles. Among antibiotics, doxycycline hyclate kills a wide range of bacteria.

OBJECTIVES

To prevent oral administration's side effects, overcome the barriers of conventional topical treatment, and improve the therapeutic effectiveness, this drug was loaded into niosomal nanocarriers for topical application.

METHODS

Doxycycline hyclate was loaded into four niosomal formulations prepared by the thin-film hydration method with different percentages of constituents. Drug-containing niosomal systems were evaluated for morphological properties via scanning electron microscopy, particle size, drug entrapment efficiency, zeta potential, in vitro drug release, physical stability after 60 days, in vitro drug permeation through rat skin, in vitro drug deposition in rat skin, toxicity on human dermal fibroblasts (HDF) by MTT method after 72 hours, and antibacterial properties against the main acne-causing bacteria via antibiogram test.

RESULTS

The best formulation had the appropriate particle size of 362.88 ± 13.05 nm to target follicles, entrapment efficiency of 56.3 ± 2.1%, the zeta potential of - 24.46±1.39 mV, in vitro drug release of 54.93 ± 1.99% after 32 hours, and the lowest permeation of the drug through the rat skin among all other formulations. Improved cell viability, increased antibacterial activity, and an approximately three-fold increase in drug deposition were the optimal niosomal formulation features relative to the free drug.

CONCLUSION

This study demonstrated the ability of nano-niosomes containing doxycycline hyclate to treat skin acne compared with the free drug.

Functionalized niosomes as a smart delivery device in cancer and fungal infection

Various diseases remain untreated due to lack of suitable therapeutic moiety or a suitable drug delivery device, especially where toxicities and side effects are the primary reason for concern. Cancer and fungal infections are diseases where treatment schedules are not completed due to severe side effects or lengthy treatment protocols. Advanced treatment approaches such as active targeting and inhibition of angiogenesis may be preferred method for the treatment for malignancy over the conventional method. Niosomes may be a better alternative drug delivery carrier for various therapeutic moieties (either hydrophilic or hydrophobic) and also due to ease of surface modification, non-immunogenicity and economical. Active targeting approach may be done by targeting the receptors through coupling of suitable ligand on niosomal surface. Moreover, various receptors (CD44, folate, epidermal growth factor receptor (EGFR) & Vascular growth factor receptor (VGFR)) expressed by malignant cells have also been reviewed. The preparation of suitable niosomal formulation also requires considerable attention, and its formulation depends upon various factors such as selection of non-ionic surfactant, method of fabrication, and fabrication parameters. A combination therapy (dual drug and immunotherapy) has been proposed for the treatment of fungal infection with special consideration for surface modification with suitable ligand on niosomal surface to sensitize the receptors (C-type lectin receptors, Toll-like receptors & Nucleotide-binding oligomerization domain-like receptors) present on immune cells involved in fungal immunity. Certain gene silencing concept has also been discussed as an advanced alternative treatment for cancer by silencing the mRNA at molecular level using short interfering RNA (si-RNA).

Streptomycin Sulfate-Loaded Niosomes Enables Increased Antimicrobial and Anti-Biofilm Activities

One of the antibiotics used to treat infections is streptomycin sulfate that inhibits both Gram-negative and -positive bacteria. Nanoparticles are suitable carriers for the direct delivery and release of drug agents to infected locations. Niosomes are one of the new drug delivery systems that have received much attention today due to their excellent biofilm penetration property and controlled release. In this study, niosomes containing streptomycin sulfate were prepared by using the thin layer hydration method and optimized based on the size, polydispersity index (PDI), and encapsulation efficiency (EE%) characteristics. It was found that the Span 60-to-Tween 60 ratio of 1.5 and the surfactant-to-cholesterol ratio of 1.02 led to an optimum formulation with a minimum of size, low PDI, and maximum of EE of 97.8 nm, 0.27, and 86.7%, respectively. The drug release investigation showed that 50.0 ± 1.2% of streptomycin sulfate was released from the niosome in 24 h and reached 66.4 ± 1.3% by the end of 72 h. Two-month stability studies at 25° and 4°C showed more acceptable stability of samples kept at 4°C. Consequently, antimicrobial and anti-biofilm activities of streptomycin sulfate-loaded niosomes against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa were found significantly higher than those of free drug, and the minimum inhibitory concentration values decreased 4- to 8-fold. Furthermore, niosome-encapsulated streptomycin up to 1,500 μg/ml exhibited negligible cytotoxicity against the human foreskin fibroblasts cell line, whereas the free drug exhibited slight cytotoxicity at this concentration. Desired physical characteristics and low toxicity of niosomal nano-carriers containing streptomycin sulfate made them a demanded candidate for the treatment of current bacterial infections and biofilms.

Implementing Spanlastics for Improving the Ocular Delivery of Clotrimazole: In vitro Characterization, Ex vivo Permeability, Microbiological Assessment and In vivo Safety Study

Purpose

The aim of this study was to encapsulate clotrimazole (CLT), an antifungal drug with poor water solubility characteristics, into spanlastics (SPs) to provide a controlled ocular delivery of the drug.

Methods

Span 60 was used in the formulation of SPs with Tween 80, Pluronic F127, or Kolliphor RH40 as an edge activator (EA). The presence of EA offers more elasticity to the membrane of the vesicles which is expected to increase the corneal permeation of CLT. SPs were prepared using ethanol injection method applying 3² complete factorial design to study the effect of formulation variables (ratio of Span 60: EA (w/w) and type of EA) on SPs characteristics (encapsulation efficiency percent (EE%), average vesicle size (VS), polydispersity index (PDI) and zeta potential (ZP)). Design-Expert software was used to determine the optimum formulation for further investigations.

Results

The optimum formulation determined was S1, which contains 20 mg of Tween 80 used as an EA and 80 mg of Span 60. S1 exhibited EE% = 66.54 ± 7.57%, VS = 206.20 ± 4.95 nm, PDI = 0.39 ± 0.00 and ZP = −29.60 ± 0.99 mV. S1 showed highly elastic sphere-shaped vesicles. Furthermore, S1 displayed a sustained release profile and a higher ex vivo permeation across rabbit cornea relative to CLT suspension. Also, S1 revealed superior inhibition of Candida albicans development compared to CLT suspension applying 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) reduction technique. Moreover, in vivo histopathological examination assured the safety of S1 after ophthalmic application in mature male albino rabbits.

Conclusion

Overall, the outcomes revealed the marked efficacy of SPs for ocular delivery of CLT.

Formulation and investigation of pilocarpine hydrochloride niosomal gels for the treatment of glaucoma: intraocular pressure measurement in white albino rabbits

The present study was focused on investigating niosomal gels loaded with cholinergic drug; pilocarpine HCl, for prolonged precorneal residence time and improved bioavailability for glaucoma treatment. Pilocarpine HCl niosomes were prepared using various nonionic surfactants (span 20, span 60 and span 80), in the presence of cholesterol in different molar ratios by ether injection method. The selected formulations were incorporated into carbopol 934 and locust bean gum-based gels. TEM analysis confirmed that niosomes formed were spherical in shape and has a definite internal aqueous space with uniform particle size. Formulation F4 composed of span 60 and cholesterol (1:1) gave the highest entrapment (93.26 ± 1.75%) and slower release results after 8 hours (Q8h = 60.35 ± 1.87%) among other formulations. The in-vitro drug permeation studies showed that there was a prolonged release of drug from niosomal gels as compared to niosomes itself. Considering the in-vitro drug release, niosomal gel formulation G2 was the best among the studied formulations. The release data were fitted to an empirical equation, which indicated that the release follows non-Fickian diffusion mechanism. The stability study revealed that incorporation of niosomes in gel increased their stability than the niosome itself. No signs of redness, inflammation, swelling or increased tear production were observed over the study period for tested formulation by Draize's test. The intraocular pressure (IOP) lowering activity of G2 formulation showed relative bioavailability 2.64 times more than bioavailability of marketed Pilopine HS® gel. These results suggest that the niosomal gels containing pilocarpine HCl are promising ocular carriers for glaucoma treatment.

Development and Characterization of Niosomal Gel System using Lallementia royaleana Benth. mucilage for the treatment of Rheumatoid Arthritis

Niosomes structural framework comprises of non-ionic surfactant-based microscopic lamellar structures which carries the potential to sustain the effect of drug from its delivery system. In present work, the attempt was made to identify the effect of different ingredients such as effect of Tweens and natural mucilage of Lallemantia royaleana Benth. on the performance of developed niosomal gel formulations in order to prolong the duration of action of drug and to minimize its side effects of topical conventional drug administration. All Ibuprofen loaded niosomes formulationswere prepared by ether injection method; using cetosteryl alcohol with different variants of Tweens and Spans. Various evaluation parameters were performed to confirm niosome formation. Further, the niosomes were incorporated into gel system and evaluated for in-vitro permeability study (ex-vivo) on excised rat skin by membrane diffusion method and in-vivo study by carrageenan induced rat paw edema model. The best selected niosome formulation F9 gave no sedimentation, layer separation and unchanged particle shapes and thus selected for gel preparation using Lallemantia royaleana Benth. mucilage and carbopol in different ratios. Ex-vivo and in-vivo studies indicated high skin retention and penetration rates within the skin for tests niosomal gel formulations (G1 & G2). The present study suggested that developed topical gel formulation provides enhance permeability and longer duration of drug action over conventional gels.

Nanovesicles of sorbitan isostearate: a novel sustained-release non-ionic surfactant

Sorbitan isostearate (Span 120) is a novel non-ionic surfactant for development of vesicular systems. The present work aimed to develop, characterise and evaluate Span 120 based niosomes for enhanced drug delivery. Span 120 niosomes were prepared by using the thin-film hydration method and naproxen sodium was used as a model drug. Fourier transform infrared spectroscopy analysis was also done for preformulation studies. Niosomes prepared with Span 120 and cholesterol (2:1) were spherical, as shown by transmission electron microscopy, with a mean size of 173 ± 2·96 nm, a polydispersity index of 0·28 ± 0·02, a zeta potential of −50 ± 1·2 mV and an entrapment efficiency of 91·92%. The in vitro release study showed a sustained release (21·9%) of naproxen sodium in 12 h. The release kinetics was uniform and followed the Korsmeyer–Peppas model, with n > 0·5. Accordingly, niosomes with a molar ratio of 2:1 was selected for in vivo anti-inflammatory activity. A carrageenan-induced paw oedema test was performed, which showed an enhanced inhibitory effect of loaded niosomes with Span 120 compared to the standard drug. In conclusion, the use of Span 120 is a promising approach to formulating niosomes with an improved and sustained effect.

Dapsone-Loaded Invasomes as a Potential Treatment of Acne: Preparation, Characterization, and In Vivo Skin Deposition Assay

Dapsone (DPS) is a unique sulfone with antibiotic and anti-inflammatory activity. Owing to its dual action, DPS has a great potential to treat acne. Topical DPS application is expected to be effective in treatment of mild to moderate acne conditions. Invasomes are novel vesicles composed of phosphatidylcholine, ethanol, and one or mixture of terpenes of enhanced percutaneous permeation. In this study, DPS-loaded invasomes were prepared using the thin film hydration technique. The effect of different terpenes (Limonene, Cineole, Fenchone, and Citral) in different concentrations on the properties of the prepared DPS-loaded invasomes was investigated using a full factorial experimental design, namely, the particle size, drug entrapment, and release efficiency. The optimized formulation was selected for morphological evaluation which showed spherical shaped vesicles. Further solid-state characterization using differential scanning calorimetry and X-ray diffractometry revealed that the drug was dispersed in an amorphous state within the prepared invasomes. Finally, the ability of the prepared DPS-loaded invasomes to deliver DPS through the skin was investigated in vivo using wistar rats. The maximum in vivo skin deposition amount of DPS was found to be 4.11 mcg/cm² for invasomes versus 1.71 mcg/cm² for the drug alcoholic solution, representing about 2.5-fold higher for the invasomes compared to the drug solution. The AUC0-10 calculated for DPS-loaded invasomes was nearly 2-fold greater than that of DPS solution (14.54 and 8.01 mcg.h/cm² for the optimized invasomes and DPS solution, respectively). These results reveal that the skin retention of DPS can be enhanced using invasomes.

Synergistic Effect of Saponin and Rhamnolipid Biosurfactants Systems on Foam Behavior

In this study, the synergistic effect of saponin and rhamnolipid biosurfactant on foam properties at an air-water interface was investigated. In order to reach the optimum hydrophilic lipophilic balance (HLB) value, samples of 2 wt% of rhamnolipid and saponin biosurfactants with different HLB values (9.6, 10, 10.4, 10.8, 11.2, 11.6, and 12) in 5 ml of DI water were prepared. Results showed that the optimum HLB value of the microemulsion system was 10.8 for the mixture of 84% rhamnolipid and 16% saponin. At that optimum HLB value and a total surfactant concentration of 2 wt%, the maximum foaming ability and foam stability of the mixed system was 48 mm and 72 min respectively. During the experiment, it was observed that at optimum HLB value the foaming ability of the system increased by increasing the concentration of rhamnolipid and saponin. Comparing the foaming ability and foam stability of biosurfactant system with the properties of SDS, Tween80 and Span80 showed that the biosurfactants have a good foaming ability. The CMC value of the biosurfactant mixtures at the optimum HLB value was lower than that of other synthetic surfactants. The results show that, the biosurfactant mixtures had a synergistic effect on foaming ability and foam stability compared to the individual biosurfactants and synthetic surfactants. Therefore, the mixture of rhamnolipid and saponin is proposed as a potential alternative for detergent, cosmetic and petroleum industry.

Pivotal role of Acitretin nanovesicular gel for effective treatment of psoriasis: ex vivo-in vivo evaluation study

The goal of the current study was to explore the potential benefits of Acitretin (Act) nanovesicular gel as a prospective antipsoriatic topical delivery system counteracting the drug challenges in terms of its extremely low aqueous solubility, instability, skin irritation, and serious systemic adverse effects. Act-loaded niosomes were successfully developed, entirely characterized, and optimized. Further evaluation of the optimized formula was conducted regarding its stability and ex vivo cytotoxicity on different cell lines. The optimized niosomal vesicles were then incorporated in gel base matrix and investigated by sequential ex vivo (skin permeation and deposition) and in vivo (skin irritation and antipsoriatic activity using mouse tail model) experiments. The optimized Act-loaded niosomes (span 60:cholesterol molar ratio 1:1) were spherical in shape and exhibited the highest entrapment efficiency (90.32±3.80%) with appropriate nanosize and zeta potential of 369.73±45.45 nm and -36.33±1.80 mV, respectively. Encapsulation of the drug in the nanovesicles was further emphasized by differential scanning calorimetric and powder X-ray diffraction studies. After 3 months storage at 4±1°C, the optimized formula preserved its stability. Act nano niosomal gel produced a remarkable enhanced ex vivo permeation profile up to 30 h and significant drug deposition in the viable epidermal-dermal layers compared with those of Act gel. The pronounced antipsoriatic activity of the medicated nano niosomes was proved ex vivo in HaCaT cells (a keratinocyte cell line). Topical application of Act nano niosomal gel to mouse tail model further established its distinct in vivo antipsoriatic superiority in terms of significantly higher orthokeratosis, drug activity, and reduction in epidermal thickness compared with the control and other gel formulations. Also, negligible skin irritation and better skin tolerability of Act nanovesicular gel were revealed by primary irritation index and histopathologic examination.

Optimized Mucoadhesive Coated Niosomes as a Sustained Oral Delivery System of Famotidine

The objective of this study is to develop an oral formulation of famotidine niosomes coated with a mucoadhesive polymer, chitosan. Famotidine (FMT) has low oral bioavailability of 40-45% and short half-life between 2.5 to 4 h. Famotidine is classified as class IV in BCS because of its low aqueous solubility (0.1% w/v) and low permeability. Thus, FMT was loaded to the bioadhesive coated niosomes to improve its solubility, enhance its oral bioavailability, and sustain FMT release pattern. Different formulations were prepared by thin-film hydration method and characterized in terms of entrapment efficiency, morphological features, vesicle size, and zeta potential. In vitro release and ex vivo permeability of famotidine from the formulations were evaluated. The optimized formula was coated with chitosan and its mucoadhesion and stability in bile salt was tested. The optimized formula showed a high entrapment efficiency of 74%, as well sustained the in vitro release of FMT in the simulated gastric medium and enhanced its permeation through an excised goat's intestinal membrane by 1.4 fold in comparison to FMT control suspension. The mucoadhesive coated formula exhibited a significantly higher (p < 0.05) mucoadhesive efficiency and more stability in the bile salt as compared to the uncoated formula. Therefore, it could be considered as an efficient delivery system to maintain the prolonged release of FMT and improve its oral bioavailability.

Effects of oil dispersants on photodegradation of parent and alkylated anthracene in seawater

This study investigated effects of three model oil dispersants on photodegradation of two model PAHs (anthracene and 9,10-dimethyanthracene (9,10-DMA)) under simulated sunlight. All three dispersants, i.e. Corexit EC9500A, Corexit EC9527A and SPC 1000, promoted the photolysis rate of 9,10-DMA, following the order of Corexit EC9500A > Corexit EC9527A > SPC 1000. The photodegradation rate was well interpreted by a two-stage, first-order kinetic law with a faster initial photolysis rate in the presence of the dispersants. Span 80, Tween 85 and kerosene were found as the key dispersant components, of which Span 80 and Tween 85 promoted the photodegradation by boosting absorbance of solar irradiation while kerosene by dispersing more PAHs in the upper layer of the water column. Dissolved oxygen (DO) inhibited photolysis of anthracene regardless of dispersant resulting from quenching the excited states of the PAH, while DO facilitated photolysis of 9,10-DMA due to the formation singlet oxygen (¹O₂) radicals in the presence of oil dispersants. The other ROS, i.e. •O₂^- and •OH, played a negligible role on the photodegradation of anthracene and 9,10-DMA. Fluorescence analysis showed that more anthracene was associated with dispersant than 9,10-DMA, which favored the direct transfer of energy to anthracene, while energy is more likely transferred to oxygen to form ¹O₂ in the case of 9,10-DMA. Direct photolysis dominated the photodegradation of anthracene and 9,10-DMA. Both direct ionization of anthracene and the electron transfer from excited 9,10-DMA to oxygen can lead to formation of the corresponding PAH radical cations. Overall, the oil dispersants accelerated the photolysis rates of the PAHs without altering the degradation pathway. The findings are useful for understanding photochemical weathering of dispersed oil components in the environment.

Microniosomes for concurrent doxorubicin and iron oxide nanoparticles loading; preparation, characterization and cytotoxicity studies

The current work deals with developing a suitable drug delivery system of doxorubicin (DOX) for intraperitoneal chemotherapy using niosomes through formulating non-ionic surfactants consisting of Brij™ 52, span™ 60 and Solulan™ C24. Entrapping the magnetite nanoparticles in the hydrophilic parts of niosomes was accompanied with high-efficient DOX loading by the current novel remote-loading method. Cytotoxicity of the prepared formulations was evaluated in vitro against A549 and PC-12 cell lines using the colorimetric WST-1 assay test. The obtained results revealed that, the cytotoxicity of DOX increased up to 22% especially on A549 cells by the current delivery system.

In-vivo disposition characteristics of PEG niosome and its interaction with serum proteins

Three different nonionic surfactants (Brij 72, Span 20 and Tween 60) were used to prepare various naked and PEG niosomes. In-vivo study demonstrated that PEGylation dramatically increased the AUC and decreased the affinity to the liver of Brij 72 and Span 20 niosomes in rats. Liver perfusion experiments suggested that the hepatic uptake of naked Brij 72 and Span 20 niosomes could mainly be ascribed to the receptor-mediated uptake, while PEGylation of these niosomes could diminish the receptor-mediated hepatic disposition. Evaluation of serum proteins associated with niosomes revealed that PEGylation of these niosomes significantly reduced the association of serum proteins with them, including typical opsonins such as IgG and C3. On the other hand, in the case of Tween 60 niosomes, naked Tween 60 niosome showed large AUC and its PEGylation did not show any additional effect on the in-vivo pharmacokinetics. Furthermore, PEGylation of Tween 60 niosome did not significantly affect the hepatic disposition or the association of serum proteins with Tween 60 niosome. These results demonstrated that niosomes would exhibit distinct in-vivo disposition characteristics depending on the physicochemical properties of surfactants used and that PEGylation of niosomes with adequate compositions would be a powerful tool to improve their in-vivo behavior.

Preparation and characterization of solid lipid nanoparticles loaded with cytarabine via a micellar composition for leukemia

The present investigation reports the fabrication, optimization and characterization of tristearin based cytarabine solid lipid nanoparticles (SLN). Higher sensitivity of the cytarabine SLN than drug solution on cell line demonstrated the potential of this developed carrier.

Synthesis and biological evaluation of a fatty acyl di-cytarabine prodrug

A fatty acyl di-cytarabine prodrug is synthesized for overcoming the disadvantage of cytarabine in biomedical applications.

Lipid Based Vesicular Drug Delivery Systems

Vesicular drug delivery system can be defined as highly ordered assemblies consisting of one or more concentric bilayers formed as a result of self-assembling of amphiphilic building blocks in presence of water. Vesicular drug delivery systems are particularly important for targeted delivery of drugs because of their ability to localize the activity of drug at the site or organ of action thereby lowering its concentration at the other sites in body. Vesicular drug delivery system sustains drug action at a predetermined rate, relatively constant (zero order kinetics), efficient drug level in the body, and simultaneously minimizes the undesirable side effects. It can also localize drug action in the diseased tissue or organ by targeted drug delivery using carriers or chemical derivatization. Different types of pharmaceutical carriers such as polymeric micelles, particulate systems, and macro- and micromolecules are presented in the form of novel drug delivery system for targeted delivery of drugs. Particulate type carrier also known as colloidal carrier system, includes lipid particles, micro- and nanoparticles, micro- and nanospheres, polymeric micelles and vesicular systems like liposomes, sphingosomes, niosomes, transfersomes, aquasomes, ufasomes, and so forth.

Provesicular granisetron hydrochloride buccal formulations: in vitro evaluation and preliminary investigation of in vivo performance

Granisetron hydrochloride (granisetron) is a potent antiemetic that has been proven to be effective in acute and delayed emesis in cancer chemotherapy. Granisetron suffers from reduced oral bioavailability (≈60%) due to hepatic metabolism. In this study the combined advantage of provesicular carriers and buccal drug delivery has been explored aiming to sustain effect and improve bioavailability of granisetron via development of granisetron provesicular buccoadhesive tablets with suitable quality characteristics (hardness, drug content, in vitro release pattern, exvivo bioadhesion and in vivo bioadhesion behavior). Composition of the reconstituted niosomes from different prepared provesicular carriers regarding type of surfactant used and cholesterol concentration significantly affected both entrapment efficiency (%EE) and vesicle size. Span 80 proniosome-derived niosomes exhibited higher encapsulation efficiency and smaller particle size than those derived from span 20. Also, the effect of %EE and bioadhesive polymer type on in vitro drug release and in vivo performance of buccoadhesive tablets was investigated. Based on achievement of required in vitro release pattern (20-30% at 2h, 40-65% at 6h and 80-95% at 12h), in vivo swelling behavior, and in vivo adhesion time (>14 h) granisetron formulation (F19, 1.4 mg) comprising HPMC:carbopol 974P (7:3) and maltodextrin coated with the vesicular precursors span 80 and cholesterol (9:1) was chosen for in vivo study. In vivo pharmacokinetic study revealed higher bioavailability of buccal formulation relative to conventional oral formulation of granisetron (AUC0-∞ is 89.97 and 38.18 ng h/ml for buccal and oral formulation, respectively). A significantly lower and delayed Cmax (12.09±4.47 ng/ml, at 8h) was observed after buccal application compared to conventional oral tablet (31.66±10.15 ng/ml, at 0.5 h). The prepared provesicular buccoadhesive tablet of granisetron (F19) might help bypass hepatic first-pass metabolism and improve bioavailability of granisetron with the possibility of reducing reported daily dose (2mg) and reducing dosing frequency.

Multi-stage tandem mass spectrometric analysis of novel β-cyclodextrin-substituted and novel bis-pyridinium gemini surfactants designed as nanomedical drug delivery agents

RATIONALE

This study aimed at evaluating the collision-induced dissociation tandem mass spectrometric (CID-MS/MS) fragmentation patterns of novel β-cyclodextrin-substituted- and bis-pyridinium gemini surfactants currently being explored as nanomaterial drug delivery agents. In the β-cyclodextrin-substituted gemini surfactants, a β-cyclodextrin ring is grafted onto an N,N-bis(dimethylalkyl)-α,ω-aminoalkane-diammonium moiety using variable succinyl linkers. In contrast, the bis-pyridinium gemini surfactants are based on a 1,1'-(1,1'-(ethane-1,2-diylbis(sulfanediyl))bis(alkane-2,1-diyl))dipyridinium template, defined by two symmetrical N-alkylpyridinium parts connected through a fixed ethane dithiol spacer.

METHODS

Detection of the precursor ion [M](2+) species of the synthesized compounds and the determination of mass accuracies were conducted using a QqTOF-MS instrument. A multi-stage tandem MS analysis of the detected [M](2+) species was conducted using the QqQ-LIT-MS instrument. Both instruments were equipped with an electrospray ionization (ESI) source.

RESULTS

Abundant precursor ion [M](2+) species were detected for all compounds at sub-1 ppm mass accuracies. The β-cyclodextrin-substituted compounds, fragmented via two main pathways: Pathway 1: the loss of one head-tail region produces a [M-(N(Me)2-R)](2+) ion, from which sugar moieties (Glc) are sequentially cleaved; Pathway 2: both head-tail regions are lost to give [M-2(N(Me)2-R)](+), followed by consecutive loss of Glc units. Alternatively, the cleavage of the Glc units could also have occurred simultaneously. Nevertheless, the fragmentation evolved around the quaternary ammonium cations, with characteristic cleavage of Glc moieties. For the bis-pyridinium gemini compounds, they either lost neutral pyridine(s) to give doubly charged ions (Pathway A) or formed complementary pyridinium alongside other singly charged ions (Pathway B). Similar to β-cyclodextrin-substituted compounds, the fragmentation was centered on the pyridinium functional groups.

CONCLUSIONS

The MS(n) analyses of these novel gemini surfactants, reported here for the first time, revealed diagnostic ions for each compound, with a universal fragmentation pattern for each compound series. The diagnostic ions will be employed within liquid chromatography (LC)/MS/MS methods for screening, identification, and quantification of these compounds within biological samples.

Niosomal encapsulation of ethambutol hydrochloride for increasing its efficacy and safety

CONTEXT

Tuberculosis (TB) is a worldwide health concern. In 2011, about 8.7 million new cases developed TB and 1.4 million people died from it.

OBJECTIVE

Enhancement of ethambutol hydrochloride activity and safety in treatment of TB through niosomal encapsulation.

MATERIALS AND METHODS

Niosomes were prepared by the thin-film hydration method. They were characterized, investigated for in vitro release, lung disposition and in vivo biological evaluation.

RESULTS

Entrapment efficiency of ethambutol hydrochloride ranged from 12.20% to 25.81%. Zeta potential values inferred stability of neutral and negatively charged formulations. In vitro release was biphasic. Lung targeting was increased by niosomal encapsulation. Biological evaluation revealed superiority of niosomal ethambutol hydrochloride over the free drug.

DISCUSSION

Neutral and negatively charged niosomal vesicles are dispersed homogenously unlike positively charged vesicles. Niosomal encapsulation results in controlled drug release. Niosomal formulations targeted more drugs to mice lungs for a prolonged period of time resulting in: decreased root-specific lung weight, bacterial counts in lung homogenates and optimizing pathological effect on guinea pigs lungs, livers and spleens.

CONCLUSION

Encapsulation of ethambutol hydrochloride in niosomal formulations for the treatment of TB provides higher efficacy and safety compared with the free drug.

Niosomes as a propitious carrier for topical drug delivery

INTRODUCTION

Topical delivery is defined as drug targeting to the pathologic sites of skin with the least systemic absorption. Drug localization in this case is a crucial issue. For these purposes vesicular drug delivery systems including niosomes, proniosomes, liposomes and transferosomes have been developed.

AREAS COVERED

This review first highlights the role of niosome in dermatology focusing on localized skin delivery and then reviews the most recent literatures regarding specific applications of niosomal drug delivery systems in clinics.

EXPERT OPINION

Niosomes are becoming popular in the field of topical drug delivery due to their outstanding characteristics like enhancing the penetration of drugs, providing a sustained pattern of drug release, increasing drug stability and ability to carry both hydrophilic and lipophilic drugs.

Modified nanoprecipitation method for preparation of cytarabine-loaded PLGA nanoparticles

The present investigation was aimed at developing cytarabine-loaded poly(lactide-coglycolide) (PLGA)-based biodegradable nanoparticles by a modified nanoprecipitation which would have sustained release of the drug. Nine batches were prepared as per 3(2) factorial design to optimize volume of the co-solvent (0.22-0.37 ml) and volume of non-solvent (1.7-3.0 ml). A second 3(2) factorial design was used for optimization of drug: polymer ratio (1:5) and stirring time (30 min) based on the two responses, mean particle size (125 ± 2.5 nm), and percentage entrapment efficiency (21.8 ± 2.0%) of the Cyt-PLGA nanoparticles. Optimized formulation showed a zeta potential of -29.7 mV indicating good stability; 50% w/w of sucrose in Cyt-PLGA NP was added successfully as cryoprotectant during lyophilization for freeze-dried NPs and showed good dispersibility with minimum increase in their mean particle sizes. The DSC thermograms concluded that in the prepared PLGA NP, the drug was present in the amorphous phase and may have been homogeneously dispersed in the PLGA matrix. In vitro drug release from the pure drug was complete within 2 h, but was sustained up to 24 h from PLGA nanoparticles with Fickian diffusion. Stability studies showed that the developed PLGA NPs should be stored in the freeze-dried state at 2-8°C where they would remain stable in terms of both mean particle size and drug content for 2 months.

Niosomes in sustained and targeted drug delivery: some recent advances

Niosomes represent an emerging class of novel vesicular systems. They are composed of nonionic surfactants which are biodegradable and relatively nontoxic. They were developed as stable and inexpensive alternatives to liposomes. Since their early introduction to cosmetic industry their role has diversified to other application areas. They are now being ardently explored as potential carriers for sustained and targeted drug delivery. In addition to conventional, oral, and parenteral routes, they are amenable to be delivered by ocular, transdermal, vaginal, and inhalation routes. Delivery of biotechnological products including vaccine delivery with niosomes is also an interesting and promising research area. The introduction of provesicular approach in the form of proniosomes has further increased the relevance of these systems. More concerted research efforts, however, are still required to realize the full potential of these novel systems. This review considers the current status and explores the potential of niosomes in drug delivery with special attention to their role in drug targeting. Their methods of preparation, formulation aspects, advantages, limitations, and applications are also discussed.

Preparation and Characterization of Propylthiouracil Niosomes

Propylthiouracil, a lyophobic drug with an antiproliferative activity, was formulated into niosomes using various classes of nonionic surfactants. Feasibility of vesicle formation by the sonication method was evaluated. Size and size distribution was measured by laser diffraction. Entrapment and drug release over 24 h were monitored by UV spectrophotometric method at 275 nm. The results revealed that niosomes readily formed from various compositions of nonionic surfactant and cholesterol, with or without a stabilizer. Entrapment of PTU in niosomes depended on bilayer composition. The release of PTU from all niosomal formulations studied was retarded and followed the first-order kinetics. Degree of slow release had a negative correlation with drug entrapment. The release rate also depended on the physical state of the bilayer. The results of this study indicate that PTU niosomes were able to control the release of PTU and might be of value to develop further into topical formulations.