A stepwise optimization strategy to formulate in situ gelling formulations comprising fluconazole-hydroxypropyl-beta-cyclodextrin complex loaded niosomal vesicles and Eudragit nanoparticles for enhanced antifungal activity and prolonged ocular delivery

Fungal keratitis and endopthalmitis are serious eye diseases. Fluconazole (FL) is indicated for their treatment, but suffers from poor topical ocular availability. This study was intended to improve and prolong its ocular availability. FL niosomal vesicles were prepared using span 60. Also, polymeric nanoparticles were prepared using cationic Eudragit RS100 and Eudragit RL100. The investigated particles had adequate entrapment efficiency (EE%), nanoscale particle size and high zeta potential. Subsequently, formulations were optimized using full factorial design. FL-HP-β-CD complex was encapsulated in selected Eudragit nanoprticles (FL-CD-ERS1) and niosmal vesicles. The niosomes were further coated with cationic and bioadhesive chitosan (FL-CD-Nios-ch). EE% for FL-CD-ERS1 and FL-CD-Nios-ch formulations were 76.4% and 61.7%; particle sizes were 151.1 and 392 nm; also, they exhibited satisfactory zeta potential +40.1 and +28.5 mV. In situ gels were prepared by poloxamer P407, HPMC and chitosan and evaluated for gelling capacity, rheological behavior and gelling temperature. To increase the precorneal residence time, free drug and selected nano-formulations were incorporated in the selected in situ gel. Release study revealed sustained release within 24 h. Permeation through excised rabbits corneas demonstrated enhanced drug flux and large AUC_0-6h in comparison to plain drug. Corneal permeation of selected formulations labeled with Rhodamine B was visualized by Confocal laser microscopy. Histopathological study and in vivo tolerance test evidenced safety. In vivo susceptibility test using Candida albicans depicted enhanced growth inhibition and sustained effect. In this study the adopted stepwise optimization strategy combined cylodextrin complexation, drug nano-encapsulation and loading within thermosenstive in situ gel. Finally, the developed innovated formulations displayed boosted corneal permeation, enhanced antifungal activity and prolonged action.     

Non-ionic surfactant vesicles mediated transcutaneous immunization against hepatitis B

Transcutaneous immunization (TI) has many practical merits compared to parenteral routes of administration. In the present study, non ionic surfactant vesicular carrier, i.e. niosomes, was evaluated for topical delivery of vaccines using hepatitis B surface protein as an antigen and cholera toxin B as an adjuvant. Niosomes were characterized for size, shape, entrapment efficiency and in process antigen stability. In vitro permeation and skin deposition studies of antigen were performed using human cadaver skin. Skin penetration efficiency of niosomes was assessed by confocal laser scanning microscopy. The immune stimulating activity of these vesicles was studied by measuring the serum IgG titer, isotype ratio IgG2a/IgG1and mucosal immune responses following transcutaneous immunization in Balb/c mice and results were compared with the alum adsorbed HBsAg given intramuscularly and topically administered plain HBsAg solution. The result shows that optimal niosomal formulation could entrap 58.11 ± 0.71 of antigen with vesicle size range of 2.83 ± 0.29 μm. Serum IgG titers after three consecutive topical administrations were significantly better than single administration of hepatitis antigen with niosomal system, suggesting an effective stimulation of serum immune response; higher IgG1/IgG2a ratio revealed CTB mixed niosomes elicit both Th1 and Th2 responses. This study suggests that topical immunization with cholera toxin B is potential adjuvant for cutaneous immune responses when coadministered with the HBsAg encapsulated niosomes. Results also suggest that the investigated niosomes systems can be effective as topical delivery of vaccines.     

Formulation and evaluation of metformin hydrochloride-loaded niosomes as controlled release drug delivery system

Abstract

Lactic acidosis is a serious, metabolic complication that may occur due to metformin hydrochloride (MH) accumulation during the treatment of diabetes mellitus. The aim of this study is to enhance the bioavailability of MH by oral route. Span 40 and cholesterol were used for the preparation of MH-loaded niosomes by the reverse phase evaporation technique. Dicetyl phosphate (DCP) and 1,2-dioleoyl-3-trimethylammonium-propane chloride salt (DOTAP) were used to obtain negatively and positively charged vesicles, respectively. The mean particle size ranged from 223.5 to 384.6?nm and the MH-loaded niosomes’ surface was negatively charged in the absence of charge inducing agents (?16.6?±?1.4?mV) and also with DCP (?26.9?±?1.0?mV), while it was positively charged (+8.7?±?1.2?mV) with DOTAP. High entrapment efficiency was observed in all the formulations. MH-loaded niosomes were found to effectively sustain the release of drug, particularly with positively charged niosomes. The bioavailability of MH-loaded niosomes was assessed by measuring the serum values of glucose and metformin in the different studied Wistar rats groups. The pharmacokinetic data of MH-loaded niosomal preparation showed a significant prolongation and increased intensity of hypoglycemic effect more than that observed for free MH solution. Area above the blood glucose levels–time curve (AAC), maximum hypoglycemic response and time of maximum response (T_max) were significantly higher (p?<?0.001) when MH was administered in niosomal form compared to free drug solution. It could be concluded that MH-loaded niosome is promising extended-release preparation with better hypoglycemic efficiency.     

Enhancement of Transdermal Absorption,Gene Expression and Stability of Tyrosinase Plasmid (pMEL34)-Loaded Elastic Cationic Niosomes: Potential Application in Vitiligo Treatment

The pMEL34 was loaded in elastic cationic niosomes (Tween61/Cholesterol/DDAB at 1:1:0.5 molar ratio) by chloroform film method with sonication and rehydrated with 25% ethanol. The amount of pMEL34 was determined by gel electrophoresis and gel documentation. The maximum loading of pMEL34 in elastic cationic niosomes was 150 mg/16 mg of the niosomal compositions. At 8 weeks, the remaining plasmid in the elastic niosomes kept at 4 ± 2 °C, 27 ± 2 °C were 49.75% and 38.57%, respectively, whereas at 45 ± 2 °C, all plasmids were degraded. For transdermal absorption through rat skin investigated by Franz diffusion cells at 6 h, the fluxes of pMEL34 loaded in elastic and nonelastic niosomes in viable epidermis and dermis (VED) were 0.022 ± 0.00 and 0.017 ± 0.01 μg/cm²/h, respectively, whereas only pMEL34 loaded in elastic cationic noisome was observed in the receiver solution. The pMEL34 loaded in elastic cationic niosomes showed the highest tyrosinase gene expression demonstrating higher tyrosinase activity than the free and the loaded plasmid in nonelastic niosomes of about four times. This study has suggested the potential application of elastic cationic niosomes as an efficient topical delivery for tyrosinase gene in vitiligo therapy. © 2010 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 99:3533-3541, 2010     

Development,characterization and efficacy of niosomal diallyl disulfide in treatment of disseminated murine candidiasis

In the current study, a novel niosome based formulation of diallyl disulfide (DADS) was evaluated for its potential to treat disseminated candidiasis in mouse model. Among various non-ionic surfactants tested, niosome formulation prepared using Span 80 was found to be most efficient in the entrapment of DADS. The DADS loaded niosomes had size dimensions in the range of 140 ± 30 nm with zeta potential of ? 30.67 ± 4.5. Liver/kidney function tests as well as histopathologic studies suggested that noisome-based DADS formulations are safe at the dose investigated. When administered to Candida albicans infected animals, the DADS bearing niosomal formulation cleared the fungal burden and increased their survival much efficiently than its free form.From the Clinical EditorIn this study, a novel niosomal formulation of the antifungal DADS was utilized in a murine candidiasis model, resulting in more efficient fungal clearance compared to the free formulation.     

Cholesterol and Phospholipid-free Multilamellar Niosomes Regulate Transdermal Permeation of a Hydrophobic Agent Potentially Administrated for Treating Diseases in Deep Hair Follicles

We designed cholesterol- and phospholipid-free multilamellar niosomes (MLNs) structured by glyceryl monooleate (GMO) and poloxamer 407 (F127), and evaluated their capacity for transdermal drug delivery. The optimized MLNs had a mean size of 97.88 ± 63.25 nm and an encapsulation efficiency of 82.68% ± 2.14%. The MLNs exhibited a remarkable sustained cargo release, and improved the permeation of the stratum corneum. Compared with the tincture, lower transdermal flux but higher skin deposition of aconitine in vitro were achieved in the MLN group (p < 0.05). Additionally, both water-soluble rhodamine B- and liposoluble coumarin 6-labeled MLNs were found to penetrate deeply into the skin through the hair follicles and could be internalized by fibroblasts Notably, the MLNs possessed greater wettability, and the study focused on delivery to deeper hair follicles and up to the outer hair sheath, which showed advantages for treating diseases of hair follicles, and was potentially superior to the hydrophobic PLGA nanoparticles (diameter: 637.87 ± 22.77 nm) which mainly accumulated in superficial hair follicles. Hair follicles were therefore demonstrated to be an important way to enhance skin permeability, and MLNs are a promising alternative for topical and transdermal drug delivery.     

Topical delivery of Idebenone using nanostructured lipid carriers: evaluations of sun-protection and anti-oxidant effects

The objective of present study was to develop nanostructured lipid carriers (NLC) for topical delivery of antioxidant drug and evaluation of its sun protection efficacy. In the present study attempts have been made to formulate Idebenone loaded nanostructured lipid carriers (INLC) by using solvent precipitation method. Preformulation study evidenced for selection of Captex 500 P as an oil phase in which Idebenone has saturation solubility of 0.266 ± 0.032 g/ml. Compritol 888 ATO and ethanol were selected as solid lipid and solvent respectively. Surfactant and co-surfactant as Labrasol and Transcutol P have given stable formulations on the basis of HLB required for stabilization, respect to oil phase. INLC has particle size of 605 ± 4.01 nm and %EE of 82.58 ± 2.20 %. Optimized batches were subjected for crystallographic investigation, in vitro skin permeation study, drug deposition study, SPF determination and antioxidant activity. XRD, DSC studies illustrated that partial amorphization of Idebenone by molecularly dispersion within lipid blend leads for entrapment of drug. Permeation data showed that optimized INLC has flux value (Jss) of 7.87 μg cm^?2 h^?1. High significance (P < 0.001) of drug deposition in skin was observed between INLC and plain Idebenone gel. SPF value for INLC has 23 which represents that lipid nanocarriers have standards of blocking of 94–96 % of UVB rays. Such high skin deposition and SPF leads to more antioxidant effect of formulations. Hence lipid nanocarriers such as NLC have potential as an antioxidant and sun protection for topical drug delivery.     

A new approach for the evaluation of niosomes as effective transdermal drug delivery systems

The central motivation for this study was to evaluate if the increased hydrophilic drug permeation across the skin, which is always observed in presence of vesicular systems, is dependent on the structural organization of niosomes, that are used to transport the active molecules, or if it is only dependent on the surfactant dual nature. To answer this question, non-ionic surfactants belonging to the class of Pluronic and sucrose esters were used both as components of niosomal systems or in the form of sub-micellar solutions. The obtained niosomes were characterized by their entrapment efficiency, size and morphology.The enhancing effect of niosomes on the ex vivo percutaneous penetration of a model drug was investigated using a Franz-type diffusion chamber and compared to that obtained by using sub-micellar solution of surfactant or achieving pretreatment of the skin with surfactants’ sub-micellar solution or empty niosomes.The results suggest that the surfactants used in this study could be considered as percutaneous permeation enhancers only when they are in the form of drug-loaded vesicular systems: no percutaneous promotion was achieved by using sub-micellar solution containing free Sulfadiazine sodium salt or performing pretreatment with empty niosomes or sub-micellar solutions of the surfactant. In our experiments, only niosomes act as effective transdermal drug delivery systems.     

Magnesium ascorbyl phosphate vesicular carriers for topical delivery; preparation,in-vitro and ex-vivo evaluation,factorial optimization and clinical assessment in melasma patients

Ascorbic acid (vitamin C) is an antioxidant that is widely used in cosmetics in skincare products. Due to the excessive low stability of ascorbic acid in cosmetic formulations, the stabilized ascorbic acid derivative, magnesium ascorbyl phosphate (MAP) was formulated as vesicular carriers; ethosomes and niosomes. The aim was to deliver MAP at the intended site of action, the skin, for sufficient time with enhanced permeation to get an effective response. Ethosomes were formulated using a full 3² factorial design to study ethanol and phospholipid concentration effect on ethosomes properties. Niosomes were formulated using 2³ factorial designs to study the effect of surfactant type, surfactant concentration and cholesterol concentration on niosomes properties. The prepared formulations were evaluated for their Entrapment efficiency, particle size, polydispersity index, zeta potential and % drug permeated. The optimized ethosomal and niosomal formulations were incorporated into carbopol gel and evaluated for their permeation, skin retention and stability. A comparative split-face clinical study was done between the ethosomal and niosomal formulations for melasma treatment using Antera 3 D^® camera. The optimized ethosomal and niosomal gels showed comparable controlled permeation and higher skin retention over their ethosomes and niosomes formulations respectively. Magnesium ascorbyl phosphate ethosomal gel showed clinically and statistically significant melanin level decrease after one month while MAP niosomal gel showed clinically and statistically significant melanin level decrease after six months. A combination of MAP ethosomes and niosomes could be promising skincare formulations for melasma and hyperpigmentation short and long-term treatment.     

Niosomal gel for site-specific sustained delivery of anti-arthritic drug: in vitro-in vivo evaluation

Celecoxib, a selective COX-2 inhibitor is commonly used in the treatment of arthritis. Recently, cardiotoxic effects associated with conventional modes of delivery of celecoxib have made it pertinent to develop alternate dosage forms capable of selectively delivering the drug topically to affected joints. The aim of the present study was to prepare and characterize niosomal gel formulation for sustained and site-specific delivery of celecoxib. Celecoxib loaded niosomes were prepared and characterized in vitro, ex-vivo and in vivo. The results of organ localization (deep skin layer + muscle) study showed that niosomal gel provided 6.5 times higher drug deposition as compared to carbopol gel (195.2+/-8.7 and 30.0+/-1.5 microg, respectively). The muscle to plasma concentration ratio for niosomal gel formulation was six (2.16+/-0.12 microg/g vs. 0.34+/-0.01 microg/ml) and for carbopol gel it was one (0.36+/-0.01 microg/g vs. 0.43+/-0.02 microg/ml). Biological effectiveness of optimized formulation was evaluated using carrageenan induced rat paw edema model. The application of niosomal gel produced significant reduction of rat paw edema as compared to that after application of conventional gel indicating better skin permeation and deposition of celecoxib from niosomes. The results of the present study demonstrated niosomal gel formulation possess great potential for enhanced skin accumulation, prolonging drug release and improving the site specificity of celecoxib.     

Transdermal Absorption Enhancement of N-Terminal Tat–GFP Fusion Protein (TG) Loaded in Novel Low-Toxic Elastic Anionic Niosomes

Elastic anionic niosomes (Tween 61/cholesterol/dicetyl phosphate at 1:1:0.05 molar ratio of 20 mM) with various concentrations of ethanol and edge activators sodium cholate (NaC) and sodium deoxycholate (NaDC) showed larger vesicular size (171.94 ± 63.52 – 683.17 ± 331.47 nm) and higher negative zeta potential (?6.45 ± 2.76 to ? 17.40 ± 2.51 mV) than the nonelastic anionic niosomes. The elasticity (deformability index) and entrapment efficiency of all elastic vesicles except the NaDC vesicles were higher than the nonelastic vesicles. The morphology, under transmission electron microscope, of elastic and nonelastic niosomes loaded and not loaded with Tat–green fluorescent protein fusion protein (TG) were in large unilamellar structure. TG loaded in elastic (1 mol% NaC) anionic niosomes gave the highest cell viability both in HT-29 (92.32 ± 3.82%) and KB cells (96.62 ± 5.96%), the highest cumulative amounts (62.75 ± 2.68 μg/cm²) and fluxes (10.46 ± 3.45 μg/cm²h) in receiving chamber in rat skin transdermal study by Franz diffusion cells. This study has not only indicated the synergistic enhancement effects of the Tat peptide and the niosomal delivery system on the cellular uptake and transdermal absorption of TG but also 1 mol% NaC as an edge activator to obtain a novel low-toxic elastic anionic niosomes for topical use of therapeutic macromolecules such as proteins, as well.     

Development and characterization of a novel antiacne niosomal gel of rosmarinic acid

Abstract

The antibacterial and anti-inflammatory potential of rosemarinic acid (ROA), a naturally occurring ester of caffeic acid has been well reported. Antibacterial effect of ROA is attributed to nucleoid damage with an increase in spatial division and condensation of genetic material. ROA has been found dynamic against many human pathogenic bacterial strains but its inhibitory prospective has never been established against skin inflammations caused by Propionibacterium acne. The skin surface in acne prone areas is colonized with Staphylococcus aureus and Propionibacterium acnes which contribute to inflammation and acne. Resistance to current antimicrobial therapies suggested the need to explore new antimicrobial agents against acne. Present work included the preparation of ROA-loaded niosomes and their in vitro antimicrobial evaluation against P. acne and S. aureus. This work also included the development of niosomal gel of rosmarinic acid for sustained delivery to bacteria infected cells. Niosomes of rosmarinic acid were formulated by reverse phase evaporation method using different ratio of span 85 and cholesterol. The prepared formulations were evaluated for its vesicle size, entrapment efficiency, in vitro release study and antibacterial activity. In vivo study of developed formulation was conducted on Swiss albino mice in comparison with solution of plain drug and a marketed formulation of benzoyl peroxide. It was evident that niosomes are novel carrier for delivery of naturally occurring antimicrobial agents, in deeper tissues of skin. The results showed that drug-loaded niosomes dispersed in the gelling agent are an effective delivery system for treatment of acne vulgaris.     

Development of Liposomal Systems of Finasteride for Topical Applications: Design,Characterization, and In Vitro Evaluation

Finasteride (FNS) is a “drug of choice” for benign prostate hypertrophy and prostate cancer. The drug has also been reported to be useful orally in the treatment of some difficult-to-treat androgen-dependent skin disorders, such as seborrhea, acne, hirsutism, and androgenetic alopecia. However, the ideal route for its administration (i.e., topical) remains unexplored. This has logically suggested the search for strategic formulation approaches to make the drug effective on topical applications, hitherto unexplored. The present study targets the encasement of drug molecules in the interiors of vesicular compartments (liposomes) made up of hydrogenated phospholipids, as an attempt toward the development of a trans-epidermal therapeutic system of FNS. Multilamellar drug-loaded liposomes were prepared by thin-film hydration with sonication method and optimized with respect to drug payload, entrapment efficiency, and size by formulating different vesicular compositions under different process conditions. The vesicular systems consisting of saturated phospholipid (100 mg), cholesterol (50 mg), and FNS (5 mg) showed highest drug payload (2.9 mg/100 mg of total lipids), and drug entrapment efficiency (88.6%). Mean (± SD) vesicle size of the prepared liposomes was found to be 3.66 ± 1.6 μm. Significantly higher skin permeation of FNS through excised abdominal mice skin of FNS was achieved from the liposomal formulations vis-à-vis corresponding solution and conventional gels. Liposomal FNS formulations also showed more than fivefold higher deposition of drug in skin than the corresponding plain drug solution and conventional gel. Stability studies indicated that the liposomal formulations were quite stable in the refrigerated conditions for 2 months with negligible drug leakage or vesicle size alteration during the storage period. Results of the current studies with FNS-loaded vesicular systems project the high plausibility of a topical liposomal formulation for effective localized delivery of Finasteride.     

Design and development of novel bioadhesive niosomal formulation for the transcorneal delivery of anti-infective agent: In-vitro and ex-vivo investigations

Gatifloxacin eye drops are frequently used in eye infections. However such formulations have a major drawback i.e. short duration of action and usually require 4–6 times installations daily. A chitosan coated niosomal formulation of gatifloxain was purposed to show a longer retention time on eyes and subsequent reduction in dosing frequency. Vesicles were prepared by solvent injection method using cholesterol and Span-60. An extensive optimization of formulation was done using different ratios of cholesterol, Span-60 and drug, revealed NS60-5 (cholesterol: span-60 50: 50 and drug content of 20 mg) to be the optimized niosome formulation. NS60-5 had shown a highest entrapment efficiency of 64.9 ± 0.66% with particle size 213.2 ± 1.5 nm and zeta potential −34.7 ± 2.2 mV. Optimized niosomes were also coated with different concentrations of chitosan and evaluated. Permeation studies had revealed that optimized niosomes (86.77 ± 1.31%) had increased the transcorneal permeation of Gatifloxacin more than two fold than simple drug solution (37.19 ± 1.1%). Longer retention potential of the coated niosomes was further verified by fluorescence microscopy. Study revealed that simple dye solution got easily washed out with in 6 h. The uncoated niosomes (NS60-5) showed a longer retention (more than 6 h), which was further enhanced in case of coated niosomes i.e. CNS60-1 (more than 12 h). Antimicrobial studies had shown the better efficacy of CNS60-1 (zone of inhibition) when compared to marketed formulation. The final chitosan formulation was found to have shown better ocular tolerability as demonstrated by corneal hydration test histopathology investigations.     

Formulation and evaluation of meloxicam niosomes as vesicular carriers for enhanced skin delivery

Context: Skin delivery of Meloxicam (MX) offers several advantages over the oral route which is associated with potential side effects.

Objectives: The aim of this study was to develop transdermal MX in niosomes.Materials and Methods: Vesicles prepared by thin film hydration method were characterized and the acute anti-inflammatory activity of 0.5% MX niosomal hydrogel was evaluated using carrageenan induced rat paw edema method. Results: The results revealed that niosomes prepared from span 60 and cholesterol at 6:4 molar ratio using 20?mg of MX were of the highest entrapment efficiency (> 55%) and with particle size (187.3?nm). There was a marked increase in the percentage inhibition of edema in animals treated with MX vesicular gel compared to those treated with free MX and piroxicam gels.

Discussion: There was an inverse proportionality between vesicle size and cholesterol content. With increased cholesterol molar ratio the bilayer stability increased and permeability decreased leading to efficiently trapping the MX. In contrast, higher amounts of cholesterol may compete with the drug for packing space within the bilayer. The inhibitory effect of MX niosomal gel may be attributed to its superior skin permeation.

Conclusions: The results suggest that niosomes may be promising vehicles for transdermal delivery of MX.     

Niosomes with Sorbitan Monoester as a Carrier for Vaginal Delivery of Insulin: Studies in Rats

To prepare and investigate the potential of the niosomes vaginal delivery system for systemic treatment of insulin is the goal of this study. Two kinds of vesicles with Span 40 and Span 60 were prepared by lipid phase evaporation methods with sonication. The niosomal entrapment efficiency was determined by column chromatography. The particle size and morphology of the vesicles also were evaluated. The results showed optimized niosomes prepared in this study had niosomal entrapment efficiency 26.68 ± 1.41% for Span 40 and 28.82 ± 1.35% for Span 60, respectively. The particle sizes of Span 40 niosomes and Span 60 niosomes were 242.5 ± 20.5 nm and 259.7 ± 33.8 nm, respectively. There were no significant differences in appearance between the two types of vesicles. The hypoglycemic effects, and insulin concentrations after vaginal administration of insulin vesicles to rats were investigated. Compared with subcutaneous administration of insulin solution, the relative pharmacological bioavailability and the relative bioavailability of vaginal administration of insulin vesicles were determined. Compared with subcutaneous administration of insulin solution, the relative pharmacological bioavailability and the relative bioavailability of insulin-Span 60 vesicles group were 8.43% and 9.61%, and insulin-Span 40 niosomes were 9.11% and 10.03% (p > 0.05). Span 60 and Span 40 niosomes were both higher than blank Span 40, Span 60 vesicles, and free insulin physical mixture groups (p < 0.05). The results indicates insulin-Span 60, Span 40 niosomes had an enhancing effect on vaginal delivery of insulin. Although the factors controlling the process for penetration of a portion of vaginally administrated niosomes into bloodstream from vaginal tract is still not fully understood, our results demonstrated that after encapsulation in niosomes of definite type, insulin became an active and efficiently therapeutic agent when administrated vaginally and might be a good carrier for vaginal delivery of protein drugs.     

Effect of formulation compositions on niosomal preparations

This study was aimed to investigate the effects of molar ratio of cholesterol to Span 60 and stabilizers (Solutol HS 15 or dicetyl phosphate (DCP)) on the entrapment of methylene blue, a model hydrophilic drug. The niosomes were prepared by the film hydration method and characterized for drug entrapment efficiency (EE), vesicle size, zeta potential and thermal properties of niosomal membrane. It was found that niosomal vesicles possessed median diameter ranging from 0.35 to 1.85 μm. The niosomes that were formulated with lower molar ratios of cholesterol to Span 60 of 0.33 and 0.50 produced significantly higher EE with both stabilizers when compared to cholesterol to Span 60 molar ratios of 1.0 and above (p < 0.05). The EE of niosomes stabilized with DCP was significantly higher (p < 0.05) than those prepared with Solutol HS 15 except at a molar ratio of cholesterol to Span 60 of 0.33. In conclusion, with low molar ratios of cholesterol to Span 60, more drugs could be entrapped within the niosomes regardless of the type of stabilizers. Furthermore, EE and median diameter of niosomes containing DCP were higher than those stabilized with Solutol HS 15.     

Preparation and evaluation of reverse-phase evaporation and multilamellar niosomes as ophthalmic carriers of acetazolamide

Niosomes have been reported as a possible approach to improve the low corneal penetration and bioavailability characteristics shown by conventional ophthalmic vehicles. Niosomes formed from Span 40 or Span 60 and cholesterol in the molar ratios of 7:4, 7:6 and 7:7 were prepared using reverse-phase evaporation and thin film hydration methods. The prepared systems were characterized for entrapment efficiency, size, shape and in vitro drug release. Stability studies were carried out to investigate the leaching of drug from niosomes during storage. The intraocular pressure (IOP) lowering activity of acetazolamide niosomal formulations in rabbits was measured using Shi?tz tonometer. Histological examination for the corneal tissues of rabbits receiving niosomal formulations was carried out for assessment of the ocular irritancy of niosomes. The results showed that the type of surfactant, cholesterol content and the method of preparation altered the entrapment efficiency and drug release rate from niosomes. Higher entrapment efficiency was obtained with multilamellar niosomes prepared from Span 60 and cholesterol in a 7:6 molar ratio. Niosomal formulations have shown a fairly high retention of acetazolamide inside the vesicles (approximately 75%) at a refrigerated temperature up to a period of 3 months. Each of the tested acetazolamide niosomes prepared by either method produced a significant decrease in IOP compared to the solution of free drug and plain niosomes. Multilamellar acetazolamide niosomes formulated with Span 60 and cholesterol in a 7:4 molar ratio were found to be the most effective and showed prolonged decrease in IOP. Histological examination of corneal tissues after instillation of niosomal formulation for 40 days showed slight irritation in the substantia propria of the eye which is reversible and no major changes in tissues were observed.     

Designing,Optimization and Characterization of Trifluralin Transfersomal Gel to Passively Target Cutaneous Leishmaniasis

Herein, Trifluralin (TFL) laden transfersomes (TFS) were investigated against Cutaneous Leishmaniasis (CL), via localized and targeted dermal delivery of TFL. Designed TFL-TFS were optimized utilizing 2³ full factorial design on the basis of desired response factors including Particle size (P.S), Polydispersity index (PDI), TFL entrapment (%EE) and deformability index (DI). Optimized formulation was found to display P.S of 140.3 ± 2.3, PDI of 0.006 ± 0.002, %EE of 86 ± 0.5 and 43.5 ± 1.0 DI. Results of TEM and XRD analysis have shown intact spherical structure of TFL-TFS and alteration in TFL crystallinity, respectively. Moreover, the optimized TFL-TFS were loaded in Carbopol-940 gel to attain protracted skin retention. TFL-TFS were found to exhibit sustain TFL release profile for up to 24 h. Ameliorated skin permeation of TFL-TFS, even in absence of permeation enhancers, has shown its suitability for cutaneous application. Macrophage uptake assay demonstrated higher intracellular penetration, evidenced by intense reddish fluorescence of rhodamine loaded TFS in comparison to rhodamine-solution. In vitro anti-leishmanial assessment was showing 2.86-folds and 3.07-folds decrement in IC₅₀-value of TFL-TFS against L. tropica KWH23 amastigotes and promastigotes, respectively. Percent inhibition assay against intra-macrophage amastigotes demonstrated that 90.87% amastigotes were assassinated at 50 μg/ml concentration of TFL-TFS, in comparison to the plain TFL-solution, exhibiting 54% parasitic killing.     

Neem (Azadirachta Indica) and silk fibroin associated hydrogel: Boon for wound healing treatment regimen

Background & ObjectivesWound healing is the complex physiological process of replacing damaged cells or tissue layers. The neem (Azadirachta Indica) has a variety of biological activities, which may hasten the rate at which the wound healing mechanism occurs. Silk fibroin is a biomaterial that is reported for its tissue regeneration activity. So, the present study was designed to assess the effectiveness of a hydrogel comprising neem and silk fibroin biomaterials for the treatment of wounds.MethodsTopical neem hydrogels (N-HG) with and without silk fibroin (N-SFB-HG) were prepared using neem extract, silk fibroin, and guar gum, which act by entrapping the components by forming a gel. Evaluation tests such as Fourier transform infrared spectroscopy (FT-IR), visual emergence, pH, rheological behavior, spreading capacity, drug content, skin irritation, anti-microbial action, in vivo wound healing activity, and stability were carried out.ResultsThe FT-IR results showed no chemical interaction between the constituents. The formed hydrogels had pH values of 5.87 ± 0.3 for N-HG and 5.76 ± 0.2 for N-SFB-HG. The preferred topical gel viscosity was observed in the N-HG (54.2 ± 3.2cPs) and N-SFB-HG (59.9 ± 4.8cPs) formulations. The formulated hydrogels were sterile and did not irritate the skin. The in vivo wound healing investigation results reveal that the N-SF-HG treatment speeds up the regeneration of the injured area faster when compared to control and N-HG treated groups.Interpretation & ConclusionThese results support the efficacy of the topical hydrogel formulation, including neem and silk fibroin. Therefore, the neem-silk fibroin hydrogel formulation is a therapeutically viable choice that, following necessary clinical research, might be utilized in novel formulations for managing chronic wounds.