Quercetin Alleviated Inflammasome-Mediated Pyroptosis and Modulated the mTOR/P70S6/P6/eIF4E/4EBP1 Pathway in Ischemic Stroke.

Stroke ranks as the world's second most prevalent cause of mortality, and it represents a major public health concern with profound economic and social implications. In the present study, we elucidated the neuroprotective role of quercetin on NLRP3-associated pyroptosis, Nrf2-coupled anti-inflammatory, and mTOR-dependent downstream pathways. Male Sprague Dawley rats were subjected to 72 h of transient middle cerebral artery ischemia, followed by the administration of 10 mg/kg of quercetin. Our findings demonstrated that MCAO induced elevated ROS which were coupled to inflammasome-mediated pyroptosis and altered mTOR-related signaling proteins. We performed ELISA, immunohistochemistry, and Western blotting to unveil the underlying role of the Nrf2/HO-1 and PDK/AKT/mTOR pathways in the ischemic cortex and striatum. Our results showed that quercetin post-treatment activated the Nrf2/HO-1 cascade, reversed pyroptosis, and modulated the autophagy-related pathway PDK/AKT/mTOR/P70S6/P6/eIF4E/4EBP1. Further, quercetin enhances the sequestering effect of 14-3-3 and reversed the decrease in interaction between p-Bad and 14-3-3 and p-FKHR and 14-3-3. Our findings showed that quercetin exerts its protective benefits and rescues neuronal damage by several mechanisms, and it might be a viable neuroprotective drug for ischemic stroke therapy.

Rutin Nanocrystals with Enhanced Anti-Inflammatory Activity: Preparation and Ex Vivo/In Vivo Evaluation in an Inflammatory Rat Model.

Rutin is a polyphenolic flavonoid with an interestingly wide therapeutic spectrum. However, its clinical benefits are limited by its poor aqueous solubility and low bioavailability. In an attempt to overcome these limitations, rutin nanocrystals were prepared using various stabilizers including nonionic surfactants and nonionic polymers. The nanocrystals were evaluated for particle size, zeta potential, drug entrapment efficiency, morphology, colloidal stability, rutin photostability, dissolution rate, and saturation solubility. The selected nanocrystal formulation was dispersed in a hydrogel base and the drug release kinetics and permeability through mouse skin were characterized. Rutin's anti-inflammatory efficacy was studied in a carrageenan-induced rat paw edema model. The nanocrystals had a size in the range of around 270-500 nm and a polydispersity index of around 0.3-0.5. Nanocrystals stabilized by hydroxypropyl beta-cyclodextrin (HP-ß-CD) had the smallest particle size, highest drug entrapment efficiency, best colloidal stability, and highest drug photostability. Nanocrystals had around a 102- to 202-fold and 2.3- to 6.7-fold increase in the drug aqueous solubility and dissolution rate, respectively, depending on the type of stabilizer. HP-ß-CD nanocrystals hydrogel had a significantly higher percent of drug released and permeated through the mouse skin compared with the free drug hydrogel. The cumulative drug amount permeated through the skin was 2.5-fold higher than that of the free drug hydrogel. In vivo studies showed that HP-ß-CD-stabilized rutin nanocrystals hydrogel had significantly higher edema inhibition compared with the free drug hydrogel and commercial diclofenac sodium gel. These results highlight the potential of HP-ß-CD-stabilized nanocrystals as a promising approach to enhance drug solubility, dissolution rate, and anti-inflammatory properties.

EthoLeciplex: a new tool for effective cutaneous delivery of minoxidil.

This work designates EthoLeciplex, a vesicular system consisting of phospholipid, CTAB, ethanol and water, as an innovative vesicular system for cutaneous/transfollicular minoxidil (MX) delivery. MX-loaded EthoLeciplex was fabricated by one-step fabrication process. Formulations were designed to study the effects of drug/phospholipid ratio, CTAB/phospholipid ratio, and ethanol concentration on vesicular size, PDI, surface charge and EE%. The optimized formulation was characterized by in vitro release, drug/excipient compatibility, ex vivo skin permeability and safety. A size of 83.6 ± 7.3 to 530.3 ± 29.4 nm, PDI of 0.214 ± 0.01 to 0.542 ± 0.08 and zeta potential of +31.6 ± 4.8 to +57.4 ± 12.5 mV were observed. Encapsulation efficiency was obtained in its maximum value (91.9 ± 16.2%) at the lowest drug/phospholipid ratio, median CTAB/phospholipid and the highest ethanol concentration. The optimized formulation was consisted of 0.3 as drug/lipid ratio, 1.25 as CTAB/lipid ratio and 30% ethanol concentration and showed responses' values in agreement with the predicted results. Differential scanning calorimetry studies suggested that EthoLeciplex existed in flexible state with complete incorporation of MX into lipid bilayer. The cumulative amount of MX permeated from EthoLeciplex, conventional liposome and ethanolic solution after 12 h were 36.3 ± 1.5 µg/ml, 21 ± 2.0 µg/ml and 55 ± 4.0 µg/ml respectively. Based on the remaining amount, the amount of MX accumulated in different skin layers can be predicted in descending order as follows; EthoLeciplex > conventional liposome > MX solution. EthoLeciplex produced marked disorder in the stratum corneum integrity and swelling with no features of skin toxicity. This new cationic system is a promising carrier for cutaneous/transfollicular drug delivery.

Combinatorial Therapy of Letrozole- and Quercetin-Loaded Spanlastics for Enhanced Cytotoxicity against MCF-7 Breast Cancer Cells.

Breast cancer is the most widespread cancer in women with rising incidence, prevalence, and mortality in developed regions. Most breast cancers (80%) are estrogen receptor-positive, indicating that disease progression could be controlled by estrogen inhibition in the breast tissue. However, drug resistance limits the benefits of this approach. Combinatorial treatment could overcome the resistance and improve the outcome of breast cancer treatment. In the current study, we prepared letrozole-(LTZSPs) and quercetin-loaded spanlastics (QuSPs) using different edge activators-Tween 80, Brij 35, and Cremophor RH40-with different concentrations. The spanlastics were evaluated for their average particles size, surface charge, and percent encapsulation efficiency. The optimized formulations were further examined using transmission electron microscopy, Fourier transform infrared spectroscopy, in vitro drug release and ex vivo skin permeation studies. The prepared spherical LTZSPs and QuSPs had average particle sizes ranged between 129-310 nm and 240-560 nm, respectively, with negative surface charge and high LTZ and Qu encapsulation (94.3-97.2% and 97.9-99.6%, respectively). The in vitro release study of LTZ and Qu from the selected formulations showed a sustained drug release for 24 h with reasonable flux and permeation through the rat skin. Further, we evaluated the in vitro cytotoxicity, cell cycle analysis, and intracellular reactive oxygen species (ROS) of the combination therapy of letrozole and quercetin either in soluble form or loaded in spanlastics against MCF-7 breast cancer cells. The LTZSPs and QuSPs combination was superior to the individual treatments and the soluble free drugs in terms of in vitro cytotoxicity, cell cycle analysis, and ROS studies. These results confirm the potential of LTZSPs and QuSPs combination for transdermal delivery of drugs for enhanced breast cancer management.

Epigallocatechin-3-Gallate-Loaded Gold Nanoparticles: Preparation and Evaluation of Anticancer Efficacy in Ehrlich Tumor-Bearing Mice.

Epigallocatechin-3-gallate (EGCG) is a pleiotropic compound with anticancer, anti-inflammatory, and antioxidant properties. To enhance EGCG anticancer efficacy, it was loaded onto gold nanoparticles (GNPs). EGCG-GNPs were prepared by a simple green synthesis method and were evaluated using different techniques. Hemocompatibility with human blood and in vivo anticancer efficacy in Ehrlich ascites carcinoma-bearing mice were evaluated. EGCG/gold chloride molar ratio had a marked effect on the formation and properties of EGCG-GNPs where well-dispersed spherical nanoparticles were obtained at a molar ratio not more than 0.8:1. The particle size ranged from ~26 to 610 nm. High drug encapsulation efficiency and loading capacity of ~93 and 32%, respectively were obtained. When stored at 4 °C for three months, EGCG-GNPs maintained over 90% of their drug payload and had small changes in their size and zeta potential. They were non-hemolytic and had no deleterious effects on partial thromboplastin time, prothrombin time, and complement protein C3 concentration. EGCG-GNPs had significantly better in vivo anticancer efficacy compared with pristine EGCG as evidenced by smaller tumor volume and weight and higher mice body weight. These results confirm that EGCG-GNPs could serve as an efficient delivery system for EGCG with a good potential to enhance its anticancer efficacy.

Polymeric micelles for the ocular delivery of triamcinolone acetonide: preparation and in vivo evaluation in a rabbit ocular inflammatory model.

The aim of this study was to prepare triamcinolone acetonide (TA)-loaded poly(ethylene glycol)-block-poly(ε-caprolactone) (PEG-b-PCL) and poly(ethylene glycol)-block-poly(lactic acid) (PEG-b-PLA) micelles as a potential treatment of ocular inflammation. The micelles were evaluated for particle size, drug loading capacity and drug release kinetics. Selected micellar formulations were dispersed into chitosan hydrogel and their anti-inflammatory properties were tested in rabbits using a carrageenan-induced ocular inflammatory model. Particle size ranged from 59.44 ± 0.15 to 64.26 ± 0.55 nm for PEG-b-PCL and from 136.10 ± 1.57 to 176.80 ± 2.25 nm for PEG-b-PLA micelles, respectively. The drug loading capacity was in the range of 6-12% and 15-25% for PEG-b-PCL and PEG-b-PLA micelles, respectively and was dependent on the drug/polymer weight ratio. TA aqueous solubility was increased by 5- and 10-fold after loading into PEG-b-PCL and PEG-b-PLA micelles at a polymer concentration as low as 0.5 mg/mL, respectively. PEG-b-PLA micelles suspended in chitosan hydrogel were able to sustain the drug release where only 42.8 ± 1.6% drug was released in one week. TA/PEG-b-PLA micelles suspended in chitosan hydrogel had better anti-inflammatory effects compared with the plain drug hydrogel or the drug micellar solution. Complete disappearance of the corneal inflammatory changes was observed for the micellar hydrogel. These results confirm the potential of PEG-b-PLA micelles suspended in chitosan hydrogel to enhance the anti-inflammatory properties of triamcinolone acetonide.

Liposomal and Ethosomal Gels for the Topical Delivery of Anthralin: Preparation, Comparative Evaluation and Clinical Assessment in Psoriatic Patients.

To enhance anthralin efficacy against psoriasis and reduce its notorious side effects, it was loaded into various liposomal and ethosomal preparations. The nanocarriers were characterized for drug encapsulation efficiency, size, morphology and compatibility between various components. Optimum formulations were dispersed in various gel bases and drug release kinetics were studied. Clinical efficacy and safety of liposomal and ethosomal Pluronic®F-127 gels were evaluated in patients having psoriasis (clinicaltrials.gov identifier is NCT03348462). Safety was assessed by recording various adverse events. Drug encapsulation efficiency ≥97.2% and ≥77% were obtained for liposomes and ethosomes, respectively. Particle sizes of 116 to 199 nm and 146 to 381 nm were observed for liposomes and ethosomes, respectively. Fourier-Transform infrared (FT-IR) spectroscopy and differential scanning calorimetry (DSC) studies confirmed the absence of interaction between anthralin and various nanocarrier components. Tested gel bases showed excellent ability to sustain drug release. At baseline, the patients had a median Psoriasis Area and Severity Index (PASI) of 3.4 for liposomes and 3.6 for ethosomes without significant difference. After treatment, mean PASI change was -68.66% and -81.84% for liposomes and ethosomes, respectively with a significant difference in favor of ethosomes. No adverse effects were detected in both groups. Anthralin ethosomes could be considered as a potential treatment of psoriasis.

Latanoprost niosomes as a sustained release ocular delivery system for the management of glaucoma.

Objective: Glaucoma is a leading cause of irreversible blindness worldwide. Whereas latanoprost is one of the most effective drugs in glaucoma treatment, its eye drops need frequent application leading to lack of patient adherence. This study aimed to develop a patient-friendly niosome-in-gel system for the sustained ocular delivery of latanoprost.Methods: Niosomes were prepared by the reverse-phase evaporation technique and optimized for different formulation parameters, such as cholesterol/surfactant and drug/surfactant ratios. Selected niosomal formulations were incorporated into different gels and their viscosity and drug release kinetics were evaluated. Optimal niosomal gel was evaluated in vivo in rabbits' eyes for irritation potential and ability to reduce intraocular pressure.Results: FT-IR studies showed that there were nonspecific interactions between latanoprost and different niosomal components leading to drug encapsulation efficiency ≥88%. Latanoprost encapsulation efficiency increased with the drug/surfactant ratio and encapsulation efficiency ∼98% was obtained at a ratio of 50%. Pluronic® F127 had the best ability to sustain drug release from the niosomes. In rabbits' eyes, this gel was free of toxic and irritant effects and reduced intraocular pressure over a period of three days, which was significantly longer than that of commercial latanoprost eye drops.Conclusion: Latanoprost niosomal Pluronic® F127 gel may find applications in glaucoma management.

Colon-targeting of progesterone using hybrid polymeric microspheres improves its bioavailability and in vivo biological efficacy.

This study aims to enhance progesterone (PG) oral bioavailability via its incorporation into hybrid colon-targeted pectin/NaCMC microspheres (MS) cross-linked with Zn2+ and Al3+. The MS were characterized for particle morphology, encapsulation efficiency, swelling behavior, drug release, mucoadhesivity and colon-specific degradability. Response-surface methodology was adopted to optimize the fabrication conditions. Enhancement of in vivo drug performance was evaluated through pharmacokinetic and pharmacodynamic studies. The optimized formulation was typically spherical with a mean diameter of 1031 µm and drug entrapment efficiency of 88.8%. This formulation exhibited pH-dependent swelling, negligible drug release in simulated gastric fluid and sustained-release pattern in simulated small intestinal fluid with a mean t50% of 26.5 h. It also showed prolonged and preferential adhesion to rat colonic mucosa, as well as expedited degradation in presence of rat caecal contents. The MS significantly increased the area under the curve and mean residence time by 1.8 and 2.3-fold, respectively compared to the free drug. Orally administered MS showed ~10 times increase in myometrial thickness compared with the drug suspension and elicited uterine responses very similar to that obtained parenterally. These results confirm the ability of this new carrier system to improve the oral bioavailability of PG and attain adequate clinical efficacy.

Spironolactone-Loaded LeciPlexes as Potential Topical Delivery Systems for Female Acne: In Vitro Appraisal and Ex Vivo Skin Permeability Studies.

Spironolactone (SP), an aldosterone antagonist with anti-androgen properties, has shown promising results in the treatment of female acne. However, its systemic side effects limit its clinical benefits. This study aimed to prepare and evaluate LeciPlexes for SP topical delivery. LeciPlexes were prepared by a one-step procedure and characterized using various techniques. Optimum LeciPlex preparation was incorporated into 1% methylcellulose gel and SP permeability was tested ex vivo in Sprague-Dawley rat skin. The maximum drug encapsulation efficiency obtained was 93.6 ± 6.9% and was dependent on the drug/phospholipid and surfactant/phospholipid ratios. A zeta potential of +49.3 ± 3.5 to +57.7 ± 3.3 mV and a size of 108 ± 25.3 to 668.5 ± 120.3 nm were observed for the LeciPlexes. FT-IR and DSC studies confirmed the incorporation of SP into the LeciPlexes through hydrophobic and hydrogen bonding interactions. SP release from the LeciPlex formulations was significantly slower than from the drug suspension. Cumulative SP permeated through rat skin from LeciPlex gel was about 2-fold higher than SP control gel. Cumulative SP deposited in the stratum corneum and other skin layers from the LeciPlex gel was about 1.8- and 2.6-fold higher than SP control gel, respectively. This new SP LeciPlex formulation is a promising carrier for the treatment of female acne.

Soy isoflavone-loaded alginate microspheres in thermosensitive gel base: attempts to improve wound-healing efficacy.

OBJECTIVES: This study aims to develop thermosensitive gel containing soy isoflavone (antioxidant and anti-inflammatory natural agent) alginate microspheres for enhancement of wound-healing performance. METHODS: Soy isoflavone microspheres were prepared by ionic cross-linking method and optimized using the Box-Behnken optimization design. Formulations were characterized in terms of particle size, encapsulation efficiency and equilibrium swelling degree. The optimized formula was incorporated in Pluronic F127 gel base and examined for in vivo wound-healing efficacy. KEY FINDINGS: Results showed mean particle size between 18 and 25 µm, encapsulation efficiency of over 75% and equilibrium swelling degree over 1.9. Thermal analysis indicated interaction between alginate and CaCl2 and embedding of soy isoflavone in microspheres. In vivo wound-healing efficacy showed significant advance in re-epithelization, mature collagen synthesis and proangiogenesis. Immunohistochemical investigation exhibited promising alpha-smooth muscle actin immunopositive cells expression, fibroblast activation and expression of proliferating cell nuclear antigen (proliferation marker) in the epidermis and in the dermis. CONCLUSIONS: The developed formulation would appear to be a promising topical preparation for accelerating healing process.

Fluorouracil-Loaded Gold Nanoparticles for the Treatment of Skin Cancer: Development, in Vitro Characterization, and in Vivo Evaluation in a Mouse Skin Cancer Xenograft Model.

Fluorouracil (5-FU) is an antimetabolite drug used in the treatment of various malignancies, such as colon and skin cancers. However, its systemic administration results in severe side effects. Topical 5-FU delivery for the treatment of skin cancer could circumvent these shortcomings, but it is limited by the drug poor permeability through the skin. To enhance 5-FU efficacy against skin cancer and reduce its systemic side effects, it was loaded into a gold nanoparticle (GNP)-based topical delivery system. 5-FU was loaded onto GNPs capped with CTAB through ionic interactions between 5-FU and CTAB. GNPs were prepared at different 5-FU/CTAB molar ratios and evaluated using different techniques. GNP stability and drug release were studied as a function of salt concentration and solution pH. Optimum 5-FU/CTAB-GNPs were incorporated into gel and cream bases, and their ex vivo permeability was evaluated in mice dorsal skin. The in vivo anticancer efficacy of the same preparations was evaluated in A431 tumor-bearing mice. The GNPs had spherical shape and a size of ∼16-150 nm. Maximum 5-FU entrapment was achieved at 5-FU/CTAB molar ratio of 1:1 and pH 11.5. Drug release from GNPs was sustained and pH-dependent. 5-FU GNP gel and cream had around 2-fold higher permeability through mice skin compared with free 5-FU gel and cream formulations. Further, in vivo studies in a mouse model having A431 skin cancer cells implanted in the subcutaneous space showed that the GNP gel and cream achieved 6.8- and 18.4-fold lower tumor volume compared with the untreated control, respectively. These results confirm the potential of topical 5-FU/CTAB-GNPs to enhance drug efficacy against skin cancer.

Enalapril maleate orally disintegrating tablets: tableting and in vivo evaluation in hypertensive rats.

The aim of this study was to develop orally disintegrating tablets (ODTs) for enalapril maleate (EnM) to facilitate its administration to the elderly or other patients having dysphagia. Compatibility between EnM and various excipients was studied using differential scanning calorimetry. ODTs of EnM were prepared by direct compression of EnM mixtures with various superdisintegrants. The tablets were evaluated for physical properties including drug content, hardness, friability, disintegration time, wetting time, and drug release. The antihypertensive effect of the optimum EnM ODTs was evaluated in vivo in hypertensive rats and compared with commercial EnM formulation. EnM ODTs had satisfactory results in terms of drug content and friability. Tablet wetting and disintegration were fast and dependent on the used superdisintegrant where croscarmellose showed the fastest wetting and disintegration time of ∼7 s. EnM release from the tablets was rapid where complete release was obtained in 10-15 min. Selected EnM ODTs rapidly and efficiently reduced the rat's blood pressure to its normal value within 1 h, compared with 4 h for EnM commercial formulation. These results confirm that EnM ODTs could find application in the management of hypertension in the elderly or other patients having dysphagia.

Mucoadhesive tablets for the vaginal delivery of progesterone: in vitro evaluation and pharmacokinetics/pharmacodynamics in female rabbits.

OBJECTIVE: To develop mucoadhesive tablets for the vaginal delivery of progesterone (P4) to overcome its low oral bioavailability resulting from drug hydrophobicity and extensive hepatic metabolism. METHODS: The tablets were prepared using mixtures of P4/Pluronic® F-127 solid dispersion and different mucoadhesive polymers. The tablets physical properties, swelling index, mucoadhesion and drug release kinetics were evaluated. P4 pharmacokinetic and pharmacodynamic properties were evaluated in female rabbits and compared with vaginal micronized P4 tablets and intramuscular (IM) P4 injection, respectively. RESULTS: The tablets had satisfactory physical properties and their swelling, in vitro mucoadhesion force and ex vivo mucoadhesion time were dependent on tablet composition. Highest swelling index and mucoadhesion time were detected for tablets containing 20% chitosan-10% alginate mixture. Most tablets exhibited burst release (∼25%) during the first 2 h but sustained the drug release for ∼48 h. In vivo study showed that chitosan-alginate mucoadhesive tablets had ∼2-fold higher P4 mean residence time (MRT) in the blood and 5-fold higher bioavailability compared with oral P4. Further, same tablets showed 2-fold higher myometrium thickness in rabbit uterus compared with IM P4 injection. CONCLUSION: These results confirm the potential of these mucoadhesive vaginal tablets to enhance P4 efficacy and avoid the side effects associated with IM injection.

High payload nanostructured lipid carriers fabricated with alendronate/polyethyleneimine ion complexes.

Oral bioavailability of the anti-osteoporotic drug alendronate (AL) is limited to ≤ 1% due to unfavorable physicochemical properties. To augment absorption across the gastrointestinal mucosa, an ion pair complex between AL and polyethyleneimine (PEI) was formed and incorporated into nanostructured lipid carriers (NLCs) using a modified solvent injection method. When compared to free AL, ion pairing with PEI increased drug encapsulation efficiency in NLCs from 10% to 87%. Drug release from NLCs measured in vitro using fasted state simulated intestinal fluid, pH 6.5 (FaSSIF-V2) was significantly delayed after PEI complexation. Stability of AL/PEI was pH-dependent resulting in 10-fold faster dissociation of AL in FaSSIF-V2 than measured at pH 7.4. Intestinal permeation properties estimated in vitro across Caco-2 cell monolayers revealed a 3-fold greater flux of AL encapsulated as hydrophobic ion complex in NLCs when compared to AL solution (Papp = 8.43 ± 0.14 × 10-6 cm/s and vs. 2.76 ± 0.42 × 10-6 cm/s). Cellular safety of AL/PEI-containing NLCs was demonstrated up to an equivalent AL concentration of 2.5 mM. These results suggest that encapsulation of AL/PEI in NLCs appears a viable drug delivery strategy for augmenting oral bioavailability of this clinically relevant bisphosphonate drug and, simultaneously, increase gastrointestinal safety.

Solubilization and Enhancement of Ex Vivo Vaginal Delivery of Progesterone Using Solid Dispersions, Inclusion Complexes and Micellar Solubilization.

BACKGROUND: Progesterone (PG), a natural female sex hormone is used clinically in menopausal hormone replacement therapy and to control reproductive functions. Its very limited aqueous solubility results in reduced oral bioavailability and low patient compliance when administered in high doses. The aim of this study was to enhance PG aqueous solubility and vaginal delivery using solid dispersion, inclusion complex and micellar solubilization techniques. METHODS: PG solid dispersions and inclusion complexes were prepared by solvent evaporation method using different polymers, such as cyclodextrins, polyvinyl pyrrolidone (PVP), poly (ethylene glycol) 6000, Pluronic® F-127 and Pluronic® F-68. PG was also incorporated into polymeric micelles of Pluronic® F-127, Pluronic® F- 68, Brij®35 and Myrj®52. The prepared solid dispersions, inclusion complexes and micelles were characterized using different techniques. Drug permeability across rabbit vaginal mucosa was also studied. RESULTS: Dissolution studies of PG solid dispersions showed that the highest drug dissolution rate was achieved at PG/polymer weight ratio of 5:5. Further, complete drug dissolution was obtained for PG/Pluronic® F-127 solid dispersion after 15 min compared to 42% dissolution for the drug alone. Brij®35 micelles had a drug loading capacity ~15%, which increased the drug aqueous solubility by more than 20 folds. PG permeability coefficients through rabbit vaginal mucosa for PG/Brij®35 micelles and PG/Pluronic® F-127 micelles were ~ two times higher than that of the drug alone. CONCLUSION: These results confirm that Brij®35 and Pluronic® F-127 micelles are promising carriers to overcome PG shortcomings through enhancing its aqueous solubility and vaginal permeability.

Enhanced skin deposition and delivery of voriconazole using ethosomal preparations.

Despite its broad-spectrum antifungal properties, voriconazole has many side effects when administered systemically. The aim of this work was to develop an ethosomal topical delivery system for voriconazole and test its potential to enhance the antifungal properties and skin delivery of the drug. Voriconazole was encapsulated into various ethosomal preparations and the effect of phospholipid and ethanol concentrations on the ethosomes properties were evaluated. The ethosomes were evaluated for drug encapsulation efficiency, particle size and morphology and antifungal efficacy. Drug permeability and deposition were tested in rat abdominal skin. Drug encapsulation efficiency of up to 46% was obtained and it increased with increasing the phospholipid concentration, whereas the opposite effect was observed for the ethanol concentration. The ethosomes had a size of 420-600 nm and negative zeta potential. The particle size of the ethosomes increased by increasing their ethanol content. The ethosomes achieved similar inhibition zones against Aspergillus flavus at a 2-fold lower drug concentration compared with drug solution in dimethyl sulfoxide. The ex vivo drug permeability through rat abdominal skin was ∼6-fold higher for the ethosomes compared with the drug hydroalcoholic solution. Similarly, the amount of drug deposited in the skin was higher for the ethosomes and was dependent on the ethanol concentration of the ethosomes. These results confirm that voriconazole ethosomal preparations are promising topical delivery systems that can enhance the drug antifungal efficacy and improve its skin delivery.

Development and in vivo evaluation of chitosan beads for the colonic delivery of azathioprine for treatment of inflammatory bowel disease.

Azathioprine is a highly efficient immunosuppressant drug used for treatment of inflammatory bowel disease (IBD). Systemic administration of azathioprine results in delayed therapeutic effect and serious adverse reactions. In the current study, we have developed, for the first time, colon-targeted chitosan beads for delivery of azathioprine in colitis rabbit model. Several characterizations were performed for the azathioprine-loaded beads (e.g. drug encapsulation efficiency, drug loading capacity, yield, size, shape and compatibility with other ingredients). The in vitro release profiles of acid-resistant capsules filled with azathioprine-loaded beads showed that most of azathioprine was released in IBD colon simulating medium. The therapeutic effects of azathioprine-loaded beads and azathioprine crude drug were examined on acetic acid-induced colitis rabbit model. Improved therapeutic outcomes were observed in the animals treated with the azathioprine-loaded beads, as compared to the untreated animal controls and the animals treated with the azathioprine free drug, based on the clinical activity score, index of tissue edema, mortality rate, colon macroscopic score and colon histopathological features. In the animals treated with the azathioprine-loaded beads, the levels of the inflammatory mediators, myeloperoxidase enzyme and tumor necrosis factor-α, were significantly reduced to levels similar to those observed in the normal rabbits. Furthermore, the activities of the antioxidant enzymes, superoxide dismutase and catalase, were restored considerably in the animals treated with the drug-loaded beads. The azathioprine-loaded beads developed in the current study might have great potential in the management of IBD.

Gold nanoparticles capped with benzalkonium chloride and poly (ethylene imine) for enhanced loading and skin permeability of 5-fluorouracil.

OBJECTIVE: To enhance 5-fluorouracil (5-FU) permeability through the skin by loading onto gold nanoparticles (GNPs) capped with two cationic ligands, benzalkonium chloride (BC) or poly (ethylene imine) (PEI). Whereas 5-FU has excellent efficacy against many cancers, its poor permeability through biological membranes and several adverse effects limit its clinical benefits. BC and PEI were selected to stabilize GNPs and to load 5-FU through ionic interactions. METHODS: 5-FU/BC-GNPs and 5-FU/PEI-GNPs were prepared at different 5-FU/ligand molar ratios and different pH values and were evaluated using different techniques. GNPs stability was tested as a function of salt concentration and storage time. 5-FU release from BC- and PEI-GNPs was evaluated as a function of solution pH. Ex vivo permeability studies of different 5-FU preparations were carried out using mice skin. RESULTS: 5-FU-loaded GNPs size and surface charge were dependent on the 5-FU/ligand molar ratios. 5-FU entrapment efficiency and loading capacity were dependent on the used ligand, 5-FU/ligand molar ratio and solution pH. Maximum drug entrapment efficiency of 59.0 ± 1.7% and 46.0 ± 1.1% were obtained for 5-FU/BC-GNPs and 5-FU/PEI-GNPs, respectively. 5-FU-loaded GNPs had good stability against salinity and after storage for 4 months at room temperature and at 4 °C. In vitro 5-FU release was pH- and ligand-dependent where slower release was observed at higher pH and for 5-FU/BC-GNPs. 5-FU permeability through mice skin was significantly higher for drug-loaded GNPs compared with drug-ligand complex or drug aqueous solution. CONCLUSION: Based on these results, BC- and PEI-GNPs might find applications as effective topical delivery systems of 5-FU.

Nanoparticles as safe and effective delivery systems of antifungal agents: Achievements and challenges.

Invasive fungal infections are becoming a major health concern in several groups of patients leading to severe morbidity and mortality. Moreover, cutaneous fungal infections are a major cause of visits to outpatient dermatology clinics. Despite the availability of several effective agents in the antifungal drug arena, their therapeutic outcome is less than optimal due to limitations related to drug physicochemical properties and toxicity. For instance, poor aqueous solubility limits the formulation options and efficacy of several azole antifungal drugs while toxicity limits the benefits of many other drugs. Nanoparticles hold great promise to overcome these limitations due to their ability to enhance drug aqueous solubility, bioavailability and antifungal efficacy. Further, drug incorporation into nanoparticles could greatly reduce its toxicity. Despite these interesting nanoparticle features, there are only few marketed nanoparticle-based antifungal drug formulations. This review sheds light on different classes of nanoparticles used in antifungal drug delivery, such as lipid-based vesicles, polymeric micelles, solid lipid nanoparticles, nanostructured lipid carriers, nanoemulsions and dendrimers with emphasis on their advantages and limitations. Translation of these nanoformulations from the lab to the clinic could be facilitated by focusing the research on overcoming problems related to nanoparticle stability, drug loading and high cost of production and standardization.