Hen's Egg Chorioallantoic Membrane Research Articles

Statistical optimization of voriconazole nanoparticles loaded carboxymethyl chitosan-poloxamer based in situ gel for ocular delivery: In vitro, ex vivo, and toxicity assessment.

The research study reflects the development of novel voriconazole (VCZ) loaded nanoparticles (NPs) for prolonged delivery for the management of ocular diseases. The in situ ophthalmic gel was prepared by incorporating NPs into carboxymethyl chitosan (CMCh) and poloxamer. The central composite design was used to optimize the process for the preparation of nanoparticles by the o/w solvent evaporation method. The developed nanoparticles were evaluated for the encapsulation efficiency (89.6 ± 1.2%), particle size (219.3 ± 1.8nm), polydispersity index (PDI, 0.1), zeta potential (- 21.1 ± 1.12mV), saturation solubility, DSC study, and drug release. The etherification process grafts carboxyl surface functional groups, on chitosan, and was confirmed by FTIR and NMR studies. The developed CMCh-poloxamer based gelling system was found to be clear and transparent with gelation temperature varying from 33 to 40°C. The nanoparticle-loaded gel containing CMCh demonstrated enhanced antifungal activity against Candida albicans. The optimized batch containing CMCh showed improved mucoadhesion by 2.86-fold compared to VCZ nanosuspension. The drug release was prolonged up to 8h with an ex vivo study suggesting the enhanced permeation across goat cornea estimated via fluorescent microscope. The hen's egg chorioallantoic membrane study revealed that the formulation was non-irritant and tolerated by the chorioallantoic membrane. The present study concludes that the VCZ loaded nanoparticulate in situ ophthalmic gel using CMCh may act as a potential alternative for traditional eye drops.

A supramolecular thermosensitive gel of ketoconazole for ocular applications: In silico, in vitro, and ex vivo studies

The incidence of corneal fungal infections continues to be a growing concern worldwide. Ocular delivery of anti-fungal drugs is challenging due to the anatomical and physiological barriers of the eye. The ocular bioavailability of ketoconazole (KTZ), a widely prescribed antifungal agent, is hampered by its limited aqueous solubility and permeation. In the study, the physicochemical properties of KTZ were improved by complexation with sulfobutylether-β-cyclodextrin (SBE-β-CD).KTZ-SBE-β-CD complex was studied in silico with docking and dynamics simulations, followed by wet-lab experiments.The optimized KTZ-SBE-β-CD complex was loaded into a thermosensitivein situ gel to increase corneal bioavailability. The supramolecular complex increased the solubility of KTZ by 5-folds and exhibited a 10-fold increment in drug release compared to the pure KTZ. Owing to the diffusion, thein situ gel exhibited a more sustained drug release profile. Theex vivocorneal permeation studies showed higher permeation from KTZ-SBE-β-CD in situ gel (flux of ∼19.11 µg/cm2/h) than KTZin situ gel (flux of ∼1.17 µg/cm2/h). The cytotoxicity assays and the hen's egg chorioallantoic membrane assay (HET-CAM) confirmed the formulations' safety and non-irritancy. In silico guided design of KTZ-SBE-β-CD inclusion complexes successfully modified the physicochemical properties of KTZ. In addition, the loading of the KTZ-SBE-β-CD complex into an in situ gel significantly increased the precorneal retention and permeation of KTZ, indicating that the developed formulation is a viable modality to treat fungal keratitis.

Voriconazole-Cyclodextrin Supramolecular Ternary Complex-Loaded Ocular Films for Management of Fungal Keratitis.

Fungal keratitis is one of the leading causes of ophthalmic mycosis affecting the vision due to corneal scarring. Voriconazole (VRC) is the most preferred azole antifungal agent for treating ocular mycotic infections. Ocular drug delivery is challenging due to the shorter corneal residence time of the formulation requiring frequent administration, leading to poor patient compliance. The present study aimed at improving the solubility, transcorneal permeation, and efficacy of voriconazole via the formation of cyclodextrin-based ternary complexes and incorporation of the complex into mucoadhesive films. A phase solubility study suggested a ∼14-fold improvement in VRC solubility, whereas physicochemical characterization confirmed the inclusion of VRC in the cyclodextrin inner cavity. In silico docking studies were performed to predict the docking conformation and stability of the inclusion complex. Complex-loaded films showed sustained release of voriconazole from the films and improved transcorneal permeation by ∼4-fold with an improved flux of 8.36 μg/(cm2 h) for ternary complex-loaded films compared to 1.86 μg/(cm2 h) for the pure VRC film. The 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and hen's egg-chorioallantoic membrane test (HET-CAM) assays confirmed that the complexes and ocular films were nonirritant and safe for ocular administration. The antifungal study performed using Aspergillus fumigatus and Fusarium oxysporum suggested improved antifungal activity compared to the pure drug film. In conclusion, the supramolecular cyclodextrin ternary complex proved to be a promising strategy for enhancing the solubility and permeability and augmenting the antifungal activity of voriconazole in the management of fungal keratitis.

Synthesis and potential vasorelaxant effect of a novel ruthenium-based nitro complex

This study aimed to investigate the synthesis and potential vasodilator effect of a novel ruthenium complex, cis-[Ru(bpy)2(2-MIM)(NO2)]PF6 (bpy = 2,2′-bipyridine and 2-MIM = 2-methylimidazole) (FOR711A), containing an imidazole derivative via an in silico molecular docking model using β1 H-NOX (Heme-nitric oxide/oxygen binding) domain proteins of reduced and oxidized soluble guanylate cyclase (sGC). In addition, pharmacokinetic properties in the human organism were predicted through computational simulations and the potential for acute irritation of FOR711A was also investigated in vitro using the hen's egg chorioallantoic membrane (HET-CAM). FOR711A interacted with sites of the β1 H-NOX domain of reduced and oxidized sGC, demonstrating shorter bond distances to several residues and negative values of total energy. The predictive study revealed molar refractivity (RM): 127.65; Log Po/w = 1.29; topological polar surface area (TPSA): 86.26 Å2; molar mass (MM) = 541.55 g/mol; low solubility, high unsaturation index, high gastrointestinal absorption; toxicity class 4; failure to cross the blood-brain barrier and to react with cytochrome P450 (CYP) enzymes CYP1A2, CYP2C19, CYP2C9, CYP2D6 and CYP3A4. After the HET-CAM assay, the FOR711A complex was classified as non-irritant (N.I.) and its vasodilator effect was confirmed through greater evidence of blood vessels after the administration and ending of the observation period of 5 min. These results suggest that FOR711A presented a potential stimulator/activator effect of sGC via NO/sGC/cGMP. However, results indicate it needs a vehicle for oral administration.

Tolerability profile of topical cannabidiol and palmitoylethanolamide: a compilation of single-centre randomized evaluator-blinded clinical and in vitro studies in normal skin.

An increasing number of studies have investigated the adverse effect profile of oral cannabinoids; however, few studies have provided sufficient data on the tolerability of topical cannabinoids in human participants. To assess the tolerability profile of several commercial topical formulations containing cannabidiol (CBD) and palmitoylethanolamide (PEA) on the skin of healthy human participants. Three human clinical trials and one in vitro study were conducted. The potential for skin irritation, sensitization and phototoxicity of several products, were assessed via patch testing on healthy human skin. The products assessed included two formulations containing CBD and PEA, one containing hemp seed oil and four concentrations of CBD alone. Ocular toxicity was tested using a traditional hen's egg chorioallantoic membrane model with three CBD, PEA and hemp seed oil formulations. There was no irritation or sensitization of the products evident via patch testing on healthy participants. Additionally, mild phototoxicity of a hemp seed oil product was found at the 48-h time point compared with the negative control. The in vitro experiment demonstrated comparable effects of cannabinoid products with historically nonirritating products. These specific formulations of CBD- and PEA-containing products are nonirritating and nonsensitizing in healthy adults, and further encourage similar research assessing their long-term safety and efficacy in human participants with dermatological diseases. There are some limitations to the study: (i) external validity may be limited as formulations from a single manufacturer were used for this study, while vast heterogeneity exists across unregulated, commercial CBD products on the market; and (ii) products were assessed only on normal, nondiseased human skin, and therefore extrapolation to those with dermatological diseases cannot be assumed.

Preparation of Natural Composite Microcapsules Containing Orchid Black Currant Fragrance and its Sustained-Release Properties on Hair Bundle

In this paper, we developed an environmentally friendly microcapsules with natural materials to replace plastic microbeads used in personal care products and studied its functionality. The microcapsules with sustained release properties of orchid black currant fragrance were prepared by microemulsion method and using maltodextrin and resistant starch as wall materials. Fourier transform infrared spectroscopy (FTIR) spectra and thermogravimetric analysis (TG) indicated the fragrance was encapsulated into microcapsules successfully, and the encapsulation ratio of microcapsule particles was 38%. Scanning electron microscopy (SEM) and dynamic light scattering laser particle size analyzer (DLS) results showed the microcapsule particles were spherical, and the particle size ranged from 1.2 to 2.2 μm with the average particle size of 1.7 μm, which can stably attach to the hair and have good slow-release properties. Adding the microcapsules to the hair conditioner and treating the real hair bundle through electrostatic adsorption, the application efficacy, sustained-release and irritating effects of the microcapsules have been evaluated. The aroma retention rate of microencapsulated fragrance treated hair is much higher at 5, 7 and 21 days than that of unencapsulated fragrance treated one, and the sensory evaluation of the aroma intensity of the hair bundles treated with encapsulated fragrances vs. fragrances showed similar results to those obtained by electronic nose test. Meanwhile, the microcapsules’ irritation on corneal have been assessed by the hen's egg chorioallantoic membrane (HET-CAM) test. The test results indicated that the prepared fragrance microcapsules have no irritating effect to human cornea, and the microcapsules are safe, green and of environmental friendliness.

Citrus aurantiifolia (Christm) Swingle: Biological potential and safety profile of essential oils from leaves and fruit peels

This study aimed to evaluate the chemical composition, irritant potential, and in vitro antioxidant and cytotoxic activities of the essential oils (EO) from leaves and fruit peels of C. aurantiifolia cultivated in southern Brazil. Analyses of chemical composition revealed the presence of 9 compounds in EO fruits (EOF), yielding 93.50% R-(+)-limonene and 20 compounds in the leaf EO (EOL), yielding 45.70% R-(+)-limonene. In vitro antioxidant analyses showed the EOL had excellent antioxidant potential, and 10-fold superior to the EOF. In vitro cytotoxic capacity was evaluated for HT-29, MDA-MB 231, and HepG2 cells. Both EO showed better response in the HT-29 cell line. Finally, the irritant potential was evaluated using Hen's egg chorioallantoic membrane test, in which no effect was observed after dilution of EO suggesting the effects are dose dependent. From the experimental results, the EOL, yielded better results, likely due to the greater chemical complexity of its biological matrix.

Intravitreal ketamine promotes neuroprotection in rat eyes after experimental ischemia

Retinal ischemia, one of the most common cause of visual loss, is associated with blood flow inadequacy and subsequent tissue injury. In this setting, some treatments that can counteract glutamate increase, arouse interest in ischemic pathogenesis. Ketamine, a potent N-methyl-d-aspartate (NMDA) receptor antagonist, provides a neuroprotective pathway via decreasing the excitotoxicity triggered by excess glutamatergic. Thus, the goal of this study was to evaluate the safety of intravitreal use of ketamine and their potential protective effects on retinal cells in retinal ischemia/reperfusion model. Initially, ketamine toxicity was evaluated by cytotoxicity assay and Hen's egg chorioallantoic membrane (HET-CAM) method. Afterward, some ketamine concentrations were tested in rat's eyes to verify the safety of the intravitreal use. To investigate the neuroprotective effect on retinal, a single intravitreal injection of ketamine in concentrations of 0.059 mmol.L−1 and 0.118 mmol.L−1 was performed one day before the retinal injury by ischemia/reperfusion model. After 7 and 15 days, the retina activity was evaluated by electroretinogram (ERG) records and, lastly, by morphological analyzes. Cytotoxicity assay reveals that the maximum ketamine concentration that could reach retinal pigmented epithelium cells is 0.353 mmol.L−1. HET-CAM assay showed that concentrations above 0.237 mmol.L−1 are irritants to the eye. Thus, Ketamine in concentrations of 0.0237 mmol.L−1, 0.118 mmol.L-1, and 0.059 mmol.L-1 were selected for in vivo toxicity test. ERG records reveal a tendency of b-wave amplitude to decrease as the luminous intensity increased, in the group receiving ketamine at 0.237 mmol.L−1. Therefore, ketamine in concentrations at 0.059 mmol.L−1 and 0.118 mmol.L-1 were chosen for the following tests. In the ischemia retinal degeneration model, pretreatment with ketamine was capable to promote a recovery of retinal electrophysiological function minimizing the ischemic effects. In histological analysis, the groups that received intravitreal ketamine showed a number of retinal cells significantly higher than the vehicle group. In TUNEL assay a reduction on TUNEL-positive cells was observed in all the layers for both concentrations which allow to affirm that ketamine contributes to reducing cell death in the retina. Transmission electron microscopy (TEM) reaffirms this finding. Ketamine intravitreal pretreatment showed reduced ultrastructural changes. Our findings demonstrate that ketamine is safe for intravitreal use in doses up to 0.118 mmol.L−1. They seem to be particularly efficient to protect the retina from ischemic injury.

Doe guided chitosan based nano-ophthalmic preparation against fungal keratitis

A recent upsurge in ocular infections is a pointer towards an enhanced prevalence of ophthalmic disorders, posing challenges for researchers globally. The caveats of conventional therapeutics demand a specifically designed Ocular Drug Delivery System (ODDS) and hence the primary objective of the present work is a fabrication of a Design of Expert (DoE) guided Chitosan based Antifungal loaded Nanoparticles (CANs), as a locoregionally effective eye formulation/drops for fungal keratitis therapy. The purported formulation was prepared using High-Pressure Homogenisation technique and was critically characterized on various parameters to check their suitability as an ODDS. The optimized formulation has fruitfully yielded irregularly spherical particles in up to a size of 200 nm and a Poly-dispersity Index (PDI) of less than 0.2 nm. The optimised formulation has further showcased a high mucoadhesion capacity thereby, suggesting the greater retention of CANs on the mucous membrane of an eye with low ocular irritancy as highlighted using HET-CAM (Hen's Egg Chorioallantoic Membrane) test. The in-vitro drug release study across a dialysis membrane has indicated both diffusion as swelling controlled release pattern for an optimized formulation. The ex-vivo corneal permeation study on goat corneal tissues using a Franz-Diffusion cell also has indicated a steady increase in the permeation of drug with time for an optimized formulation. Further, the optimised formulation was found to be non-irritant and ocular safe in ex-vivo transcorneal toxicity studies on goat corneal tissues. In conclusion, the designing of a proposed nanosized formulation, offers a promising step towards the management of external ocular diseases with a positive attributes of high patient compliance, controlled drug delivery, prolonged drug precorneal residence time and enhanced ocular bioavailability. The optimized CANs could be further exploited as a potential ODDS.

Dual Targeting of VEGFR2 and C-Met Kinases via the Design and Synthesis of Substituted 3-(Triazolo-thiadiazin-3-yl)indolin-2-one Derivatives as Angiogenesis Inhibitors.

The vascular endothelial growth factor receptor 2 (VEGFR2) and c-mesenchymal epithelial transition factor (c-Met) are members of receptor tyrosine kinases which have a crucial role in the process of angiogenesis. Isatin moiety is a versatile group that is shared in many compounds targeting both c-Met and VEGFR2 kinases. In this study, we designed and synthesized different derivatives of substituted 3-(triazolo-thiadiazin-3-yl)indolin-2-one derivatives (6a–y) as dual inhibitors for c-Met and VEGFR2 enzymes. Eight compounds 6a, 6b, 6e, 6l, 6n, 6r, 6v, and 6y were assessed for their anticancer activities against a panel of 58 cancer cell lines according to the US-NCI protocol. Compound 6b revealed the most effective antiproliferative potency (GI %), with broad-spectrum activity against different subpanels of the most NCI 58 tumor cell lines. An in vivo hen’s egg-chorioallantoic membrane (HET-CAM) angiogenic study was carried out for 21 compounds 6a, b, d, f, h, i, k–o, t, and 6x to check their mortality and toxicity. At 100 μM concentration, all compounds produced 100% mortality of the chick embryos. At 40 μM concentration, 13 compounds did not exhibit any detectable mortality (nontoxic) and revealed a potent antiangiogenic effect. Seven compounds 6b, 6d, 6f, 6n, 6o, 6t, and 6x significantly decreased the number of blood vessels, and compound 6b was the most effective antiangiogenic agent comparable to dexamethasone. Molecular docking studies were conducted for compound 6b to investigate its mode of interaction within the binding site of both c-Met and VEGFR2 kinases.

Formulation of Chitosan Polymeric Vesicles of Ciprofloxacin for Ocular Delivery: Box-Behnken Optimization, In Vitro Characterization, HET-CAM Irritation, and Antimicrobial Assessment.

Ciprofloxacin is a commonly used antibiotic for treatment of bacterial conjunctivitis. The conventional eye drop dosage form is the widely used mode of treatment, but it has low corneal residence time. This drawback can be overcome by developing a bioadhesive noisome system (chitosan-coated) for enhanced corneal residence time. The niosomes were prepared by thin-film hydration technique and optimized by using Box-Behnken statistical design software. Cholesterol (A), Span 60 (B), and sonication time (C) were selected as independent variables, whereas vesicle size (Y1 in nm), entrapment efficiency (Y2 in %), and drug release (Y3 in %) were chosen as dependent variables. The vesicle size, entrapment efficiency, and drug release of optimized CIP niosomes (CIP-NSMopt) were found to be 180.34 ± 5.13nm, 78.32 ± 4.49%, and 82.87 ± 4.01% (in 12h), respectively. Further CIP-NSMopt was coated with different chitosan concentrations (0.1 to 0.3%) to enhance mucoadhesion. Finally, optimized chitosan-coated niosomes (chitosomes; CIP-CHTopt) showed a vesicle size of 210.65 ± 2.76nm, zeta potential of - 35.17 ± 2.25Mv, and PDI of 0.221. CIP-CHTopt exhibited sustained release profile (75.31% in 12h) with the Korsmeyer-Peppas kinetic model (R2 = 0.980). The permeation study showed 1.79-fold enhancements in corneal permeation compared with marketed CIP eye drop. The hen's egg chorioallantoic membrane (HET-CAM) study showed 0 scores (no irritation), and it was further confirmed by corneal hydration and histopathology study. The antimicrobial study exhibited a significant high zone (P < 0.05) of inhibition against tested organism. Our findings demonstrated that chitosan-coated niosomes are a promising drug carrier to enhance corneal contact time and treatment of bacterial conjunctivitis.

Ocular Tolerability and Efficacy of Ebastine Colloidal Formulation in Allergic Conjunctivitis

Allergic conjunctivitis (AC), defined by ocular itching, hyperemia, lacrimation and edema, impairs the quality of life across the globe. Ebastine is available as an oral antihistamine formula, such as tablets and syrup, for allergic disorders. Topical antihistamines are preferred over oral agents since their direct application at the site of action results in rapid onset and superior efficacy with less systemic side effects. The objective of the present work was to evaluate the antiallergic potential of optimized ebastine (1% w/v) colloidal ocular formulation by performing in vitro study like hen's egg chorioallantoic membrane test (HET-CAM) for tolerability and in vivo efficacy study in ovalbumin (OA)-induced allergic conjunctivitis (AC) with acute ocular irritation study. Eye scratching behavior and edema were evaluated after topical antigen challenge. Edema was scored at periodic interval after the instillation of ovalbumin followed by histopathology. The results showed that ebastine (1% w/v) colloidal ocular formulation was effective in inhibiting symptoms of eye inflammation induced by ovalbumin. Further, the study indicated that said formulation has a quick onset and the duration of effect sufficient to provide relief from symptoms for 24 hr. Ocular irritation by HET-CAM assay showed that the developed formulation does not cause any irritation to the blood vessels. Acute ocular irritation test was performed using rabbits and results showed that developed formulation was non-irritant to the eye. The present study revealed that the ocular ebastine formulation could offer a novel therapeutic opportunity against IgE-mediated allergic conjunctivitis.

Optimization of menthol-loaded nanocapsules for skin application using the response surface methodology

Menthol is used as a natural coolant in numerous consumer healthcare products. However, low aqueous solubility and high volatility limit its applications. This study aimed to encapsulate menthol in lipid-core nanocapsules by using a nanoprecipitation method and to explore its skin application. Experiments were performed using a Box-Behnken design to investigate the influence of relevant causal parameters (weight proportions of menthol, poly(ε-caprolactone) and poloxamer 188) on responses, including the hydrodynamic diameter, zeta potential and entrapment efficiency, of menthol in the nanocapsules. The optimized nanocapsules with good physicochemical features consisted of 150 mg menthol, 84 mg poly(ε-caprolactone) and 125 mg poloxamer 188. The menthol-loaded nanocapsules were subsequently characterized in terms of physicochemical properties, skin localization and permeation, irritation potential and cytotoxicity. Nile Red-labelled nanocapsules supported rapid ex vivo skin penetration. Hair follicle and trans-epidermal routes played an important role in the rapid percutaneous absorption of menthol. Hen's egg chorioallantoic membrane results and cytotoxicity analysis in HaCaT and human dermal fibroblast cells suggested the safety of topically applied nanocapsules. The developed nanocapsules not only have the potential to enhance the aqueous solubility of menthol and improve the thermal stability but also are an alternative option for cosmetotextiles with fast dermal absorption properties.

Development of Timolol-Loaded Galactosylated Chitosan Nanoparticles and Evaluation of Their Potential for Ocular Drug Delivery

This study was conducted to develop timolol maleate (TM)-loaded galactosylated chitosan (GC) nanoparticles (NPs) (TM-GC-NPs) followed by optimization via a four-level and three-factor Box-Behnken statistical experimental design. The optimized nanoparticles showed a particle size of 213.3 ± 6.83nm with entrapment efficiency of 38.58 ± 1.31% and drug loading of 17.72 ± 0.28%. The NPs were characterized with respect to zeta potential, pH, surface morphology, and differential scanning calorimetry (DSC). The determination of the oil-water partition coefficient demonstrated that the TM-GC-NPs had a high liposolubility at pH 6 as compared to timolol-loaded chitosan nanoparticles (TM-CS-NPs) and commercial TM eye drops. The in vitro release study indicated that TM-GC-NPs had a sustained release effect compared with the commercial TM eye drops. Ocular tolerance was studied by the hen's egg chorioallantoic membrane (HET-CAM) assay and the formulation was non-irritant and could be used for ophthalmic drug delivery. The in vitro transcorneal permeation study and confocal microscopy showed enhanced penetration, and retention in the cornea was achieved with TM-GC-NPs compared with the TM-CS-NPs and TM eye drops. Preocular retention study indicated that the retention of TM-GC-NPs was significantly longer than that of TM eye drops. The in vivo pharmacodynamic study suggested TM-GC-NPs had a better intraocular pressure (IOP) lowering efficacy and a prolonged working time compared to commercial TM eye drops (P ≤ 0.05). The optimized TM-GC-NPs could be prepared successfully promising their use as an ocular delivery system.

Gellan–thioglycolic acid conjugate: Synthesis, characterization and evaluation as mucoadhesive polymer

Gellan–thioglycollic acid conjugate was synthesized with the objective to improve its mucoadhesive properties. Synthesis of conjugate was confirmed by –SH stretch in the Fourier-transform infrared spectra at 2571cm−1. It was found to contain 13.92mM of thiol groups/g of the conjugate. Thiolation of gellan gum was found to slightly increase its degree of crystallinity and decrease its sensitivity to Ca2+-induced gelation. On screening of gellan–thioglycollic acid conjugate for ex-vivo ocular tolerance using hen's egg chorio-allantoic membrane test and for biocompatibility by resazurin assay on Vero-cells, it was found to be non-irritant and biocompatible. Metronidazole gels formulated using gellan thioglycollic acid conjugate as bioadhesive agent showed 1.82-fold higher mucoadhesive strength than the gels formulated using gellan gum. Further, the metronidazole gels containing gellan and gellan–thioglycollic conjugate released the drug following first-order and Higuchi's square-root release kinetics. In conclusion, gellan–thioglycollic acid conjugate is a promising bioadhesive excipient.

Conjunctival and corneal tolerability assessment of ocular naltrexone niosomes and their ingredients on the hen's egg chorioallantoic membrane and excised bovine cornea models

This study aimed at combining the hen's egg test-chorioallantoic membrane (HET-CAM), bovine corneal opacity and permeability (BCOP) test and histological examination of excised corneas to evaluate the conjunctival and corneal toxicity of niosomes and their ingredients. Various surfactant/lipid combinations and concentrations (1–10%, w/v) were investigated for the ocular delivery of an ambitious drug (naltrexone hydrochloride) for treatment of diabetic keratopathy. Four niosomal formulations were investigated and found to be non irritant to the 10 days old HET-CAMs (an acceptable conjunctival model). Only one of the tested ingredients (sodium cholate – CH) showed moderate irritation, however such an effect was diminished when incorporated into niosomes. Corneal opacity and fluorescein permeability scores for the test substances correlated well with the HET-CAM test results. Corneal erosion and stromal thickness were found to be in agreement with the HET-CAM and BCOP results, which discriminated well between moderately and mildly irritant test substances. Corneal histological examination revealed toxicity signs included epithelial erosion, stromal condensation and stromal vacuolisation, which allowed better discrimination between strong and moderate irritants. It is concluded that the prepared niosomes possess good ocular tolerability and minimal ocular tissue irritation. They can be further investigated as ocular delivery systems using appropriate animal models.

Evaluation of Eye Irritation Potential of Aqueous Leaf Extract of Achyranthes aspera by In Vitro and In Vivo Method

The present paper is an attempt to investigate the eye irritation potential of aqueous leaf extract of Achyranthes aspera by in vitro, Hen's Egg Chorioallantoic Membrane Test (HET-CAM) and in vivo acute eye irritation test in rabbits. The irritation score (IS) obtained after treatment of the extract on HET-CAM is 0.07 and that of in rabbits is 0.55, Which does not comes under either category 1 or 2 as per the harmonized integrated classification system. The aqueous extract of Achyranthes aspera showed no eye irritation properties both in vitro and in vivo methods when compared with negative control whereas positive controls showed eye irritation potential.

Physically crosslinked gelatins functionalized with tyrosine moieties do not induce angiogenesis or thrombus formation in the developing vasculature in the avian chorioallantoic membrane

Gelatins functionalized with desaminotyrosine or desaminotyrosyl tyrosine form physically crosslinked polymer networks due to the interactions between the introduced aromatic moeties. In the swollen state, their mechanical properties can be tailored in a range similar to the elasticity of soft tissues. The aim of this study was to evaluate their potential as biomaterials by determining whether these materials - in comparison to plain gelatin - induce bleedings, thrombotic processes, or angiogenesis. These investigations were performed using the hen's egg chorioallantoic membrane (HETCAM) assay. These results indicate that the gelatin-based hydrogels did not possess angiogenic effects and also did not induce bleedings, thrombotic processes or vessel destruction (avascular zones). The biocompatibility of the materials in vitro motivates the exploration of their application as matrix in local drug-release systems with short half-life times (1 hour up to several days).

Efficacy of anise oil, dwarf-pine oil and chamomile oil against thymidine-kinase-positive and thymidine-kinase-negative herpesviruses

Abstract The effect of anise oil, dwarf-pine oil and chamomile oil against different thymidine-kinase-positive (aciclovir-sensitive) and thymidine-kinase-negative (aciclovir-resistant) herpes simplex virus type 1 (HSV-1) strains was examined. Clinical HSV-1 isolates containing frameshift mutations in the thymidine kinase (TK) gene, an insertion or a deletion, yield a non-functional thymidine kinase enzyme resulting in phenotypical resistance against aciclovir. The inhibitory activity of three different essential oils against herpes simplex virus isolates was tested in-vitro using a plaque reduction assay. All essential oils exhibited high levels of antiviral activity against aciclovir-sensitive HSV strain KOS and aciclovir-resistant clinical HSV isolates as well as aciclovir-resistant strain Angelotti. At maximum noncytotoxic concentrations of the plant oils, plaque formation was significantly reduced by 96.6–99.9%, when herpesviruses were preincubated with drugs before attachment to host cells. No significant effect on viral infectivity could be achieved by adding these compounds during the replication phase. These results indicate that anise oil, dwarf-pine oil and chamomile oil affected the virus by interrupting adsorption of herpesviruses and in a different manner than aciclovir, which is effective after attachment inside the infected cells. Thus the investigated essential oils are capable of exerting a direct effect on HSV and might be useful in the treatment of drug-resistant viruses. Chamomile oil did not reveal any irritating potential on hen's egg chorioallantoic membrane, demonstrated the highest selectivity index among the oils tested and was highly active against clinically relevant aciclovir-resistant HSV-1 strains.

In vivo evaluation of the angiogenic effects of the multiblock copolymer PDC using the hen's egg chorioallantoic membrane test

Multiblock copolymers with shape-memory capability attracted tremendous interest as promising candidate materials for smart, degradable implants. In the present study the hen's egg-chorioallantoic membrane test (HET-CAM test) was used to investigate the angiogenic properties of a thermoplastic, biodegradable multiblock copolymer PDC composed of poly(p-dioxanone) hard segments (PPDO) and crystallizable poly(ε-caprolactone) switching segments (PCL), whereby PPDO and PCL homopolymers were investigated as controls. According to our HET-CAM test data, only PDC induced significant microvessel attraction and formation in the contact area of the test specimen after 48 hours of incubation showing newly formed blood vessels along the outer edge of the material. In contrast, no newly formed blood vessels were observed around the PPDO or PCL specimen after the same incubation period. These in vivo results indicate that the multiblock copolymer PDC possibly possesses an angiogenic effect and it can induce blood vessel formation in its direct vicinity when it is implanted in vivo.