Fabrication of architectonic nanosponges for intraocular delivery of Brinzolamide: An insight into QbD driven optimization, in vitro characterization, and pharmacodynamics

The intricate structure of the eye poses difficulties in drug targeting, which can be surmounted with the help of nanoformulation strategies. With this view, brinzolamide nanosponges (BNS) were prepared using the emulsion solvent evaporation technique and optimized via Box-Behnken statistical design. The optimized BNS were further incorporated into a poloxamer 407 in situ gel (BNS-ISG) and evaluated. The optimized BNS showed spherical morphology, entrapment efficiency of 83.12 ± 1.2 % with particle size of 114 ± 2.32 nm and PDI of 0.11 ± 0.01. The optimized BNS-ISG exhibited a pseudoplastic behavior and depicted a gelling temperature and gelation time of 35 ± 0.5 °C and 10 ± 2 s respectively. In-vitro release and ex- vivo permeation studies of BNS-ISG demonstrated a sustained release pattern as compared to Brinzox®. Additionally, the HET-CAM and in vitro cytotoxicity studies (using SIRC cell line) ensured that the formulation was non-irritant and nontoxic for ophthalmic delivery. The in vivo pharmacodynamic study using rabbit model depicted that BNS-ISG treatment significantly lowers the intra ocular pressure for prolonged period of time when compared with Brinzox®. In conclusion, the BNS-ISG is an efficient and scalable drug delivery system with significant potential as the targeted therapy of posterior segment eye diseases.

A Novel Phytotherapy Application: Preparation, Characterization, Antioxidant Activities and Determination of Anti-inflammatory Effects by In vivo HET-CAM Assay of Chitosan-based DDSs Containing Endemic Helichrysum pamphylicum P.H. Davis & Kupicha Methanolic Extract

BACKGROUND

Numerous pharmaceutical applications for chitosan, a polysaccharide made from the shells of crustaceans by deacetylating chitin that occurs naturally, are currently being researched. Chitosan, a natural polymer, is successfully used to prepare many drug-carrier systems, such as gel, film, nanoparticle, and wound dressing.

OBJECTIVE

Preparing chitosan gels without external crosslinkers is less toxic and environmentally friendly.

METHODS

Chitosan-based gels containing Helichrysum pamphylicum P.H. Davis & Kupicha methanolic extract (HP) were produced successfully.

RESULTS

The F9-HP coded gel prepared with high molecular weight chitosan was chosen as the optimum formulation in terms of pH and rheological properties. The amount of HP was found to be 98.83% ± 0.19 in the F9-HP coded formulation. The HP release from the F9-HP coded formula was determined to be slower and 9 hours prolonged release compared to pure HP. It was determined that HP release from F9-HP coded formulation with the DDSolver program was by anomalous (non-fickian) diffusion mechanism. The F9-HP coded formulation significantly showed DPPH free radical scavenger, ABTS•+ cation decolorizing and metal chelating antioxidant activity while weakly reducing antioxidant potential. According to the HET-CAM scores, strong anti-inflammatory activity was obtained by the F9-HP coded gel at a dose of 20 μg.embryo-1 (p<0.05 compared with SDS).

CONCLUSION

In conclusion, it can be said that chitosan-based gels containing HP, which can be used in both antioxidant and anti-inflammatory treatment, were successfully formulated and characterized.

Determination of the Toxicity Preferences of Ocular Drug Delivery System by Comparing Two Different Toxicity Bioassays

Ocular drug delivery methods are highly favored for boosting bioavailability, patient compliance, and lower adverse effects and dose frequency. In addition to preventing adverse effects from the active ingredient, the parts of drug delivery systems must be nontoxic and nonallergic as well. Mitochondrial toxicity test (MTT) and Hen's egg chorioallantois membrane (HET-CAM) assay are the most often utilized tests based on this dilemma. The toxicity of loteprednol etabonate loaded solid lipid nanoparticles, lipid nanostructured carriers, and nanoemulsion were compared. Oleic acid, Precirol®ATO5, and Pluronic® F68 were used in the preparation. Their toxicities were evaluated by using two different toxicity tests (MTT and HET-CAM). The results suggest that there are no significant differences between the HET-CAM and MTT assays. It is noteworthy that the HET-CAM assay offers a more cost-effective and environmentally friendly alternative to the MTT assay, as it does not require cell culture and generates less toxic waste. This information may be useful to consider when selecting between the two assays.

Influence of Benincasa hispida Peel Extracts on Antioxidant and Anti-Aging Activities, including Molecular Docking Simulation

Benincasa hispida peel, a type of postconsumer waste, is considered a source of beneficial phytochemicals. Therefore, it was subjected to investigation for biological activities in this study. B. hispida peel was extracted using 95% v/v, 50% v/v ethanol and water. The obtained extracts were B95, B50 and BW. B95 had a high flavonoid content (212.88 ± 4.73 mg QE/g extract) and phenolic content (131.52 ± 0.38 mg GAE/g extract) and possessed high antioxidant activities as confirmed by DPPH, ABTS and lipid peroxidation inhibition assays. Moreover, B95 showed inhibitory effects against collagenase and hyaluronidase with values of 41.68 ± 0.92% and 29.17 ± 0.66%, which related to anti-aging activities. Via the HPLC analysis, one of the potential compounds found in B95 was rutin. Molecular docking has provided an understanding of the molecular mechanisms underlying the interaction of extracts with collagenase and hyaluronidase. All extracts were not toxic to fibroblast cells and did not irritate the hen's egg chorioallantoic membrane, which indicated its safe use. In conclusion, B. hispida peel extracts are promising potential candidates for further use as antioxidant and anti-aging agents in the food and cosmetic industries.

Exploring Penetration Ability of Carbonic Anhydrase Inhibitor-Loaded Ultradeformable Bilosome for Effective Ocular Application

Brinzolamide is an effective carbonic anhydrase inhibitor widely used in glaucoma therapy but limits its application due to inadequate aqueous solubility and permeability. The aim of the present research work is the development and characterization of brinzolamide-loaded ultradeformable bilosomes to enhance the corneal permeation of the drug. These ultradeformable bilosomes were prepared by ethanol injection method and evaluated for physicochemical properties, particle size, morphology, drug release, ultra-deformability, corneal permeation, and irritation potential. The optimized formulation exhibited an average particle size of 205.4 ± 2.04 nm with mono-dispersity (0.109 ± 0.002) and showed entrapment efficiency of 75.02 ± 0.017%, deformability index of 3.91, and release the drug in a sustained manner. The brinzolamide-loaded ultradeformable bilosomes released 76.29 ± 3.77% of the drug in 10 h that is 2.25 times higher than the free drug solution. The bilosomes were found non-irritant to eyes with a potential irritancy score of 0 in Hen's egg-chorioallantoic membrane assay. Brinzolamide-loaded ultradeformable bilosomes showed 83.09 ± 5.1% of permeation in 6 h and trans-corneal permeability of 8.78 ± 0.14 cm/h during the ex vivo permeation study. The acquired findings clearly revealed that the brinzolamide-loaded ultradeformable bilosomes show promising output and are useful in glaucoma therapy.

Timolol-loaded ethosomes for ophthalmic delivery: Reduction of high intraocular pressure in vivo

The beta-adrenoceptor blocker timolol maleate (TML) is a commonly used pharmaceutical agent for the management of glaucoma. Conventional eye drops have limitations due to biological or pharmaceutical factors. Therefore, TML-loaded ethosomes have been designed to mitigate these restrictions and give a viable solution for reducing elevated intraocular pressure (IOP). The ethosomes were prepared using the thin film hydration method. Integrating the Box-Behnken experimental strategy, the optimal formulation was identified. The physicochemical characterization studies were performed on the optimal formulation. Then, in vitro release and ex vivo permeation studies were conducted. The irritation assessment was also carried out with Hen's Egg Test-Chorioallantoic Membrane model (HET-CAM), and in vivo evaluation of the IOP lowering effect was also performed on rats. The physicochemical characterization studies demonstrated that the components of the formulation were compatible with each other. The particle size, zeta potential, and encapsulation efficiency (EE%) were found as 88.23 ± 1.25 nm, -28.7 ± 2.03 mV, and 89.73 ± 0.42 %, respectively. The in vitro drug release mechanism was found as Korsmeyer-Peppas kinetics (R²=0.9923). The HET-CAM findings verified the formulation's eligibility for biological applications. The IOP measurements revealed no statistical difference (p>0.05) between the once-a-day application of the optimal formulation and the three-times-a-day application of the conventional eye drop. A similar pharmacological response was observed at lowered application frequencies. Therefore, it was concluded that the novel TML-loaded ethosomes could be a safe and efficient alternative for glaucoma treatment.

Investigating the Effectiveness of Difluprednate-Loaded Core-Shell Lipid-Polymeric Hybrid Nanoparticles for Ocular Delivery

Uveitis is a sight-threatening disease that causes inflammation in the uvea; difluprednate (DFB) is the first approved drug molecule for postoperative pain, inflammation, and endogenous uveitis. Complex ocular physiology and structure make it difficult to deliver drugs to the eye. Increased permeation and retention in the layer of the eye are required to improve the bioavailability of ocular drugs. In the current research investigation, DFB-loaded lipid polymer hybrid nanoparticles (LPHNPs) were designed and fabricated to enhance the corneal permeation and sustained release of DFB. A well-established two-step approach was used to fabricate the DFB-LPHNPs, comprising of Poly-Lactic-co-Glycolic Acid (PLGA) core that entrapped the DFB and DFB loaded PLGA NPs covered by lipid shell. The manufacturing parameters were optimized for the preparation of DFB-LPHNPs; the optimal DFB-LPHNPs showed a mean particle size of 117.3±2.9 nm, suitable for ocular administration and high entrapment efficiency of 92.45 ± 2.17 % with neutral pH (7.18 ±0.02) and isotonic Osmolality (301±3 mOsm/kg). Microscopic examination confirms the core-shell morphological structure of DFB-LPHNPs. The prepared DFB-LPHNPs were extensively characterized using spectroscopic techniques and physicochemical characterization, which confirms the entrapment of the drug and the formation of the DFB-LPHNPs. The confocal laser scanning microscopy studies revealed that Rhodamine B-loaded LPHNPs were penetrated into stromal layers of the cornea in ex-vivo conditions. The DFB-LPHNPs showed a sustained release pattern in simulated tear fluid and 4- folds enhanced permeation of DFB as compared to pure DFB solution. The ex-vivo histopathological studies revealed that DFB-LPHNPs didn't cause any damage or no alteration in the cellular structure of the cornea. Additionally, the results of the HET-CAM assay confirmed that the DFB-LPHNPs were not toxic for ophthalmic administration.

Formulation and Characterization of Epalrestat-Loaded Polysorbate 60 Cationic Niosomes for Ocular Delivery

The aim of this work was to develop niosomes for the ocular delivery of epalrestat, a drug that inhibits the polyol pathway and protects diabetic eyes from damage linked to sorbitol production and accumulation. Cationic niosomes were made using polysorbate 60, cholesterol, and 1,2-di-O-octadecenyl-3-trimethylammonium propane. The niosomes were characterized using dynamic light scattering, zeta-potential, and transmission electron microscopy to determine their size (80 nm; polydispersity index 0.3 to 0.5), charge (-23 to +40 mV), and shape (spherical). The encapsulation efficiency (99.76%) and the release (75% drug release over 20 days) were measured with dialysis. The ocular irritability potential (non-irritating) was measured using the Hen's Egg Test on the Chorioallantoic Membrane model, and the blood glucose levels (on par with positive control) were measured using the gluc-HET model. The toxicity of the niosomes (non-toxic) was monitored using a zebrafish embryo model. Finally, corneal and scleral permeation was assessed with the help of Franz diffusion cells and confirmed with Raman spectroscopy. Niosomal permeation was higher than an unencapsulated drug in the sclera, and accumulation in tissues was confirmed with Raman. The prepared niosomes show promise to encapsulate and carry epalrestat through the eye to meet the need for controlled drug systems to treat the diabetic eye.

In vitro eye irritation testing models may play pivotal role in effort to pursue mild baby cleansers

In recent years, mild baby cleansers have experienced ever-growing demand from caregivers. In the meantime, formulation developers are in practical need for a method(s) to screen mild formulations. In the present study, we aim to repurpose the HET-CAM and SkinEthic™ models to further classify in vivo nonirritant baby cleansing formulations into mild and less mild categories. Both methods were modified to best describe the samples' irritation potential. The results showed that both models successfully classified the formulations into mild and less mild categories according to our customized criteria. For the HET-CAM, the medians of mean irritation scores (IS) were 3.0 for mild formulations (with 0 ≤ mean IS ≤4.5), and 5.0 for less mild formulations (with mean IS values all equaled 5), respectively. And for the SkinEthic™ model, the median relative viabilities were 69.46% for less mild formulations (with 46.80% ≤ mean relative viability ≤84.76%), and 99.96% for mild formulations (with 90.57% ≤ mean relative viability ≤124.58%). Thirty out of 35 formulations were predicted consistently between the HET-CAM and SkinEthic™ model. Statistical analysis of the agreement between predictions made by the two models demonstrated substantial agreement with a Cohen's kappa coefficient of 0.713 (P < 0.001). We conclude that the HET-CAM and SkinEthic™ models are promising in vitro alternatives for screening mild formulations.

Gas Flow Shaping via Novel Modular Nozzle System (MoNoS) Augments kINPen-Mediated Toxicity and Immunogenicity in Tumor Organoids

Medical gas plasma is an experimental technology for anticancer therapy. Here, partial gas ionization yielded reactive oxygen and nitrogen species, placing the technique at the heart of applied redox biomedicine. Especially with the gas plasma jet kINPen, anti-tumor efficacy was demonstrated. This study aimed to examine the potential of using passive flow shaping to enhance the medical benefits of atmospheric plasma jets (APPJ). We used an in-house developed, proprietary Modular Nozzle System (MoNoS; patent-pending) to modify the flow properties of a kINPen. MoNoS increased the nominal plasma jet-derived reactive species deposition area and stabilized the air-plasma ratio within the active plasma zone while shielding it from external flow disturbances or gas impurities. At modest flow rates, dynamic pressure reduction (DPR) adapters did not augment reactive species deposition in liquids or tumor cell killing. However, MoNoS operated at kINPen standard argon fluxes significantly improved cancer organoid growth reduction and increased tumor immunogenicity, as seen by elevated calreticulin and heat-shock protein expression, along with a significantly spurred cytokine secretion profile. Moreover, the safe application of MoNoS gas plasma jet adapters was confirmed by their similar-to-superior safety profiles assessed in the hen's egg chorioallantoic membrane (HET-CAM) coagulation and scar formation irritation assay.

Development of Guar Gum Hydrogel Containing Sesamol-Loaded Nanocapsules Designed for Irritant Contact Dermatitis Treatment Induced by Croton Oil Application

Irritant contact dermatitis is usually treated with corticosteroids, which cause expressive adverse effects. Sesamol is a phenolic compound with anti-inflammatory and antioxidant properties. This study was designed to evaluate a hydrogel containing sesamol-loaded ethylcellulose nanocapsules for the treatment of irritant contact dermatitis. The nanocapsules presented a size in the nanometric range, a negative zeta potential, a sesamol content close to the theoretical value (1 mg/mL), and a 65% encapsulation efficiency. Nanoencapsulation protected sesamol against UVC-induced degradation and increased the scavenging activity assessed by ABTS and DPPH radicals. The hydrogels were prepared by thickening the nanocapsule suspensions with guar gum (2.5%). The hydrogels maintained the nanometric size of the nanocapsules and a sesamol content of approximately 1 mg/g. The HET-CAM assay classified the hydrogels as nonirritating. The in vitro release of the hydrogel containing sesamol in the nanoencapsulated form demonstrated an initial burst effect followed by a prolonged sesamol release and a lower skin permeation in comparison with the hydrogel containing free sesamol. In addition, it exhibited the best anti-inflammatory effect in the irritant contact dermatitis model induced by croton oil, reducing ear edema and inflammatory cells infiltration, similar to dexamethasone (positive control). Therefore, the hydrogel containing sesamol in the nanoencapsulated form seemed to have a therapeutic potential in treating irritant contact dermatitis.

Ketorolac Tromethamine Loaded Nano-Spray Dried Nanoparticles: Preparation, Characterization, Cell Viability, COL1A1 Gene Simulation and Determination of Anti-inflammatory Activity by In vivo HET-CAM Assay

BACKGROUND

Ketorolac tromethamine (KT) is a non-steroidal anti-inflammatory drug from the heteroaryl acetic acid derivatives family. The most widely used new nanotechnological approaches for topical drug delivery are polymeric nanoparticles (NPs).

OBJECTIVE

Successful results have been obtained with low doses in many treatments, such as cancer, antimicrobial, pain, made with nanoparticle formulations of drug active ingredients.

METHODS

NPs were prepared using Nano Spray-Dryer. The cytotoxicity of the optimum formulation in BJ (ATCC® CRL-2522™) human fibroblast cells was determined by the WST- 1 method and the gene activity was elucidated by mRNA isolation and real-time polymerase chain reaction (RT-PCR). The in vivo HET- CAM assay was performed for anti-inflammatory activity.

RESULTS

NPs presented PDI values lower than 0.5, and therefore particle size distribution was decided to be monodisperse. Positive zeta potential values of NPs highlighted the presence of the cationic ammonium group of Eudragit® RS 100. The release rates observed from KT-NP coded formulations after 24 hours were 78.4% ± 2.9, demonstrating extended release from all formulations, relative to pure KT. The lowest concentration of KT-NP increased fibroblast cell proliferation higher than the highest concentration of KT. The 5-fold increased effect of KT-NP formulation on collagen gene expression compared to KT is also related to the enhanced anti-inflammatory effect in line with the in vivo HET-CAM assay results.

CONCLUSION

With the obtained cell viability, gene expression, and HET-CAM results, it has the hope of a successful nano-topical formulation, especially in both wound healing and anti-inflammatory treatment.

Development of Ciprofloxacin-Loaded Bilosomes In-Situ Gel for Ocular Delivery: Optimization, In-Vitro Characterization, Ex-Vivo Permeation, and Antimicrobial Study

Conventional eye drops are most commonly employed topically in the eye for the management of bacterial conjunctivitis. Eye drops have a low corneal residence time and 90−95% of the administered dose is eliminated from the eye by blinking and the nasolacrimal drainage system. This problem can be minimized by formulating a mucoadhesive ocular in-situ gel system that undergoes sol-gel transition upon stimulation by temperature, pH, and ions. The goal of this study was to develop ciprofloxacin (CIP) loaded bilosomes (BLO) in-situ gel for the improvement of therapeutic efficacy. The BLO was prepared by the thin-film hydration method and optimized by the Box−Behnken design. Cholesterol (CHO), surfactant (Span 60), and bile salt (sodium deoxycholate/SDC) were used as formulation factors. The vesicle size (nm) and entrapment efficiency (%) were selected as responses (dependent factors). The optimized CIP-BLO (CIP-BLO-opt) formulation displayed a vesicle size of 182.4 ± 9.2 nm, a polydispersity index of 0.274, a zeta potential of −34,461.51 mV, and an entrapment efficiency of 90.14 ± 1.24%. Both x-ray diffraction and differential scanning calorimetry spectra did not exhibit extensive peaks of CIP in CIP-BLO-opt, revealing that CIP is encapsulated in the BLO matrix. The CIP-BLO-opt formulation was successfully incorporated into an in-situ gel system using a gelling agent, i.e., Carbopol 934P and hydroxyl propyl methyl cellulose (HPMC K100 M). CIP-BLO-opt in-situ gel formulation (CIP-BLO-opt-IG3) was evaluated for gelling capacity, clarity, pH, viscosity, in-vitro CIP release, bio-adhesive, ex-vivo permeation, toxicity, and antimicrobial study. The CIP-BLO-opt-IG3 exhibited satisfactory gelling properties with a viscosity of 145.85 ± 9.48 cP in the gelling state. CIP-BLO-opt-IG3 displayed sustained CIP release (83.87 ± 5.24%) with Korsmeyer−Peppas kinetic as a best-fitted model (R2 = 0.9667). CIP-BLO-opt-IG3 exhibited a 1.16-fold than CIP-IG and a 2.08-fold higher permeability than pure CIP. CIP-BLO-opt-IG3 displayed a significantly greater bio-adhesion property (924.52 ± 12.37 dyne/cm2) than tear film. Further, CIP-BLO-opt-IG3 does not display any toxicity as confirmed by corneal hydration (76.15%), histology, and the HET-CAM test (zero scores). CIP-BLO-opt-IG3 shows significantly higher (p < 0.05) antimicrobial activity against P. aeruginosa and S. aureus than pure CIP. From all these findings, it could be concluded that CIP-BLO-opt-IG3 might be an effective strategy for the increment of corneal residence time and therapeutic activity of CIP.

In Vitro and In Ovo Evaluation of the Potential Hepatoprotective Effect of Metformin

Background and Objectives: Metformin is currently the leading drug of choice for treating type 2 diabetes mellitus, being one of the most widely used drugs worldwide. The beneficial effects of Metformin, however, extend far beyond the reduction of blood glucose. Therefore, this study aimed to evaluate Metformin's effects both in vitro and in ovo. Materials and Methods: Metformin has been tested in five different concentrations in human hepatocytes -HepaRG, in terms of cell viability, morphology, structure and number of nuclei and mitochondria, as well as the effect on cell migration. Through the application of HET-CAM, the biocompatibility and potential anti-irritant, as well as protective effects on the vascular plexus were also assessed. Results: According to the results obtained, Metformin increases cell viability without causing morphological changes to cells, mitochondria, or nuclei. Metformin displayed an anti-irritant activity rather than causing irritation at the level of the vascular plexus. Conclusions: In conclusion, Metformin enhances cell viability and proliferation and, has a protective effect on the vascular plexus. Nonetheless, more studies are required to clarify the mechanism of hepatoprotective effect of metformin.

Comparison of the different protocols of the Hen's Egg Test-Chorioallantoic Membrane (HET-CAM) by evaluating the eye irritation potential of surfactants

The Hen's Egg Test - Chorioallantoic Membrane (HET-CAM) is a valid alternative method used to assess the potential for eye irritation from chemicals. This method is the only one that mimics the conjunctivae of the eye and aims to semi-quantitatively evaluate the irritant potential of a chemical on the chorioallantoic membrane surrounding the chicken embryo in egg by observing the irritation effects on the membrane immediately after the pure or diluted chemical is applied. The purpose of this study was to compare the different protocols of the HET-CAM, the French and German protocols, by evaluating the eye irritation potential of surfactants. The comparison led to the optimization of the French protocol, generating an adapted one, to reduce subjectivity in the test evaluation, ensuring more accurate results and greater quality control. The comparison showed that there are no significant differences between the results obtained in the French and German protocols. HET-CAM is known to overestimate the results and to be able to accurately identify non-irritant products and it is a great candidate to be part of a Bottom-up test strategy. It also can be used in a battery of tests to completely replace rabbits.

Mycofabrication of AgONPs derived from Aspergillus terreus FC36AY1 and its potent antimicrobial, antioxidant, and anti-angiogenesis activities

BACKGROUND

There is an emergency need for the natural therapeutic agents to treat arious life threatening diseases such as cardio- vascular disease, Rheumatoid arthritis and cancer. Among these diseases, cancer is found to be the second life threatening disease; in this view the present study focused to synthesize the silver oxide nanoparticles (AgONPs) from endophytic fungus.

METHODS

The endophytic fungus was isolated from a medicinal tree Aegle marmelos (Vilva tree) and the potential strain was screened through antagonistic activity. The endophytic fungus was identified through microscopic (Lactophenol cotton blue staining and spore morphology in culture media) and Internal Transcribed Spacer (ITS) 1, ITS 4 and 18S rRNA amplification. The endophyte was cultured for the synthesis of AgONPs and the synthesized NPs were characterized through UV- Vis, FT- IR, EDX, XRD and SEM. The synthesized AgONPs were determined for antimicrobial, antioxidant and anti- angiogenic activity.

RESULTS

About 35 pigmented endophytic fungi were isolated, screened for antagonistic activity against 12 pathogens and antioxidant activity through DPPH radical scavenging assay; among the isolates, FC36AY1 explored the highest activity and the strain FC36AY1 was identified as Aspergillus terreus. The AgONPs were synthesized from the strain FC36AY1 and characterized for its confirmation, functional groups, nanostructures with unit cell dimensions, size and shape, presence of elements through UV-Vis spectrophotometry, FT-IR, XRD, SEM with EDX analysis. The myco-generated AgONPs manifested their antimicrobial and antioxidant properties with maximum activity at minimum concentration. Moreover, the inhibition of angiogenesis by the AgONPs in Hen's Egg Test on the Chorio-Allantoic Membrane analysis were tested on the eggs of Chittagong breed evinced at significant bioactivity least concentration at 0.1 µg/mL.

CONCLUSIONS

Thus, the results of this study revealed that the fungal mediated AgONPs can be exploited as potential in biomedical applications.

Achyrocline satureioides (Lam.) DC (Asteraceae) Extract-Loaded Nanoemulsions as a Promising Topical Wound Healing Delivery System: In Vitro Assessments in Human Keratinocytes (HaCaT) and HET-CAM Irritant Potential

Achyrocline satureioides (Lam.) DC Asteraceae extracts (ASEs) have been investigated for the treatment of various skin disorders. This study reports the effects of ASE-loaded nanoemulsions (NE_ASE) on the cellular viability, death by necrosis, and migration of immortalized human keratinocytes (HaCaT cell line), as well as the irritant potential through the hen’s egg chorioallantoic membrane test (HET-CAM). NE_ASE exhibited a polydispersity index above 0.12, with a droplet size of 300 nm, ζ-potential of −40 mV, and content of flavonoids close to 1 mg/mL. No cytotoxicity of the ASE was observed on HaCaT by MTT assay (up to 10 µg/mL). A significant increase of HaCaT viability was observed to NE_ASE (up to 5 μg/mL of flavonoids), compared to treatment with the ASE. The necrosis death evaluation demonstrated that only NE_ASE did not lead to cell death at all the tested concentrations. The scratch assay demonstrated that NE_ASE was able to increase the cell migration at low flavonoid concentrations. Finally, the HET-CAM test proved the non-irritative potential of NE_ASE. Overall, the results indicate the potential of the proposed formulations for topical use in wound healing, in view of their promising effects on proliferation and migration in keratinocytes, combined with an indication of the absence of cytotoxicity and non-irritating potential.

Comparison of Quantification of Target-Specific Accumulation of [18F]F-siPSMA-14 in the HET-CAM Model and in Mice Using PET/MRI

Simple Summary

Animal studies are essential for the development of new radiopharmaceuticals to determine specific accumulation and biodistribution. Alternative models, such as the HET-CAM model, offer the possibility of reducing animal experiments in accordance with the 3Rs principles. Accurate quantification of tumor accumulation of a PSMA-specific ligand in the HET-CAM model and comparison with corresponding animal experiments was performed using the imaging modalities PET and MRI. It was demonstrated that the HET-CAM model leads to comparable results and is suitable as an alternative to animal experiments for the initial assessment of target-specific binding of novel radiopharmaceuticals. However, as evaluation of biodistribution in ovo is still limited, further animal experiments with promising compounds are mandatory.

Abstract

Assessment of biodistribution and specific tumor accumulation is essential for the development of new radiopharmaceuticals and requires animal experiments. The HET-CAM (hens-egg test—chorioallantoic membrane) model can be used in combination with the non-invasive imaging modalities PET and MRI for pre-selection during radiopharmaceutical development to reduce the number of animal experiments required. Critical to the acceptance of this model is the demonstration of the quantifiability and reproducibility of these data compared to the standard animal model. Tumor accumulation and biodistribution of the PSMA-specific radiotracer [¹⁸F]F-siPSMA-14 was analyzed in the chick embryo and in an immunodeficient mouse model. Evaluation was based on MRI and PET data in both models. γ-counter measurements and histopathological analyses complemented these data. PSMA-specific accumulation of [¹⁸F]F-siPSMA-14 was successfully demonstrated in the HET-CAM model, similar to the results obtained by mouse model studies. The combination of MR and PET imaging allowed precise quantification of peptide accumulation, initial assessment of biodistribution, and accurate determination of tumor volume. Thus, the use of the HET-CAM model is suitable for the pre-selection of new radiopharmaceuticals and potentially reduces animal testing in line with the 3Rs principles of animal welfare.

[Rose-scented geranium essential oil from Algeria (Pelargonium graveolens L'Hérit.): Assessment of antioxidant, anti-inflammatory and anticancer properties against different metastatic cancer cell lines]

INTRODUCTION

The study of natural products is one of the strategies implemented for the discovery of new compounds that can be used in cancer therapy. Aromatic herbs and medicinal plants found in Algeria and their anti-angiogenesis and cytotoxic potentials against cancer have not been much explored.

OBJECTIVES

Our work aimed to evaluate the antioxidant, anti-inflammatory and anticancer properties of the essential oil (EO) extracted from rose-scented geranium (Pelargonium graveolens) and its major (citronellol) and characteristic (linalool) constituents.

RESULTS

The chemical composition of EO was determined with chromatographic analysis and revealed the presence of citronellol as the major compound (25.84%). A strong chelating power of terpene alcohols (IC50 = 1.58 ± 0.23 mg/mL for citronellol) was found, with a significant difference (p < 0.05) compared with the standard antioxidants used (L-ascorbic acid and butylated hydroxyanisole). The EO is distinguished by an interesting anti-inflammatory effect with the lowest IC₅₀ (4.63 ± 0.3 mg/mL), and it constitutes a good stabilizer of the erythrocyte membrane. Citronellol also exhibited the best anti-inflammatory effect (IC50 = 0.74 ± 0.09 mg/mL). We also assessed the anticancer effect of EO on two main pathways involved in cancer development, angiogenesis and cell proliferation, using in ovo bioassays with a chorio-allantoic membrane (CAM) of chicken eggs and in vitro assays of its cytotoxicity on different metastatic breast cancer (MDA-MB-231), gastric (AGS) and melanoma (MV3) cell lines. In the CAM model, the density of micro-vessels is 75 ± 10 in the group supplemented with EO compared to 140 ± 9 for the control group (b-FGF). In addition, the EO significantly reduced the number of newly formed vessels. The cytotoxicity was evaluated using the cell proliferation inhibition method and cell viability was measured using the MTT test. Results revealed that the treatment of cancer lines with different concentrations of EO reduces the rate of cell viability in a dose-dependent manner. EO showed the greatest cytotoxicity on the AGS line with an inhibition rate of 92.87 ± 0.13% at the highest dose (4 µL/mL), followed by the MV3 line (88.76 ± 0.96%). Conclusion and Prospects: Data demonstrated that rose-scented geranium EO has an anti-tumor potential on metastatic cancer cell lines. It is distinguished by its anti-proliferative, anti-angiogenic, and anti-inflammatory activities. Medicinal plants might contain new molecules, with new structures, which could become lead candidate among future anticancer drugs.

Studying the ophthalmic toxicity potential of developed ketoconazole loaded nanoemulsion in situ gel formulation for ophthalmic administration

Ocular fungal infections are one of the essential reasons for vision loss, especially in developing countries for tropical regions. Ketoconazole (KZ), a broad-spectrum antifungal drug, is a lipophilic compound and practically insoluble in water. Since topical ophthalmic drug delivery confronts low bioavailability, an in situ gel formulation is designed to improve the residence time and consequently the bioavailability. Safety of the developed formulation as a carrier for ophthalmic drug delivery was measured using three different methods: MTT assay for measuring cell viability in which the human retinal pigmentation epithelial cells (RPE) were used, HET-CAM as a borderline method between in vivo and in vitro techniques for investigating the irritation potential of the chosen formulation which was done by adding formulation directly on the CAM surface and visually monitoring the vessels in terms of irritation reactions, and finally the modified Draize test for evaluating tolerability of the selected formulation on eyes. According to our results from the MTT test, cell viability for KZ-NE in situ gel formulation at 0.1% concentration was acceptable. The results obtained from the HET-CAM investigation didn't show any sign of vessel injury on the CAM surface for prepared formulation. Additionally, during 24 hours, the developed formulation was tolerable by rabbit eyes. Regarding our results, KZ-NE in situ gel formulation was non-irritant and non-toxic and can be well-tolerated and presented as an applicable vehicle for ophthalmic delivery of the anti-fungal drug.

Ocular toxicity assessment of nanoemulsion in-situ gel formulation of fluconazole

PURPOSE

Fluconazole is an effective anti-fungal drug. Due to the limitations of fluconazole, such as poor water solubility and consequently low ocular bioavailability, an optimized fluconazole nanoemulsion in-situ gel formulation (temperature-sensitive) was developed.

METHODS AND MATERIALS

To verify formulation's safety for ophthalmic use, preparation was tested for potential ocular toxicity using a cell viability assay on retinal cells. The hen's egg test-chorioallantoic membrane (HET-CAM), as a borderline test between in vivo and in vitro techniques, was chosen for investigating the irritation potential of the formulation. HET-CAM test was done by adding the formulation directly to the CAM surface and monitoring the vessels visually in terms of irritation reactions. Eye tolerance was determined using the modified Draize test.

RESULTS

Viability assay on retinal cells displayed that fluconazole nanoemulsion in-situ gel formulation was non-toxic and can be safely used in the eye at concentrations of 0.1% and 0.5%. HET-CAM and Draize tests revealed that optimized formulation of fluconazole did not result in any irritation and was considered non-irritant and well-tolerated for ocular use.

CONCLUSION

Regarding to the findings of the three mentioned methods, fluconazole nanoemulsion in-situ gel formulation is harmless and as a proper and safe alternative, can be considered for ocular delivery of fluconazole in the future.

Application of in vitro methods to evaluate the safety of baby care products

Draize rabbit eye irritation and skin irritation tests are widely used in the chemical industry as traditional methods to evaluate the safety of cosmetics. However, great differences among laboratories have caused great doubt in the industry. In addition, with vigorous development of the global animal protection movement, developed countries have launched the "3R" campaign, and various kinds of in vitro alternative methods have emerged. Hen's egg test on the chorioallantoic membrane (HET-CAM), which is similar to the structure of the human cornea and has a clear and complete vascular system, is based on the characteristics of the chorioallantoic membrane (CAM) in mid-term SPF egg embryos. The reconstructed human epidermis (EpiSkin®) is composed of normal human keratinocytes that are histologically similar to human epidermises seen in vivo, and it is cultured on a collagen matrix. Similar to EpiSkin®, Human Corneal Epithelium (SkinEthic™) is another reconstructed 3D human-corneal structure that is an alternative to the traditional eye irritation test. Three in vitro methods were conducted to evaluate the safety of 12 baby care products, which included the most common types. In addition, a consumer research study was also carried out for two weeks to evaluate the safety. The results of the reconstructed human epidermis model, human corneal epithelium model and consumer research showed that no irritation was found in any test products; however, HET-CAM tests showed positive results.

Alternative model organisms for toxicological fingerprinting of relevant parameters in food and nutrition

In the field of (food) toxicology, there is a strong trend of replacing animal trials with alternative methods for the assessment of adverse health effects in humans. The replacement of animal trials is not only driven by ethical concerns but also by the number of potential testing substances (food additives, packaging material, contaminants, and toxicants), which is steadily increasing. In vitro 2D cell culture applications in combination with in silico modeling might provide an applicable first response. However, those systems lack accurate predictions of metabolic actions. Thus, alternative in vivo models could fill the gap between cell culture and animal trials. In this review, we highlight relevant studies in the field and spotlight the applicability of alternative models, including C. elegans, D. rerio, Drosophila, HET-CAM and Lab-on-a-chip.

Strategy Combining Nonanimal Methods for Ocular Toxicity Evaluation

Historically, the ocular toxicity of manufactured consumer materials has been evaluated using the rabbit in vivo Draize rabbit eye test. The animal data obtained were used by the United Nations Globally Harmonized System of Classification and Labelling of Chemicals (UN GHS) to define the classification and labelling (C&L) for eye damage/irritation endpoint. However, the Draize test, a method which was never formally validated, has been widely criticized because of its technical limitations. In addition, ethical and economic issues and advances in scientific knowledge, and political and public pressures have made animal experimentation unsustainable. This scenario has consequently led to the development of nonanimal testing and protocols/approaches with considerable predictive value and relevance for humans. It is widely accepted that one single nonanimal method cannot cover all the criteria of damage/inflammation assessed by regulatory adopted in vivo animal testing. Thus, integrated testing strategies (ITS) have been proposed, including a tiered testing approach combining different nonanimal testing with different endpoints, which have been used for regulatory purposes, on a case-by-case basis and within integrated approaches to testing and assessment (IATA), to identify materials according to their ability to trigger eye damage. In particular, the top-down and bottom-up approaches have been recommended for the C&L of materials, which cause serious eye damage or eye irritation, respectively. This chapter describes detailed protocols for eye irritation testing based on cells (Short Time Exposure-STE, OECD No. 491/2017), a vascularized membrane (the Hen's Egg Test-Chorioallantoic Membrane-HET-CAM) and corneal tissue (Bovine Corneal Opacity and Permeability-BCOP, OECD No. 437/2017), which can be applied using top-down or bottom-up approaches. In addition, it suggests making a corneal histomorphometric evaluation as an additional parameter in the BCOP method to differentiate materials that cause serious eye tissue damage (UN GHS Cat. 1) from materials that have reversible eye irritation effects (UN GHS Cat. 2).

Acute, reproductive, and developmental toxicity of essential oils assessed with alternative in vitro and in vivo systems

Essential oils (EOs) have attracted increased interest for different applications such as food preservatives, feed additives and ingredients in cosmetics. Due to their reported variable composition of components, they might be acutely toxic to humans and animals in small amounts. Despite the necessity, rigorous toxicity testing in terms of safety evaluation has not been reported so far, especially using alternatives to animal models. Here, we provide a strategy by use of alternative in vitro (cell cultures) and in vivo (Caenorhabditis elegans, hen’s egg test) approaches for detailed investigation of the impact of commonly used rosemary, citrus and eucalyptus essential oil on acute, developmental and reproductive toxicity as well as on mucous membrane irritation. In general, all EOs under study exhibited a comparable impact on measured parameters, with a slightly increased toxic potential of rosemary oil. In vitro cell culture results indicated a concentration-dependent decrease of cell viability for all EOs, with mean IC₅₀ values ranging from 0.08 to 0.17% [v/v]. Similar results were obtained for the C. elegans model when using a sensitized bus-5 mutant strain, with a mean LC₅₀ value of 0.42% [v/v]. In wild-type nematodes, approximately tenfold higher LC₅₀ values were detected. C. elegans development and reproduction was already significantly inhibited at concentrations of 0.5% (wild-type) and 0.1% (bus-5) [v/v] of EO, respectively. Gene expression analysis revealed a significant upregulation of xenobiotic and oxidative stress genes such as cyp-14a3, gst-4, gpx-6 and sod-3. Furthermore, all three EOs under study showed an increased short-time mucous membrane irritation potential, already at 0.5% [v/v] of EO. Finally, GC–MS analysis was performed to quantitate the relative concentration of the most prominent EO compounds. In conclusion, our results demonstrate that EOs can exhibit severe toxic properties, already at low concentrations. Therefore, a detailed toxicological assessment is highly recommended for each EO and single intended application.

Spitting cobras: Experimental assay employing the model of chicken embryo and the chick chorioallantoic membrane for imaging and evaluation of effects of venom from African and Asian species (Naja ashei, Naja nigricollis, Naja siamensis, Naja sumatrana)

Among the captivating world of venomous snakes, an outstanding group of cobras from the family Elapidae is characterized by a distinctive structure of proteroglyphous venom apparatus that allows the ejection of venom from the fangs and formation of aerosol particles. The venom of "spitting" cobras is innocuous when sprayed over the intact skin, but contact with the eye surface is followed by ophthalmia and a temporary blindness, that may remain permanent, unless immediate and adequate medical interventions are carried out. The aim of this work was to monitor and evaluate induced vasoactive effects as well as embryotoxic effects with the regard to the whole crude venom of four "spitting" cobra species (African species Naja ashei and Naja nigricollis, Asian species Naja siamensis and Naja sumatrana). Vasoactive effects were visualized using the Hen's Egg Test - Chorioallantoic membrane (HET-CAM) test. The Chick Embryotoxicity Screening Test (CHEST) was used to estimate embryotoxicity and the data were then processed using statistical analysis. The highest embryonic mortality rate was observed after administration of venom from Naja nigricollis among the whole crude venoms tested. All tested venoms induced fast spreading of pathological alterations in the blood vessels on the chorioallantoic membrane. Our study discloses a detailed insight into microscopic level processes in venom-induced changes observed on the chicken embryos and on the vascular network in their chorioallantoic membrane. This article also highlights the increasing importance of the role of the chicken embryos and the importance of observing changes in the chorioallantoic membrane applied for toxicological and medical research as an appropriate alternative animal model in relation to 3R's principles.

Clarithromycin-Loaded Ocular Chitosan Nanoparticle: Formulation, Optimization, Characterization, Ocular Irritation, and Antimicrobial Activity

Purpose

The topically administered drugs through conventional delivery systems have low bioavailability. Henceforth, the present study was designed to prepare and optimize clarithromycin (CTM)-loaded chitosan nanoparticles (CHNPs) to demonstrate the efficacy against microorganisms.

Methods

Clarithromycin-loaded chitosan nanoparticles (CTM-CHNPs) were prepared by ionotropic gelation method. The formulation was optimized by box-Behnken design using the formulation variables like CH (A), STPP concentration (B), and stirring speed (C). Their effects were evaluated on the independent variables like particle size (Y₁) and entrapment efficiency (Y₂). Further, CTM-CHNPs were evaluated for physicochemical parameters, in-vitro drug release, ex-vivo permeation, bioadhesive study, corneal hydration, histopathology, HET-CAM, and antibacterial study.

Results

The optimized formulation (CTM-CHNPopt) showed the low particle size (152±5 nm), which is desirable for ocular delivery. It also showed high encapsulation (70.05%), zeta potential (+35.2 mV), and was found in a spherical shape. The drug release study revealed a sustained drug release profile (82.98±3.5% in 12 hours) with Korsmeyer peppas kinetic (R²=0.996) release model. It showed a 2.7-fold higher corneal permeation than CTM-solution. CHNPs did not exhibit any sign of damage to excised goat cornea, which is confirmed by hydration, histopathology, and HET-CAM test. It exhibited significant (P<0.05) higher antibacterial susceptibility than CTM-solution.

Conclusion

The finding of the study concluded that CTM-CHNPs can be used for effective management of bacterial conjunctivitis by increasing the precorneal residence time.

Optimization to development of chitosan decorated polycaprolactone nanoparticles for improved ocular delivery of dorzolamide: In vitro, ex vivo and toxicity assessments

The present research work was designed to develop dorzolamide-loaded chitosan-coated polycaprolactone nanoparticles (DRZ-CS-PCL-NPs) for improved ocular delivery. The nanoparticles were prepared by single-step emulsification technique and optimized using the three-factor three-level Box-Behnken design. The optimized DRZ-CS-PCL-NPs prepared with the composition of polycaprolactone (60 mg), chitosan (0.6%) and polyvinyl alcohol (1.5%). The particle size, polydispersity index, zeta potential and encapsulation efficiency of optimized DRZ-CS-PCL-NPs were found to be 192.38 ± 6.42 nm, 0.18 ± 0.04, +5.21 ± 1.24 mV, and 72.48 ± 5.62%, respectively. The dependent and independent response variables showed excellent correlation and signifying the rationality of the optimized DRZ-CS-PCL-NPs. The DRZ release from CS-PCL-NPs showed biphasic behaviour with initial burst release for 2 h after that sustained-release up to 12 h of study. The corneal flux experiment showed many fold enhancement in permeation across goat cornea. DRZ-CS-PCL-NPs exhibited 3.7 fold higher mucoadhesive strength compared to the control. Furthermore, the histopathological assessment and HET-CAM study revealed that the DRZ-CS-PCL-NPs were non-irritant and safe for ocular administration. Therefore, from the present study, it can be concluded that the optimized DRZ-CS-PCL-NPs are safe and have the potential for successful ocular delivery and improved therapeutic efficacy.

In vitro and in vivo amelioration of colitis using targeted delivery system of cyclosporine a in New Zealand rabbits

Necessity to develop the efficient targeted delivery of highly potent immunosuppressant for IBD in order to avoid surgical procedure, led to fabrication and evaluation of its anti-inflammatory potential. Previously formulated cyclosporine A (Cyp A) into enteric coated capsules was further evaluated for its site-specificity in the treatment of TNBS induced colitis. Contact angle measurement studies showed excellent spreadability of the developed formulation over the hydrophilic biological tissue substrate. HET-CAM study demonstrates that the formulation prepared is nonirritant to the highly vascular tissues and hence can be used for the immunological sensitive tissues like inflamed intestine in IBD. Further the developed formulation has been characterized for site specificity to distal parts of intestine by pharmacokinetic studies. The appearance of drug in systemic circulation at approximately 5 hours in New Zealand strain of rabbits confirms drug delivery at distal parts of intestine. Significant reduced levels of TNF-α, IL-6 and IL-10 in drug treated animals signifies inhibition of inflammatory reactions at the TNBS treated site. Simultaneously, the change in body weight of same group of animals was observed for 15 days. Results showed a marginal recovery of body weight in Cyp A treated TNBS induced colitis animals. In conclusion, all in vitro and in vivo results confirm the successful site specific delivery and anti-inflammatory efficacy of developed formulation of Cyp A in TNBS induced colitis in New Zealand rabbits.

Investigating the ocular toxicity potential and therapeutic efficiency of in situ gel nanoemulsion formulations of brinzolamide

Glaucoma is an ocular disease i.e. more common in older adults with elevated intraocular pressure and a serious threat to vision if it is not controlled. Due to the limitations regarding the conventional form of brinzolamide (Azopt®), two optimum formulations of in situ gel nanoemulsion were developed. To ensure the safety and efficacy of developed formulations for ocular drug delivery, the current study was designed. MTT assay was carried out on the human retinal pigmentation epithelial cells. To investigate the irritation potential of the chosen formulations, hen's egg test-chorioallantoic membrane as a borderline test between in vivo and in vitro methods has been done. The modified Draize method was utilized to evaluate eye tolerance against the selected formulations. Intraocular pressure was measured by applying the prepared formulations to the eyes of normotensive albino rabbits in order to assess the therapeutic efficacy. Based on MTT test, cell viability for NE-2 at 0.1% and NE-1 at 0.1 and 0.5% concentrations was acceptable. The results of the hen's egg test-chorioallantoic membrane test indicated no sign of vessel injury on the chorioallantoic membrane surface for both formulations. Also, during 24 h, both formulations were well-tolerated by rabbit eyes. The pharmacodynamics effects of formulations had no difference or were even higher than that of suspension in case of adding lower concentration (0.5%) of brinzolamide to the formulations. With regard to the results of the mentioned methods, our advanced formulations were effective, safe, and well-tolerated, thus can be introduced as an appropriate vehicle for ocular delivery of brinzolamide.

Multi-Modal PET and MR Imaging in the Hen's Egg Test-Chorioallantoic Membrane (HET-CAM) Model for Initial in Vivo Testing of Target-Specific Radioligands

The validation of novel target-specific radioligands requires animal experiments mostly using mice with xenografts. A pre-selection based on a simpler in vivo model would allow to reduce the number of animal experiments, in accordance with the 3Rs principles (reduction, replacement, refinement). In this respect, the chick embryo or hen’s egg test–chorioallantoic membrane (HET-CAM) model is of special interest, as it is not considered an animal until day 17. Thus, we evaluated the feasibility of quantitative analysis of target-specific radiotracer accumulation in xenografts using the HET-CAM model and combined positron emission tomography (PET) and magnetic resonance imaging (MRI). For proof-of-principle we used established prostate-specific membrane antigen (PSMA)-positive and PSMA-negative prostate cancer xenografts and the clinically widely used PSMA-specific PET-tracer [⁶⁸Ga]Ga-PSMA-11. Tracer accumulation was quantified by PET and tumor volumes measured with MRI (n = 42). Moreover, gamma-counter analysis of radiotracer accumulation was done ex-vivo. A three- to five-fold higher ligand accumulation in the PSMA-positive tumors compared to the PSMA-negative tumors was demonstrated. This proof-of-principle study shows the general feasibility of the HET-CAM xenograft model for target-specific imaging with PET and MRI. The ultimate value for characterization of novel target-specific radioligands now has to be validated in comparison to mouse xenograft experiments.

In Vitro and Ex Vivo Evaluation of Nepafenac-Based Cyclodextrin Microparticles for Treatment of Eye Inflammation

The aim of this study was to design and evaluate novel cyclodextrin (CD)-based aggregate formulations to efficiently deliver nepafenac topically to the eye structure, to treat inflammation and increase nepafenac levels in the posterior segment, thus attenuating the response of inflammatory mediators. The physicochemical properties of nine aggregate formulations containing nepafenac/γ-CD/hydroxypropyl-β (HPβ)-CD complexes as well as their rheological properties, mucoadhesion, ocular irritancy, corneal and scleral permeability, and anti-inflammatory activity were investigated in detail. The results were compared with a commercially available nepafenac suspension, Nevanac^® 3 mg/mL. All formulations showed microparticles, neutral pH, and negative zeta potential (–6 to –27 mV). They were non-irritating and nontoxic and showed high permeation through bovine sclera. Formulations containing carboxymethyl cellulose (CMC) showed greater anti-inflammatory activity, even higher than the commercial formulation, Nevanac^® 0.3%. The optimized formulations represent an opportunity for topical instillation of drugs to the posterior segment of the eye.

Preliminary evaluation of application of a 3-dimensional network structure of siloxanes Dergall preparation on chick embryo development and microbiological status of eggshells

The spatial network structure of Dergall is based on substances nontoxic to humans and the environment which, when applied on solid surfaces, creates a coating that reduces bacterial cell adhesion. The bacteriostatic properties of siloxanes are based on a purely physical action mechanism which excludes development of drug-resistant microorganisms. The aims of the present study were to 1) evaluate a Dergall layer formed on the eggshell surface regarding the potential harmful effects on the chick embryo; 2) evaluate antimicrobial activity and estimate the prolongation time of Dergall's potential antimicrobial activity. Dergall at a concentration of 0.6% formed a layer on the eggshell surface. In vitro testing of the potential harmful effects of Dergall by means of a hen embryo test of the chorioallantoic membrane showed no irritation reaction at a concentration of 3% and lower. The hatchability of the groups sprayed with a Dergall water solution with a concentration of 0 to 5% was 89.1 to 93.8% for fertilized eggs (P > 0.05) but decreased to 63.7% (P < 0.05) in the group sprayed with a 6% concentration of the solution. This phenomenon was caused by embryo mortality in the first week of incubation. At the concentration of 0.6%, Dergall exhibited strong antibacterial properties against bacteria such as Staphylococcus aureus, Escherichia coli, Shigella dysenteriae, Shigella flexneri, and Salmonella typhimurium. For Streptococcus pyogenes, the highest antibacterial activity of Dergall was reported in the concentrations of 100 and 50%. For Pseudomonas aeruginosa, no antibacterial activity of Dergall was generally observed, but in vivo testing showed a strong decrease of all gram-negative bacteria growth. Moreover, a prolonged antimicrobial effect lasting until 3 D after disinfection was observed, which makes Dergall a safe and efficient disinfectant.

Spirulina, Palmaria Palmata, Cichorium Intybus, and Medicago Sativa extracts in cosmetic formulations: an integrated approach of in vitro toxicity and in vivo acceptability studies

Background/Aims: The selection of suitable raw materials in the cosmetic research and development is a key point, not only in order to obtain the expected results but also to avoid undesirable side effects. This study evaluated the in vitro toxicity potential of four different plant extracts and their in vivo acceptability studies. Methods: Spirulina, Palmaria palmata, Cichorium intybus and Medicago sativa extracts were analysed alone or in combination and added in cosmetic formulations. The in vitro toxicity evaluation, Hen's Egg Chorioallantoic Membrane Test (HET-CAM) and 3T3 NRU phototoxicity test were performed to evaluate in vitro potential ocular irritation and photo safety, respectively. Twenty subjects were enrolled in the acceptability studies, who were evaluated for the absence of harmful effects of the formulation by visual assessment and by transepidermal water loss, a biophysical technique, for 30 days. Results: HET-CAM assay showed that the studied extracts added to a gel-cream formulation had no irritant potential. In addition, the combination of Palmaria palmata, alfalfa and chicory extracts did not show phototoxic potential in vitro. Acceptability studies showed that the formulation containing the four extracts combined did not provoke any transepidermal water loss (TEWL) alteration, sensory irritation or erythema in the forearms for the period of analysis. Conclusion: The studied active ingredients, alone or in combination, present no cytotoxicity potential and when added to a gel-cream formulation had no irritant potential in vitro. These results predicting no harmful effects were confirmed in the acceptability tests, which showed no alteration on skin barrier function and no report of irritation perception of sign of erythema, suggesting the potential of these extracts for the development of safe cosmetic products.

The proteolytic fraction from Vasconcellea cundinamarcensis accelerates wound healing after corneal chemical burn in rabbits

INTRODUCTION

Chemical ocular burns are among the most frequently eye-related injuries, which require immediate and intensive evaluation and care since they may lead to potential complications such as superinfection, corneal perforation, and blindness.Vasconcellea cundinamarcensis, a species from Caricaceae family, contains highly active proteolytic enzymes in its latex that show healing activity in animal models bearing lesions of different etiologies.

METHODS

We evaluate the ocular toxicity of the proteolytic fraction from V. cundinamarcensis (P1G10) by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and Hen's Egg Test-Chorioallantoic Membrane test. The corneal healing property of P1G10 was studied by the ethanol-chemical burn in the rabbit's eyes.

RESULTS

P1G10 is safe for ocular administration, except when administrated at 10μg/mL. P1G10 at 1μg/mL accelerates the corneal re-epithelization achieving complete wound closure after 72h of chemical burn. Also, P1G10 modulated the inflammatory response and controlled the arrangement of collagen fibers in the stroma, demonstrating its potential corneal healing properties.

CONCLUSIONS

Our work was the first one to evaluate the ophthalmic application of P1G10. Here we demonstrated that P1G10 is suitable for ocular administration and it has a promising corneal healing activity which may emerge as a new pharmacological tool to the development of a new drug for ocular surface chemical injuries in the future.

Antioxidant activity and irritation property of venoms from Apis species

Pharmacological effects of bee venom has been reported, however, it has been restricted to the bee venom collected from European honey bee (Apis mellifera). The aim of the present study was to compare the antioxidant activities and irritation properties of venoms collected from four different Apis species in Thailand, which includes Apis cerena (Asian cavity nesting honeybee), Apis florea (dwarf honeybee), Apis dorsata (giant honeybee), and A. mellifera. Melittin content of each bee venom extracts was investigated by using high-performance liquid chromatography. Ferric reducing antioxidant power, 2, 2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid), and 1, 1-diphenyl-2-picrylhydrazyl assay were used to determine the antioxidant activity, whereas, hen's egg test chorioallantoic membrane assay was used to determine the irritation property of each bee venom extracts. Melittin was the major constituent in all bee venom extracts. The melittin content in A. dorsata, A. mellifera, A. florea, and A. cerena were 95.8 ± 3.2%, 76.5 ± 1.9%, 66.3 ± 8.6%, and 56.8 ± 1.8%, respectively. Bee venom extract from A. dorsata possessed the highest antioxidant activity with the inhibition of 41.1 ± 2.2% against DPPH, Trolox equivalent antioxidant capacity of 10.21 ± 0.74 mM Trolox/mg and equivalent concentration (EC₁) of 0.35 ± 0.02 mM FeSO₄/mg. Bee venom extract from A. mellifera exhibited the highest irritation, followed by A. cerena, A. dorsata, and A. florea, respectively. Melittin was the compound responsible for the irritation property of bee venom extracts since it could induce severe irritation (irritation score was 13.7 ± 0.5, at the concentration of 2 mg/ml). The extract from A. dorsata which possessed the highest antioxidant activity showed no irritation up to the concentration of 0.1 mg/ml. Therefore, bee venom extract from A. dorsata at the concentration not more than 0.1 mg/ml would be suggested for using as cosmetic ingredients since it possessed the highest antioxidant activity with no irritation. This study is the first report to compare the bee venom extracts from different Apis species and display their potential application of bee venom extracts in cosmetic products.

Lipid Nanocarrier: an Efficient Approach Towards Ocular Delivery of Hydrophilic Drug (Valacyclovir)

This research focuses on the fabrication and evaluation of solid lipid nanoparticles (SLNs) for improved ocular delivery of valacyclovir (VAC). Stearic acid and tristearin were selected as the lipid carrier while Poloxamer 188 and sodium taurocholate were used as surfactant and co-surfactant, respectively. The physiochemical properties of the optimized batch (SLN-6) fulfil the prerequisites needed for an ideal ocular formulation like submicron size (202.5 ± 2.56 nm), narrow PDI (0.252 ± 0.06), high zeta potential (-34.4 ± 3.04 mV) and good entrapment efficiency (58.82 ± 2.45%). The in vitro release study of SLN-6 exhibited a sustained release profile (>60% in 12 h). The ex vivo studies performed on excised cornea exhibited enhanced drug permeation of SLNs (22.17 ± 1.41 μg/cm² h) in comparison to the drug solution (3.78 ± 1.34 μg/cm² h). Apart, the corneal hydration studies, histopathology and Hen's Egg Test Chorio Allantoic Membrane (HETCAM) assay, confirmed the non-irritancy of SLNs. The in vivo study confirmed improved ocular bioavailability of VAC from SLN-6 (AUC_0-12: 856.47 ± 7.86 μg h/mL) in contrast to the drug solution (AUC_0-12: 470.75 ± 8.91 μg h/mL). Hence, the overall studies suggested the potential of SLNs in efficient ocular delivery of a hydrophilic molecule like VAC.

The Hen's Egg Test on Chorioallantoic Membrane: An Alternative Assay for the Assessment of the Irritating Effect of Vaccine Adjuvants

Local reactions are the most frequent adverse event associated with vaccines. Adjuvants are major constituents of many vaccines and they are frequently involved in these reactions, associated with their irritating effect and the stimulation of local inflammation. The hen's egg test on chorioallantoic membrane (HET-CAM) is an alternative toxicological method widely used to determine ocular irritation potential, but very few studies have demonstrated the utility of this method for assessing the irritant properties of vaccine adjuvants. In this work, known/experimental adjuvants were evaluated by both HET-CAM and an in vivo local toxicity study in mice to compare irritation scores to determine whether there was a correlation (Pearson test). Based on these data (r = 0.9034; P < 0.0001), the HET-CAM assay can be used as an alternate method for the prediction of the local toxicity potential of adjuvant candidates to be used in vaccines.

Solid lipid nanoparticle: an efficient carrier for improved ocular permeation of voriconazole

This research focuses on the fabrication and evaluation of solid lipid nanoparticles (SLNs) for improved ocular delivery of voriconazole (VCZ). Compritol and palmitic acid were selected as lipid carriers based on drug solubility and partitioning behavior. Poloxamer and soya lecithin were the choice for surfactant, while sodium taurocholate was used as a co-surfactant. The particle sizes of the SLNs determined by zetasizer and transmission electron microscopy (TEM) were found within the desired range. The in vitro release study of SLNs exhibited a sustained-release property of the drug. The ex vivo studies displayed enhanced corneal drug permeation from SLNs in comparison to the drug suspension. Further, the corneal hydration studies, histopathology and Hen's Egg Test Chorio Allantoic Membrane (HETCAM) assay confirmed the non-irritancy of the nano-formulation. The in vivo study confirmed the higher availability of VCZ (from SLN) in aqueous humor with minimal nasolacrymal drainage in contrast to the drug suspension. A good in-vitro in-vivo correlation (IVIVC) further confirmed the potential of SLN as an effective carrier for ocular delivery.

Application of Box-Behnken design for preparation of levofloxacin-loaded stearic acid solid lipid nanoparticles for ocular delivery: Optimization, in vitro release, ocular tolerance, and antibacterial activity

The aim of the present study was to develop and optimize levofloxacin loaded solid lipid nanoparticles for the treatment of conjunctivitis. Box-Behnken experimental design was applied for optimization of solid lipid nanoparticles. The independent variables were stearic acid as lipid (X1), Tween 80 as surfactant (X2) and sodium deoxycholate as co-surfactant (X3) while particle size (Y1) and entrapment efficiency (Y2) were the dependent variables. Further in vitro release and antibacterial activity in vitro were also performed. The optimized formulation of levofloxacin provides particle size of 237.82 nm and showed 78.71% entrapment efficiency and achieved flux 0.2,493 μg/cm(2)/h across excised goat cornea. In vitro release study showed prolonged drug release from the optimized formulation following Korsmeyer-Peppas model. Antimicrobial study revealed that the developed formulation possesses antibacterial activity against Staphylococcus aureus, and Escherichia coli equivalent to marketed eye drops. HET-CAM test demonstrated that optimized formulation was found to be non-irritant and safe for topical ophthalmic use. Our results concluded that solid lipid nanoparticles are an efficient carrier for ocular delivery of levofloxacin and other drugs.

Liposomal voriconazole (VOR) formulation for improved ocular delivery

Treating infectious eye diseases topically requires a drug delivery system capable of overcoming the eye's defense mechanisms, which efficiently reduce the drug residence time right after its administration, therefore reducing absorption. In order to try to surpass such administration issues and improve life quality for patients with fungal keratitis, liposomal voriconazol (VOR) formulations were prepared. Formulations were composed of soy phosphatidylcholine (PC) containing or not 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) and cholesterol. Liposomes were characterized by their drug entrapment efficiency (EE), drug recovery (DR), average diameter (size) and polydispersivity index (PdI). In vitro mucosal interaction and irritancy levels, ex vivo permeation, as well as the short-term stability were also assessed. Liposomal VOR formulation produced with 7.2:40mM VOR:PC showed to be the most promising formulation: mean size of 116.6±5.9nm, narrow PdI (0.17±0.06), negative zeta potential (∼-7mV) and over 80% of EE and yield, remaining stable for at least 30 days in solution and 90 days after lyophilization. This formulation was classified as 'non-irritant' after HET-CAM's test and was able to deliver about 47.85±5.72μg/cm(2) of VOR into porcine cornea after 30min of permeation test. Such drug levels are higher than the minimal inhibitory concentrations (MIC) of several fungi species isolated from clinical cases of corneal keratitis. Overall results suggest VOR can be effectively incorporated in liposomes for potential topical treatment of fungal keratitis.

Development and evaluation of a novel in situ gel of sparfloxacin for sustained ocular drug delivery: in vitro and ex vivo characterization

Conventional eye drops are the most popular delivery systems in the treatment of various eye infections. However, the major problem encountered in these dosage forms is precorneal elimination of the drug, resulting in poor bioavailability and therapeutic response. To overcome the side effects of pulsed dosing, an attempt has been made to formulate and evaluate a novel in situ gelling system of Sparfloxacin for sustained ocular drug delivery (ion and pH triggered gelling system). These gelling systems involve the use of sodium alginate (ion sensitive polymer) used as gelling agent and methylcellulose as viscosity-enhancing agent. The developed formulations were evaluated for clarity, pH, gelling capacity, rheological study, in vitro release study, ex vivo corneal permeation study, ocular irritation studies (HET-CAM test) and histopathological study using isolated goat corneas. The formulations were found to be stable, non-irritant and showed sustained release of the drug for a period up to 24 h with no ocular damage. In situ gel of sparfloxacin could be prepared successfully promising their use in ophthalmic delivery.

Carbon nanotubes for delivery of small molecule drugs

In the realm of drug delivery, carbon nanotubes (CNTs) have gained tremendous attention as promising nanocarriers, owing to their distinct characteristics, such as high surface area, enhanced cellular uptake and the possibility to be easily conjugated with many therapeutics, including both small molecules and biologics, displaying superior efficacy, enhanced specificity and diminished side effects. While most CNT-based drug delivery system (DDS) had been engineered to combat cancers, there are also emerging reports that employ CNTs as either the main carrier or adjunct material for the delivery of various non-anticancer drugs. In this review, the delivery of small molecule drugs is expounded, with special attention paid to the current progress of in vitro and in vivo research involving CNT-based DDSs, before finally concluding with some consideration on inevitable complications that hamper successful disease intervention with CNTs.

Controlled penetration of ceramides into and across the stratum corneum using various types of microemulsions and formulation associated toxicity studies

Several skin diseases such as psoriasis and atopic dermatitis are associated with the depletion or disturbance of stratum corneum (SC) lipids such as ceramides (CERs), free fatty acids and cholesterol. Studies suggested that replenishment of these lipids might help to treat diseased, affected or aged skin. With this premises in mind, there are some formulations in the market that contain SC lipids and currently, to facilitate permeation of the lipids deep into the SC, various CERs, and other SC lipid microemulsions (MEs) were developed and characterised using lecithin or TEGO® CARE PL 4 (TCPL4) as base surfactants. However, to date, there are no reports that involve the permeability of SC lipids into and across the SC, and therefore, the penetration of CER [NP] as a model ceramide from various formulations was investigated ex vivo using Franz diffusion cell. Besides, the toxicity of the MEs was assessed using hen's egg test chorioallantoic membrane (HET-CAM). The results of the study showed that CER [NP] could not permeate into deeper layers of the SC from a conventional hydrophilic cream. Unlike the cream, CER [NP] permeated into the deeper layers of the SC from both type of MEs, where permeation of the CER was more and into deeper layers from droplet type and lecithin-based MEs than bicontinuous (BC) type and TCPL4 based MEs, respectively. The CER also permeated into deeper layers from ME gels which was, however, shallow and to a lesser extent when compared with the MEs. The results of HET-CAM showed that both MEs are safe to be used topically, with lecithin-based MEs exhibiting better safety profiles than TCPL4 based MEs. Concluding, the study showed that the MEs are safe to be used on the skin for the controlled penetration of CER [NP] deep into the SC.