Unlocking the Potential of Oleanolic Acid: Integrating Pharmacological Insights and Advancements in Delivery Systems.

The growing interest in oleanolic acid (OA) as a triterpenoid with remarkable health benefits prompts an emphasis on its efficient use in pharmaceutical research. OA exhibits a range of pharmacological effects, including antidiabetic, anti-inflammatory, immune-enhancing, gastroprotective, hepatoprotective, antitumor, and antiviral properties. While OA demonstrates diverse pharmacological effects, optimizing its therapeutic potential requires overcoming significant challenges. In the field of pharmaceutical research, the exploration of efficient drug delivery systems is essential to maximizing the therapeutic potential of bioactive compounds. Efficiently delivering OA faces challenges, such as poor aqueous solubility and restricted bioavailability, and to unlock its full therapeutic efficacy, novel formulation strategies are imperative. This discussion thoroughly investigates different approaches and advancements in OA drug delivery systems with the aim of enhancing the biopharmaceutical features and overall efficacy in diverse therapeutic contexts.

Encapsulation of Olive Leaf Polyphenol-Rich Extract in Polymeric Micelles to Improve Its Intestinal Permeability.

In the present study, polymeric micelles were developed to improve the intestinal permeability of an extract of Olea europaea L. leaf with a high content of total polyphenols (49% w/w), with 41% w/w corresponding to the oleuropein amount. A pre-formulation study was conducted to obtain a stable formulation with a high loading capacity for extract. The freeze-drying process was considered to improve the stability of the formulation during storage. Micelles were characterized in terms of physical and chemical properties, encapsulation efficiency, stability, and in vitro release. The optimized system consisted of 15 mg/mL of extract, 20 mg/mL of Pluronic L121, 20 mg/mL of Pluronic F68, and 10 mg/mL of D-α-tocopheryl polyethylene glycol succinate (TPGS), with dimensions of 14.21 ± 0.14 nm, a polydisersity index (PdI) of 0.19 ± 0.05 and an encapsulation efficiency of 66.21 ± 1.11%. The influence of the micelles on polyphenol permeability was evaluated using both Parallel Artificial Membrane Permeability Assay (PAMPA) and the Caco-2 cell monolayer. In both assays, the polymeric micelles improved the permeation of polyphenols, as demonstrated by the increase in Pe and Papp values.

The Protective Role of Oleuropein Aglycone against Pesticide-Induced Toxicity in a Human Keratinocytes Cell Model.

The extensive use of agricultural pesticides to improve crop quality and yield significantly increased the risk to the public of exposure to small but repeated doses of pesticides over time through various routes, including skin, by increasing the risk of disease outbreaks. Although much work was conducted to reduce the use of pesticides in agriculture, little attention was paid to prevention, which could reduce the toxicity of pesticide exposure by reducing its impact on human health. Extra virgin olive oil (EVOO), a major component of the Mediterranean diet, exerts numerous health-promoting properties, many of which are attributed to oleuropein aglycone (OleA), the deglycosylated form of oleuropein, which is the main polyphenolic component of EVOO. In this work, three pesticides with different physicochemical and biological properties, namely oxadiazon (OXA), imidacloprid (IMID), and glyphosate (GLYPHO), were compared in terms of metabolic activity, mitochondrial function and epigenetic modulation in an in vitro cellular model of human HaCaT keratinocytes to mimic the pathway of dermal exposure. The potential protective effect of OleA against pesticide-induced cellular toxicity was then evaluated in a cell pre-treatment condition. This study showed that sub-lethal doses of OXA and IMID reduced the metabolic activity and mitochondrial functionality of HaCaT cells by inducing oxidative stress and altering intracellular calcium flux and caused epigenetic modification by reducing histone acetylation H3 and H4. GLYPHO, on the other hand, showed no evidence of cellular toxicity at the doses tested. Pretreatment of cells with OleA was able to protect cells from the damaging effects of the pesticides OXA and IMID by maintaining metabolic activity and mitochondrial function at a controlled level and preventing acetylation reduction, particularly of histone H3. In conclusion, the bioactive properties of OleA reported here could be of great pharmaceutical and health interest, as they could be further studied to design new formulations for the prevention of toxicity from exposure to pesticide use.

Pentacyclic Triterpenes from Olive Leaves Formulated in Microemulsion: Characterization and Role in De Novo Lipogenesis in HepG2 Cells.

Olea europaea L. leaves contain a wide variety of pentacyclic triterpenes (TTPs). TTPs exhibit many pharmacological activities, including antihyperlipidemic effects. Metabolic alterations, such as dyslipidemia, are an established risk factor for hepatocellular carcinoma (HCC). Therefore, the use of TTPs in the adjunctive treatment of HCC has been proposed as a possible method for the management of HCC. However, TTPs are characterized by poor water solubility, permeability, and bioavailability. In this work, a microemulsion (ME) loading a TTP-enriched extract (EXT) was developed, to overcome these limits and obtain a formulation for oral administration. The extract-loaded microemulsion (ME-EXT) was fully characterized, assessing its chemical and physical parameters and release characteristics, and the stability was evaluated for two months of storage at 4 °C and 25 °C. PAMPA (parallel artificial membrane permeability assay) was used to evaluate the influence of the formulation on the intestinal passive permeability of the TTPs across an artificial membrane. Furthermore, human hepatocarcinoma (HepG2) cells were used as a cellular model to evaluate the effect of EXT and ME-EXT on de novo lipogenesis induced by elevated glucose levels. The effect was evaluated by detecting fatty acid synthase expression levels and intracellular lipid accumulation. ME-EXT resulted as homogeneous dispersed-phase droplets, with significantly increased EXT aqueous solubility. Physical and chemical analyses showed the high stability of the formulation over 2 months. The formulation realized a prolonged release of TTPs, and permeation studies demonstrated that the formulation improved their passive permeability. Furthermore, the EXT reduced the lipid accumulation in HepG2 cells by inhibiting de novo lipogenesis, and the ME-EXT formulation enhanced the inhibitory activity of EXT on intracellular lipid accumulation.

Antinociceptive Action of Thymoquinone-Loaded Liposomes in an In Vivo Model of Tendinopathy.

Tendinopathies represent about 45% of musculoskeletal lesions and they are a big burden in clinics characterized by activity-related pain, focal tendon tenderness and intra-tendinous imaging changes. Many approaches have been proposed for tendinopathies' management (e.g., nonsteroidal anti-inflammatory drugs, corticosteroids, eccentric exercises, laser therapy), unfortunately with very little support of efficacy or serious side effects, thus making the identification of new treatments fundamental. The aim of the study was to test the protective and pain reliever effect of thymoquinone (TQ)-loaded formulations in a rat model of tendinopathy induced by carrageenan intra-tendon injection (20 µL of carrageenan 0.8% on day 1). Conventional (LP-TQ) and hyaluronic acid (HA)-coated TQ liposomes (HA-LP-TQ) were characterized and subjected to in vitro release and stability studies at 4 °C. Then, TQ and liposomes were peri-tendon injected (20 µL) on days 1, 3, 5, 7 and 10 to evaluate their antinociceptive profile using mechanical noxious and non-noxious stimuli (paw pressure and von Frey tests), spontaneous pain (incapacitance test) and motor alterations (Rota rod test). Liposomes containing 2 mg/mL of TQ and covered with HA (HA-LP-TQ2) reduced the development of spontaneous nociception and hypersensitivity for a long-lasting effect more than the other formulations. The anti-hypersensitivity effect matched with the histopathological evaluation. In conclusion, the use of TQ encapsulated in HA-LP liposomes is suggested as a new treatment for tendinopathies.

Escinosome thermosensitive gel optimizes efficacy of CAI-CORM in a rat model of rheumatoid arthritis.

Rheumatoid arthritis is among the most common disabling diseases associated with chronic inflammation. The efficacy of the current therapeutic strategies is limited; therefore, new pharmacological agents and formulation approaches are urgently needed. In this work, we developed a thermosensitive gel incorporating escinosomes, innovative nanovesicles made of escin, stabilized with 10% of tween 20 and loaded with a Carbonic Anhydrase Inhibitor (CAI) bearing a Carbon Monoxide Releasing Moiety (CORM) (i.e., CAI-CORM 1), previously synthesized by some of the authors as a new potent pain-relieving agent. The light scattering analysis of the developed formulation showed optimal physical parameters, while the chromatographic analysis allowed the quantification of the encapsulation efficiency (90.1 ± 5.91 and 91.6 ± 8.46 for CAI-CORM 1 and escin, respectively). The thermosensitive gel, formulated using 23% w/v of poloxamer 407, had a sol-gel transition time of 40 s and good syringeability. Its stability in simulated synovial fluid (SSF) was morphologically evaluated by electron microscopy. Nanovesicles were physically stable in contact with the medium for two weeks, maintaining their original dimensions and spherical shape. The viscosity increased by about 30- to 100-fold with the temperature change from 25 °C to 37 °C. The gel erosion in SSF occurred within 9 h (88.2 ± 0.743%), and the drug's passive diffusion from escinosomes lasted 72 h, allowing a potential sustained therapeutic effect. The efficacy of a single intra-articular injection of the gel containing escinosomes loaded with CAI-CORM 1 (3 mg/mL; 30 µL, CAI-CORM 1 formulation) and the gel containing unloaded escinosomes (30 µL, blank formulation) was evaluated in a rat model of Complete Freund's Adjuvant (CFA)-induced rheumatoid arthritis. CAI-CORM 1 formulation was assessed to counteract mechanical hyperalgesia, spontaneous pain, and motor impairments on days 7 and 14 after treatment. The histological evaluation of the joints stressed the improvement of several morphological parameters in CFA + CAI-CORM 1 formulation-treated rats. In conclusion, the hybrid molecule CAI-CORM 1 formulated in escinosome-based thermosensitive gel could represent a new valid approach for managing rheumatoid arthritis.

Ameliorative Effect of Posidonia oceanica on High Glucose-Related Stress in Human Hepatoma HepG2 Cells.

Metabolic disorders characterized by elevated blood glucose levels are a recognized risk factor for hepatocellular carcinoma (HCC). Lipid dysregulation is critically involved in the HCC progression, regulating energy storage, metabolism, and cell signaling. There is a clear link between de novo lipogenesis in the liver and activation of the NF-κB pathway, which is involved in cancer metastasis via regulation of metalloproteinases MMP-2/9. As conventional therapies for HCC reach their limits, new effective and safe drugs need to be found for the prevention and/or adjuvant therapy of HCC. The marine plant Posidonia oceanica (L.) Delile is endemic to the Mediterranean and has traditionally been used to treat diabetes and other health disorders. The phenol-rich leaf extract of Posidonia oceanica (POE) is known to have cell-safe bioactivities. Here, high glucose (HG) conditions were used to study lipid accumulation and fatty acid synthase (FASN) expression in human HepG2 hepatoma cells using Oil Red O and Western blot assays. Under HG conditions, the activation status of MAPKs/NF-κB axis and MMP-2/9 activity were determined by Western blot and gelatin zymography assays. The potential ameliorative role of POE against HG-related stress in HepG2 cells was then investigated. POE reduced lipid accumulation and FASN expression with an impact on de novo lipogenesis. Moreover, POE inhibited the MAPKs/NF-κB axis and, consequently, MMP-2/9 activity. Overall, these results suggest that P. oceanica may be a potential weapon in the HCC additional treatment.

Evaluation of Conventional and Hyaluronic Acid-Coated Thymoquinone Liposomes in an In Vitro Model of Dry Eye.

Dry eye disease (DED) is a common ocular disorder characterized by an inadequate lubrication of the eye by tears leading to inflammation and the alteration of the ocular surface. Current treatments are often limited due to their side effects and ineffectiveness. Thymoquinone (TQ) is a natural compound present in the essential oil of Nigella sativa L., with anti-inflammatory and antioxidant activities. In this study, conventional and hyaluronic acid-coated liposomes were developed to improve TQ activity at ocular level. In the present study, the cytoprotective effects of TQ or TQ liposomes were assessed against oxidative and inflammatory processes in human corneal epithelial cells (HCE-2). Hyperosmolarity conditions (450 mOsm) were used as a model of DED. Interleukin-1ß (IL-1ß), Interleukin-6 (IL-6) and tumor necrosis factor (TNFα) were quantified by quantitative real-time polymerase chain reaction (RT-qPCR); COX-2 and Phospho-NF-κB p65 (p-p65) by Western blotting (WB). Moreover, the mitochondrial reactive oxygen species (mtROS) levels were measured by MitoSOX assay. The hyperosmotic treatment induced a significant increase of the proinflammatory genes and proteins expression that were significantly decreased in the liposomes-treated cells. The coincubation with hyaluronic acid-coated liposomes significantly reverted the increase of mtROS production, evidently stimulated by the hyperosmotic stress. Our data suggest that TQ-loaded liposomes have potential as a therapeutic agent in dry eye disease, improving the TQ efficacy.

Development and Evaluation of Khellin-loaded Microemulgel for Dermatological Applications.

Microemulsions are optically nanosized emulsions, isotropic and thermodynamically stable. They represent versatile drug delivery systems with high potential because they can be administered regardless of route. In the present study, we report on the formulation of a microemulsion made with glycerol (2.25%), Labrasol (20.25%) vitamin E acetate (2.50%), and water (75.00%), which was developed using the pseudo-ternary phase diagram. Globules of the microemulsion had PdI less than 0.25 and size of about 17 nm, evaluated by DLS analysis. These values did not change after loading khellin, a natural lipophilic molecule with interesting biological activities, used as a model of lipophilic drug. Carboxymethyl cellulose was selected as gelling polymer to obtain a microemulgel. Viscosity was 22 100.0 ± 1555.6 mPas·s at 21 ± 2 °C, while it was 8916.5 ± 118.1 mPas·s at 35 ± 2 °C, remaining stable over time. Khellin recovery was 93.16 ± 4.39% and was unchanged after 4 weeks of storage (93.23 ± 2.14%). The pH was 6.59 ± 0.19 and it was found to be 6.42 ± 0.34 at the end of the storage lifetime. The diffusion of khellin from the developed formulation was prolonged over an extended period. Based on overall results and due to the dermatological properties of the ingredients of the formulation, the developed microemulgel loaded with khellin is very promising and suitable for skin care applications.

Usnic Acid-Loaded Polymeric Micelles: An Optimal Migrastatic-Acting Formulation in Human SH-SY5Y Neuroblastoma Cells.

Usnic acid (UA) is one of the most abundant and common metabolites of lichens, known for its numerous pharmacological properties. Nevertheless, it presents some criticalities that severely limit its use in therapy: poor solubility in water and significant hepatotoxicity. Soluplus and Solutol HS15 and D-α-Tocopherol polyethylene glycol 1000 succinate (TPGS) were employed to develop polymeric micelles (UA-PM). The chemical and physical properties of the system were characterized, including the size, homogeneity, zeta potential, critical micellar concentration (CMC), encapsulation efficiency (EE%), and in vitro release. The freeze-drying process was considered to prevent agglomeration and improve the stability of the formulation. The stability of the micelles and the freeze-dried product (UA-PML) was also evaluated. The anti-migratory activity of UA and UA-PM was evaluated in human neuroblastoma SH-SY5Y cells using the wound healing assay. Their effect on the activity of metalloproteinases (MMP)-2/9 involved in the migration process of cells was verified by gelatin zymography. The optimized UA-PM contained Soluplus, Solutol HS15, and TPGS in a 1:4:0.5 weight ratio and increased the aqueous solubility to about 150-fold solubilized, solubilizing 0.5 mg/mL of UA. UA-PM has a small size (45.39 ± 0.31 nm), a polydispersity index (PDI) of 0.26 ± 0.01, and an EE% of 82.13 ± 5.57%. The colloidal dispersion was stable only for 9 days at 4 °C, while the freeze-drying process improved the stability for up to 30 days. UA was released for a prolonged period during the in vitro release study. The in vitro cell-based experiments showed that UA-PM (0.2 µg/mL) inhibited SH-SY5Y cell migration and the gelatinolytic activity of MMP-2/9 in culture media, while free UA at the same concentration exerted no biological activity. This study demonstrates that polymeric micelles are an excellent formulation for UA to manifest inhibitory action on neuroblastoma cell migration.

Bioactive Molecules from Plants: Discovery and Pharmaceutical Applications.

The plant kingdom is one of the richest sources of bioactive compounds with pharmaceutical potential [...].

Microemulsions Enhance the In Vitro Antioxidant Activity of Oleanolic Acid in RAW 264.7 Cells.

Oleanolic acid (OA) is the main triterpenic acid of olive leaves known for numerous pharmacological properties, including antioxidant activity. However, it is poorly soluble in water and consequently with low bioavailability, which limits its pharmacological application. Microemulsions (MEs) are dispersed systems consisting of two immiscible phases that promote rapid solubilization and absorption in the gastrointestinal tract. To improve both solubility and intestinal permeability of this molecule, OA has been formulated in two different microemulsions (ME-1 and ME-2). A solubility screening was carried out to select the ME components, and pseudoternary phase diagrams were constructed to evaluate the region of existence and select the appropriate amount of the constituents. ME-1 was prepared using Capmul PG-8/NF as the oily phase, and Transcutol and Tween 20 (7:3) as surfactants, while ME-2 contained Nigella oil and Isopropil myristate as the oily phase, and Transcutol HP and Cremophor EL (2:1) as surfactants. The OA solubility was increased by 1000-fold and 3000-fold in ME-1-OA and ME-2-OA, respectively. The MEs' droplet size and the PdI were evaluated, and the stability was assessed for 8 weeks by monitoring chemical and physical parameters. The parallel artificial membrane permeability assay (PAMPA) also demonstrated an enhanced intestinal permeability of both OA formulations compared with free OA. The potential ability of both MEs to enhance the bioactivity of OA against LPS-induced oxidative stress in RAW 264.7 murine macrophages was also investigated. Overall, this study suggests that both MEs promote a bio-enhancement of the protective action of OA against the LPS-induced pro-oxidant stress in macrophages. Overall, this study suggests that MEs could be an interesting formulation to improve OA oral bioavailability with potential clinical applications.

Solubility and Permeability Enhancement of Oleanolic Acid by Solid Dispersion in Poloxamers and γ-CD.

Oleanolic acid (OA) is a pentacyclic triterpenoid widely found in the Oleaceae family, and it represents 3.5% of the dry weight of olive leaves. OA has many pharmacological activities, such as hepatoprotection, anti-inflammatory, anti-oxidant, anti-diabetic, anti-tumor, and anti-microbic activities. Its therapeutic application is limited by its poor water solubility, bioavailability, and permeability. In this study, solid dispersions (SDs) were developed to overcome these OA limitations. Solubility studies were conducted to evaluate different hydrophilic polymers, drug-to-polymer ratios, and preparation methods. Poloxamer 188, Poloxamer 407, and γ-CD exhibited the highest increases in terms of OA solubility, regardless of the method of preparation. Binary systems were characterized using differential scanning calorimetry (DSC), X-ray diffraction (XRPD), and Fourier transform infrared spectroscopy (FTIR). In addition, pure compounds and SDs were analyzed using scanning electron microscopy (SEM) in order to observe both the morphology and the particle surface. In vitro dissolution studies were performed for P407, P188, and γ-CD SDs. Preparation using the solvent evaporation method (SEM) produced the highest increase in the dissolution profiles of all three polymers with respect to the OA solution. Finally, the effect of SDs on OA permeability was evaluated with an in vitro parallel artificial membrane permeability assay (PAMPA). The formulation improved passive permeation across the simulated barrier due to OA increased solubility. The dissolution and PAMPA results indicate that the amorphization of OA by SD preparation could be a useful method to enhance its oral absorption, and it is also applicable on an industrial scale.

Escinosomes: Safe and Successful Nanovesicles to Deliver Andrographolide by a Subcutaneous Route in a Mice Model of Oxaliplatin-Induced Neuropathy.

Andrographolide (AG) is a natural diterpene lactone endowed with considerable therapeutic potential for treating numerous diseases, including neurological disorders, but its low aqueous solubility and scarce bioavailability limit its clinical use. To overcome this problem, AG was encapsulated in escinosomes, special nanovesicles made of escin (ESN), a natural saponin, and phosphatidylcholine. Escinosomes loaded with AG had an average size of 164.7 ± 13.30 nm, optimal polydispersity index (0.190 ± 0.0890) and high ζ-potential (-35.4 ± 0.451 mV), and significantly loaded the active substance-the encapsulation efficiency of AG was about 88%. Escinosomes allowed the prolonged release of AG over time, without burst effects-about 85% AG was released after 24 h. Morphological analysis by cryo-transmission electron microscopy showed nanovesicles with a spherical shape, unilamellar and oligolamellar structures, and dimensions in agreement with those measured by dynamic light scattering. In addition, stability studies were performed on AG-loaded escinosomes stored for one month at 4 °C. The pain-relieving efficacy of these nanovesicles was tested in a rat model of oxaliplatin-induced neuropathy. AG-loaded escinosomes, subcutaneously administered, effectively reduced the thermal allodynia characteristic of chemotherapy-induced neuropathy, enhancing and prolonging the effect of the natural compound. Overall, AG-loaded escinosomes were found to be excellent for loading AG, physically and chemically stable for one-month storage, and with controlled-release properties, making the formulation an ideal pharmacological approach for persistent pain treatment.

Evaluation of the increase of the thymoquinone permeability formulated in polymeric micelles: In vitro test and in vivo toxicity assessment in Zebrafish embryos.

Thymoquinone (TQ) is a natural compound present in the essential oil and in the fixed oil of Nigella sativa L. Like many natural substances, it is characterized by poor aqueous solubility and low stability which limit its bioavailability. Soluplus®-Solutol® HS15 polymeric micelles (TQ-MP) were developed to increase the permeability of TQ with particular attention to overcoming intestinal barrier and the blood brain barrier, for possible oral and parenteral administration. The optimized micelles have dimensions < 100 nm and PdI < 0.2 indicating that the formulation was homogeneous as confirmed also by TEM experiments. EE% was 92.4 ± 0.3%. Stability studies showed a stable formulation following subsequent dilutions and in the gastric-intestinal media. In vitro studies have revealed that the carrier enhances the permeability of TQ in the intestine and in the blood-brain barrier using Parallel Artificial Membrane Permeability Assay (PAMPA) assay and cellular tests with Caco-2 cells and hCMEC/D3 monolayer cells. Up-take study, cell viability and cytotoxicity studies were also conducted. Fluorescent micelles (FITC-MP), were also optimized to perform in vitro up-take study in Caco-2 cells and to study their toxicity in Zebrafish model. The toxicity was evaluated on three lines of Zebrafish: wild type, transgenic line Tg(Myl7:EGFP) in which cardiomyocytes are marked with green fluorescence protein and Tg(flk1-GFP) line which expresses GFP under the control of the vascular endothelial growth factor receptor 2 (vegfr2) promoter.

Applications of innovative technologies to the delivery of antipsychotics.

Psychosis is a high-incidence pathology associated with a profound alteration in the perception of reality. The limitations of drugs available on the market have stimulated the search for alternative solutions to achieve effective antipsychotic therapies. In this review, we evaluate innovative formulations of antipsychotic drugs developed through the application of modern pharmaceutical technologies, including classes of micro and nanocarriers, such as lipid formulations, polymeric nanoparticles (NPs), solid dispersions, and cyclodextrins (CDs). We also consider alternative routes of administration to the oral and parenteral ones currently used. Improved solubility, stability of preparations, and pharmacokinetic (PK) and pharmacodynamic (PD) parameters confirm the potential of these new formulations in the treatment of psychotic disorders.

Nanostructured Lipid Carriers Can Enhance Oral Absorption of Khellin, a Natural Pleiotropic Molecule.

A novel formulation based on nanostructured lipid carriers (NLCs) was developed to increase solubility and intestinal absorption of khellin. K-NLCs were prepared with stearic acid, hempseed oil, Brij S20, and Labrafil M 1944 CS, using the emulsification-ultrasonication method. Developed nanoparticles were chemically and physically characterized by liquid chromatography, light scattering techniques, and electron microscopy. The size, about 200 nm, was optimal for oral delivery, and the polydispersity index (around 0.26), indicated high sample homogeneity. Additionally, K-NLCs showed a spherical morphology without aggregation by microscopic analysis. The encapsulation efficiency of khellin was about 55%. In vitro release studies were carried out in media with different pH to mimic physiological conditions. K-NLCs were found to be physically stable in the simulated gastric and intestinal fluids, and they preserved about 70% of khellin after 6 h incubation. K-NLCs were also successfully lyophilized testing different lyoprotectants, and obtained freeze-dried K-NLCs demonstrated good shelf life over a month. Lastly, permeability studies on Caco-2 cells were performed to predict khellin passive diffusion across the intestinal epithelium, demonstrating that nanoparticles increased khellin permeability by more than two orders of magnitude. Accordingly, developed NLCs loaded with khellin represent a versatile formulation with good biopharmaceutical properties for oral administration, possibly enhancing khellin's bioavailability and therapeutic effects.

Preparation of Liposomal Formulations for Ocular Delivery of Thymoquinone: In Vitro Evaluation in HCEC-2 e HConEC Cells.

Thymoquinone (TQ) is the main constituent of Nigella sativa L. essential oil. In vitro studies have shown its protective effect against H2O2-induced oxidative stress in human retinal pigment epithelium cells, and in vivo experiments have demonstrated its effect in decreasing corneal neovascularization and reducing the inflammation in an experimental dry eye model in mice. Its therapeutic use is limited by poor bioavailability, low solubility, and scarce permeability. In this study, two liposomal formulations have been developed, both of which consist of phosphatidylcholine and Plurol Oleique, a liquid lipid, and one of which is coated with 0.1% w/v hyaluronic acid (HA) to increase both TQ solubility and its ocular therapeutic potential. Each formulation has a size <200 nm and an EE% around 70%, determined by scattering techniques and the HPLC-DAD analytical method, respectively, and they result in a 2-fold increase in TQ solubility. HA-coated liposomes are stable over 2 months at +4 °C, and coated and uncoated liposomes present a gradual and prolonged release of TQ. Two cell lines, human corneal epithelial cells (HCEC-2) and human conjunctival epithelial cells (HConEC) were used to investigate the safety of the liposomal formulations. Uptake studies were also performed using fluorescent liposomes. Both liposomes and, in particular, HA-coated liposomes reduce the TQ toxicity observed at high doses in both HCEC-2 and HConEC cells, and both formulations increase the absorption at the cellular level and especially at the nucleus level, with a more pronounced effect for HA-coated liposomes.

The Anti-Arthritic Efficacy of Khellin Loaded in Ascorbyl Decanoate Nanovesicles after an Intra-Articular Administration.

Osteoarthritis is the most widespread joint-affecting disease. The management of persistent pain remains inadequate and demands new therapeutic strategies. In this study, we explored the pain relieving and protective properties of a single intra-articular (i.a.) injection of khellin loaded in nanovesicles (K-Ves) based on ascorbyl decanoate plus phosphatidylcholine in a rat model of osteoarthritis (OA) induced by monosodium iodoacetate (MIA) treatment. The developed nanovesicles (approximately 136 nm) had a narrow size distribution (PdI 0.26), a good recovery (about 80%) and a worthy encapsulation efficiency (about 70%) with a ζ-potential of about -40 mV. The stability of K-Ves was assessed in simulated synovial fluid. Seven days after the articular damage with MIA, both K-Ves and a suspension of khellin (K, 50 µL) were i.a. injected. K-Ves significantly counteracted MIA-induced hypersensitivity to mechanical noxious (paw pressure test) and non-noxious stimuli (von Frey test) and significantly reduced the postural unbalance related to spontaneous pain (incapacitance test) and the motor alterations (beam balance test) 7 and 14 days after the i.a. injection. K was partially active only on day 7 after the treatment. The histology emphasized the improvement of several morphological factors in MIA plus K-Ves-treated animals. In conclusion, K-Ves could be successfully used for the local treatment of osteoarthritis.

Development and optimisation of biopharmaceutical properties of a new microemulgel of cannabidiol for locally-acting dermatological delivery.

Cannabidiol (CBD) is a pleiotropic phytocannabinoid, recently investigated to treat many skin diseases. This study aimed to develop a CBD-loaded O/A microemulsion (CBD-ME) formulated as microemulgel (CBD-MEgel), suitable for local administration. The developed CBD-ME consisted of Solutol HS 15 (20%, surfactant), Transcutol P (9%, cosolvent), isopropyl myristate (5%, oil phase), water (66%) and 1% w/w CBD. Globules had polydispersity index less than 0.23 ± 0.02 and size of 35 ± 2 nm; these values did not change after loading CBD and gelling the formulation with Sepigel 305 obtaining a clear and homogeneous formulation with a pH of 6.56 ± 0.20, suitable for cutaneous application. Viscosity properties were investigated by the rotational digital viscometer, at both 21 ± 2 °C and 35 ± 2 °C. Viscosities of CBD-MEgel were 439,000 ± 4,243 mPa·s and 391,000 ± 1,414 mPa·s respectively. The release studies displayed that 90 ± 24 µg/cm2 of CBD were released in 24 h. The CBD permeability, evaluated using Franz diffusion cells and rabbit ear skin, was 3 ± 1 µg/cm2. Skin-PAMPATM gave a CBD effective permeability of (1.67 ± 0.16) ·10-7 cm/s and an absorbed dose of 115.30 ± 16.99 µg/cm2 after 24 h. Lastly, physical and chemical stability of both CBD-ME and CBD-MEgel were evaluated over a period of 3 months, showing optimal shelf-life at the storage conditions.