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

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

Development and machine-learning optimization of mucoadhesive nanostructured lipid carriers loaded with fluconazole for treatment of oral candidiasis.

The aim of this work was to prepare and optimize mucoadhesive nanostructured lipid carrier (NLC) impregnated with fluconazole for better management of oral candidiasis. The NLCs were fabricated using an emulsification/sonication technique. The nanoparticles consisted of stearic acid, oleic acid, Pluronic F127, and lecithin. Box-Behnken design, artificial neural networking, and variable weight desirability were employed to optimize the joint effect of drug concentration in the drug/lipid mixture, solid lipid concentration in the solid/liquid lipid mixture, and surfactant concentration in the total mixture on size and entrapment. The optimized NLCs were coated with chitosan. The nanoparticles were characterized by surface charge, spectroscopic, thermal, morphological, mucoadhesion, release, histopathological, and antifungal properties. The nanoparticles are characterized by a particle size of 335 ± 13.5 nm, entrapment efficiency of 73.1 ± 4.9%, sustained release, minor histopathological effects on rabbit oral mucosa, and higher fungal inhibition efficiency for an extended period of time compared with fluconazole solution. Coating the nanoparticles with chitosan increased its adhesion to rabbit oral buccal mucosa and improved its anti-candidiasis activity. It is concluded that mucoadhesive lipid-based nanoparticles amplify the effect of fluconazole on Candida albicans in vitro. This finding warrants pre-clinical and clinical studies in oral candidiasis disease models to corroborate in vitro findings.

Pharmacokinetics of Dexmedetomidine in Infants and Children After Orthotopic Liver Transplantation.

BACKGROUND: Dexmedetomidine (DEX) is a sedative and analgesic medication that is frequently used postoperatively in children after liver transplantation. Hepatic dysfunction, including alterations in drug clearance, is common immediately after liver transplantation. However, the pharmacokinetics (PK) of DEX in this population is unknown. The objective of this study was to determine the PK profile of DEX in children after liver transplantation. METHODS: This was a single-center, open-label PK study of DEX administered as an intravenous loading dose of 0.5 µg/kg followed by a continuous infusion of 0.5 µg/kg/h. Twenty subjects, 1 month to 18 years of age, who were admitted to the pediatric intensive care unit after liver transplantation were enrolled. Whole blood was collected and analyzed for DEX concentration using a dried blood spot method. Nonlinear mixed-effects modeling was used to characterize the population PK of DEX. RESULTS: DEX PK was best described by a 2-compartment model with first-order elimination. A typical child after liver transplantation with an international normalized ratio (INR) of 1.8 was found to have a whole blood DEX clearance of 52 L/h (95% confidence interval [CI], 31-73 L/h). In addition, intercompartmental clearance was 246 L/h (95% CI, 139-391 L/h), central volume of distribution was 186 L/70 kg (95% CI, 140-301 L/70 kg), and peripheral volume of distribution was 203 L (95% CI, 123-338 L). Interindividual variability ranged from 11% to 111% for all parameters. Clearance was not found to be associated with weight but was found to be inversely proportional to INR. An increase in INR to 3.2 resulted in a 50% decrease in DEX clearance. Weight was linearly correlated with central volume of distribution. All other covariates, including age, ischemic time, total bilirubin, and alanine aminotransferase, were not found to be significant predictors of DEX disposition. CONCLUSIONS: Children who received DEX after liver transplantation have large variability in clearance, which was not found to be associated with weight but is influenced by underlying liver function, as reflected by INR. In this population, titration of DEX dosing to clinical effect may be important because weight-based dosing is poorly associated with blood concentrations. More attention to quality of DEX sedation may be warranted when INR values are changing.

Antimicrobial Disposition During Pediatric Continuous Renal Replacement Therapy Using an Ex Vivo Model.

OBJECTIVES: Little is known on the impact of continuous renal replacement therapy on antimicrobial dose requirements in children. In this study, we evaluated the pharmacokinetics of commonly administered antimicrobials in an ex vivo continuous renal replacement therapy model. DESIGN: An ex vivo continuous renal replacement therapy circuit was used to evaluate drug-circuit interactions and determine the disposition of five commonly used antimicrobials (meropenem, piperacillin, liposomal amphotericin B, caspofungin, and voriconazole). SETTING: University research laboratory. PATIENTS: None. INTERVENTIONS: Antimicrobials were administered into a reservoir containing whole human blood. The reservoir was connected to a pediatric continuous renal replacement therapy circuit programmed for a 10 kg child. Continuous renal replacement therapy was performed in the hemodiafiltration mode and in three phases correlating with three different continuous renal replacement therapy clearance rates: 1) no clearance (0 mL/kg/hr, to measure adsorption), 2) low clearance (20 mL/kg/hr), and 3) high clearance (40 mL/kg/hr). Blood samples were drawn directly from the reservoir at baseline and at 5, 20, 60, and 180 minutes during each phase. Five independent continuous renal replacement therapy runs were performed to assess inter-run variability. Antimicrobial concentrations were measured using validated liquid chromatography-mass spectrometry assays. A closed-loop, flow-through pharmacokinetic model was developed to analyze concentration-time profiles for each drug. MEASUREMENTS AND MAIN RESULTS: Circuit adsorption of antimicrobials ranged between 13% and 27%. Meropenem, piperacillin, and voriconazole were cleared by the continuous renal replacement therapy circuit and clearance increased with increasing continuous renal replacement therapy clearance rates (7.66 mL/min, 4.97 mL/min, and 2.67 mL/min, respectively, for high continuous renal replacement therapy clearance). Amphotericin B and caspofungin had minimal circuit clearance and did not change with increasing continuous renal replacement therapy clearance rates. CONCLUSIONS: Careful consideration of drug-circuit interactions during continuous renal replacement therapy is essential for appropriate drug dosing in critically ill children. Antimicrobials have unique adsorption and clearance profiles during continuous renal replacement therapy, and this knowledge is important to optimize antimicrobial therapy.

Development, Optimization, and In Vitro/In Vivo Characterization of Enhanced Lipid Nanoparticles for Ocular Delivery of Ofloxacin: the Influence of Pegylation and Chitosan Coating.

This study aims to investigate whether modification of solid lipid nanoparticles (SLNs) with chitosan (CTS) and polyethylene glycol (PEG) coatings enhances corneal retention time and transcorneal bioavailability. Ofloxacin (OFLOX) was selected as the model drug because of its potential benefits for the treatment of local eye infections. The OFLOX-CTS-PEG-SLN was prepared by a modified emulsion/solvent evaporation technique. A central composite design was implemented to investigate the influence of total lipid/drug ratio, surfactant concentration, PEG stearate concentration in the lipid mixture, and CTS concentration on size, entrapment, transcorneal permeation, and adhesion to the corneal mucosal membrane. The optimized OFLOX-CTS-PEG-SLN was characterized for OFLOX cumulative percentage released in simulated tear fluid and permeated across the excised bovine corneal membrane. Moreover, nanoparticle morphology, eye irritation via histopathological analysis, and OFLOX concentration in the ocular fluids and tissues were determined. A total lipid/drug ratio of 19:1, Tween 80 of 2%, PEG stearate concentration in the lipid mixture (% w/w) of 2.6%, and CTS concentration (% w/v) of 0.23% produced 132.9 nm particles entrapping 74.8% of the total drug added. The particles detached from the corneal membrane at a force of 3700 dyne/cm2. The %OFLOX released from the optimized nanoparticles was 63.3, and 66% of the drug permeated after 24 h. Compared to Oflox® drops, the optimized OFLOX-CTS-PEG-SLN exhibited similar tolerability but two- to threefold higher concentrations in the eyes of rabbits. Coating of SLN with chitosan and PEG augments the ocular bioavailability of OFLOX by increasing transcorneal permeation and enhancing mucoadhesion strength.

Development of a nanogel formulation for transdermal delivery of tenoxicam: a pharmacokinetic-pharmacodynamic modeling approach for quantitative prediction of skin absorption.

This study investigates potentials of solid lipid nanoparticles (SLN)-based gel for transdermal delivery of tenoxicam (TNX) and describes a pharmacokinetic-pharmacodynamic (PK-PD) modeling approach for predicting concentration-time profile in skin. A 23 factorial design was adopted to study the effect of formulation factors on SLN properties and determine the optimal formulation. SLN-gel tolerability was investigated using rabbit skin irritation test. Its anti-inflammatory activity was assessed by carrageenan-induced rat paw edema test. A published Hill model for in vitro inhibition of COX-2 enzyme was fitted to edema inhibition data. Concentration in skin was represented as a linear spline function and coefficients were estimated using non-linear regression. Uncertainty in predicted concentrations was assessed using Monte Carlo simulations. The optimized SLN was spherical vesicles (58.1 ± 3.1 nm) with adequate entrapment efficiency (69.6 ± 2.6%). The SLN-gel formulation was well-tolerated. It increased TNX activity and skin level by 40 ± 13.5, and 227 ± 116%, respectively. Average Cmax and AUC0-24 predicted by the model were 2- and 3.6-folds higher than the corresponding values computed using in vitro permeability data. SLN-gel is a safe and efficient carrier for TNX across skin in the treatment of inflammatory disorders. PK-PD modeling is a promising approach for indirect quantitation of skin deposition from PD activity data.

Pharmacokinetics and placental transfer of magnesium sulfate in pregnant women.

BACKGROUND: Magnesium sulfate is one of the most commonly prescribed intravenous medications in obstetrics. Despite its widespread use, there are limited data about magnesium pharmacokinetics, and magnesium is prescribed empirically without dose adjustment for different indications. OBJECTIVE: The aim of this study was to characterize the pharmacokinetics and placental transfer of magnesium sulfate in pregnant women and to determine key covariates that impact the pharmacokinetics. STUDY DESIGN: This is a prospective pharmacokinetic cohort study of pregnant women who were prescribed magnesium sulfate for preeclampsia, preterm labor, or extreme prematurity. Women received a 4-g loading dose and 2 g/h maintenance dose as clinically indicated. Maternal blood samples were obtained before and at multiple time points during and after magnesium administration. Cord blood also was sampled at delivery. A population pharmacokinetic approach that used a nonlinear mixed-effects modeling was used to characterize magnesium disposition. RESULTS: Pharmacokinetic profiles of 111 pregnant women were analyzed. Magnesium clearance was 3.98 L/h in preeclamptic women and 5.88 L/h non-preeclamptic women. Steady-state concentration of magnesium was 7.2 mg/dL in preeclamptic women compared with 5.1 mg/dL in non-preeclamptic women. Maternal weight significantly impacted time to steady state. The ratio of the mean umbilical vein magnesium level to the mean maternal serum magnesium level at the time of delivery was 0.94 ± 0.15. CONCLUSIONS: The study accurately characterizes the pharmacokinetics of magnesium administered to pregnant women. Preeclamptic status and maternal weight significantly impact serum magnesium levels. This pharmacokinetic model could be applied to larger cohorts to help tailor magnesium treatment and account for these covariates.

Pharmacokinetics of prophylactic cefazolin in parturients undergoing cesarean delivery.

The objectives of this work were (i) to characterize the pharmacokinetics of cefazolin in pregnant women undergoing elective cesarean delivery and in their neonates; (ii) to assess cefazolin transplacental transmission; (iii) to evaluate the dosing and timing of preoperative, prophylactic administration of cefazolin to pregnant women; and (iv) to investigate the impact of maternal dosing on therapeutic duration and exposure in newborns. Twenty women received 1 g of cefazolin preoperatively. Plasma concentrations of total cefazolin were analyzed from maternal blood samples taken before, during, and after delivery; umbilical cord blood samples obtained at delivery; and neonatal blood samples collected 24 h after birth. The distribution volume of cefazolin was 9.44 liters. [corrected] The values for pre- and postdelivery clearance were 7.18 and 4.12 liters/h, respectively. Computer simulations revealed that the probability of maintaining free cefazolin concentrations in plasma above 8 mg/liter during scheduled caesarean surgery was <50% in the cord blood when cefazolin was administered in doses of <2 g or when it was administered <1 h before delivery. Therapeutic concentrations of cefazolin persisted in neonates >5 h after birth. Cefazolin clearance increases during pregnancy, and larger doses are recommended for surgical prophylaxis in pregnant women to obtain the same antibacterial effect as in nonpregnant patients. Cefazolin has a longer half-life in neonates than in adults. Maternal administration of up to 2 g of cefazolin is effective and produces exposure within clinically approved limits in neonates.

Repurposing celecoxib for colorectal cancer targeting via pH-triggered ultra-elastic nanovesicles: Pronounced efficacy through up-regulation of Wnt/ß-catenin pathway in DMH-induced tumorigenesis.

Celecoxib (CLX), a selective inhibitor for cyclooxygenase 2 (COX-2), has manifested potential activity against diverse types of cancer. However, low bioavailability and cardiovascular side effects remain the major challenges that limit its exploitation. In this work, we developed ultra-elastic nanovesicles (UENVs) with pH-triggered surface charge reversal traits that could efficiently deliver CLX to colorectal segments for snowballed tumor targeting. CLX-UENVs were fabricated via a thin-film hydration approach. The impact of formulation factors (Span 80, Tween 80, and sonication time) on the nanovesicular features was evaluated using Box-Behnken design, and the optimal formulation was computed. The optimum formulation was positively coated with polyethyleneimine (CLX-PEI-UENVs) and then coated with Eudragit S100 (CLX-ES-PEI-UENVs). The activity of the optimized nano-cargo was explored in 1,2-dimethylhydrazine-induced colorectal cancer in Wistar rats. Levels of COX-2, Wnt-2 and ß-catenin were assessed in rats' colon. The diameter of the optimized CLX-ES-PEI-UENVs formulation was 253.62 nm, with a zeta potential of -23.24 mV, 85.64% entrapment, and 87.20% cumulative release (24 h). ES coating hindered the rapid release of CLX under acidic milieu (stomach and early small intestine) and showed extended release in the colon section. In colonic environments, the ES coating layer was removed due to high pH, and the charge on the nanovesicular corona was shifted from negative to positive. Besides, a pharmacokinetics study revealed that CLX-ES-PEI-UENVs had superior oral bioavailability by 2.13-fold compared with CLX suspension. Collectively, these findings implied that CLX-ES-PEI-UENVs could be a promising colorectal-targeted nanoplatform for effective tumor management through up-regulation of the Wnt/ß-catenin pathway.

Polymeric Nanoparticles for Delivery of Natural Bioactive Agents: Recent Advances and Challenges.

In the last few decades, several natural bioactive agents have been widely utilized in the treatment and prevention of many diseases owing to their unique and versatile therapeutic effects, including antioxidant, anti-inflammatory, anticancer, and neuroprotective action. However, their poor aqueous solubility, poor bioavailability, low GIT stability, extensive metabolism as well as short duration of action are the most shortfalls hampering their biomedical/pharmaceutical applications. Different drug delivery platforms have developed in this regard, and a captivating tool of this has been the fabrication of nanocarriers. In particular, polymeric nanoparticles were reported to offer proficient delivery of various natural bioactive agents with good entrapment potential and stability, an efficiently controlled release, improved bioavailability, and fascinating therapeutic efficacy. In addition, surface decoration and polymer functionalization have opened the door to improving the characteristics of polymeric nanoparticles and alleviating the reported toxicity. Herein, a review of the state of knowledge on polymeric nanoparticles loaded with natural bioactive agents is presented. The review focuses on frequently used polymeric materials and their corresponding methods of fabrication, the needs of such systems for natural bioactive agents, polymeric nanoparticles loaded with natural bioactive agents in the literature, and the potential role of polymer functionalization, hybrid systems, and stimuli-responsive systems in overcoming most of the system drawbacks. This exploration may offer a thorough idea of viewing the polymeric nanoparticles as a potential candidate for the delivery of natural bioactive agents as well as the challenges and the combating tools used to overcome any hurdles.

Novel nasal niosomes loaded with lacosamide and coated with chitosan: A possible pathway to target the brain to control partial-onset seizures.

This work aimed to develop and produce lacosamide-loaded niosomes coated with chitosan (LCA-CTS-NSM) using a thin-film hydration method and the Box-Behnken design. The effect of three independent factors (Span 60 amount, chitosan concentration, and cholesterol amount) on vesicle size, entrapment efficiency, zeta potential, and cumulative release (8 h) was studied. The optimal formulation of LCA-CTS-NSM was chosen from the design space and assessed for morphology, in vitro release, nasal diffusion, stability, tolerability, and in vivo biodistribution for brain targeting after intranasal delivery. The vesicle size, entrapment, surface charge, and in vitro release of the optimal formula were found to be 194.3 nm, 58.3%, +35.6 mV, and 81.3%, respectively. Besides, it exhibits sustained release behavior, enhanced nasal diffusion, and improved physical stability. Histopathological testing revealed no evidence of toxicity or structural damage to the nasal mucosa. It demonstrated significantly more brain distribution than the drug solution. Overall, the data is encouraging since it points to the potential for non-invasive intranasal administration of LCA as an alternative to oral or parenteral routes.

Intranasal Nanotransferosomal Gel for Quercetin Brain Targeting: II. Antidepressant Effect in an Experimental Animal Model.

Depression is a serious mental disorder and the most prevalent cause of disability and suicide worldwide. Quercetin (QER) demonstrated antidepressant effects in rats exhibiting anxiety and depressive-like behaviors. In an attempt to improve QER's antidepressant activity, a QER-loaded transferosome (QER-TFS) thermosensitive gel for intranasal administration was formulated and optimized. The therapeutic effectiveness of the optimized formulation was assessed in a depressed rat model by conducting a behavioral analysis. Behavioral study criteria such as immobility, swimming, climbing, sucrose intake, number of crossed lines, rearing, active interaction, and latency to feed were all considerably enhanced by intranasal treatment with the QER-TFS in situ gel in contrast to other formulations. A nasal histopathological study indicated that the QER-TFS thermosensitive gel was safe for the nasal mucosa. An immunohistochemical analysis showed that the animals treated with the QER-TFS thermosensitive gel had the lowest levels of c-fos protein expression, and brain histopathological changes in the depressed rats were alleviated. According to pharmacodynamic, immunohistochemical, and histopathological experiments, the intranasal administration of the QER-TFS thermosensitive gel substantially alleviated depressive symptoms in rats. However, extensive preclinical investigations in higher animal models are needed to anticipate its effectiveness in humans.

Intranasal Nanotransferosomal Gel for Quercetin Brain Targeting: I. Optimization, Characterization, Brain Localization, and Cytotoxic Studies.

Numerous neurological disorders have a pathophysiology that involves an increase in free radical production in the brain. Quercetin (QER) is a nutraceutical compound that shields the brain against oxidative stress-induced neurodegeneration. Nonetheless, its low oral bioavailability diminishes brain delivery. Therefore, the current study aimed to formulate QER-loaded transferosomal nanovesicles (QER-TFS) in situ gel for QER brain delivery via the intranasal route. This study explored the impacts of lipid amount, edge activator (EA) amount, and EA type on vesicle diameter, entrapment, and cumulative amount permeated through nasal mucosa (24 h). The optimum formulation was then integrated into a thermosensitive gel after its physical and morphological characteristics were assessed. Assessments of the optimized QER-TFS showed nanometric vesicles (171.4 ± 3.4 nm) with spherical shapes and adequate entrapment efficiency (78.2 ± 2.8%). The results of short-term stability and high zeta potential value (-32.6 ± 1.4 mV) of QER-TFS confirmed their high stability. Compared with the QER solution, the optimized QER-TFS in situ gel formulation exhibited sustained release behavior and augmented nasal mucosa permeability. CT scanning of rat brains demonstrated the buildup of gold nanoparticles (GNPs) in the brains of all treatment groups, with a greater level of GNPs noted in the rats given the transferosomal gel. Additionally, in vitro studies on PCS-200-014 cells revealed minimal cytotoxicity of QER-TFS in situ gel. Based on these results, the developed transferosomal nanovesicles may be a suitable nanocarrier for QER brain targeting through the intranasal route.

Development of thermosensitive hydrogel of Amphotericin-B and Lactoferrin combination-loaded PLGA-PEG-PEI nanoparticles for potential eradication of ocular fungal infections: In-vitro, ex-vivo and in-vivo studies.

The most prevalent conditions among ocular surgery and COVID-19 patients are fungal eye infections, which may cause inflammation and dry eye, and may cause ocular morbidity. Amphotericin-B eye drops are commonly used in the treatment of ocular fungal infections. Lactoferrin is an iron-binding glycoprotein with broad-spectrum antimicrobial activity and is used for the treatment of dry eye, conjunctivitis, and ocular inflammation. However, poor aqueous stability and excessive nasolacrimal duct draining impede these agens' efficiency. The aim of this study was to examine the effect of Amphotericin-B, as an antifungal against Candida albicans, Fusarium, and Aspergillus flavus, and Lactoferrin, as an anti-inflammatory and anti-dry eye, when co-loaded in triblock polymers PLGA-PEG-PEI nanoparticles embedded in P188-P407 ophthalmic thermosensitive gel. The nanoparticles were prepared by a double emulsion solvent evaporation method. The optimized formula showed particle size (177.0 ± 0.3 nm), poly-dispersity index (0.011 ± 0.01), zeta-potential (31.9 ± 0.3 mV), and entrapment% (90.9 ± 0.5) with improved ex-vivo pharmacokinetic parameters and ex-vivo trans-corneal penetrability, compared with drug solution. Confocal laser scanning revealed valuable penetration of fluoro-labeled nanoparticles. Irritation tests (Draize Test), Atomic force microscopy, cell culture and animal tests including histopathological analysis revealed superiority of the nanoparticles in reducing signs of inflammation and eradication of fungal infection in rabbits, without causing any damage to rabbit eyeballs. The nanoparticles exhibited favorable pharmacodynamic features with sustained release profile, and is neither cytotoxic nor irritating in-vitro or in-vivo. The developed formulation might provide a new and safe nanotechnology for treating eye problems, like inflammation and fungal infections.

Exploring the potential of quercetin/aspirin-loaded chitosan nanoparticles coated with Eudragit L100 in the treatment of induced-colorectal cancer in rats.

Growing evidence suggests quercetin and aspirin may have anticancer properties, notably in the case of colorectal cancer. The goal of this study was to create Pluronic F127 and polyethylene glycol4000 solid dispersion-loaded chitosan nanoparticles for colonic quercetin and aspirin delivery. In 1:1 polymeric stoichiometric ratio, solubility and complex formation were verified. Solid dispersion-loaded chitosan nanoparticles with a diameter of 244.45 ± 8.5 nm, a surface charge of 34.1 ± 3.3 mV, and encapsulation effectiveness of 76.3 ± 4.3% were generated under ideal conditions. In some cases, coating with Eudragit L100 resulted in a decrease in zeta potential and an increase in particle size. The coated formulation released the actives in a pH-dependent manner, considering their physicochemical features. Surprisingly, when compared to the actives' suspension and uncoated formulation, the coated formulation had greater anti-inflammatory efficacy, with a substantial reduction of PGE2 and IL-8 production in colonic tissues (16.9 ± 7.9 ng/g tissue and 134.9 ± 10.1 pg/g tissue, respectively). It also reversed most of the dimethyl hydrazine-induced histological alterations in the colon. It also demonstrated a greater reduction in TNF expression in colonic tissues. As a result, Eudragit L100-coated QT/AS-loaded chitosan nanoparticles are suggested to provide a potential platform for colonic delivery of quercetin and aspirin.

Chitosan on the surface of nanoparticles for enhanced drug delivery: A comprehensive review.

The ability of chitosan (CTS) to promote mucoadhesion, trigger positive/negative surface interactions, and open tight junctions has inspired researchers to coat lipid-based and polymeric-based nanoparticles with CTS in an attempt to reach new heights in the delivery of drugs and nutraceuticals across different routes. This article discusses literature relevant to the pharmaceutical and biomedical area published in the last 10 years on nanoparticles overlaid with CTS. Herein, we addressed the technical aspects of the coating procedure by adding CTS solution to nanoparticles that have already been produced or during the production phase. Besides, we reviewed the applications of CTS coated nanoparticles as drug delivery systems in the oral and non-oral routes of administrations. Special attention was paid to the physicochemical and biological benefits of the CTS coating, such as improving physicochemical stability, enhancing cell and tissue interactions, controlled drug release, and augmentation of active substance bioavailability and efficacy. Moreover, this review projects the current standing and future prospects of the delivery system. The future calls for more investigations on therapeutic proteins, genes and vaccines as potential cargos. Extensive studies on the merits of integrating CTS with hydropolymer-synthesized nanoparticles and using longer-chain and chemically-modified variants of CTS are also warranted.

Fabrication and In Vitro/In Vivo Appraisal of Metronidazole Intra-Gastric Buoyant Sustained-Release Tablets in Healthy Volunteers.

Helicobacter pylori is thought to be the most common cause of peptic and duodenal ulcers. Eradication of this organism is now considered one of the lines of treatment of gastric and duodenal ulcers. This can be achieved via local delivery of antibacterial agents in high concentrations. Accordingly, our objective was to fabricate and evaluate sustained release floating tablets for metronidazole to extend the gastric residence period and control the release rate of metronidazole. Floating tablets containing cellulose derivatives and Avicel were prepared using direct compression. The rate of metronidazole release from the floating tablets (K = 6.278 mg min-1/2) was significantly lower than that from conventional tablets (K = 10.666 mg min-1/2), indicating sustained drug release, according to the Higuchi model, for more than 6 h in an acidic medium of 0.1 N HCl. In vivo study in healthy volunteers revealed significantly improved bioavailability; increased Tmax, AUC, and MRT; and significantly lower absorption rate constant after a single oral dose of 150 mg metronidazole as floating tablets. In addition, the significant increase in MRT indicated an in vivo sustained drug release. The floating tablets provided several benefits, including ease of preparation, absence of effervescent ingredients, and reliance on a pH-independent gel-forming agent to deliver metronidazole in a sustained manner. In conclusion, the prepared tablets could be promising for enhancing both local and systemic metronidazole efficacy.

Role of ADMA/DDAH-1 and iNOS/eNOS signaling in the gastroprotective effect of tadalafil against indomethacin-induced gastric injury.

Non-steroidal anti-inflammatory drugs (NSAIDs)-induced gastric ulcers represent a significant clinical concern and adversely affect the quality of life. Inducible nitric oxide synthase/endothelial nitric oxide synthase (iNOS/eNOS) and asymmetric dimethylarginine/ dimethylarginine dimethylaminohydrolase-1 (ADMA/DDAH-1) signaling are key players in gastric ulcer pathogenesis. This work was planned to explore the role of iNOS/eNOS and ADMA/DDAH-1 signaling in rats with indomethacin-induced gastric ulcer, as potential pathways for the gastro-protective effect of tadalafil. Split into 5 separate groups, rats were assigned to control, tadalafil (10 mg/kg, p.o), indomethacin (single oral dose of 60 mg/kg), indomethacin + pantoprazole (40 mg/kg, p.o), and indomethacin + tadalafil (10 mg/kg, p.o). The results indicated that pretreatment with tadalafil significantly reduced ulcer index (UI), increased preventive index (PI), and counteracted indomethacin-induced histopathological aberrations. Tadalafil significantly reduced the gastric content of NO while it significantly elevated that of GSH and enhanced SOD activity. It significantly reduced the gastric expression of TNF-α and ADMA while it significantly elevated that of COX-2, PGE-2, and DDAH-1. Western blot analysis revealed that pretreatment with tadalafil significantly reduced iNOS protein expression while it significantly elevated that of eNOS. Collectively, these data suggest that tadalafil exerts potential protective effect against indomethacin-induced ulcer through suppression of inflammation, attenuation of oxidative stress, and boosting of antioxidants. Moreover, tadalafil protective effects are mediated via upregulation of PGE-2 with modulating the signaling pathways of ADMA/DDAH-1, and iNOS/eNOS. As a result, the current evidence corroborates the use of tadalafil in controlling gastric ulcers and preventing NSAID gastric side effects.

Effect of Pirfenidone on Risk of Pulmonary Fibrosis in COVID-19 Patients Experiencing Cytokine Storm.

OBJECTIVES: Severe stages of COVID-19 infection have been associated with the excessive discharge of pro-inflammatory mediators such as cytokines, resulting in lung deterioration, which progresses rapidly to lung fibrosis leading to acute respiratory distress syndrome. In this investigation, the efficacy and safety of the novel antifibrotic and anti-inflammatory agent, Pirfenidone, were assessed in COVID-19 patients with pulmonary fibrosis secondary to cytokine storm. In this randomized controlled study, we assigned 100 adult COVID-19 patients cytokine storm and admitted to the intensive care isolation unit into either pirfenidone added to the standard therapy (n = 47), or the standard protocol only (n = 53). High-resolution computed tomography of the chest was performed in all patients to evaluate fibrotic lesions and their progression. The results showed that the percentage of patients who developed pulmonary fibrosis during cytokine storm onset in the pirfenidone group relative to the standard group was 29.8% and 35.8%, respectively, with no significant difference between the two groups; while there was a significant increase in the proportion of patients discharged from the isolation unit with pulmonary fibrosis without progression in fibrotic lesions in the pirfenidone group compared to the standard group (21.3% and 5.7%, respectively). Furthermore, there was a significant difference concerning liver enzyme elevation and GIT disturbance incidences in the studied groups (p = 0.006 and 0.01, respectively). Our findings show that Pirfenidone inhibits fibrosis advancement in COVID-19 patients with pulmonary fibrosis and is associated with hepatotoxicity and GI distress. It may be beneficial in patients with mild to moderate COVID-19-induced pulmonary fibrosis; however, additional research is necessary.

Chitosan Silver and Gold Nanoparticle Formation Using Endophytic Fungi as Powerful Antimicrobial and Anti-Biofilm Potentialities.

Nanotechnology is emerging as a new technology with encouraging innovations. Global antibiotic use has grown enormously, with antibiotic resistance increasing by about 80 percent. In view of this alarming situation, intensive research has been carried out into biogenic nanoparticles and their antibacterial, antifungal, and antitumor activities. Many methods are available to enhance stability and dispersion via peroration of conjugate with a polymer, such as chitosan, and other bioactive natural products. Two marine fungi were isolated and identified as Aspergillus sp. and Alternaria sp. via sequencing of the 16S rRNA gene. In this work, these strains were used to form the conjugation of biogenic silver nanoparticles (AgNPs) from Aspergillus sp. Silv2 extract and gold nanoparticles (AuNPs) from Alternaria sp. Gol2 extracts with chitosan to prepare chitosan-AgNPs and chitosan-AuNP conjugates. A variety of imaging and analytical methods, such as UV-vis, X-ray powder diffraction (XRD), FTIR spectroscopy, transmission electron microscopy (TEM), and scanning electron microscopy (SEM) were utilized to characterize biogenic nanoparticles and conjugates. The biosynthesized Ag and Au nanoparticles along with the prepared conjugates were evaluated for their antimicrobial effects on Gram-negative and Gram-positive bacterial isolates, including Escherichia coli and Staphylococcus aureus. Both chitosan-AgNP and AuNP showed powerful antimicrobial activities compared to the control. On the other hand, chitosan-AgNP conjugation had better antibacterial ctivity than chitosan-AuNPs, which exhibited moderate activity against S. aureus and very low activity against E. coli. Furthermore, the antibiofilm potentials of the prepared conjugates were tested against four biofilm-forming bacteria, including P. aeruginosa, B. subtilis, E. coli, and S. aureus. The obtained results indicate that the chitosan-AgNP showed a promising anti-biofilm activities on all strains, especially S. aureus, while chitosan-AuNP conjugates showed moderate anti-biofilm against B. subtilis and weak activities against the other three strains. These results showed the superiority of chitosan-AgNP as a promising antibacterial as well as biofilm formation inhibitors.