Development and Characterization of Eudragit®-Based Electrospun Nanofibrous Mats and Their Formulation into Nanofiber Tablets for the Modified Release of Furosemide

On-Demand Sequential Release of Dual Drug from pH-Responsive Electrospun Janus Nanofiber Membranes toward Wound Healing and Infection Control

Drugs against bacteria and abnormal cells, such as antibiotics and anticancer drugs, may save human lives. However, drug resistance is becoming more common in the clinical world. Nowadays, a synergistic action of multiple bioactive compounds and their combination with smart nanoplatforms has been considered an alternative therapeutic strategy to fight drug resistance in multidrug-resistant cancers and microorganisms. The present study reports a one-step fabrication of innovative pH-responsive Janus nanofibers loaded with two active compounds, each in separate polymer compartments for synergistic combination therapy. By dissolving one of the compartments from the nanofibers, we could clearly demonstrate a highly yielded anisotropic Janus structure with two faces by scanning electron microscopy (SEM) analysis. To better understand the distinctive attributes of Janus nanofibers, several analytical methods, such as X-ray diffraction (XRD), FTIR spectroscopy, and contact angle goniometry, were utilized to examine and compare them to those of monolithic nanofibers. Furthermore, a drug release test was conducted in pH 7.4 and 6.0 media since the properties of Janus nanofibers correlate significantly with different environmental pH levels. This resulted in the on-demand sequential codelivery of octenidine (OCT) and curcumin (CUR) to the corresponding pH stimulus. Accordingly, the antibacterial properties of Janus fibers against Escherichia coli and Staphylococcus aureus, tested in a suspension test, were pH-dependent, i.e., greater in pH 6 due to the synergistic action of two active compounds, and Eudragit E100 (EE), and highly satisfactory. The biocompatibility of the Janus fibers was confirmed in selected tests.

The Study of Amorphous Kaempferol Dispersions Involving FT-IR Spectroscopy

Attenuated total reflection-Mid-Fourier transform-infrared (ATR-Mid-FT-IR) spectroscopy combined with principal component analysis (PCA) has been applied for the discrimination of amorphous solid dispersion (ASD) of kaempferol with different types of Eudragit (L100, L100-55, EPO). The ASD samples were prepared by ball milling. Training and test sets for PCA consisted of a pure compound, physical mixture, and incomplete/complete amorphous solid dispersion. The obtained results confirmed that the range 400-1700 cm-1 was the major contributor to the variance described by PC1 and PC2, which are the fingerprint region. The obtained PCA model selected fully amorphous samples as follows: five for KMP-EL100, two for KMP-EL100-55, and six for KMP-EPO (which was confirmed by the XRPD analysis). DSC analysis confirmed full miscibility of all ASDs (one glass transition temperature). FT-IR analysis confirmed the formation of hydrogen bonds between the -OH and/or -CH groups of KMP and the C=O group of Eudragits. Amorphization improved the solubility of kaempferol in pH 6.8, pH 5.5, and HCl 0.1 N.

pH-sensitive bilayer electrospun nanofibers based on ethyl cellulose and Eudragit S-100 as a dual delivery system for treatment of the burn wounds; preparation, characterizations, and in-vitro/in-vivo assessment

A pH-sensitive bilayer electrospun nanofibrous mat containing both antibiotic (gentamicin sulfate, GEN) and non-steroidal anti-inflammatory (diclofenac sodium, DIC) drugs was fabricated for burn wound dressing by electrospinning technique, in which ethyl cellulose (EC) and ethyl cellulose/Eudragit S-100 (EC/ES-100) formed the top and bottom layers, respectively. The fabricated pH-sensitive bilayer electrospun nanofibrous mats were characterized from aspects of both structure and efficiency. Physicochemical properties were investigated via SEM, FTIR, and TGA. The swelling ratio and in vitro drug release of the fabricated nanofibrous mats were studied in different pHs. MTT was applied to assess the safety of the fiber mats. Finally, the in vivo efficiency of the designed pH-sensitive bilayer electrospun nanofibrous mats was examined on the male Wistar rats. Based on the histological analysis and wound healing test (in vivo animal experiments), the (ES100/EC-DIC/GEN)-(EC) pH-sensitive bilayer nanofibrous mat displayed faster wound healing than other bilayer nanofibrous mat. As a result, (ES100/EC-DIC/GEN)-(EC) bilayer nanofibrous mat with pH-responsion could accelerate the burn wound healing process via decreasing the adverse effects of GEN and DIC as topical antimicrobial and anti-inflammatory agents, receptively.

Development of Novel Pharmaceutical Forms of the Marine Bioactive Pigment Echinochrome A Enabling Alternative Routes of Administration

Echinochrome A (EchA), a marine bioactive pigment isolated from various sea urchin species, is the active agent of the clinically approved drug Histochrome^®. EchA is currently only available in the form of an isotonic solution of its di- and tri-sodium salts due to its poor water solubility and sensitivity to oxidation. Electrospun polymeric nanofibers have lately emerged as promising drug carriers capable of improving the dissolution and bioavailability of drugs with limited water solubility. In the current study, EchA isolated from sea urchins of the genus Diadema collected at the island of Kastellorizo was incorporated in electrospun micro-/nanofibrous matrices composed of polycaprolactone and polyvinylpyrrolidone in various combinations. The physicochemical properties of the micro-/nanofibers were characterized using SEM, FT-IR, TGA and DSC analyses. The fabricated matrices exhibited variable dissolution/release profiles of EchA, as evidenced in in vitro experiments using gastrointestinal-like fluids (pH 1.2, 4.5 and 6.8). Ex vivo permeability studies using the EchA-loaded micro-/nanofibrous matrices showed an increased permeation of EchA across the duodenum barrier. The results of our study clearly show that electrospun polymeric micro-/nanofibers represent promising carriers for the development of new pharmaceutical formulations with controlled release, as well as increased stability and solubility of EchA, suitable for oral administration, while offering the potential for targeted delivery.

Electrospun nanofibres in drug delivery: advances in controlled release strategies

Emerging drug-delivery systems demand a controlled or programmable or sustained release of drug molecules to improve therapeutic efficacy and patient compliance. Such systems have been heavily investigated as they offer safe, accurate, and quality treatment for numerous diseases. Amongst newly developed drug-delivery systems, electrospun nanofibres have emerged as promising drug excipients and are coming up as promising biomaterials. The inimitable characteristics of electrospun nanofibres in terms of their high surface-to-volume ratio, high porosity, easy drug encapsulation, and programmable release make them an astounding drug-delivery vehicle.

Development of Robust Tablet Formulations with Enhanced Drug Dissolution Profiles from Centrifugally-Spun Micro-Fibrous Solid Dispersions of Itraconazole, a BCS Class II Drug

Fibre-based oral drug delivery systems are an attractive approach to addressing low drug solubility, although clear strategies for incorporating such systems into viable dosage forms have not yet been demonstrated. The present study extends our previous work on drug-loaded sucrose microfibres produced by centrifugal melt spinning to examine systems with high drug loading and investigates their incorporation into realistic tablet formulations. Itraconazole, a model BCS Class II hydrophobic drug, was incorporated into sucrose microfibres at 10, 20, 30, and 50% w/w. Microfibres were exposed to high relative humidity conditions (25 °C/75% RH) for 30 days to deliberately induce sucrose recrystallisation and collapse of the fibrous structure into powdery particles. The collapsed particles were successfully processed into pharmaceutically acceptable tablets using a dry mixing and direct compression approach. The dissolution advantage of the fresh microfibres was maintained and even enhanced after humidity treatment for drug loadings up to 30% w/w and, importantly, retained after compression into tablets. Variations in excipient content and compression force allowed manipulation of the disintegration rate and drug content of the tablets. This then permitted control of the rate of supersaturation generation, allowing the optimisation of the formulation in terms of its dissolution profile. In conclusion, the microfibre-tablet approach has been shown to be a viable method for formulating poorly soluble BCS Class II drugs with improved dissolution performance.

Electrospun Silica-Polyacrylonitrile Nanohybrids for Water Treatments

In this work, the removal of NOM (natural organic matter) as represented by humic acid by means of electrospun nanofiber adsorptive membranes (ENAMs) is described. Polyacrylonitrile (PAN) was used for the preparation of ENAMs incorporating silica nanoparticles as adsorbents. The addition of silica to the polymer left visible changes on the structural morphology and fibers' properties of the membrane. The membrane samples were characterized by pure water permeability, contact angle measurement, SEM, XPS, and XRD. This study assesses the preliminary performance of PAN-Si membranes for the removal of natural organic matter (NOM). The membrane rejected the humic acid, a surrogate of NOM, from 69.57% to 87.5%.

Preparation and characterization of flexible furosemide-loaded biodegradable microneedles for intradermal drug delivery

Transdermal drug delivery systems are a useful and minimally invasive alternative to other drug administration routes. Biodegradable polymeric microneedles (MNs) are widely used in controlled-release drug delivery due to their tunable properties and ease of patient self-administration. Polylactic-co-glycolic acid (PLGA) is often used for sustained drug release owing to special intrinsic properties including biocompatibility and biodegradability, which offer excellent applicability in preparing MNs. Congestive heart failure (CHF) is characterized by fluid overload during acute exacerbation, necessitating frequent patient hospitalization for continuous intravenous (i.v.) diuretic therapy. In the present study, we incorporated furosemide (FUR) as a model drug into flexible PLGA MN skin patches for potential intradermal delivery to overcome the limitations associated with i.v. diuresis. The MNs were fabricated by a casting-mold technique and consisted of two main parts, PLGA needle tips loaded with varying concentrations of FUR and a flexible backing layer comprising sodium alginate and glycerol. MN formulations were characterized by SEM and exhibited a uniform pyramidal shape. The measured surface pH of all samples suggested that no skin irritation is expected upon application. High encapsulation efficiency was obtained for FUR-MN formulations in which a decrease was noted as the FUR/PLGA ratio decreased. Drug loading content ranged from 19.1 ± 1% to 28.9 ± 1.4%. Successful insertion of MNs into a Parafilm® skin simulant model suggested that MNs will easily penetrate the skin's outermost layer, the stratum corneum, and will permit intradermal delivery of FUR. The MNs were further characterized by analytical methods. Finally, the MNs exhibited an initial burst release followed by a sustained release of FUR. Self-administered FUR-MNs can open new avenues to overcome i.v. drip limitations and increase patient compliance.

Development and Evaluation of a Novel Methotrexate-Loaded Electrospun Patch to Alleviate Psoriasis Plaques

OBJECTIVE

To achieve an effective topical formulation of Methotrexate (MTX) as a first-line treatment of psoriasis, we formulated three MTX-loaded electrospun nanofibrous patches composed of polycaprolactone (PCL), Eudragit L100, and a mixture of them.

SIGNIFICANCE

Topical delivery of MTX provides an appropriate therapeutic performance while circumventing the life-threatening side effects of systemic administration.

METHODS

Three MTX-loaded electrospun nanofibrous patches were prepared and characterized in terms of size and morphology (using SEM), thermal behavior (by TGA and DSC), and crystalline structure (using XRD). Furthermore, the wettability and mechanical strength of samples were investigated through water contact angle and tensile strength tests. Also, the encapsulation efficiency of MTX was calculated. Subsequently, in vitro drug release profile of each formulation was obtained and different kinetic models were fitted to achieve the best-matched model. Accordingly, the ex vivo skin permeation of MTX was studied for the optimum formulation.

RESULTS

All samples showed appropriate morphology, thermal behavior, and encapsulation efficiency. Also, XRD results showed that MTX is dispersed within the polymeric matrices in the amorphous state (with no crystalline region). Release studies demonstrated that MTX-loaded Eudragit L100-PCL formulation outperformed in terms of mechanical behavior and in vitro drug release. This formulation also exhibited better skin permeation.

CONCLUSION

The obtained controlled-release MTX-loaded electrospun patches seem promising to provide a long-acting topical treatment of psoriatic plaques with minimized systemic side effects.

Site-selective oral delivery of therapeutic antibodies to the inflamed colon via a folic acid-grafted organic/inorganic hybrid nanocomposite system

This study aimed to develop a pH-responsive folic acid-grafted organic/inorganic hybrid nanocomposite system for site-selective oral delivery of therapeutic antibodies. A folic acid-grafted aminoclay (FA-AC) was prepared via an in situ sol‒gel method. Then, a drug-loaded nanocomplex was prepared via the electrostatic interaction of FA-AC with infliximab (IFX), a model antibody, and coated with Eudragit® S100 (EFA-AC-IFX). FA-AC exhibited favorable profiles as a drug carrier including low cytotoxicity, good target selectivity, and capability to form a nanocomplex with negatively charged macromolecules. A pH-responsive FA-AC-based nanocomplex containing IFX (EFA-AC-IFX) was also obtained in a narrow size distribution with high entrapment efficiency (>87%). The conformational stability of IFX entrapped in EFA-AC-IFX was well maintained in the presence of proteolytic enzymes. EFA-AC-IFX exhibited pH-dependent drug release, minimizing premature drug release in gastric conditions and the upper intestine. Accordingly, oral administration of EFA-AC-IFX to colitis-induced mice was effective in alleviating the progression of ulcerative colitis, while oral IFX solution had no efficacy. These results suggest that a pH-responsive FA-AC-based nanocomposite system can be a new platform for the site-selective oral delivery of therapeutic antibodies.

Physicomechanical characterization and tablet compression of theophylline nanofibrous mats prepared by conventional and ultrasound enhanced electrospinning

Theophylline (TEO) nanofibers with polyethylene oxide (PEO) were prepared by conventional electrospinning (ES) and novel needleless ultrasound-enhanced electrospinning (USES). They were compared for Young's modulus, elongation at rupture and rupture stress, tabletability and drug release. Placebo (PEO) or drug-loaded (PEO/TEO 90:10) nanofibers were examined by scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC) and infrared spectroscopy (ATR-FTIR). Nanofibers prepared by USES were thinner than ES nanofibers and drug-loaded nanofibers thinner than placebo. Drug was mostly amorphous and interacted weakly with PEO. Mats generated by USES and also drug-loaded mats demonstrated higher Young's modulus (stiffness) and higher rupture stress. Under compression, USES and drug-loaded nanofibers demonstrated greater compaction work, higher yield pressure (Heckel and K-L models), and produced stronger tablets than ES and placebo respectively. Principal Component Analysis revealed two significant components explaining 91.05% of the variance. The first comprised the compaction work, yield pressure (ductility) and Young's modulus that were positively intercorrelated and elongation at rupture that was correlated negatively. The second comprised the mat rupture stress and tablet breaking load. Drug release from nanofibrous tablets was faster than tablets of physical mixture but there was no difference between the tablets of the two electrospinning methods.

Combinatorial therapy using RNAi and curcumin nano-architectures regresses tumors in breast and colon cancer models

Cancer is a debilitating disease and one of the leading causes of death in the world. In spite of the current clinical management being dependent on applying robust pathological variables and well-defined therapeutic strategies, there is an imminent need for novel and targeted therapies with least side effects. RNA interference (RNAi) has gained attention due to its precise potential for targeting multiple genes involved in cancer progression. Nanoparticles with their enhanced permeability and retention (EPR) effect have been found to overcome the limitations of RNAi-based therapies. With their high transportation capacity, nanocarriers can target RNAi molecules to tumor tissues and protect them from enzymatic degradation. Accumulating evidence has shown that tyrosine kinase Ephb4 is overexpressed in various cancers. Therefore, we report here the development and pre-clinical validation of curcumin-chitosan-loaded: eudragit-coated nanocomposites conjugated with Ephb4 shRNA as a feasible bio-drug to suppress breast and colon cancers. The proposed bio-drug is non-toxic and bio-compatible with a higher uptake efficiency and through our experimental results we have demonstrated the effective site-specific delivery of this biodrug and the successfull silencing of their respective target genes in vivo in autochthonous knockout models of breast and colon cancer. While mammary tumors showed a considerable decrease in size, oral administration of the biodrug conjugate to Apc knockout colon models prolonged the animal survival period by six months. Hence, this study has provided empirical proof that the combinatorial approach involving RNA interference and nanotechnology is a promising alliance for next-generation cancer therapeutics.

Management of Acute Radiodermatitis in Non-Melanoma Skin Cancer Patients Using Electrospun Nanofibrous Patches Loaded with Pinus halepensis Bark Extract

Simple Summary

The most frequent adverse effect for patients receiving radiotherapy, an effective treatment for skin cancer when surgical removal of the tumor is impossible, is acute radiodermatitis, affecting patients’ physical function and often leading to therapy termination. Creams and other topical formulations used so far for the prevention of acute radiodermatitis are applied at regular intervals but do not ensure a constant and controlled transepidermal absorption. The aqueous extract of Aleppo pine bark, previously preclinically and clinically assessed in the form of gel, was herein loaded on micro/nanofibrous patches and clinically evaluated in comparison with a commercially used reference cream on non-melanoma skin carcinoma patients undergoing radiotherapy. The experimental patch significantly contributed to prophylaxis and successful management of acute radiodermatitis, safely restoring skin and its biophysical parameters to normal levels and reducing patients’ discomfort. Topical application of pine-loaded micro/nanofibrous patches holds great potential for the development of a new generation of anti-inflammatory skin care dressings against radiodermatitis.

Abstract

Acute radiodermatitis is the most common side effect in non-melanoma skin cancer patients undergoing radiotherapy. Nonetheless, despite the ongoing progress of clinical trials, no effective regimen has been found yet. In this study, a non-woven patch, comprised of electrospun polymeric micro/nanofibers loaded with an aqueous extract of Pinus halepensis bark (PHBE), was fabricated and clinically tested for its efficacy to prevent radiodermatitis. The bioactivity of the PHBE patch was evaluated in comparison with a medical cream indicated for acute radiodermatitis. Twelve volunteer patients were selected and randomly assigned to two groups, applying either the PHBE patch or the reference cream daily. Evaluation of radiation-induced skin reactions was performed during the radiotherapy period and 1 month afterwards according to the Radiation Therapy Oncology Group (RTOG) grading scale, photo-documentation, patient-reported outcomes (Visual Analog Scale, questionnaire), biophysical measurements (hydration, transepidermal water loss, erythema, melanin), and image analysis. In contrast with the reference product, the PHBE patch showed significant anti-inflammatory activity and restored most skin parameters to normal levels 1 month after completion of radiation therapy. No adverse event was reported, indicating that the application of the PHBE patch can be considered as a safe medical device for prophylactic radiodermatitis treatment.

Probing the Release of Bupropion and Naltrexone Hydrochloride Salts from Biopolymeric Matrices of Diverse Chemical Structures

In the last decades, the notion of including excipients in the formulations, as inert substances aiding production processes, has changed and they are recently viewed as multifunctional discrete entities. It is now well documented that excipients serve several roles, spreading from the stabilization and modified release, to providing biocompatible properties and targeting moieties. The aim of this study was to develop matrix-based oral drug delivery systems of bupropion hydrochloride (BUP·HCl) and naltrexone hydrochloride (NTX·HCl), suitable for releasing these active substances in a modified manner, providing a stable level of drug release, which is simultaneously therapeutically effective and non-toxic, thus reducing side effects, after a single dose administration, throughout the gastrointestinal tract. The new formulations, employing hydroxypropylmethycellulose (HPMC K15M) (a cellulosic polymer, which, generally hydrates to form a gelatinous layer that is critical to prevent wetting and rapid drug release from the matrices), poly(methacylic acid-co-ethyl acrylate) 1:1 (Eudragit^® L100-55: effective for site specific drug delivery in intestine), poly(ethylene oxide) (PEO) (7 × 10⁶: a high molecular weight polymer, water-soluble, in micro-granular powder form), as the rate controlling polymers, were chosen to lead to a "soothing out" release pattern of these drugs, at 0 ≤ t ≤ 120 min. Moreover, the release of the two drugs from the ulvan-based tablets, was found to follow the desired profile, throughout the entire course of the dissolution experiments.

Electrospinning nanofiber technology: a multifaceted paradigm in biomedical applications

This review focuses on the process of preparation of nanofibers via Es, the design and setup of the instrument, critical parameter optimization, preferable polymers, solvents, characterization techniques, and recent development and biomedical applications of nanofibers.

Electrospinning for healthcare: recent advancements

This perspective explores recent developments and innovations in the electrospinning technique and their potential applications in biomedicine.

New Oral Coaxial Nanofibers for Gadodiamide-Prospective Intestinal Magnetic Resonance Imaging and Theranostic

PURPOSE

Gadodiamide (GDD) is a widely used magnetic resonance imaging (MRI) contrast agent. It is available only as intravenous injection. Unfortunately, it exhibits a high renal toxicity. In this respect, the author investigated the possibility of developing nanofibers (NFs, one-dimensional (1D) nanostructures) of GDD that would be promising for oral administration in intestinal imaging. NFs are prepared by electrospinning technique in which a strong electrostatic field is applied on a polymer solution.

METHODS

NFs were prepared by coaxial electrospinning technique using Eudragit S100 (ES 100) as a shell layer and GDD loaded with polyvinylpyrrolidone K90 (PVP K90) and hydroxypropyl-beta-cyclodextrin (HP-β-CyD) as core fibers. Compatibility study of the NFs ingredients was attested through ATR and DSC investigations. Thermogravimetric analysis of NFs was done to insure its stability. In vitro release of GDD in the intestinal medium with different pH values was measured. In vitro cytotoxicity test was done to prove its safety. Additionally, stability of NFs to perform its function was examined by X-ray.

RESULTS

NFs experienced high entrapment efficiency of about 94.3% ± 3.1%. The ingredients of NFs were compatible through FT-IR and DSC study. The in vitro release data of GDD from coaxial NFs were slow (˂14%) in pH 1.2 till 2 h, while at pH 7.4 it showed burst release of about 12% in the first 2 min. Thermogravimetric analysis proved the NFs are stable. The in vitro cytotoxicity study proved the safety of NFs. Using mammography, the coaxial NFs behaved the same as GDD plain indicating its ability to be a contrasting agent.

CONCLUSION

Coaxial NFs of GDD as a core with PVP K90 and HP-β-CyD and ES 100 as a shell were stable and efficient as oral imaging dosage form for the intestine. It might be a prospective theranostic.

Design and evaluation of pH-responsive hydrogel for oral delivery of amifostine and study on its radioprotective effects

The purpose of this study was to develop a novel pH-sensitive hydrogel which was used to regulate the acute radiation syndrome (ARS). The hydrogel was fabricated by grafting polycaprolactone onto methacrylic acid copolymer (MAC-g-PCL). Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (¹H NMR) confirmed the obtaining of MAC-g-PCL hydrogel. The hydrogel was pH-sensitive, at pH 1.2, it was compact hydrogel, but at pH7.4, it was dissolved solution. Its inner 3D morphology was observed by scanning electron microscope (SEM). Cell experiments indicated that the MAC-g-PCL hyrogel was out of cytotoxicity. The release profile of amifostine showed that small amount drug release in simulated gastric fluid (pH 1.2) and burst release in simulated intestinal fluid (pH 7.4). Thus, the pH-sensitive hydrogels could protect amifostine from enzymatic degradation in acidic stomach and deliver effectively in the intestine. The radioprotective efficacy was determined by peripheral complete blood parameters and 30-day survival study in mice acutely exposed to 4 Gy γ-ray total body irradiation. Results suggested that oral administration MAC-g-PCL/Ami before total body irradiation protected the mice from hematopoietic ARS and enhanced their survival. Furthermore, in vivo bio-distribution studies indicated that the drug could be sustained delivered at intestinal tract and entered the bloodstream. These results demonstrated that oral administration of amifostine hydrogel provided effective radioprotection to reduce the ARS injury.