Preparing composite nanoparticles for immediate drug release by modifying electrohydrodynamic interfaces during electrospraying

Fabrication of hierarchical porous ethyl cellulose fibrous membrane by electro-centrifugal spinning for drug delivery systems with excellent integrated properties

Drug delivery systems (DDSs) based on micro-and nano- fibrous membrane have been developed for decades, in which great attention has been focused on achieving controlled drug release. However, the study on the integrated performance of these drug-loaded membranes in the use of in-vitro drug delivery dressing is lacking, as clinical medication also needs consideration from the perspectives of wound safety and patient convenience. Herein, a trilayered hierarchical porous ethyl cellulose (EC) fibrous membrane based DDS (EC-DDS) was developed by electro-centrifugal spinning. Significantly, the hierarchical porous structure of the EC-DDSs with high specific surface area (34.3 m²g^-1) and abundant long-regulative micro-and nano- channels demonstrated its merits in improving the hydrophobicity (long-term splash resistance (CA > 130°) and prolonging the drug release (the release time of ~80 % tetracycline hydrochloride (TCH) prolonged from 10 min to 24 h). Meanwhile, the trilayered EC-DDS also revealed excellent biocompatibility, antibacterial activity, air permeability, moisture permeability, water absorption capacity, mechanical strength, and flexibility. With these excellent integrated features, the EC-DDS could prevent external fluids, avoid infection, and provide comfort. Furthermore, this work also provides a new guide for the high-efficiency fabrication of porous fibrous membranes.

Phase transited asymmetric membrane floating nanoparticles: a means for better management of poorly water-soluble drugs

PURPOSE

Effective remedy to gastrointestinal (GI) side effects caused by poorly water-soluble drugs remains a challenge. Researching for novel techniques to reduce these side effects and increase patient adherence to medical treatment is of interest. The current study aims to develop an innovative nano-sized gastro-retentive drug delivery for better management of poorly water-soluble drugs.

METHOD

A non-disintegrating ibuprofen-asymmetric membrane floating nanoparticle (Ibuprofen-AMFNP) was prepared by phase inversion technique to increase the gastric residence of the drug. Powder characterization, solubility, in vitro buoyancy, effect on in vivo inflammatory markers, and polymer diffusibility studies were conducted on the prepared formulation. All UV-spectrophotometric analysis was accomplished through a fiber optic system.

RESULTS

The prepared Ibuprofen-AMFNPs were in the nano range of 114.45 nm ±1.31 nm. The formulation was buoyant for 12 h in the dissolution media indicating increased gastric residence, had better solubility and powder characteristics compared to the pure drug. Scanning electron microscopy revealed an outer non-porous and inner porous asymmetric membrane. Ibuprofen-AMFNP followed Higuchi drug release kinetics (p=0.9925) and had a Fickian diffusion release mechanism (n=0.05). Polymer diffusibility study showed that the 24 h stored formulation had faster drug release with no lag time (-923.08 nm/h) compared to a fresh formulation (2526.32 nm/h). The prepared nano-formulation showed a higher percentage of anti-inflammatory (85.144%) effect compared to the pure drug (78.336%).

CONCLUSION

Ibuprofen-AMFNP is envisioned to help reduce drug-related GI side effects, improve drug delivery, and thereby increase patient adherence to medical treatment.

Electrospraying as a novel process for the synthesis of particles/nanoparticles loaded with poorly water-soluble bioactive molecules

Hydrophobicity and low aqueous-solubility of different drugs/nutraceuticals remain a persistent challenge for their development and clinical/food applications. A range of nanotechnology strategies have been implemented to address this issue, and amongst which a particular emphasis has been made on those that afford an improved biological performance and tunable release kinetic of bioactives through a one-step process. More recently, the technique of electrospraying (or electrohydrodynamic atomization) has attained notable impulse in virtue of its potential to tune attributes of nano/micro-structured particles (e.g., porosity, particle size, etc.), rendering a near zero-order release kinetics, diminished burst release manner, as well as its simplicity, reproducibility, and applicability to a broad spectrum of hydrophobic and poorly water-soluble bioactives. Controlled morphology or monodispersity of designed particles could be properly obtained via electrospraying, with a high encapsulation efficiency and without unfavorable denaturation of thermosensitive bioactives upon encapsulation. This paper overviews the recent technological advances in electrospraying for the encapsulation of low queues-soluble bioactive agents. State-of-the-art, advantages, applications, and challenges for its implementation in pharmaceutical/food researches are also discussed.

Comparison of Amorphous Solid Dispersions of Spironolactone Prepared by Spray Drying and Electrospinning: The Influence of the Preparation Method on the Dissolution Properties

This research aimed to compare two solvent-based methods for the preparation of amorphous solid dispersions (ASDs) made up of poorly soluble spironolactone and poly(vinylpyrrolidone-co-vinyl acetate). The same apparatus was used to produce, in continuous mode, drug-loaded electrospun (ES) and spray-dried (SD) materials from dichloromethane and ethanol-containing solutions. The main differences between the two preparation methods were the concentration of the solution and application of high voltage. During electrospinning, a solution with a higher concentration and high voltage was used to form a fibrous product. In contrast, a dilute solution and no electrostatic force were applied during spray drying. Both ASD products showed an amorphous structure according to differential scanning calorimetry and X-ray powder diffraction results. However, the dissolution of the SD sample was not complete, while the ES sample exhibited close to 100% dissolution. The polarized microscopy images and Raman microscopy mapping of the samples highlighted that the SD particles contained crystalline traces, which can initiate precipitation during dissolution. Investigation of the dissolution media with a borescope made the precipitated particles visible while Raman spectroscopy measurements confirmed the appearance of the crystalline active pharmaceutical ingredient. To explain the micro-morphological differences, the shape and size of the prepared samples, the evaporation rate of residual solvents, and the influence of the electrostatic field during the preparation of ASDs had to be considered. This study demonstrated that the investigated factors have a great influence on the dissolution of the ASDs. Consequently, it is worth focusing on the selection of the appropriate ASD preparation method to avoid the deterioration of dissolution properties due to the presence of crystalline traces.

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.

Electrospun Multiple-Chamber Nanostructure and Its Potential Self-Healing Applications

To address the life span of materials in the process of daily use, new types of structural nanofibers, fabricated by multifluid electrospinning to encapsulate both epoxy resin and amine curing agent, were embedded into an epoxy matrix to provide it with self-healing ability. The nanofibers, which have a polyacrylonitrile sheath holding two separate cores, had an average diameter of 300 ± 140 nm with a uniform size distribution. The prepared fibers had a linear morphology with a clear three-chamber inner structure, as verified by scanning electron microscope and transmission electron microscope images. The two core sections were composed of epoxy and amine curing agents, respectively, as demonstrated under the synergistic characterization of Fourier transform infrared spectroscopy, thermogravimetric analysis (TGA), and differential scanning calorimetry. The TGA results disclosed that the core-shell nanofibers contained 9.06% triethylenetetramine and 20.71% cured epoxy. In the electrochemical corrosion experiment, self-healing coatings exhibited an effective anti-corrosion effect, unlike the composite without nanofibers. This complex nanostructure was proven to be an effective nanoreactor, which is useful to encapsulate reactive fluids. This engineering process by multiple-fluid electrospinning is the first time to prove that this special multiple-chamber structure has great potential in the field of self-healing.

On-line dissolution analysis of multiple drugs encapsulated in electrospun nanofibers

Electrospun nanofiber is a very attractive material which can be used as the support to form multiple-drug dosage. Understanding the dissolution process of different active drug ingredients released from electrospun fibers is of great importance to control and evaluate the quality of medicated nanofibers. Here we present the first study of on-line automatic analysis of dissolution of multiple drugs in electrospun fiber mats. Single-needle electrospinning technology is utilized to combine polymers, hydrophilic polyvinylpyrrolidone (PVP) and hydrophobic polycaprolactone (PCL) as carrier to load three poorly water-soluble non-steroidal anti-inflammatory drugs (paracetamol, nimesulide, and ibuprofen). The loading of the drugs in PVP/PCL electrospun fibers are characterized by various techniques, including scanning electron microscopy, X-ray diffraction, Fourier infrared spectroscopy and differential scanning calorimetry. The in vitro dissolution is investigated by our home-made portable analyzer, which can simultaneously on-line determine multiple drugs released from the nanofibers by a single step. The analysis shows a wide linear detection range of the drugs with limit-of-detection (LOD) down to μg/mL-level. The dissolution profiles of three ingredients in nanofibers can be monitored every thirty seconds from the beginning to the end in the entire dissolution process from only one HSCE run. The kinetic information of the dissolution, including the dissolution curve, characteristic dissolution time and dissolution efficiency, is obtained and evaluated for different dissolution media, drug loading content and the ratio of PVP/PCL. Our study provides a promising method for rapid and accurate dissolution testing of nanofiber-based drugs, and would extend the applications of separation techniques in pharmaceutical analysis.

Core-Shell Eudragit S100 Nanofibers Prepared via Triaxial Electrospinning to Provide a Colon-Targeted Extended Drug Release

In this study, a new modified triaxial electrospinning is implemented to generate an Eudragit S100 (ES100)-based core-shell structural nanofiber (CSF), which is loaded with aspirin. The CSFs have a straight line morphology with a smooth surface, an estimated average diameter of 740 ± 110 nm, and a clear core-shell structure with a shell thickness of 65 nm, as disclosed by the scanning electron microscopy and transmission electron microscopy results. Compared to the monolithic composite nanofibers (MCFs) produced using traditional blended single-fluid electrospinning, aspirin presented in both of them amorously owing to their good compatibility. The CSFs showed considerable advantages over the MCFs in providing the desired drug-controlled-release profiles, although both of them released the drug in an erosion mechanism. The former furnished a longer time period of time-delayed-release and a smaller portion released during the first two-hour acid condition for protecting the stomach membranes, and also showed a longer time period of aspirin-extended-release for avoiding possible drug overdose. The present protocols provide a polymer-based process-nanostructure-performance relationship to optimize the reasonable delivery of aspirin.

Electrospray: More than just an ionization source

Electrospraying (ES) is a potential-driven process of liquid atomization, which is employed in the field of analytical chemistry, particularly as an ionization technique for mass spectrometric analyses of biomolecules. In this review, we demonstrate the extraordinary versatility of the electrospray by overviewing the specifics and advanced applications of ES-based processing of low molecular mass compounds, biomolecules, polymers, nanoparticles, and cells. Thus, under suitable experimental conditions, ES can be used as a powerful tool for highly controlled deposition of homogeneous films or various patterns, which may sometimes even be organized into 3D structures. We also emphasize its capacity to produce composite materials including encapsulation systems and polymeric fibers. Further, we present several other, less common ES-based applications. This review provides an insight into the remarkable potential of ES, which can be very useful in the designing of innovative and unique strategies.

Electrosprayed Ultra-Thin Coating of Ethyl Cellulose on Drug Nanoparticles for Improved Sustained Release

In nanopharmaceutics, polymeric coating is a popular strategy for modifying the drug release kinetics and, thus, new methods for implementing the nanocoating processes are highly desired. In the present study, a modified coaxial electrospraying process was developed to formulate an ultra-thin layer of ethyl cellulose (EC) on a medicated composite core consisting of tamoxifen citrate (TAM) and EC. A traditional single-fluid blending electrospraying and its monolithic EC-TAM nanoparticles (NPs) were exploited to compare. The modified coaxial processes were demonstrated to be more continuous and robust. The created NPs with EC coating had a higher quality than the monolithic ones in terms of the shape, surface smoothness, and the uniform size distribution, as verified by the SEM and TEM results. XRD patterns suggested that TAM presented in all the NPs in an amorphous state thanks to the fine compatibility between EC and TAM, as indicated by the attenuated total reflection (ATR)-FTIR spectra. In vitro dissolution tests demonstrated that the NPs with EC coating required a time period of 7.58 h, 12.79 h, and 28.74 h for an accumulative release of 30%, 50%, and 90% of the loaded drug, respectively. The protocols reported here open a new way for developing novel medicated nanoparticles with functional coating.

Combining Electrospinning and Electrospraying to Prepare a Biomimetic Neural Scaffold with Synergistic Cues of Topography and Electrotransduction

The nerve tissue consists of aligned fibrous nerve bundles, in which neurons communicate and transmit information through electrical signals. Hence, biocompatibility, oriented fibrous structure, and electrical conductivity are key factors for the biomimetic design of nerve scaffolds. Herein, we built a technical platform to combine electrospinning and electrospraying for preparing a biomimetic scaffold with conductivity and aligned fibrous structure. The highly aligned polycaprolactone (PCL) microfibrous scaffolds with co-sprayed collagen and conductive polypyrrole nanoparticles (PPy NPs) showed good bioactivity, supplying a platform for exploring the effects of topographical guidance, fiber conductivity, and its mediated external electrical signals on neurogenesis. The results revealed that collagen-coated highly aligned PCL microfibrous scaffold induced PC12 cells oriented and elongated along the direction of fibers. In addition, the improved conductivity of PPy-coated aligned fibers and its mediated external electrical stimulation collectively contributed to the functional expression, including elongation, gene expression, and protein expression, of PC12 cells. We further demonstrated the potential mechanism where the fiber conductivity and its mediated external electrical signals resulted in the upregulation of voltage-gated calcium channel, leading to the influx of Ca²⁺, thereby activating intracellular signaling cascades, ultimately enhancing neurogenesis. This approach provides a strategy to design aligned fibrillary scaffolds with bioactive adhesion domains and electroconductivity for neural regeneration.

Electrosprayed nanoparticles of poly(p-dioxanone-co-melphalan) macromolecular prodrugs for treatment of xenograft ovarian carcinoma

Ovarian cancer is considered to be the most fatal reproductive cancers. Melphalan is used to treat ovarian cancer as an intraperitoneal chemotherapy agent. However, elucidating its pharmacokinetic behavior and preparing it for administration are challenging since it undergoes spontaneous hydrolysis. In this study, melphalan is transformed into a macromolecular prodrug by copolymerizing with p-dioxanone. The hydrophobicity of copolymer chains protects melphalan from hydrolysis. Poly(p-dioxanone-co-melphalan; PDCM) is electrosprayed and converted into nanoparticles (PDCM NPs) with diameters of ~300-350 nm to facilitate its intracellular delivery. UPLC-MS and HPLC are applied to verify and monitor the release of melphalan from PDCM NPs. PDCM NPs could suppress the proliferation of SKOV-3 cells. The IC50 of 4.3% melphalan-containing PDCM-3 NP was 70 mg/L, 72 h post administration. These suppression characteristics not only affected by the degradation and then the extracellular release of melphalan from PDCM NPs, but also the uptake via phagocytosis phenomenon in SKOV-3 cells. As revealed by flow cytometry, phagocytosis is a first-order process. Once phagocytosed, PDCM NPs are digested by lysosomes, causing a rapid release of melphalan into the cytoplasm, which ultimately causes suppression of SKOV-3 cell proliferation. Finally, the in vivo antitumor effects of PDCM NPs are verified in xenograft ovarian carcinoma. After a 20-day treatment, the tumor growth rate of the PDCM-3 NP group was (266 ± 178%) which was lower than those in the free melphalan group (367 ± 150%) and control group (648 ± 149%). Besides, significant tissue necrosis and growth suppression were observed in animals administered injections of PDCM NPs. Furthermore, the in vivo tracing results of Nile red-labeled PDCM NPs demonstrated that PDCM-3 NPs might be phagocytosed by macrophages and then taken to adjacent lymph nodes, which is a way of prevention or early treatment of lymphatic metastasis of tumors.

Electrospun Environment Remediation Nanofibers Using Unspinnable Liquids as the Sheath Fluids: A Review

Electrospinning, as a promising platform in multidisciplinary engineering over the past two decades, has overcome major challenges and has achieved remarkable breakthroughs in a wide variety of fields such as energy, environmental, and pharmaceutics. However, as a facile and cost-effective approach, its capability of creating nanofibers is still strongly limited by the numbers of treatable fluids. Most recently, more and more efforts have been spent on the treatments of liquids without electrospinnability using multifluid working processes. These unspinnable liquids, although have no electrospinnability themselves, can be converted into nanofibers when they are electrospun with an electrospinnable fluid. Among all sorts of multifluid electrospinning methods, coaxial electrospinning is the most fundamental one. In this review, the principle of modified coaxial electrospinning, in which unspinnable liquids are explored as the sheath working fluids, is introduced. Meanwhile, several typical examples are summarized, in which electrospun nanofibers aimed for the environment remediation were prepared using the modified coaxial electrospinning. Based on the exploration of unspinnable liquids, the present review opens a way for generating complex functional nanostructures from other kinds of multifluid electrospinning methods.

Compression-Responsive Photonic Crystals Based on Fluorine-Containing Polymers

Fluoropolymers represent a unique class of functional polymers due to their various interesting and important properties such as thermal stability, resistance toward chemicals, repellent behaviors, and their low refractive indices in comparison to other polymeric materials. Based on the latter optical property, fluoropolymers are particularly of interest for the preparation of photonic crystals for optical sensing application. Within the present study, photonic crystals were prepared based on core-interlayer-shell particles focusing on fluoropolymers. For particle assembly, the melt-shear organization technique was applied. The high order and refractive index contrast of the individual components of the colloidal crystal structure lead to remarkable reflection colors according to Bragg’s law of diffraction. Due to the special architecture of the particles, consisting of a soft core, a comparably hard interlayer, and again a soft shell, the resulting opal films were capable of changing their shape and domain sizes upon applied pressure, which was accompanied with a (reversible) change of the observed reflection colors as well. By the incorporation of adjustable amounts of UV cross-linking agents into the opal film and subsequent treatment with different UV irradiation times, stable and pressure-sensitive opal films were obtained. It is shown that the present strategy led to (i) pressure-sensitive opal films featuring reversibly switchable reflection colors and (ii) that opal films can be prepared, for which the written pattern—resulting from the compressed particles—could be fixed upon subsequent irradiation with UV light. The herein described novel fluoropolymer-containing photonic crystals, with their pressure-tunable reflection color, are promising candidates in the field of sensing devices and as potential candidates for anti-counterfeiting materials.

Thermal Extrusion 3D Printing for the Fabrication of Puerarin Immediate-Release Tablets

Thermal extrusion (TE) 3D printing is a thermoplastic semisolid-based rapid prototyping process, which is capable of building complex structures. The aim of this study was to manufacture rapid-release puerarin tablets without solvent through TE 3D printing. Novel rapid-release tablets were fabricated with polyethylene glycol (PEG 4000) as the carrier at appropriate puerarin/PEG 4000 ratios, assessed through differential scanning calorimetry (DSC), solubility, and dissolution tests. The novel structures of 3D-printed tablets with five different values were formed by printing paths, which established a flexible way of adjusting in vitro drug release. An obvious acceleration (85% of cumulative release about 7.5 min at the soonest) was observed for the tablets with internal structural design. It was inferred that puerarin formed simple eutectic mixtures with PEG 4000 and that puerarin dispersed into the carrier based on DSC and X-Ray powder diffraction (XRD). This highlights the combined advantage of PEG as a soluble polymer with TE 3D printing and provides a suitable system for rapid puerarin release.

Optical Fiber Refractometer Based Metal Ion Sensors

Research into optical fiber refractometers yielded remarkable results over the past decade. Numerous sensing schemes were proposed and demonstrated, which possessed different advantages while facing unique limitations. On top of their obvious applications in measuring refractive index changes of the ambient environment, several studies reported advanced applications of such sensors in heavy metal ion detection by means of surface coating of the refractometers with heavy metal ion sensitive materials. This paper surveys the effort these optical fiber metal ion sensors based on surface coated optical fiber refractometer, discusses different technologies and methods involved, and highlights recent notable advancements.

Neem gum based pH responsive hydrogel matrix: A new pharmaceutical excipient for the sustained release of anticancer drug

The present research work was aimed to synthesize neem gum-based site-specific drug delivery device for anticancer drug methotrexate at different pH condition. The hydrogel-based drug delivery device was synthesized by optimizing reaction parameters using a factorial design approach response surface method. This model comprised of various sets of reactions with varying concentrations of solvent, crosslinker, initiator and monomer under microwave radiation. Characterization of the candidate hydrogel was done using UV-visible spectrophotometer, FTIR, SEM, Raman, and XRD techniques. The release profile of the hydrogels network was studied through a methotrexate under different pH conditions. The drug encapsulation capacity was found to be around 93% and 90% in pH 7.4 and 6.8. Drug release through the synthesized hydrogel matrix was found to show non-Fickian behaviour at each medium. The hydrogel network showed less release in pH 6.8 than pH 7.4, suggesting that hydrogels may be suitable drug carriers for release of anticancer drug delivery system. Hemolysis testing was also done to check the compatibility of the synthesized drug delivery device with the four different blood samples. Hemolysis was found to be less than 1% in the case of all blood groups, which indicates that the synthesized candidate polymers are biocompatible with all blood groups.

The Relationships between the Working Fluids, Process Characteristics and Products from the Modified Coaxial Electrospinning of Zein

The accurate prediction and manipulation of nanoscale product sizes is a major challenge in material processing. In this investigation, two process characteristics were explored during the modified coaxial electrospinning of zein, with the aim of understanding how this impacts the products formed. The characteristics studied were the spreading angle at the unstable region (θ) and the length of the straight fluid jet (L). An electrospinnable zein core solution was prepared and processed with a sheath comprising ethanolic solutions of LiCl. The width of the zein nanoribbons formed (W) was found to be more closely correlated with the spreading angle and straight fluid jet length than with the experimental parameters (the electrolyte concentrations and conductivity of the shell fluids). Linear equations W = 546.44L - 666.04 and W = 2255.3θ - 22.7 could be developed with correlation coefficients of Rwl2 = 0.9845 and Rwθ2 = 0.9924, respectively. These highly linear relationships reveal that the process characteristics can be very useful tools for both predicting the quality of the electrospun products, and manipulating their sizes for functional applications. This arises because any changes in the experimental parameters would have an influence on both the process characteristics and the solid products' properties.

Fast dissolving oral films for drug delivery prepared from chitosan/pullulan electrospinning nanofibers

In this study, Chitosan/pullulan composite nanofiber fast dissolving oral films (FDOFs) were prepared via electrospinning technology. The ratio of chitosan/pullulan (C/P) had an influence on solution property and nanofiber morphology, with the increase of chitosan, viscosity and conductivity of solutions increased, the morphology obtained by scanning electron microscopy indicated that the diameter of nanofibers decreased initially then increased. The Fourier transform infrared spectra indicated hydrogen bond interactions between chitosan and pullulan molecules. X-ray diffraction analysis proved that electrospinning process decreased the crystallinity of materials. Thermal analysis showed that melting point, degradation temperature and glass transition temperature increased with the addition of chitosan content in the FDOF. Water solubility test proved that the FDOF can dissolve in water completely within 60 s. Finally, in order to prove its practicability in future, a model drug of aspirin was encapsulated in the FDOF successfully.

The Relationships between Process Parameters and Polymeric Nanofibers Fabricated Using a Modified Coaxial Electrospinning

The concrete relationship between the process parameters and nanoproduct properties is an important challenge for applying nanotechnology to produce functional nanomaterials. In this study, the relationships between series of process parameters and the medicated nanofibers’ diameter were investigated. With an electrospinnable solution of hydroxypropyl methylcellulose (HPMC) and ketoprofen as the core fluid, four kinds of nanofibers were prepared with ethanol as a sheath fluid and under the variable applied voltages. Based on these nanofibers, a series of relationships between the process parameters and the nanofibers’ diameters (D) were disclosed, such as with the height of the Taylor cone (H, D = 125 + 363H), with the angle of the Taylor cone (α, D = 1576 − 19α), with the length of the straight fluid jet (L, D = 285 + 209L), and with the spreading angle of the instable region (θ, D = 2342 − 43θ). In vitro dissolution tests verified that the smaller the diameters, the faster ketoprofen (KET) was released from the HPMC nanofibers. These concrete process-property relationships should provide a way to achieve new knowledge about the electrostatic energy-fluid interactions, and to meanwhile improve researchers’ capability to optimize the coaxial process conditions to achieve the desired nanoproducts.

The Process⁻Property⁻Performance Relationship of Medicated Nanoparticles Prepared by Modified Coaxial Electrospraying

In pharmaceutical nanotechnology, the intentional manipulation of working processes to fabricate nanoproducts with suitable properties for achieving the desired functional performances is highly sought after. The following paper aims to detail how a modified coaxial electrospraying has been developed to create ibuprofen-loaded hydroxypropyl methylcellulose nanoparticles for improving the drug dissolution rate. During the working processes, a key parameter, i.e., the spreading angle of atomization region (θ, °), could provide a linkage among the working process, the property of generated nanoparticles and their functional performance. Compared with the applied voltage (V, kV; D = 2713 - 82V with RθV2 = 0.9623), θ could provide a better correlation with the diameter of resultant nanoparticles (D, nm; D = 1096 - 5θ with RDθ2 = 0.9905), suggesting a usefulness of accurately predicting the nanoparticle diameter. The drug released from the electrosprayed nanoparticles involved both erosion and diffusion mechanisms. A univariate quadratic equation between the time of releasing 95% of the loaded drug (t, min) and D (t = 38.7 + 0.097D - 4.838 × 105D2 with a R2 value of 0.9976) suggests that the nanoparticle diameter has a profound influence on the drug release performance. The clear process-property-performance relationship should be useful for optimizing the electrospraying process, and in turn for achieving the desired medicated nanoparticles.

Interactions Between Paracetamol and Hypromellose in the Solid State

Hydroxypropyl methylcellulose (hypromellose) is a widely known excipient commonly used in the preparation of drug formulations. It can interact with some active pharmaceutical ingredients (APIs), thereby contributing to a reduction in crystallinity, serve as a solvent for API or form stable dispersion with no tendency to aggregation. The aim of the present study was to investigate the effect of hypromellose on the solubility, miscibility and amorphization of paracetamol in mixture with this polymer. Homogenized mixtures of paracetamol with hypromellose were studied using differential scanning calorimetry (DSC), hot-stage microscopy (HSM), Fourier transform infrared (FT-IR) and Raman methods to obtain a deeper insight into the interactions between ingredients in solid state including phase diagram construction for crystalline API and amorphous polymer. A DSC study revealed potential interaction between ingredients resulting in reduced paracetamol crystallinity. This was proved using heating-cooling-heating test to confirm paracetamol amorphization. FT-IR and Raman investigations excluded chemical reaction and hydrogen bonding between ingredients. The phase diagram developed facilitates predictions on the solubility of API in polymer, on the mutual miscibility of ingredients and on the temperature of mixture glass transition.

Fabrication of cellulose nanoparticles through electrospraying

This study reports the fabrication of cellulose nanoparticles through electrospraying the solution of cellulose in N,N-dimethylacetamide/lithium chloride solvent as well as investigating the effect of electrospraying conditions and molecular weight on the average size of electrosprayed nanoparticles. Electrospraying of cellulose was carried out with the following range for each factor, namely concentration = 1-3 wt%, voltage = 15-23 kV, nozzle-collector distance = 10-25 cm, and feed rate = 0.03-0.0875 ml/h. The smallest nanoparticles had an average size of around 40 nm. Results showed that lowering the solution concentration and feed rate, as well as increasing the nozzle-collector distance and applied voltage led to a decrease in the average size of the electrosprayed cellulose nanoparticles. Fourier transform infrared analysis proved that no chemical change had occurred in the cellulose structure after the electrospraying process. According to X-ray diffraction (XRD) results, cellulose nanoparticles showed a lower degree of crystallinity in comparison with the raw cellulose powder. XRD results also proved the absence of LiCl salt in the electrosprayed nanoparticles.

Fast Dissolving of Ferulic Acid via Electrospun Ternary Amorphous Composites Produced by a Coaxial Process

Enhancing the dissolution of insoluble active ingredients comprises one of the most important issues in the pharmaceutical and biomaterial fields. Here, a third generation solid dispersion (3rd SD) of ferulic acid was designed and fabricated by a modified coaxial electrospinning process. A traditional second generation SD (2nd SD) was also prepared by common one-fluid blending electrospinning and was used as a control. With poly(vinyl alcohol) as the fiber matrix and polyvinylpyrrolidone K10 as an additive in the 3rd SDs, the two electrospinning processes were investigated. The prepared 2nd and 3rd SDs were subjected to a series of characterizations, including X-ray diffraction (XRD), scanning electron microscope (SEM), hydrophilicity and in vitro drug dissolving experiments. The results demonstrate that both SDs were monolithic nanocomposites and that the drugs were amorphously distributed within the matrix. However, the 3rd SDs had better morphology with smaller size, narrower size distribution, and smaller water contact angles than the 2nd SDs. Dissolution tests verified that the 3rd SDs could release their loaded cargoes within 60 s, which was over three times faster than the 2nd SDs. Therefore, a combined strategy based on the modified coaxial electrospinning and the logical selections of drug carriers is demonstrated for creating advanced biomaterials.

Fast dissolving drug delivery membrane based on the ultra-thin shell of electrospun core-shell nanofibers

Structural nanocomposites that provide fast dissolving drug release profiles are highly in demand in pharmaceutics. In this study, a poorly water-soluble drug such as quercetin or tamoxifen citrate (TC) was selected as a model active pharmaceutical ingredient. Core-shell nanofibers with ultra-thin shells were designed and prepared using modified coaxial electrospinning. Polyvinylpyrrolidone (PVP) K90 or Polycaprolactone (PCL) was selected as core. The drugs and PVP K10 were selected as shell. All types of solutions can be used as the shell fluids in modified coaxial process regardless of their electrospinnability, which means the increasing functional ingredients and unspinnable matrix can be processed. Evaluations via SEM and TEM demonstrated that the core-shell nanofibers had linear morphology with a shell thickness smaller than 100 nm. XRD and FTIR results showed that the model drug was distributed in the polymeric matrix amorphously and that PVP K10 had good compatibility with quercetin or TC. In vitro dissolution tests suggested that the core-shell nanofibers with ultra-thin shells released the loaded cargoes in the dissolution media within 1 min. The present investigation paved a new way for implementing the modified coaxial processes, which can be utilized to fabricate structural nanocomposites with ultra-thin shells for enhancing the fast dissolution of poorly water-soluble drugs.

Electrospun Blank Nanocoating for Improved Sustained Release Profiles from Medicated Gliadin Nanofibers

Nanomaterials providing sustained release profiles are highly desired for efficacious drug delivery. Advanced nanotechnologies are useful tools for creating elaborate nanostructure-based nanomaterials to achieve the designed functional performances. In this research, a modified coaxial electrospinning was explored to fabricate a novel core-sheath nanostructure (nanofibers F2), in which a sheath drug-free gliadin layer was successfully coated on the core ketoprofen (KET)-gliadin nanocomposite. A monolithic nanocomposite (nanofibers F1) that was generated through traditional blending electrospinning of core fluid was utilized as a control. Scanning electron microscopy demonstrated that both nanofibers F1 and F2 were linear. Transmission electron microscopy verified that nanofibers F2 featured a clear core-sheath nanostructure with a thin sheath layer about 25 nm, whereas their cores and nanofibers F1 were homogeneous KET-gliadin nanocomposites. X-ray diffraction patterns verified that, as a result of fine compatibility, KET was dispersed in gliadin in an amorphous state. In vitro dissolution tests demonstrated that the thin blank nanocoating in nanofibers F2 significantly modified drug release kinetics from a traditional exponential equation of nanofibers F1 to a zero-order controlled release model, linearly freeing 95.7 ± 4.7% of the loaded cargoes over a time period of 16 h.