Electrospun water soluble polymer mat for ultrafast release of Donepezil HCl

Unmet technological demands in orodispersible films for age-appropriate paediatric drug delivery

Age-appropriateness of a formulation is the ability to deliver variable but accurate doses to the paediatric population in a safe and acceptable manner to improve medical adherence and reduce medication errors. Paediatric drug delivery is a challenging area of formulation research due to the existing gap in knowledge. This includes the unknown safety of excipients in the paediatric population, the need for an age-appropriate formulation, the lack of an effective taste-masking method and the lack of paediatric pharmacokinetic data and patient acceptability. It is equally important to establish methods for predicting the biopharmaceutical performance of a paediatric formulation as a function of age. Overcoming the challenges of existing technologies and providing custom-made solutions for the development of age-appropriate formulation is, therefore, a daunting task. Orodispersible films (ODF) are promising as age-appropriate formulations, an unmet need in paediatric drug delivery. New technological improvements in taste masking, improving solubility and rate of dissolution of insoluble drugs, the flexibility of dosing and extemporaneous preparation of these films in a hospital good manufacturing practises (GMP) setup using 3D printing can increase its acceptance among clinicians, patients and caregivers. The current review discusses the problems and possibilities in ODF technology to address the outstanding issues of age-appropriateness, which is the hallmark of patient acceptance and medical adherence in paediatrics.

Nanofibers as precursors for the rapid formation of hydrogels

Hydrogels can be used in surgeries, which require a support material to maintain the correct anatomy. One major limitation is however the time required for the preparation of hydrogels under urgent conditions. Herein, we report a new method for a very fast preparation of hydrogels at room temperature. Nanofibers of dextran containing vinyl groups produced by electrospinning are loaded with redox- or photo-initiators for radical polymerization. Once dissolved in water, the nanofibers yield hydrogels either spontaneously or upon irradiation with UV light. We also show that the nanofibers can be loaded with active fillers so that hydrogels embedding nanocapsules are obtained. This concept could be applied for the rapid preparation of functional hydrogels which are needed as implants.

Orally disintegrating drug carriers for paediatric pharmacotherapy

Non-compliance, dosing inaccuracy, choking risk, flavour, and instability, are some of the issues associated with paediatric, oral dosage forms - tablets, capsules, solutions, and suspensions. Orally disintegrating drug carriers, a dosage form with growing interest, are thought to overcome several of the challenges associated with these conventional formulations by rapidly disintegrating within the buccal cavity without the need for water. This review serves as an up-to-date report on the various types of orodispersible delivery systems, currently being developed or commercialized, by detailing their characteristics, manufacturing processes, and applications in the paediatric population. Mentioned are orodispersible tablets, films, wafers and lyophilisates, mini-tablets, capsules, granules, electrospun fibers and webs. Also highlighted are the choice of excipients, quality control requirements, and expected pharmacokinetics of orally disintegrating drug carriers concerning the paediatric population. Overall, orodispersible formulations, particularly tablets, films, and lyophilisates/wafers, have shown to be a valuable addition to medication administration in minors, thus the execution of more targeted research and development activities is expected to lead to enhanced paediatric care and outcomes.

Electrospun Poly (Vinyl Alcohol) Nanofibrous Mat Loaded with Green Propolis Extract, Chitosan and Nystatin as an Innovative Wound Dressing Material

Purposes

The objective of this work was to produce and characterise biodegradable poly (vinyl alcohol) (PVA) nanofibre loaded with green propolis extract (GPE), chitosan (CS) and nystatin (NYS) alone and in mixtures as a potential wound dressing material.

Methods

The GPE, NYS and CS1% were loaded in electrospinning compositions based on PVA 7%, 8% and 12% solubilised in milli-Q water or a mixture of water and glacial acetic acid. The electrospinning compositions without actives (blank) and those loaded with actives were characterised by determining the pH, electrical conductivity and rheological properties. An image analysis procedure applied to photomicrographs obtained by scanning electronic microscopy (SEM) allowed the determination of the nanofibres' diameter distribution and average surface porosity. The disintegration time and swelling ratio of the nanofibre mats were also determined.

Results

The physicochemical parameters of the electrospinning compositions (pH, electrical conductivity and rheology) and the incorporated active ingredients (GPE, CS and NYS) affected the electrospun nanofibre mats properties. The electrospun nanofibres' mean diameters and surface porosity ranged from 151.5 to 684.5 nm and from 0.29 ± 0.04 to 0.50 ± 0.05. The PVA/CS electrospun nanofibres fibres exhibited the smallest diameters, high surface porosity, water absorption capacity and disintegration time. The characteristics of the PVA/CS nanofibres mat associated with the biodegradability of the polymers make them a novel material with the potential to be applied as wound and burn dressings.

The impact of the lamination pressure on the properties of electrospinned nanofibrous films

The purpose of this work is to explore the preparation of nanofibrous orally dispersible films (ODFs) by needleless electrospinning from the active pharmaceutical ingredient (API) Tadalafil using particles suspended in a solution of polymers and other excipients. The prepared films were characterized by a combination of scanning electron microscopy, mechanical tests, measurements of the disintegration time and dissolution characteristic, X-ray diffraction, and differential scanning calorimetry. Furthermore, we investigated the impact of lamination pressures in the range of 0 to 5 bars combined with films at various relative humidity values on the mechanical properties of the ODF. An increase in lamination pressure resulted in higher Young's modulus values, with the maximum value observed for a sample laminated at a pressure of 5 bar and the maximum stress and strain of the prepared ODF at a lamination pressure of 1.2 bar. Moreover, there was a significant increase in the disintegration time with increase in lamination pressure. The disintegration time ranged from 0.35 s for non-laminated samples to 12 s for samples laminated at a pressure of 5 bar. On the contrary, the lamination pressure did not reveal to have any impact on the dissolution kinetics. These results confirmed that the lamination pressure can improve the processability of ODFs without affecting the API dissolution kinetics.

Orodispersible Membranes from a Modified Coaxial Electrospinning for Fast Dissolution of Diclofenac Sodium

The dissolution of poorly water-soluble drugs has been a longstanding and important issue in pharmaceutics during the past several decades. Nanotechnologies and their products have been broadly investigated for providing novel strategies for resolving this problem. In the present study, a new orodispersible membrane (OM) comprising electrospun nanofibers is developed for the fast dissolution of diclofenac sodium (DS). A modified coaxial electrospinning was implemented for the preparation of membranes, during which an unspinnable solution of sucralose was explored as the sheath working fluid for smoothing the working processes and also adjusting the taste of membranes. SEM and TEM images demonstrated that the OMs were composed of linear nanofibers with core-sheath inner structures. XRD and ATR-FTIR results suggested that DS presented in the OMs in an amorphous state due to the fine compatibility between DS and PVP. In vitro dissolution measurements and simulated artificial tongue experiments verified that the OMs were able to release the loaded DS in a pulsatile manner. The present protocols pave the way for the fast dissolution and fast action of a series of poorly water-soluble active ingredients that are suitable for oral administration.

A new mode of Thinfilm and Nanofiber for burst release of the drug for Alzheimer disease; A complete scenario from dispersible polymer to formulation methodology

Alzheimer's disease (AD) is usually caused intellectual deterioration which happened due to the degeneration of cholinergic neurons. Donepezil is employed for cholinesterase enzyme Inhibition (ChEI) to treat AD in a wider population. Over the years, researchers finding difficulties prompted through traditional dosage forms particularly in geriatric patience. To avoid swallowing difficulties brought about with the aid of the AD population, researchers majorly focused on oral thin-film technology (OTF). This technology strongly eliminates issues caused by solid oral dosage forms. It is one of the quality strategies to an alternate drug that is used in the first-pass metabolism or pre systematic metabolism. The solubility of the drug is a higher trouble and it can expand by way of lowering particle size. Nanofibers are the excellent desire to minimize the drug particles to the submicron stage and can increase the drug release rate drastically. It can be prepared by Electrospinning technology by incorporating polymeric material into poorly soluble drugs. Mostly natural and biodegradable polymers prefer in all pharmaceutical preparations. Polymers employed for oral delivery should be stable, possess mucoadhesive property, and should release the drug by diffusion, degradation, and swelling mechanism. The objective of the present review explains various thin-film and nanofiber formulations used for faster drug release in the treatment of Alzheimer's disease.

The Impact of the Preparation Method on the Properties of Orodispersible Films with Aripiprazole: Electrospinning vs. Casting and 3D Printing Methods

Orodispersible films (ODFs) address the needs of pediatric and geriatric patients and people with swallowing difficulties due to fast disintegration in the mouth. Typically, they are obtained using the solvent casting method, but other techniques such as 3D printing and electrospinning have already been investigated. The decision on the manufacturing method is of crucial importance because it affects film properties. This study aimed to compare electrospun ODFs containing aripiprazole and polyvinyl alcohol with films prepared using casting and 3D printing methods. Characterization of films included DSC and XRD analysis, microscopic analysis, the assessment of mechanical parameters, disintegration, and dissolution tests. Simplified stability studies were performed after one month of storage. All prepared films met acceptance criteria for mechanical properties. Electrospun ODFs disintegrated in 1.0 s, which was much less than in the case of other films. Stability studies have shown the sensitivity of electrospun films to the storage condition resulting in partial recrystallization of ARP. These changes negatively affected the dissolution rate, but mechanical properties and disintegration time remained at a desirable level. The results demonstrated that electrospun fibers are promising solutions that can be used in the future for the treatment of patients with swallowing problems.

An Update on the Routes for the Delivery of Donepezil

Dementia is a significant public health problem in the 21st century. Alzheimer's disease (AD) is an essential factor in dementia. Currently, the drugs used for the treatment of AD are mainly acetylcholine inhibitors (AChEIs). As an AChEI, donepezil (DP) can improve patients' cognitive ability with low side effects and has been accepted by most patients and doctors. For AD patients, the dosage regimen is also crucial due to aging and diseases. Although there are DP oral tablets on the market, there are still many problems to be solved. At present, more and more research is conducted to optimize the route of administration of DP to improve the self-administration of patients. The research fields of DP administration include oral administration, injection administration, intranasal administration, and transdermal administration. This Review is to present the development of different DP administrations and evaluates the advantages and limitations of those works, hoping to optimize the DP dosage regimen for AD patients.

Electrospun PVP/PVA Nanofiber Mat as a Novel Potential Transdermal Drug-Delivery System for Buprenorphine: A Solution Needed for Pain Management

Over the past several decades, the formulation of novel nanofiber-based drug-delivery systems has been a frequent focus of scientists around the world. Aiming to introduce a novel nanofibrous transdermal drug-delivery system to treat pain, the nanofiber mats of buprenorphine-loaded poly (vinyl pyrrolidone) (Bup/PVP) and buprenorphine-loaded poly(vinyl alcohol)/poly(vinyl pyrrolidone) (Bup/PVP/PVA) were successfully fabricated by the electrospinning process for transdermal drug delivery. Similarly, PVP and PVP/PVA nanofibers were fabricated in the same conditions for comparison. The viscosity and electrical conductivity of all electrospinning solutions were measured, and nanofiber mats were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared (FT-IR) spectroscopy and contact angle analysis. The conductivity of PVP and PVP/PVA solutions showed a considerable increase by the addition of buprenorphine due to the polarity of buprenorphine. SEM images showed a smooth, fine and porous nanofibrous structure without any adhesion or knot for all of the samples. The contact angle analysis showed the increased hydrophilicity and wettability of PVP/PVA and Bup/PVP/PVA nanofibers compared to PVP and Bup/PVP nanofibers which can be attributed to the addition of PVA. Attenuated total reflectance (ATR) FT-IR results confirmed that the electrospinning process did not affect the chemical integrity of the drug. For the modification of the drug release rate, the cross-linking of nanofiber mats was carried out using glutaraldehyde. Drug release measurements using high-performance liquid chromatography (HPLC) analysis demonstrated that Bup/PVP/PVA nanofibers exhibited better physical and chemical properties compared to Bup/PVP. Furthermore, the cross-linking of nanofibers led to an increase in drug release time. Thus, the novel buprenorphine-loaded nanofibers can be efficient biomaterial patches for transdermal delivery against pain improving carrier retention and providing a controlled release of the drug.

Fast Dissolution Electrospun Medicated Nanofibers for Effective Delivery of Poorly Water-Soluble Drugs

BACKGROUND

Electrospinning is developing rapidly from an earlier laboratory method into an industrial process. The clinical applications are approached in various ways through electrospun medicated nanofibers. The fast-dissolving oral drug delivery system (DDS) among them is one of the most promising routes in the near future for commercial applications.

METHODS

Related papers are investigated, including the latest research results, on electrospun nanofiber-based fast-dissolution DDSs.

RESULTS

Several relative topics have been concluded: 1) the development of electrospinning, ranging from 1-fluid blending to multi-fluid process and potential applications in the formation of medicated nanofibers involving poorly water-soluble drugs; 2) Selection of appropriate polymer matrices and drug carriers for filament formation; 3) Types of poorly water-soluble drugs ideal for fast oral delivery; 4) The methods for evaluating fast-dissolving nanofibers; 5) The mechanisms that promote the fast dissolution of poorly water-soluble drugs by electrospun nanofibers; 6) the important issues for further development of electrospun medicated nanofibers as oral fast-dissolving drug delivery systems. Conclusions & Perspectives: The unique properties of electrospun-medicated nanofibers can be used as oral fast dissolving DDSs of poorly water-soluble drugs. However, some significant issues need to be investigated, such as scalable productions and solid dosage form conversions.

A Potential Alternative Orodispersible Formulation to Prednisolone Sodium Phosphate Orally Disintegrating Tablets

The orally disintegrating tablet (ODT) has shown vast potential as an alternative oral dosage form to conventional tablets wherein they can disintegrate rapidly (≤30 s) upon contact with saliva fluid and should have an acceptable mouthfeel as long as their weight doesn’t exceed 500 mg. However, owing to the bitterness of several active ingredients, there is a need to find a suitable alternative to ODTs that maintains their features and can be taste-masked more simply and inexpensively. Therefore, electrospun nanofibers and solvent-cast oral dispersible films (ODFs) are used in this study as potential OD formulations for prednisolone sodium phosphate (PSP) that is commercially available as ODTs. The encapsulation efficiency (EE%) of the ODFs was higher (≈100%) compared to the nanofibers (≈87%), while the disintegration time was considerably faster for the electrospun nanofibers (≈30 s) than the solvent-cast ODFs (≈700 s). Hence, accelerated release rate of PSP from the nanofibers was obtained, due to their higher surface area and characteristic surface morphology that permitted higher wettability and thus, faster erosion. Taste-assessment study using the electronic-tongue quantified the bitterness threshold of the drug and its aversiveness concentration (2.79 mM). Therefore, a taste-masking strategy would be useful when further formulating PSP as an OD formulation.

Detecting and targeting neurodegenerative disorders using electrospun nanofibrous matrices: current status and applications

Neurodegeneration is defined as the progressive atrophy and loss of function of neurons; it is present in neurodegenerative disorders such as Multiple Sclerosis, Alzheimer's, Huntington's, and Parkinson's diseases. The detection of such disorders is performed by various imaging modalities while their therapeutic management is quite challenging. Besides, the pathogenesis of neurodegenerative disorders is still under ongoing research due to complex and multi-factorial mechanisms. Currently, targeting the specific proteins responsible for neurodegeneration is of great interest to many researchers. Furthermore, nanotechnology-based approaches for targeting the affected neurons became an emerging field of interest. Nanostructures of various forms have been developed aiming to act as therapeutics for neurodegeneration, in which electrospun nanofibers seem to play an important role as biomedical products for both detection and management of the diseases. Electrospinning is an intriguing method able to produce nanofibers with a wide range of sizes and morphological characteristics. Such nanofibrous matrices can be delivered through different administration routes to target various diseases. In this review, the most recent advancements in electrospun nanofibrous systems that target or detect multiple neurodegenerative diseases have been enlightened and an introduction to the general aspects of neurodegenerative diseases and the electrospinning process has been made. Finally, future perspectives of neurodegeneration targeting were also discussed.

Encapsulation of emulsion droplets and nanoparticles in nanofibers as sustainable approach for their transport and storage

HYPOTHESIS

Emulsions are metastable and can be destabilized by coalescence and Ostwald ripening, which lead to phase separation. Immobilizing emulsion droplets in a solid material shall improve their stability during storage.

EXPERIMENTS

Miniemulsions and dispersions of nanocapsules are electrospun to immobilize colloids in polymer nanofibers. The nanofibers are dissolved after various period of time to re-disperse nanodroplets and nanocapsules.

FINDINGS

The size of nanodroplets and nanocapsules are close to the size of the original colloids before electrospinning, meaning that the emulsion droplets are efficiently stored overtime in nanofibers. Entrapping droplets in nanofibers by electrospinning allows a reduction of weight and volume of the emulsion of up to 82%. This method is therefore beneficial for improving shelf-life of emulsions, decreasing storage volume, and decreasing energy consumption for transportation of emulsions.

Progress in the design and development of "fast-dissolving" electrospun nanofibers based drug delivery systems - A systematic review

Electrospinning has emerged as most viable approach for the fabrication of nanofibers with several beneficial features that are essential to various applications ranging from environment to biomedicine. The electrospun nanofiber based drug delivery systems have shown tremendous advancements over the controlled and sustained release complemented from their high surface area, tunable porosity, mechanical endurance, offer compatible environment for drug encapsulation, biocompatibility, high drug loading and tailorable release characteristics. The dosage formulation of poorly water-soluble drugs often faces several challenges including complete dissolution with maximum therapeutic efficiency over a short period of time especially through oral administration. In this context, challenges associated with the dosage formulation of poorly-water soluble drugs can be addressed through combining the beneficial features of electrospun nanofibers. This review describes major developments progressed in the preparation of electrospun nanofibers based "fast dissolving" drug delivery systems by employing variety of polymers, drug molecules and encapsulation approaches with primary focus on oral delivery. Furthermore, the review also highlights current scientific challenges and provide an outlook with regard to future prospectus.

Preparation and Characterization of Fenofibrate-Loaded PVP Electrospun Microfibrous Sheets

Fenofibrate-loaded electrospun microfibrous sheets were prepared in an attempt to enhance the dissolution of the poorly soluble antihyperlipidemic agent and to improve its bioavailability. Physicochemical changes that appeared during the electrospinning process were monitored using a wide array of solid-state characterization techniques, including attenuated total reflectance Fourier-transformed infrared spectroscopy and positron annihilation lifetime spectroscopy, while fiber morphology was monitored via scanning electron microscopy. Dissolution studies carried out both in 0.025 M sodium dodecyl sulfate and in water revealed an immediate release of the active agent, with an approximately 40-fold release rate enhancement in water when compared to the micronized active agent. The dramatic increase in dissolution was attributed partially to the amorphous form of the originally crystalline active agent and the rapid disintegration of the electrospun microfibrous sheet due to its high surface area and porosity. The obtained results could pave the way for a formulation of the frequently used antihyperlipidemic agent with increased bioavailability.

Electrospinning Nanofibers for Therapeutics Delivery

The limitations of conventional therapeutic drugs necessitate the importance of developing novel therapeutics to treat diverse diseases. Conventional drugs have poor blood circulation time and are not stable or compatible with the biological system. Nanomaterials, with their exceptional structural properties, have gained significance as promising materials for the development of novel therapeutics. Nanofibers with unique physiochemical and biological properties have gained significant attention in the field of health care and biomedical research. The choice of a wide variety of materials for nanofiber fabrication, along with the release of therapeutic payload in sustained and controlled release patterns, make nanofibers an ideal material for drug delivery research. Electrospinning is the conventional method for fabricating nanofibers with different morphologies and is often used for the mass production of nanofibers. This review highlights the recent advancements in the use of nanofibers for the delivery of therapeutic drugs, nucleic acids and growth factors. A detailed mechanism for fabricating different types of nanofiber produced from electrospinning, and factors influencing nanofiber generation, are discussed. The insights from this review can provide a thorough understanding of the precise selection of materials used for fabricating nanofibers for specific therapeutic applications and also the importance of nanofibers for drug delivery applications.

Corona alternating current electrospinning: A combined approach for increasing the productivity of electrospinning

Corona alternating current electrospinning (C-ACES), a scaled-up productivity electrospinning method was developed by combining the intense forces of the alternating electrostatic field and a sharp-edged spinneret design with increased free surface. C-ACES reached two orders of magnitude higher productivity (up to 1200 mL/h) than the classical single needle direct current electrospinning (DCES) without any alteration of fiber properties. Polyvinylpyrrolidone K90 (PVPK90), a water soluble high molecular weight nonionic polymer was processed for the first time with single needle alternating current electrospinning (ACES) and C-ACES in order to prepare fast dissolving amorphous solid dispersions of spironolactone (SPIR), a poorly water-soluble antihypertensive model drug. The limited spinnability of PVPK90 with AC high voltage could only be resolved by optimizing the solution conductivity with organophilic salts such as sodium dodecyl sulfate (SDS) demonstrating the importance of conductivity during ACES. The effects of varied solution properties (composition and conductivity) and scaling-up were investigated by SEM imaging. Solid state analyses revealed that SPIR was dispersed in an amorphous form in the fibrous mats. In vitro dissolution tests showed ultrafast drug release in case of the amorphous formulations even when prepared with scaled-up C-ACES. Besides the enhancement of conductivity SDS also prevents SPIR from precipitation from the dissolution media due to its solubilization ability.

Continuous manufacturing of orally dissolving webs containing a poorly soluble drug via electrospinning

An orally dissolving web (ODW) formulation of poorly soluble carvedilol (CAR) was developed and manufactured continuously using electrospinning (ES) as a key technology. Phase solubility tests revealed that hydroxypropyl-β-cyclodextrin (HPβCD) solubilizer alone cannot ensure sufficient solubility (6.25 mg CAR in 20 mL) in the oral cavity even if citric acid was present to ionize the basic drug. In turn, electrospun amorphous nanofibers of polyvinylpyrrolidone K30 (PVPK30) and CAR exhibited notable supersaturation of the drug in the presence of citric acid. Differential scanning calorimetry (DSC) and X-ray powder diffraction (XRPD) confirmed the amorphous state of CAR. The final ODW was prepared by layering the nanofibers onto pullulan, a well-soluble polysaccharide film carrying citric acid. The double-layered formulation showed ultrafast disintegration and dissolution modeling the oral cavity meeting regulatory requirements (<30 s). The continuous production was accomplished using our recently developed continuous model system by controlled deposition of the nanofibers onto the carrier film strained to a wheel collector and followed by cutting into final dosage units. Performance tests of the continuous system revealed satisfactory content uniformity over time (average acceptance value = 9.45), while residual solvent content measurements showed trace amounts of ethanol (EtOH) after production and acceptable dimethyl-formamide (DMF) content with secondary drying at room temperature. The presented work demonstrates how ES can be part of a continuous manufacturing system as an advanced drying tool during the formulation of challenging drugs.

Electrospun fixed dose formulations of amlodipine besylate and valsartan

Increasing numbers of elderly people require multi-drug therapies. One route to improve adherence rates is to prepare fixed dose combinations (FDCs), in which multiple active ingredients are loaded into a single formulation. Here, we report the use of electrospinning to prepare fast-dissolving oral FDCs containing amlodipine besylate and valsartan, two drugs prescribed as FDCs for the treatment of hypertension. Electrospun fibers were prepared loaded with one or both drugs, using polyvinylpyrrolidone as the polymer matrix. The fibers were largely cylindrical in morphology and comprise amorphous solid dispersions except with the highest loadings of amlodipine besylate. HPLC demonstrated drug entrapment efficiencies of >85% of the theoretical dose. The mats have folding endurances and thicknesses suitable for use as oral films. The amlodipine besylate-loaded systems are fast-dissolving, with >90% release obtained within 120 s. In contrast, valsartan release from its single-drug formulations took longer, ranging from 360 s to 24 min. With the FDC formulations, rapid release within 360 s was achieved when the loading was 5% w/w of each drug, but again the release time increased with drug loading. Electrospun fibers therefore have significant promise as FDCs, but the target drug and its loading need to be carefully considered.

Quantification and spatial distribution of salicylic acid in film tablets using FT-Raman mapping with multivariate curve resolution

In this study, we proposed a rapid and sensitive method for quantification and spatial distribution of salicylic acid in film tablets using FT-Raman spectroscopy with multivariate curve resolution (MCR). For this purpose, the constituents of film tablets were identified by using FT-Raman spectroscopy, and then eight different concentrations of salicylic acid tablets were visualized by Raman mapping. MCR was applied to mapping data to expose the active pharmaceutical ingredients in the presence of other excipients by monitoring distribution maps and combination of FT-Raman mapping with MCR enabled the determination of lower salicylic acid concentrations. In addition, the distribution of major excipient, lactose, was examined in the tablet form. A calibration curve was obtained by plotting the intensity of the Raman signal at 1635 cm⁻¹ versus the concentration of salicylic acid and the correlation was found to be linear within the range of 0.5%–3.9% with a correlation coefficient of 0.99. The limit of detection for the technique was determined 0.35%. The ability of the technique to quantify salicylic acid in tablet test samples was also investigated.

Oromucosal multilayer films for tailor-made, controlled drug delivery

INTRODUCTION

The oral mucosa has recently become increasingly important as an alternative administration route for tailor-made, controlled drug delivery. Oromucosal multilayer films, assigned to the monograph oromucosal preparations in the Ph.Eur. may be a promising dosage form to overcome the requirements related to this drug delivery site. Areas covered: We provide an overview of multilayer films as drug delivery tools, and discuss manufacturing processes and characterization methods. We focus on the suitability of characterization methods for particular requirements of multilayer films. A classification was performed covering indication areas and APIs incorporated in multilayer film systems for oromucosal use in order to provide a summary of data published in this field. Expert opinion: The shift in drug development to high molecular weight drugs will influence the field of pharmaceutical development and delivery technologies. For a high number of indication areas, such as hormonal disorders, cardiovascular diseases or local treatment of infections, the flexible layer design of oromucosal multilayer films provides a promising option for tailor-made, controlled delivery of APIs to or through defined surfaces in the oral cavity. However, there is a lack of discriminating or standardized testing methods to assess the quality of multilayer films in a reliable way.

"Practical" Electrospinning of Biopolymers in Ionic Liquids

To address the need to scale up technologies for electrospinning of biopolymers from ionic liquids to practical volumes, a setup for the multi-needle electrospinning of chitin using the ionic liquid 1-ethyl-3-methylimidazolium acetate, [C₂ mim]-[OAc], was designed, built, and demonstrated. Materials with controllable and high surface area were prepared at the nanoscale using ionic-liquid solutions of high-molecular-weight chitin extracted with the same ionic liquid directly from shrimp shells.

Two Different Approaches for Oral Administration of Voriconazole Loaded Formulations: Electrospun Fibers versus β-Cyclodextrin Complexes

In this work, a comparison between two different preparation methods for the improvement of dissolution rate of an antifungal agent is presented. Poly(ε-caprolactone) (PCL) electrospun fibers and β-cyclodextrin (β-CD) complexes, which were produced via an electrospinning process and an inclusion complexation method, respectively, were addressed for the treatment of fungal infections. Voriconazole (VRCZ) drug was selected as a model drug. PCL nanofibers were characterized on the basis of morphology while phase solubility studies for β-CDs complexes were performed. Various concentrations (5, 10, 15 and 20 wt %) of VRCZ were loaded to PCL fibers and β-CD inclusions to study the in vitro release profile as well as in vitro antifungal activity. The results clearly indicated that all formulations showed an improved VRCZ solubility and can inhibit fungi proliferation.

Tailoring spatial distribution of Eu(TTA)3phen within electrospun polyacrylonitrile nanofibers for high fluorescence efficiency

Three different electrospinning processes were employed to tailor the distribution of the fluorescent complex Eu(TTA)₃phen within polyacrylonitrile nanofibers.

Fabrication and In Vitro/In Vivo Performance of Mucoadhesive Electrospun Nanofiber Mats Containing α-Mangostin

This study aimed to fabricate mucoadhesive electrospun nanofiber mats containing α-mangostin for the maintenance of oral hygiene and reduction of the bacterial growth that causes dental caries. Synthesized thiolated chitosan (CS-SH) blended with polyvinyl alcohol (PVA) was selected as the mucoadhesive polymer. α-Mangostin was incorporated into the CS-SH/PVA solution and electrospun to obtain nanofiber mats. Scanning electron microscopy, differential scanning calorimetry, X-ray diffraction, and tensile strength testing were used to characterize the mats. The swelling degree and mucoadhesion were also determined. The nanofiber mats were further evaluated regarding their α-mangostin content, in vitro α-mangostin release, antibacterial activity, cytotoxicity, in vivo performance, and stability. The results indicated that the mats were in the nanometer range. The α-mangostin was well incorporated into the mats, with an amorphous form. The mats showed suitable tensile strength, swelling, and mucoadhesive properties. The loading capacity increased when the initial amount of α-mangostin was increased. Rapid release of α-mangostin from the mats was achieved. Additionally, a fast bacterial killing rate occurred at the lowest concentration of nanofiber mats when α-mangostin was added to the mats. The mats were less cytotoxic after use for 72 h. Moreover, in vivo testing indicated that the mats could reduce the number of oral bacteria, with a good mouth feel. The mats maintained the amount of α-mangostin for 6 months. The results suggest that α-mangostin-loaded mucoadhesive electrospun nanofiber mats may be a promising material for oral care and the prevention of dental caries.

Nanofibers for drug delivery - incorporation and release of model molecules, influence of molecular weight and polymer structure

Nanofibers were prepared from polycaprolactone, polylactide and polyvinyl alcohol using Nanospider(TM) technology. Polyethylene glycols with molecular weights of 2 000, 6 000, 10 000 and 20 000 g/mol, which can be used to moderate the release profile of incorporated pharmacologically active compounds, served as model molecules. They were terminated by aromatic isocyanate and incorporated into the nanofibers. The release of these molecules into an aqueous environment was investigated. The influences of the molecular length and chemical composition of the nanofibers on the release rate and the amount of released polyethylene glycols were evaluated. Longer molecules released faster, as evidenced by a significantly higher amount of released molecules after 72 hours. However, the influence of the chemical composition of nanofibers was even more distinct - the highest amount of polyethylene glycol molecules released from polyvinyl alcohol nanofibers, the lowest amount from polylactide nanofibers.

5-Fluorouracil loaded Eudragit fibers prepared by electrospinning

A series of 5-fluorouracil (5-FU) loaded core/shell electrospun fibers is reported. The fibers have shells made of Eudragit S100 (ES-100), and drug-loaded cores comprising poly(vinylpyrrolidone), ethyl cellulose, ES-100, or drug alone. Monolithic 5-FU loaded ES-100 fibers were also prepared for comparison. Electron microscopy showed all the fibers to have smooth cylindrical shapes, and clear core-shell structures were visible for all samples except the monolithic fibers. 5-FU was present in the amorphous physical form in all the materials prepared. Dissolution studies showed that the ES-100 shell was not able to prevent drug release at pH 1.0, even though the polymer is completely insoluble at this pH: around 30-80% of the maximum drug release was reached after 2h immersion at pH 1.0. These observations are ascribed to the low molecular weight of 5-FU permitting it to diffuse through pores in the ES-100 coating, and the relatively high acid solubility of the drug providing a thermodynamic impetus for this to happen. In addition, the fibers were observed to be broken or merged following 2h at pH 1.0, giving additional escape routes for the 5-FU.