Melt-electrospinning as a method to improve the dissolution and physical stability of a poorly water-soluble drug

Electrospinning: A New Frontier in Peptide Therapeutics

The nanofiber technology has recently undergone an unprecedented transformation, finding widespread utilities across diverse scientific disciplines. It is noteworthy that electrospinning approaches have emerged as an adaptable and successful approach to generate fibers ranging in rapidly as a class of therapeutic agents with a high level of target specificity. Peptides encounter several challenges as drugs, including swift breakdown by the body, rapid elimination from the bloodstream, inadequate stability, and restricted ability to cross cell membranes. This renders it challenging to employ them as drugs. However, electrospun nanofibers might address these problems. This review explores the promising potential of electrospinning nanofibers for peptide delivery. We delve into recent advancements in this technique, highlighting its effectiveness in overcoming challenges associated with peptide drug delivery. It provides an analysis of the trends identified in the use of the electrospinning technique and its role in peptide drug delivery systems, based on a review of data collected over a period of five to seven years.

Electrospun nanofibers: Focus on local therapeutic delivery targeting infectious disease

Whether it be due to genetic variances, lack of patient adherence, or sub-optimal drug metabolism, the risk of antibiotic resistance from medications administered systemically continues to pose significant challenges to fighting infectious diseases. Ideally, infections would be treated locally for maximal efficacy while minimizing off-target effects. The electrospinning of biomaterials has recently facilitated the creation of electrospun nanofibers as an alternative delivery vehicle for local treatment. This review describes electrospun nanofiber applications to locally target various infectious diseases. Electrospinning is first reviewed as a method to fabricate nanofiber platforms with advantageous properties for developing drug delivery systems. The emergence of artificial intelligence to facilitate the development of nanofiber formulations and the evaluation of operating parameters to customize therapeutic behavior are described. A range of biomaterials utilized for electrospinning nanofibers is summarized in the context of properties suitable for drug delivery, particularly to treat infectious diseases. The current body of literature for electrospun nanofiber applications to tackle infectious diseases, including sexually transmitted infections, oral infections, and Staphylococcus Aureus infections is described. We anticipate that the advantages of electrospun nanofibers to facilitate targeted application while minimizing antibiotic resistance will substantially expand their clinical use in coming years.

Electrospinning of Biomedical Nanofibers/Nanomembranes: Effects of Process Parameters

Nanotechnology has attracted great attention from researchers in modern science because nanomaterials have innovative and superior physical, chemical, and biological properties, and they can be altered and modified accordingly. As particles get smaller, their surface area increases compared to their volume. Electrospinning is one of the advanced techniques to produce ultrathin nanofibers and membranes, and it is one of the best ways to create continuous nanomaterials with variable biological, chemical, and physical properties. The produced fibers can be utilized in various domains such as wound dressing, drug release, enzyme immobilization, etc. This review examines the biomedical nanofibers/membranes produced by electrospinning techniques to investigate the effects of process parameters (e.g., solution characteristics, applied voltage, and ambient conditions) on nanofiber characteristics (physical, chemical, and mechanical properties). The solution parameters like (i) optimum concentration, (ii) higher molecular weight, and (iii) higher conductivity produce uniform nanofibers, smoother nanofibers, and a smaller and more uniform fiber diameter, respectively. In addition, process parameters such as (i) higher voltage and (ii) slower flow rate produce more polymer ejection from the nozzle and enhance the smoother fiber production, respectively. The optimum tip-to-collector distance is considered to be 13-15 cm. The ambient conditions such as (i) higher humidity and (ii) higher temperature produce thicker and thinner nanofibers, respectively. The controlled parameters through optimization process determine the size and quality of the fibers. The effects of each parameter are discussed in this review. The applications of nanofibers are also discussed.

The Effect of Carrier-Drug Ratios on Dissolution Performances of Poorly Soluble Drug in Crystalline Solid Dispersion System

The choice of carrier and drug ratio are critical factors as far as the type of solid dispersion is concerned. Amorphous solid dispersion has been cited as the most desirable type among the different types of solid dispersion due to the benefit of amorphicity in increasing the drug solubility of a poorly soluble drug. Recent reports delineated that a partially crystalline solid dispersion system may perform better due to the inherent issue of solution mediated recrystallisation of a completely amorphous system. In oppose to the conventional choice of using amorphous polymer, this study aimed to investigate the use of a crystalline carrier, polyethylene glycol (PEG) for dissolution enhancement of a model poorly soluble drug, Flurbiprofen (FBP), a BCS Class II candidate. Solid dispersions of different FBP to PEG 6000 molar ratios via solvent evaporation were prepared. Physical characterisation of preparations was performed using differential scanning calorimetry (DSC), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) and optical microscope. DSC and ATR-FTIR analyses suggest the obtained solid dispersion exhibits crystalline FBP. This is then supported by the optical microscope analysis as the birefringence of crystals was noted. Further increasing the drug-carrier molar ratio to one-to-three and one-to-six showed that there was an amorphous FBP constituent in the system. DSC analysis revealed the melting point depression of FBP by the carrier which signifies interaction between the drug and polymer. Dissolution study showed the solid dispersion of FBP improves the drug solubility and drug release compared to the pure drug. A higher carrier ratio in the formulation results in a higher drug release.

Melt Electrospinning of Polymers: Blends, Nanocomposites, Additives and Applications

Melt electrospinning has been developed in the last decade as an eco-friendly and solvent-free process to fill the gap between the advantages of solution electrospinning and the need of a cost-effective technique for industrial applications. Although the benefits of using melt electrospinning compared to solution electrospinning are impressive, there are still challenges that should be solved. These mainly concern to the improvement of polymer melt processability with reduction of polymer degradation and enhancement of fiber stability; and the achievement of a good control over the fiber size and especially for the production of large scale ultrafine fibers. This review is focused in the last research works discussing the different melt processing techniques, the most significant melt processing parameters, the incorporation of different additives (e.g., viscosity and conductivity modifiers), the development of polymer blends and nanocomposites, the new potential applications and the use of drug-loaded melt electrospun scaffolds for biomedical applications.

Melt Electrospinning of Nanofibers from Medical-Grade Poly(ε-Caprolactone) with a Modified Nozzle

Melt electrospun fibers, in general, have larger diameters than normally achieved with solution electrospinning. This study uses a modified nozzle to direct-write melt electrospun medical-grade poly(ε-caprolactone) onto a collector resulting in fibers with the smallest average diameter being 275 ± 86 nm under certain processing conditions. Within a flat-tipped nozzle is a small acupuncture needle positioned so that reduces the flow rate to ≈0.1 µL h^-1 and has the sharp tip protruding beyond the nozzle, into the Taylor cone. The investigations indicate that 1-mm needle protrusion coupled with a heating temperature of 120 °C produce the most consistent, small diameter nanofibers. Using different protrusion distances for the acupuncture needle results in an unstable jet that deposited poor quality fibers that, in turn, affects the next adjacent path. The material quality is notably affected by the direct-writing speed, which became unstable above 10 mm min^-1 . Coupled with a dual head printer, first melt electrospinning, then melt electrowriting could be performed in a single, automated process for the first time. Overall, the approach used here resulted in some of the smallest melt electrospun fibers reported to date and the smallest diameter fibers from a medical-grade degradable polymer using a melt processing technology.

Micellisation Mechanism and Behaviour of Soluplus®⁻Furosemide Micelles: Preformulation Studies of an Oral Nanocarrier-Based System

In this study, self-assembling Soluplus^® micelles were examined for inherent properties. Through calorimetric analysis, the critical micelle concentration (CMC) could be determined at 25 and 37 °C, and the influence of three media (Milli-Q water, phosphate-buffered saline (PBS) with a pH of 7.4 and 0.1 M HCl) on the lower critical solution temperature (LCST) was detected. Furthermore, the solubilisation of a poorly soluble drug, furosemide, into the Soluplus^® micelles was studied. The concentration-dependent properties of the micellar system were assessed through an examination of the micellar size, polydispersity, morphology, viscosity and solubilising properties, which were all found to be affected by the concentration, but temperature, pH and the composition of the test medium were also found to have an effect. Homogeneity in the estimated micellar size and morphology was shown for monophasic micelle dispersions in lower concentrations and with a shift towards more complex structures or aggregates in higher concentrations. The micelles were further investigated in terms of drug release and biocompatibility with mucus-producing HT29-MTX cells, where no biocompatibility issues were found. In this research, the implications for oral drug delivery are discussed and valuable preformulation information is provided on the micellar properties of a Soluplus^® drug system in a liquid or semi-solid form.