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Background: Drug-eluting gastrointestinal (GI) stents are emerging as promising platforms for the treatment of GI cancers and provide the combined advantages of mechanical support to prevent lumen occlusion and as a reservoir for localized drug delivery to tumors. Therefore, in this work we present a detailed quality assurance study of 5-fluorouracil (5FU) drug-eluting stents (DESs) as potential candidates for the treatment of obstructive GI cancers., Methods: The 5FU DESs were fabricated via a simple two-step sequential dip-coating process of commercial GI self-expanding nitinol stents with a 5FU-loaded polyurethane basecoat and a drug-free protective poly(ethylene-co-vinyl acetate) topcoat. The drug loading, content uniformity and drug stability were determined using a validated high-performance liquid chromatography (HPLC) method, which is also recommended in the United States Pharmacopeia. In vitro drug release studies were performed in phosphate buffered saline to determine the drug releasing properties of the two 5FU-loaded stents. Gas chromatography (GC) and HPLC were employed to determine total residual tetrahydrofuran and N,N -dimethylformamide in the stents remaining from the manufacturing process. Sterilization of the stents was performed using gamma radiation and stability testing was carried out for 3 months., Results: The drug loading analysis revealed excellent uniformity in the distribution of 5FU between and within individual stents. Determination of drug stability in the biorelevant release media confirmed that 5FU remains stable over 100 d. In vitro drug release studies from the stents revealed sustained release of 5FU across two different time scales (161 and 30 d), and mathematical modeling of drug release profiles revealed a diffusion-controlled mechanism for the sustained 5FU release. GC and HPLC analysis revealed that the daily residual solvent leached from the stents was below the United States (US) Food and Drug Administration (FDA) guidelines, and therefore, unlikely to cause localized/systemic toxicities. Sterilization of the stents with gamma radiation and accelerated stability tests over a period of 3 months revealed no significant effect on the stability or in vitro release of 5FU., Conclusion: Our results demonstrate that the 5FU DESs meet relevant quality standards and display favourable drug release characteristics for the potential treatment of GI cancers and related obstructions., Competing Interests: The authors report no conflicts of interest in this work., (© 2021 Arafat et al.)

Oesophageal stents have been widely used to prevent occlusion or stenosis in the treatment of oesophageal cancers. However, stent restenosis caused by tumour ingrowth occurs frequently after stent placement. Incorporating anti-cancer drugs into endoluminal stents is a promising strategy to provide a sustained release of drugs to oesophageal malignant tissues while prolonging the retention of the stent and relieving dysphagia. Recognizing the potential of 3D printing to produce personalised stents with patient specific geometries, we herein report the development of a drug-loaded 3D printed stent for the sustained local delivery of 5-fluorouracil (5-FU) to treat oesophageal cancer. The 3D printed drug-eluting stents (DESs) were fabricated via fused deposition modelling using 5-FU-loaded polyurethane filament. Determination of the 5-FU in the filament and stent (>97%) confirmed that minimal degradation of the drug occurred during the thermal extrusion and 3D printing processes. The physicochemical properties of the stents were investigated using photoacoustic Fourier-transform infrared (PA-FTIR) spectrophotometry, X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA) and mechanical testing. In vitro release studies revealed that the drug-loaded stents provided a sustained release of 5-FU over a period of 110 days and allowed the constant diffusion of 5-FU when in contact with oesophageal mucosa. Furthermore, the 3D printed stents exhibited good stability following sterilization with gamma or UV irradiation, and during accelerated storage. This study demonstrates that 3D printing is a powerful tool for manufacturing DESs which could easily be customized to provide personalized, patient specific geometries and drug doses.

5-fluorouracil (5-FU), commercially available as a topical product, is approved for non-melanoma skin cancer (NMSC) treatment with several clinical limitations. This work aimed to develop 5-FU-loaded topical patches as a potential alternative to overcome such drawbacks. The patches offer accurate dosing, controlled drug release and improved patient compliance. Our study highlights the development of Eudragit® E (EuE)-based drug-in-adhesive (DIA) patches containing a clinically significant high level of 5-FU (approximately 450 µg/cm2) formulated with various chemical permeation enhancers. The patches containing Transcutol® (Patch-TRAN) or oleic acid (Patch-OA) demonstrated significantly higher skin penetration ex vivo than their control counterpart, reaching 5-FU concentrations of 76.39 ± 27.7 µg/cm2 and 82.56 ± 8.2 µg/cm2, respectively. Furthermore, the findings from in vitro permeation studies also validated the superior skin permeation of 5-FU achieved by Patch-OA and Patch-TRAN over 72 h. Moreover, the EuE-based DIA patch platform demonstrated suitable adhesive and mechanical properties with an excellent safety profile evaluated through an inaugural in vivo human study involving 11 healthy volunteers. In conclusion, the DIA patches could be a novel alternative option for NMSC as the patches effectively deliver 5-FU into the dermis layer and receptor compartment ex vivo for an extended period with excellent mechanical and safety profiles. [ABSTRACT FROM AUTHOR]

Self-expanding metal stents (SEMSs) are currently the gold standard for the localised management of malignant gastrointestinal (GI) stenosis and/or obstructions. Despite encouraging clinical success, in-stent restenosis caused by tumour growth is a significant challenge. Incorporating chemotherapeutic drugs into GI stents is an emerging strategy to provide localised and sustained release of drugs to intestinal malignant tissues to prevent tumour growth. Therefore, the aim of this work was to develop and evaluate a local GI stent-based delivery system that provides a controlled release of 5-fluorouracil (5FU) over a course of several weeks to months, for the treatment of colorectal cancer and cancer-related stenosis/obstructions. The 5FU-loaded GI stents were fabricated via sequential dip-coating of commercial GI stents with a drug-loaded polyurethane (PU) basecoat and a drug-free poly(ethylene-co-vinyl acetate) (PEVA) topcoat. For comparison, two types of commercial stents were investigated, including bare and silicone (Si) membrane-covered stents. The physicochemical properties of the 5FU-loaded stents were evaluated using photoacoustic Fourier-transform infrared (PA-FTIR) spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and thermal analysis. In vitro release studies in biological medium revealed that the 5FU-loaded stents provided a sustained release of drug over the period studied (18 d), and cell viability, cell cycle distribution and apoptosis assays showed that the released 5FU had comparable anticancer activity against human colon cancer cells (HCT-116) to pure 5FU. This study demonstrates that dip-coating is a facile and reliable approach for fabricating drug-eluting stents (DESs) that are promising candidates for the treatment of GI obstructions and/or restenosis. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel green chromatographic method for the simultaneous determination of 5-fluorouracil and cisplatin. • Evaluation of the greenness profile using NEMI, GAPI, Eco-scale and AGREE tools. • Application of a newly developed HPLC method to evaluate the drug release of co-loaded 5-fluorouracil and cisplatin films. The combination of 5-fluorouracil (5-FU) and cisplatin (Cis) has been used for the treatment of many cancers. The combination demonstrates synergy and improved clinical outcomes encouraging developing a formulation with both drugs. An analytical procedure is essential for formulation studies; however, no method has been reported for the concurrent determination and quantification of both 5-FU and Cis to date. A novel, simple, accurate, and precise HPLC method was developed using a C 18 column (250 mm × 4.6 mm, 5 µm) and mobile phase composed of 0.5 mM sodium dodecyl sulfate: methanol (98:2, v/v), adjusted to pH 2.5 with phosphoric acid. A flow rate of 0.5 mL/min was applied and a photodiode array was utilized for detection and the retention times were 9.89 min (265 nm) for 5-FU and 5.36 min (210 nm) for Cis. Validation procedures were performed, and the method was found to be linear at ranges of 0.9–60.0 µg/mL for 5-FU and 6.0–60.0 µg/mL for Cis. The limits of detection (LOD) and quantitation (LOQ) were 0.10 and 0.25 µg/mL for 5-FU and 2.00 and 4.00 µg/mL for Cis, respectively. Other parameters such as precision, selectivity, robustness, and stability results were within acceptable limits. The method was applied to a model co-eluting film and its release profile was studied. Additionally, the method's greenness was evaluated by four assessment tools namely the national environmental method index (NEMI), analytical eco scale assessment (ESA), green analytical procedure index (GAPI), and Analytical GREEnness Metric Approach and Software (AGREE). The results demonstrated compliance with green analytical chemistry (GAC) practices. This research acts as a step towards further investigation of drug stability under different stress conditions and quantification of the intact drugs in presence of their degradation products. [ABSTRACT FROM AUTHOR]

[Display omitted] Adjuvant chemotherapy is highly recommended for liver cancer to enhance survival rates due to its tendency to recur frequently. Localized drug-eluting implants have gained traction as an alternative to overcome the limitations of systemic chemotherapy. This work describes the development of biodegradable 3D printed (3DP) bilayer films loaded with 5-fluorouracil (5FU) and cisplatin (Cis) with different infill percentages where the 5FU layers were 40%, 30%, and 30% and Cis layers were 10%, 15%, and 10% for films A, B, and C, respectively. The relevant characterization tests were performed, and the drug content of films was 0.68, 0.50, and 0.50 mg of 5FU and 0.39, 0.80, and 0.34 mg of Cis for films A, B, and C, respectively. Cis release was affected by the alterations to the film design, where films A, B, and C showed complete release at 12, 14, and 23 days, respectively. However, 5FU was released over 24 h for all films. The films were stable for up to two weeks after storage at 25 °C/65% relative humidity and four weeks at 4 °C where drug content, tensile strength, FTIR, and thermal analysis results demonstrated negligible alterations. The cytotoxicity of the films was assessed by MTS assays using HepG2 cell lines demonstrating up to 81% reduction in cell viability compared to blank films. Moreover, apoptosis was confirmed by Western Blots and the determination of mitochondrial cell potential, highlighting the potential of these films as a promising approach in adjuvant chemotherapy. [ABSTRACT FROM AUTHOR]

[Display omitted] • Drug-in-adhesive patches containing 5-fluorouracil for the treatment of skin cancer. • Pressure-sensitive adhesives using Eudragit® E and plasticizers for topical application. • Solubility parameters and thermal analysis for polymer-plasticizer miscibility evaluation. Topical patches containing 5-fluorouracil (5-FU) are a feasible alternative to overcome the shortcomings of commercial cream for the treatment of non-melanoma skin cancer (NMSC). Plasticizers are a critical component of drug-in-adhesive (DIA) patches as they can significantly affect the mechanical, adhesive and drug release characteristics of the patches. Eudragit® E (EuE) is a methacrylate-based cationic copolymer capable of producing flexible and adhesive films for topical application. In this study, the effect of plasticizers on the mechanical, adhesive and 5-FU release characteristics of EuE-based patches was comprehensively evaluated. While the elongation at break (%) and adhesion of the films were significantly increased with increasing triacetin, dibutyl sebacate (DBS) and triethyl citrate (TEC) concentrations, the tensile strength showed an inverse relationship. EuE plasticized with 40% triacetin, 30% DBS or 40% w/w TEC produced elastic and adhesive films most suitable for topical application. In vitro release studies of the 5-FU-loaded patches demonstrated an initial burst release pattern during the first 10 min followed by a slow release over 120 min. In summary, this study provides important information on effect of plasticizers for preparation of EuE-based patches with desired mechanical, adhesive and release characteristics of 5-FU towards their potential application in the treatment of NMSC. [ABSTRACT FROM AUTHOR]