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On page 1 showing 1 ~ 20 papers out of 125 papers

Why sildenafil and sildenafil citrate monohydrate crystals are not stable?

  • Somchai Sawatdee‎ et al.
  • Saudi pharmaceutical journal : SPJ : the official publication of the Saudi Pharmaceutical Society‎
  • 2015‎

Sildenafil citrate was crystallized by various techniques aiming to determine the behavior and factors affecting the crystal growth. There are only 2 types of sildenafil obtaining from crystallization: sildenafil (1) and sildenafil citrate monohydrate (2). The used techniques were (i) crystallization from saturated solutions, (ii) addition of an antisolvent, (iii) reflux and (iv) slow solvent evaporation method. By pursuing these various methods, our work pointed that the best formation of crystal (1) was obtained from technique no. (i). Surprisingly, the obtained crystals (1) were perfected if the process was an acidic pH at a cold temperature then perfect crystals occurred within a day. Crystals of compound (2) grew easily using technique no. (ii) which are various polar solvents over a wide range of pH and temperature preparation processes. The infrared spectroscopy and nuclear magnetic resonance spectra fit well with these two X-ray crystal structures. The crystal structures of sildenafil free base and salt forms were different from their different growing conditions leading to stability difference.


Physicochemical and Microbiological Stability of the Extemporaneous Sildenafil Citrate Oral Suspension.

  • Attawadee Sae Yoon‎ et al.
  • Scientia pharmaceutica‎
  • 2015‎

Sildenafil is a potent and selective phosphodiesterase-5 inhibitor that is effectively used in the treatment of pulmonary arterial hypertension. In several countries, hospital pharmacists prepare the drug in an extemporaneous liquid preparation as there are no liquid formulations available for pediatric and adult uses. The purpose of this study was to evaluate the stability of an extemporaneous sildenafil citrate oral suspension for 90 days, according to the ASEAN guideline on stability studies of drug products. The results showed that the preparation was a white suspension with a sweet taste. It was a viscous and weakly acidic mixture with pseudoplastic behavior. The drug content was in the range between 99.23% and 102.23%, and the microbial examination met the general requirements throughout the study period. Therefore, the extemporaneously compounded sildenafil suspensions were physically, chemically, and microbiologically stable for at least 90 days when stored at 30° and 40°C. Furthermore, the in-use stability study showed that the preparations had acceptable attributes at least 14 days after the first-time use. This might provide an alternative option when the commercial suspension is unavailable.


Inhibition of ATP-citrate lyase improves NASH, liver fibrosis, and dyslipidemia.

  • Marisa R Morrow‎ et al.
  • Cell metabolism‎
  • 2022‎

Elevated liver de novo lipogenesis contributes to non-alcoholic steatohepatitis (NASH) and can be inhibited by targeting acetyl-CoA carboxylase (ACC). However, hypertriglyceridemia limits the use of pharmacological ACC inhibitors as a monotherapy. ATP-citrate lyase (ACLY) generates acetyl-CoA and oxaloacetate from citrate, but whether inhibition is effective for treating NASH is unknown. Here, we characterize a new mouse model that replicates many of the pathological and molecular drivers of NASH and find that genetically inhibiting ACLY in hepatocytes reduces liver malonyl-CoA, oxaloacetate, steatosis, and ballooning as well as blood glucose, triglycerides, and cholesterol. Pharmacological inhibition of ACLY mirrors genetic inhibition but has additional positive effects on hepatic stellate cells, liver inflammation, and fibrosis. Mendelian randomization of human variants that mimic reductions in ACLY also associate with lower circulating triglycerides and biomarkers of NASH. These data indicate that inhibiting liver ACLY may be an effective approach for treatment of NASH and dyslipidemia.


Citrate Promotes Excessive Lipid Biosynthesis and Senescence in Tumor Cells for Tumor Therapy.

  • Yangjing Zhao‎ et al.
  • Advanced science (Weinheim, Baden-Wurttemberg, Germany)‎
  • 2022‎

Metabolic disorder is one of the hallmarks of cancers, and reprogramming of metabolism is becoming a novel strategy for cancer treatment. Citrate is a key metabolite and critical metabolic regulator linking glycolysis and lipid metabolism in cellular energy homeostasis. Here it is reported that citrate treatment (both sodium citrate and citric acid) significantly suppresses tumor cell proliferation and growth in various tumor types. Mechanistically, citrate promotes excessive lipid biosynthesis and induces disruption of lipid metabolism in tumor cells, resulting in tumor cell senescence and growth inhibition. Furthermore, ATM-associated DNA damage response cooperates with MAPK and mTOR signaling pathways to control citrate-induced tumor cell growth arrest and senescence. In vivo studies further demonstrate that citrate administration dramatically inhibits tumor growth and progression in a colon cancer xenograft model. Importantly, citrate administration combined with the conventional chemotherapy drugs exhibits synergistic antitumor effects in vivo in the colon cancer models. These results clearly indicate that citrate can reprogram lipid metabolism and cell fate in cancer cells, and targeting citrate can be a promising therapeutic strategy for tumor treatment.


Combined oral administration of bovine collagen peptides with calcium citrate inhibits bone loss in ovariectomized rats.

  • JunLi Liu‎ et al.
  • PloS one‎
  • 2015‎

Collagen peptides (CPs) and calcium citrate are commonly used as bone health supplements for treating osteoporosis. However, it remains unknown whether the combination of oral bovine CPs with calcium citrate is more effective than administration of either agent alone.


ER resident protein 44 promotes malignant phenotype in nasopharyngeal carcinoma through the interaction with ATP citrate lyase.

  • Hui Tian‎ et al.
  • Journal of translational medicine‎
  • 2021‎

Nasopharyngeal carcinoma (NPC) is one of the most common malignancy in head and neck. With the development of treatments, the prognosis has improved these years, but metastasis is still the main cause of treatment failure. The endoplasmic reticulum (ER) resident protein 44 is a UPR-induced ER protein of the protein disulphide isomerase (PDI) family. This study investigated the role of ERp44 in NPC progression.


TOF-SIMS Analysis Using Bi3 + as Primary Ions on Au Nanoparticles Supported by SiO2/Si: Providing Insight into Metal-Support Interactions.

  • Il Hee Kim‎ et al.
  • ACS omega‎
  • 2019‎

Au nanoparticles with a mean diameter of 20 nm with a coverage of ∼20% of the surface were distributed on a Si wafer surface and studied both before and after being annealed (at 100 and 300 °C). The two types of samples were analyzed using secondary ion mass spectroscopy (SIMS) with Bi3 + clusters as the primary ions combined with surface etching using Ar1000 + clusters. We observed a substantial difference in the SIMS spectra combined with a relatively short sputtering time of Ar1000 +. In the nonannealed samples, bare Au cluster cations and Si+ were observed in the SIMS spectra; AuSi+ clusters were also observed in the annealed samples. These results indicate Au-silicide formation at a part of the periphery of the Au nanoparticles upon annealing. We suggest that SIMS experiments using cluster ions such as Bi3 + can not only be used for surface elemental analyses but also provide information on local chemical environments of elements on the surface. This is an important issue in heterogeneous catalysis (e.g., strong metal-support interactions). We also advise that one should be careful interpreting the SIMS data combined with a longer Ar1000 + sputtering time because this can deteriorate the surfaces from their original structures.


Silica-coated magnetic-nanoparticle-induced cytotoxicity is reduced in microglia by glutathione and citrate identified using integrated omics.

  • Tae Hwan Shin‎ et al.
  • Particle and fibre toxicology‎
  • 2021‎

Nanoparticles have been utilized in brain research and therapeutics, including imaging, diagnosis, and drug delivery, owing to their versatile properties compared to bulk materials. However, exposure to nanoparticles leads to their accumulation in the brain, but drug development to counteract this nanotoxicity remains challenging. To date, concerns have risen about the potential toxicity to the brain associated with nanoparticles exposure via penetration of the brain blood barrier to address this issue.


Radiosensitizing effect of gold nanoparticle loaded with small interfering RNA-SP1 on lung cancer: AuNPs-si-SP1 regulates GZMB for radiosensitivity.

  • Ming Zhuang‎ et al.
  • Translational oncology‎
  • 2021‎

Radioresistance is a major challenge that largely limits the efficacy of radiotherapy in lung cancer. Gold nanoparticles (AuNPs) are emerging as novel radiosensitizers for cancer patients. Therefore, this study was designed to explore the radiosensitizing effect and mechanism of AuNPs loaded with small interfering RNA (siRNA)-SP1 (AuNPs-si-SP1) on lung cancer. AuNPs-si-SP1 was prepared by the noncovalent binding between AuNPs and siRNA-SP1. The adsorption capacity of AuNPs to siRNA-SP1 was analyzed by gel electrophoresis. The cell uptake of AuNPs-si-SP1 was observed under a laser confocal microscopy. Silencing efficacy of AuNPs-si-SP1 was validated by RT-qPCR and Western blot analysis. Cell viability was determined by CCK-8 assay, radiosensitization by plate colony formation assay, cell apoptosis and cell cycle by flow cytometry, and DNA double strand breaks by immunofluorescence in the presence or absence of AuNPs-si-SP1 or GZMB. The downstream mechanism of SP1 was predicted by bioinformatics analysis, followed by verification by Western blot analysis. Subcutaneous tumorigenesis in nude mice was established to verify the radiosensitization of AuNPs-si-SP1 and GZMB in vivo. AuNPs-si-SP1 effectively absorbed SP1 siRNA and was highly internalized by A549 cells to reduce SP1 protein expression. AuNPs-si-SP1 or GZMB overexpression promoted cells to G2/M phase, DNA double strand breaks, and enhanced radiosensitivity. SP1 could repress GZMB expression in lung cancer cells. In vivo experiments manifested that AuNPs-si-SP1 could inhibit the growth of solid tumor in nude mice to achieve radiosensitization by inhibiting SP1 to upregulate GZMB. AuNPs-si-SP1 might increase the radiosensitivity of lung cancer by inhibiting SP1 to upregulate GZMB.


Distinct dual roles of p-Tyr42 RhoA GTPase in tau phosphorylation and ATP citrate lyase activation upon different Aβ concentrations.

  • Kim Cuong Cap‎ et al.
  • Redox biology‎
  • 2020‎

Both the accumulation of Amyloid-β (Aβ) in plaques and phosphorylation of Tau protein (p-Tau) in neurofibrillary tangles have been identified as two major symptomatic features of Alzheimer's disease (AD). Despite of critical role of Aβ and p-Tau in AD progress, the interconnection of signalling pathways that Aβ induces p-Tau remains elusive. Herein, we observed that a popular AD model mouse (APP/PS1) and Aβ-injected mouse showed an increase in p-Tyr42 Rho in hippocampus of brain. Low concentrations of Aβ (1 μM) induced RhoA-mediated Ser422 phosphorylation of Tau protein (p-Ser422 Tau), but reduced the expression of ATP citrate lyase (ACL) in the HT22 hippocampal neuronal cell line. In contrast, high concentrations of Aβ (10 μM) along with high levels of superoxide production remarkably attenuated accumulation of p-Ser422 Tau, but augmented ACL expression and activated sterol regulatory element-binding protein 1 (SREBP1), leading to cellular senescence. Notably, a high concentration of Aβ (10 μM) induced nuclear localization of p-Tyr42 Rho, which positively regulated NAD kinase (NADK) expression by binding to the NADK promoter. Furthermore, severe AD patient brain showed high p-Tyr42 Rho levels. Collectively, our findings indicate that both high and low concentrations of Aβ are detrimental to neurons via distinct two p-Tyr42 RhoA-mediated signalling pathways in Ser422 phosphorylation of Tau and ACL expression.


Development of a Sildenafil Citrate Microemulsion-Loaded Hydrogel as a Potential System for Drug Delivery to the Penis and Its Cellular Metabolic Mechanism.

  • Apichart Atipairin‎ et al.
  • Pharmaceutics‎
  • 2020‎

Sildenafil citrate is used to treat mild to moderate erectile dysfunction and premature ejaculation. However, it has low oral bioavailability, numerous adverse effects, and delayed onset of action. These problems may be resolved by transdermal delivery to the penis. Hence, sildenafil citrate was formulated as a microemulsion system using isopropyl myristate, Tween 80, PEG400, and water (30:20:40:10). The hydrogel used in the microemulsion was 2% w/w poloxamer 188. The sildenafil microemulsion-loaded hydrogels were characterised for their appearance, particle size, pH, spreadability, swelling index, viscosity, sildenafil drug content, membrane permeation, epithelial cell cytotoxicity, and in vitro drug metabolism. The optimised formulated microemulsion showed the lowest droplet size and highest solubility of sildenafil citrate. The in vitro skin permeation of the sildenafil citrate microemulsion-loaded hydrogel was significantly higher than that of the sildenafil suspension, with a 1.97-fold enhancement ratio. The formulated microemulsion exhibited a 100% cell viability, indicating its safety for skin epithelial cells. The major metabolic pathway of sildenafil citrate loaded in the microemulsion formulation was hydroxylation. Furthermore, loading sildenafil in the microemulsion reduced the drug metabolite by approximately 50% compared to the sildenafil in aqueous suspension. The sildenafil citrate-loaded isopropyl myristate-based microemulsion hydrogels were physically and chemically stable over 6 months of storage. The sildenafil citrate microemulsion-loaded hydrogel showed in vitro results suitable for used as a transdermal drug delivery system.


Production of itaconate by whole-cell bioconversion of citrate mediated by expression of multiple cis-aconitate decarboxylase (cadA) genes in Escherichia coli.

  • Junyoung Kim‎ et al.
  • Scientific reports‎
  • 2017‎

Itaconate, a C5 unsaturated dicarboxylic acid, is an important chemical building block that is used in manufacturing high-value products, such as latex and superabsorbent polymers. Itaconate is produced by fermentation of sugars by the filamentous fungus Aspergillus terreus. However, fermentation by A. terreus involves a long fermentation period and the formation of various byproducts, resulting in high production costs. E. coli has been developed as an alternative for producing itaconate. However, fermentation of glucose gives low conversion yields and low productivity. Here, we report the whole-cell bioconversion of citrate to itaconate with enhanced aconitase and cis-aconitate decarboxylase activities by controlling the expression of multiple cadA genes. In addition, this bioconversion system does not require the use of buffers, which reduces the production cost and the byproducts released during purification. Using this whole-cell bioconversion system, we were able to catalyze the conversion of 319.8 mM of itaconate (41.6 g/L) from 500 mM citrate without any buffer system or additional cofactors, with 64.0% conversion in 19 h and a productivity of 2.19 g/L/h. Our bioconversion system suggests very high productivity for itaconate production.


Phenolic Profile of Nipa Palm Vinegar and Evaluation of Its Antilipidemic Activities.

  • Moragot Chatatikun‎ et al.
  • Evidence-based complementary and alternative medicine : eCAM‎
  • 2020‎

Obesity and overweight are strongly associated with dyslipidemia which can promote the development of cardiovascular diseases. Recently, natural products have been suggested as alternative compounds for antioxidant and antilipidemic activity. The objective of this study was to determine the phenolic compounds and assess the inhibitory activities on pancreatic lipase, cholesterol esterase, and cholesterol micellization of nipa palm vinegar (NPV). Total phenolic content was assessed and phenolic compounds were determined using the Folin-Ciocalteu assay and liquid chromatography-mass spectrometry (LC-MS), respectively. Pancreatic lipase and cholesterol esterase inhibitory activities of the NPV were measured using enzymatic colorimetric assays. The formation of cholesterol micelles was assessed using a cholesterol assay kit. The phenolic content of NPV was 167.10 ± 10.15 µg GAE/mL, and LC-MS analyses indicated the presence of gallic acid, isoquercetin, quercetin, catechin, and rutin as bioactive compounds. Additionally, the NPV inhibited pancreatic lipase and cholesterol esterase activities in a concentration-dependent manner. Moreover, the NPV also suppressed the formation of cholesterol micellization. These results suggest that phenolic compounds, especially gallic acid, isoquercetin, quercetin, catechin, and rutin, from NPV may be the main active compounds with possible cholesterol-lowering effects through inhibition of pancreatic lipase and cholesterol esterase activities as well as the inhibition of solubility of cholesterol micelles. Therefore, NPV may delay postprandial dyslipidemia, and it could be used as a natural source of bioactive compounds with antilipidemic activity. However, NPV should be extensively evaluated by animal and clinical human studies.


A prospective study on the long-term storage of sputum and the recovery of nontuberculous mycobacteria.

  • Byoung Soo Kwon‎ et al.
  • Therapeutic advances in respiratory disease‎
  • 2023‎

There is little information on the optimal storage conditions for recovery of nontuberculous Mycobacterium spp. (NTM) from refrigerated sputum.


PTPRM, a candidate tumor suppressor gene in small intestinal neuroendocrine tumors.

  • Elham Barazeghi‎ et al.
  • Endocrine connections‎
  • 2019‎

Small intestinal neuroendocrine tumors (SI-NETs) are small, slow growing neoplasms with loss of one copy of chromosome 18 as a common event. Frequently mutated genes on chromosome 18 or elsewhere have not been found so far. The aim of this study was to investigate a possible tumor suppressor role of the transmembrane receptor type tyrosine phosphatase PTPµ (PTPRM at 18p11) in SI-NETs. Immunohistochemistry, quantitative RT-PCR, colony formation assay and quantitative CpG methylation analysis by pyrosequencing were performed. Undetectable/very low levels of PTPRM or aberrant pattern of immunostaining, with both negative and positive areas, were detected in the majority of tumors (33/40), and a significantly reduced mRNA expression in metastases compared to primary tumors was observed. Both the DNA methylation inhibitor 5-aza-2'-deoxycytidine and the S-adenosylhomocysteine hydrolase inhibitor 3-deazaneplanocin A (DZNep) induced PTPRM expression in CNDT2.5 and KRJ-I SI-NET cells. CpG methylation of upstream regulatory regions, the promoter region and the exon 1/intron 1 boundary was detected by pyrosequencing analysis of the two cell lines and not in the analyzed SI-NETs. Overexpression of PTPRM in the SI-NET cell lines reduced cell growth and cell proliferation and induced apoptosis. The tyrosine phosphatase activity of PTPRM was not involved in cell growth inhibition. The results support a role for PTPRM as a dysregulated candidate tumor suppressor gene in SI-NETs and further analyses of the involved mechanisms are warranted.


Surface Layer Alteration of Multi-Oxide Silicate Glasses at a Near-Neutral pH in the Presence of Citric and Tartaric Acid.

  • Juho Yliniemi‎
  • Langmuir : the ACS journal of surfaces and colloids‎
  • 2022‎

This study aimed at determining the chemical alterations occurring at the surface of multi-oxide silicate glasses in the presence of organic ligands─citrate and tartrate─at a near-neutral pH. Batch surface titration experiments for basaltic glass and blast furnace slag (BFS) were conducted in the range of 6.4 < pH < 8 to investigate the element release, and speciation and solid phase saturation were modeled with PHREEQC software. Surface sensitive XPS and zeta potential measurements were used to characterize the alterations occurring on the surface. The results show that, while Al/Si and Fe/Si surface molar ratios of the raw materials increase at a near-neutral pH, the presence of organic ligands prevents the accumulation of Al and Fe on the surface and increases their concentration in the solution, particularly at pH 6.4. The Al- and Fe-complexing ligands decrease the effective concentration of these cations in the solution, consequently decreasing the surface cation/Si ratio, which destabilizes the silicate surface and increases the extent of dissolution by 300% within the 2 h experiment. Based on the thermodynamic modeling, 1:1 metal-to-ligand complexes are the most prevalent aqueous species under these experimental conditions. Moreover, changes in Ca/Si and Mg/Si surface ratios are observed in the presence of organic ligands; the direction of the change depends on the type of ligand and pH. The coordination of Al and Fe on the surface is different depending on the ligand and pH. This study provides a detailed description of the compositional changes occurring between the surface of multi-oxide silicate materials and the solution in the presence of citrate and tartrate. The surface layer composition is crucial not only for understanding and controlling the dissolution of these materials but also for determining the activated surface complexes and secondary minerals that they evolve into.


Putative Silicon Transporters and Effect of Temperature Stresses and Silicon Supplementation on Their Expressions and Tissue Silicon Content in Poinsettia.

  • Jiangtao Hu‎ et al.
  • Plants (Basel, Switzerland)‎
  • 2020‎

Silicon (Si) is a beneficial element for plants. To understand Si uptake and accumulation in poinsettia, the Si transporters and their expression patterns were investigated. Nodulin 26-like intrinsic membrane proteins (NIPs) act as transporters of water and small solutes, including silicic acid. In this study, one NIP member, designated EpLsi1, was identified. Additionally, a protein from the citrate transporter family, designated EpLsi2, was identified. Sequence analyses indicated that EpLsi1 belonged to the NIP-I subgroup, which has a low Si uptake capacity. Consistently, the measured tissue Si content in the poinsettia was less than 1.73 ± 0.17 mg·g-1 dry weight, which was very low when compared to that in high Si accumulators. The expressions of EpLsi1 and EpLsi2 in poinsettia cuttings treated with 0 mg·L-1 Si decreased under temperature stresses. A short-term Si supplementation decreased the expressions of both EpLsi1 and EpLsi2 in the roots and leaves, while a long-term Si supplementation increased the expression of EpLsi1 in the leaves, bracts, and cyathia, and increased the expression of EpLsi2 in the roots and leaves. Tissue Si content increased in the roots of cuttings treated with 75 mg·L-1 Si at both 4 and 40 °C, indicating that the transport activities of the EpLsi1 were enhanced under temperature stresses. A long-term Si supplementation increased the tissue Si content in the roots of poinsettia treated with 75 mg·L-1 Si. Overall, poinsettia was a low Si accumulator, the expressions of Si transporters were down-regulated, and the tissue Si content increased with temperature stresses and Si supplementation. These results may help the breeding and commercial production of poinsettia.


A Standardized Composition Comprised of Extracts from Rosmarinus officinalis, Annona squamosa and Zanthoxylum clava-herculis for Cellulite.

  • Mesfin Yimam‎ et al.
  • Pharmacognosy research‎
  • 2017‎

Cellulite, characterized by changes in the skin morphology presented as dimpled or puckered skin appearance, is highly prevalent among postadolescent women. Cellulite management ranges from topical cream applications to invasive procedures. While some interventions showed improvements in physical appearances of affected areas, so far, none have reversed the condition to a full recovery. These unsuccessful measures signify the intricate nature of cellulite etiology highlighting its complexity leading to the possibility for a combination treatment approach to target multiple mechanisms.


Optimization of Tyrosine Kinase Inhibitor-Loaded Gold Nanoparticles for Stimuli-Triggered Antileukemic Drug Release.

  • Andra-Sorina Tatar‎ et al.
  • Journal of functional biomaterials‎
  • 2023‎

Tyrosine kinase inhibitor (TKI) therapy is gaining attraction in advanced cancer therapeutics due to the ubiquity of kinases in cell survival and differentiation. Great progress was made in the past years in identifying tyrosine kinases that can function as valuable molecular targets and for the entrapment of their corresponding inhibitors in delivery compounds for triggered release. Herein we present a class of drug-delivery nanocompounds based on TKI Midostaurin-loaded gold nanoparticles that have the potential to be used as theranostic agents for the targeting of the FMS-like tyrosine kinase 3 (FLT3) in acute myeloid leukemia. We optimized the nanocompounds' formulation with loading efficiency in the 84-94% range and studied the drug release behavior in the presence of stimuli-responsive polymers. The therapeutic activity of MDS-loaded particles, superior to that of the free drug, was confirmed with toxicities depending on specific dosage ranges. No effect was observed on FLT3-negative cells or for the unloaded particles. Beyond druggability, we can track this type of nanocarrier inside biological structures as demonstrated via dark field microscopy. These properties might contribute to the facilitation of personalized drug dosage administration, critical for attaining a maximal therapeutic effect.


Development of 3D-Printed Bicompartmental Devices by Dual-Nozzle Fused Deposition Modeling (FDM) for Colon-Specific Drug Delivery.

  • Fatemeh Shojaie‎ et al.
  • Pharmaceutics‎
  • 2023‎

Dual-nozzle fused deposition modeling (FDM) is a 3D printing technique that allows for the simultaneous printing of two polymeric filaments and the design of complex geometries. Hence, hybrid formulations and structurally different sections can be combined into the same dosage form to achieve customized drug release kinetics. The objective of this study was to develop a novel bicompartmental device by dual-nozzle FDM for colon-specific drug delivery. Hydroxypropylmethylcellulose acetate succinate (HPMCAS) and polyvinyl alcohol (PVA) were selected as matrix-forming polymers of the outer pH-dependent and the inner water-soluble compartments, respectively. 5-Aminosalicylic acid (5-ASA) was selected as the model drug. Drug-free HPMCAS and drug-loaded PVA filaments suitable for FDM were extruded, and their properties were assessed by thermal, X-ray diffraction, microscopy, and texture analysis techniques. 5-ASA (20% w/w) remained mostly crystalline in the PVA matrix. Filaments were successfully printed into bicompartmental devices combining an outer cylindrical compartment and an inner spiral-shaped compartment that communicates with the external media through an opening. Scanning electron microscopy and X-ray tomography analysis were performed to guarantee the quality of the 3D-printed devices. In vitro drug release tests demonstrated a pH-responsive biphasic release pattern: a slow and sustained release period (pH values of 1.2 and 6.8) controlled by drug diffusion followed by a faster drug release phase (pH 7.4) governed by polymer relaxation/erosion. Overall, this research demonstrates the feasibility of the dual-nozzle FDM technique to obtain an innovative 3D-printed bicompartmental device for targeting 5-ASA to the colon.


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