Drug Database
FE

fentanyl citrate (OX20 / Rapinyl / EN 3267)

✓ Approved

Kyowa Kirin Co., Ltd. · Small Molecule · Small Molecule

What is fentanyl citrate?

fentanyl citrate is a small molecule developed by Kyowa Kirin Co., Ltd.. It is approved for therapeutic indications via oral (po) or sublingual (sl)/oral transmucosal or topical.

Drug Profile

Brand NamesOX20, Rapinyl, EN 3267
CompanyKyowa Kirin Co., Ltd.
Drug ClassSmall Molecule
RouteOral (PO), Sublingual (SL)/Oral Transmucosal, Topical
StatusApproved
Sources: ClinicalTrials.gov, Kyowa Kirin Co., Ltd.

Therapeutic Indications

fentanyl citrate is developed for 1 unique indication across 1 therapeutic area.

Therapeutic AreaConditionPhase
Neoplasms benign, malignant and unspecified (incl cysts and polyps)Cancer pain✓ Approved

Related Research Articles

PubMedIndian journal of anaesthesia2026-07-25

Comparative evaluation of segmental spinal anaesthesia with conventional spinal anaesthesia in endoscopic transurethral surgery.

Kumar Prashant P, Kumari Twinkal T, Vashishth Sumedha S, Kaur Kiranpreet K et al.

Lumbar spinal anaesthesia (LSA) for endoscopic urological procedures often causes extensive sympathetic blockade, leading to hypotension, bradycardia, and delayed ambulation. Thoracic segmental spinal anaesthesia (TSSA) offers targeted sensory blockades with limited motor involvement and improved haemodynamic stability. The primary objective of the study was to compare motor block onset between TSSA and LSA. Secondary objectives included sensory block characteristics, two-segment regression time, haemodynamics, perioperative complications, and patient and surgeon satisfaction. Forty American Society of Anesthesiologists (ASA) class I-II patients were randomised to group T (TSSA, n = 20; 1 mL 0.5% isobaric ropivacaine + 20 µg fentanyl at T11-T12) or group S (LSA, n = 20; 2 mL 0.5% hyperbaric ropivacaine + 20 µg fentanyl at L3-L4). Sensory and motor block, haemodynamic parameters, rescue analgesia, satisfaction scores, and adverse events were recorded. Group T achieved faster sensory block to T10 (1.7 ± 1.08 vs 4.48 ± 1.97 min, P < 0.001), quicker maximum block height (3.42 ± 1.46 vs 8.95 ± 3.3 min, P < 0.001), and shorter two-segment regression (58 ± 6.5 vs 88.77 ± 7.73 min, P < 0.001). Motor block onset was similar (6.6 ± 2.96 vs 5.8 ± 1.67 in groups T and S, respectively), but group S had higher Bromage scores and prolonged blockade (time to Bromage score 0: 61.85 ± 26.37 vs 184.21 ± 30.06 min, P < 0.001). Group S showed greater heart rate and mean arterial pressure reductions (P < 0.05). Patients in Group T ambulated earlier than group S (152.25 ± 29.76 vs 284 ± 26.04 min; P < 0.001). TSSA provides less motor blockade, targeted sensory block, maintains haemodynamic stability, and enables earlier ambulation, making it a safe and effective alternative in endoscopic urological surgery.

PMID 42500634
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PubMedCureus2026-07-25

Progression of Atrioventricular Conduction Disorder Induced by Radiofrequency Ablation for Hepatocellular Carcinoma.

Nakama Rakuhei R, Sone Miyuki M, Shoji Masaaki M, Ogura Nozomu N et al.

Radiofrequency ablation (RFA) is generally considered a safe treatment for hepatocellular carcinoma. Although cardiovascular complications have been occasionally reported, they are primarily attributed to sedatives and analgesics or the vasovagal reflex. However, a unique case is presented where RFA itself was suspected of inducing a progressive atrioventricular disorder. An 80-year-old male underwent RFA for hepatocellular carcinoma. His electrocardiogram showed a first-degree atrioventricular block on admission. Prior to ablation, fentanyl and propofol were administered. Severe bradycardia developed immediately after initiation of ablation. RFA and propofol infusion were terminated, leading to prompt heart rate recovery. After approximately five minutes, ablation was resumed without propofol, but severe bradycardia recurred. The electrocardiogram during RFA revealed a complete atrioventricular block. Therefore, the procedure was terminated. A 12-lead electrocardiogram performed after the aborted procedure revealed progression to a second-degree AV block (Mobitz type II) requiring pacemaker implantation. The exact mechanism of this effect remains unclear, though progression of the atrioventricular conduction disorder was considered to be induced by RFA. Careful intraoperative patient management is crucial during RFA.

PMID 42500801
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PubMedNational science review2026-07-25

Metal-defect pairs for near-stoichiometric electrocatalytic C-N coupling.

Wu Yandong Y, Chen Wei W, Zou Yuqin Y, Wang Jinbo J et al.

Geminal-site catalysts (GSCs) are prospective candidates for fulfilling the goal of aqueous electrochemical reductive cross-coupling reactions (ERCR) at near-stoichiometric yields. Nevertheless, a problem lies in the lack of a synthetic route for GSCs with few single sites. Here we report a defect-accompanying strategy for synthesizing GSCs containing metal-defect catalytic pairs (M-D GSCs), meaning that Fe-D GSCs can realize the electrochemical synthesis of cyclohexanone oximes (CHOs) from high concentrations (0.5 M) of nitrites (NO2 -) and cyclohexanone (CYC) at near-stoichiometric yields (the Faradic efficiency or yieldC/N: 91.3%). Multiple in-/ex-situ characterizations demonstrated that metal-citrate complexes were converted to metal-defect catalytic pairs via the liberation of gaseous carbon/nitrogen species during pyrolysis. Furthermore, we developed an innovative cathodic oxime-alkali process, where high concentration NaNO2 and CYC can be electrochemically converted to high-purity products including NaOH and CHO. This work showcases the enormous potential of M-D GSCs in achieving near-stoichiometric conversion for ERCR reactions.

PMID 42500738
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PubMedSurgical endoscopy2026-07-25

Transversus abdominis plane block improved surgical conditions in neuromuscular blocker-free pediatric laparoscopic hernia repair: a randomized trial.

Tian Jia-He JH, Zhang Ning N, Wang Chen-Chen CC, Zhu Xiao-Rong XR et al.

Pediatric laparoscopic hernia repair (LHR) is a short, commonly performed ambulatory procedure that can be conducted under general anesthesia without neuromuscular blocker (NMB). This prospective randomized controlled trial evaluated whether a transversus abdominis plane (TAP) block facilitates the implementation of NMB-free anesthesia in this surgical setting. Eighty pediatric patients scheduled for LHR without NMB were stratified by age (≤ 3 or > 3 years) and randomized to receive either a bilateral TAP block after induction (TAPB group) or surgical-site local infiltration at closure (Control group). The primary outcome was the mean intraoperative Leiden Surgical Rating Scale (L-SRS) score. The TAPB group demonstrated significantly higher mean L-SRS scores compared with controls (mean difference, 0.9; 95% CI, 0.69-1.11; p < 0.001), consistent across age subgroups. Age-stratified analysis revealed a markedly increased risk of intraoperative hemodynamic stress responses in the Control group, with adjusted odds ratios of 10.09 (95% CI, 3.46-29.42; Cochran's p < 0.001) for mean arterial pressure elevation ≥ 15% and 4.78 for heart rate elevation ≥ 15%, as well as a higher need for remifentanil rescue (adjusted odds ratio, 10.09; 95% CI, 3.44-29.60; Cochran's p < 0.001). The TAPB group also exhibited improved postoperative recovery, with significantly lower rates of emergence delirium (10 vs. 37.5%), moderate-to-severe pain (37.5 vs. 80%), and postoperative fentanyl rescue (2.5 vs. 20%; all p < 0.05). The addition of a TAP block significantly improved surgical conditions during pediatric LHR under an NMB-free general anesthesia strategy, while attenuating stress responses and enhancing postoperative recovery quality.

PMID 42498867
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PubMedPhoton science2026-07-25

Uncertainty-Aware Machine Learning for Small-Angle X‑ray Scattering Analysis in Autonomous Experimentation.

Cao Chuntian C, Kim Hyeong Jin HJ, Carbone Matthew R MR, Reyes Kristofer K et al.

Small-angle X-ray scattering (SAXS) is a powerful high-throughput characterization tool for probing nanoscale structure in native sample environments, providing real-time morphological information such as nanoparticle size and shape during synthesis. However, automated SAXS data analysis for extracting meaningful structural parameters is non-trivial and remains a bottleneck in closed-loop experimentation towards autonomous materials discovery, which demands fast, reliable, and uncertainty-aware data analysis. Here, we develop a machine-learning approach for automated SAXS analysis tailored to closed-loop nanoparticle synthesis. A Random Forest (RF) regression model is trained on 100,000 synthetic SAXS curves generated from polydisperse spherical nanoparticles with realistic background contributions. Using normalized one-dimensional SAXS intensity profiles as input, the RF model directly predicts nanoparticle radius, size polydispersity, and background parameters, while the ensemble standard deviation across trees provides built-in uncertainty quantification (UQ). On synthetic data, we show that combining fit-quality metrics (R2, MAE) with thresholds on prediction uncertainty reliably identifies accurate parameter estimates without access to ground truth. We then apply the trained model to 365 experimental SAXS profiles of citrate-reduced gold nanoparticles synthesized using an automated droplet-flow microreactor with in situ SAXS at a synchrotron beamline, classifying the results into high- and low-confidence subsets based on UQ metrics. Finally, we integrate RF-based SAXS analysis into a simulated closed-loop optimization campaign using Gaussian process Bayesian optimization to minimize nanoparticle polydispersity, benchmarking against conventional automated Levenberg-Marquardt fitting. The RF-guided campaign exhibits substantially faster convergence and lower relative opportunity cost (∼0.07 vs ∼0.3), demonstrating that uncertainty-aware machine-learning SAXS analysis significantly enhances the efficiency and robustness of autonomous nanomaterials synthesis workflows.

PMID 42499321
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PubMedACS omega2026-07-24

In Situ Growth of Vertically Aligned Gold Nanoparticles within Functionalized Polyvinylidene Fluoride Nanochannels for Optical Property Tuning.

Aubrit Florian F, Sigallon Marie M, Oral Ozlem O, Medjoubi Kadda K et al.

A solid synthetic pathway for the localized formation of vertically aligned and well-distributed individual gold nanoparticles (AuNPs) in transparent ion-track-etched polyvinylidene fluoride membranes is herein reported. After a successful preconcentration of the Au-(III) precursor within the functionalized cylindrical nanochannels of these membranes, i.e., ion-track-etched radiografted with poly-(4-vinylpyridine) (P4VP), a Au-(IIII)-to-Au(0) chemical reduction was performed to in situ grow AuNPs inside the nanopores. Four classical reducing agents [ascorbic acid, hydroquinone, sodium citrate, and sodium borohydride (NaBH4)] were studied, which led, at first glance, to similar composites. The reducing power of each reducing agent has been shown to affect the AuNP nucleation and growth processes. At room temperature, the reduction led to the synthesis of well-dispersed AuNPs along the whole pore length, with the exception of sodium citrate, which was found to be too weak to reduce efficiently the gold precursor. When energy was provided to the system by operating the reaction at 70 °C, the reduction was boosted and the synthesis with sodium citrate gave similar results to those obtained with the other reducing agents at 20 °C, i.e., well-distributed AuNPs of around 30 nm of mean size. Increasing the number of reduction cycles resulted in an increase in AuNP size and, in the case of hydroquinone, in the elongation of the gold nanocrystals. This phenomenon was attributed to template-assisted AuNP growth in the nanopores. Despite the low amount of gold in the material (less than 0.2 %), the alignment of individual AuNPs all along the high aspect ratio nanopores (50:10,000) had a significant effect on the optical properties of the whole material, with the appearance of plasmonic properties for the nanocomposite membranes (λplasmon around 530 nm) and a further decrease of the effective refractive index of the nanoporous membranes.

PMID 42495378
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