The molecular basis of dapsone activation of CYP2C9-catalyzed nonsteroidal anti-inflammatory drug oxidation.

Positive heterotropic cooperativity, or "activation," results in an instantaneous increase in enzyme activity in the absence of an increase in protein expression. Thus, cytochrome P450 (CYP) enzyme activation presents as a potential drug-drug interaction mechanism. It has been demonstrated previously that dapsone activates the CYP2C9-catalyzed oxidation of a number of nonsteroidal anti-inflammatory drugs in vitro. Here, we conducted molecular dynamics simulations (MDS) together with enzyme kinetic investigations and site-directed mutagenesis to elucidate the molecular basis of the activation of CYP2C9-catalyzed S-flurbiprofen 4'-hydroxylation and S-naproxen O-demethylation by dapsone. Supplementation of incubations of recombinant CYP2C9 with dapsone increased the catalytic efficiency of flurbiprofen and naproxen oxidation by 2.3- and 16.5-fold, respectively. MDS demonstrated that activation arises predominantly from aromatic interactions between the substrate, dapsone, and the phenyl rings of Phe114 and Phe476 within a common binding domain of the CYP2C9 active site, rather than involvement of a distinct effector site. Mutagenesis of Phe114 and Phe476 abrogated flurbiprofen and naproxen oxidation, and MDS and kinetic studies with the CYP2C9 mutants further identified a pivotal role of Phe476 in dapsone activation. MDS additionally showed that aromatic stacking interactions between two molecules of naproxen are necessary for binding in a catalytically favorable orientation. In contrast to flurbiprofen and naproxen, dapsone did not activate the 4'-hydroxylation of diclofenac, suggesting that the CYP2C9 active site favors cooperative binding of nonsteroidal anti-inflammatory drugs with a planar or near-planar geometry. More generally, the work confirms the utility of MDS for investigating ligand binding in CYP enzymes.

Synthesis, molecular dynamics simulation, and evaluation of biological activity of novel flurbiprofen and ibuprofen-like compounds.

The frequent use of anti-inflammatory drugs and the side effects of existing drugs keep the need for new compounds constant. For this purpose, flurbiprofen and ibuprofen-like compounds, which are frequently used anti-inflammatory compounds in this study, were synthesized and their structures were elucidated. Like ibuprofen and flurbiprofen, the compounds contain a residue of phenylacetic acid. On the other hand, it contains a secondary amine residue. Thus, it is planned to reduce the acidity, which is the biggest side effect of NSAI drugs, even a little bit. The estimated ADME parameters of the compounds were evaluated. Apart from internal use, local use of anti-inflammatory compounds is also very important. For this reason, the skin permeability values of the compounds were also calculated. And it has been found to be compatible with reference drugs. The COX enzyme inhibitory effects of the obtained compounds were tested by in vitro experiments. Compound 2a showed significant activity against COX-1 enzyme with an IC50 = 0.123 + 0.005 µM. The interaction of the compound with the enzyme active site was clarified by molecular dynamics studies.

Nonlinear Pharmacokinetics of Topical Flurbiprofen Gel in a Phase I Study Among Chinese Healthy Adults.

INTRODUCTION: PDX-02 (Flurbiprofen sodium) is a topical nonsteroidal anti-inflammatory drug in gel formulation for local analgesia and anti-inflammation. A Phase I clinical trial was conducted to assess the safety, tolerability, and pharmacokinetics of single and multiple doses of PDX-02 gel in Chinese healthy adults. METHODS: The trial comprised three parts: (1) a single-dose ascending study with three dose levels (0.5%, 1% to 2% PDX-02 gel) applied on a 136 cm2 skin area; (2) a multiple-dose study with either 1% or 2% PDX-02 gel applied on a 136 cm2 skin area for 7 consecutive days; and (3) a high dose group with 2% PDX-02 gel on an 816 cm2 skin area and a frequent multiple dose group with 2% PDX-02 gel on a 272 cm2 skin area four times a day for 7 consecutive days. The safety, tolerability and pharmacokinetics of the PDX-02 gel were evaluated in each part. RESULTS: A total of sixty participants completed the trial, with all adverse events recovered and all positive skin reaction being transient and recovered. The overall absorption of topical PDX-02 gel was slow with a mean peak time exceeding 9 h. The elimination rate remained consistent between dose groups. A less-than-dose-proportional nonlinear pharmacokinetics relationship was observed within the studied dose range, and this is likely due to the autoinduction of skin first-pass metabolism. CONCLUSION: The topical PDX-02 gel showed favorable safety and tolerability in both single and multiple dosing studies, with a less-than-dose-proportional nonlinear pharmacokinetics observed.

Potential and performance of anisotropic 19F NMR for the enantiomeric analysis of fluorinated chiral active pharmaceutical ingredients.

Controlling the enantiomeric purity of chiral drugs is of paramount importance in pharmaceutical chemistry. Isotropic 1H NMR spectroscopy involving chiral agents is a widely used method for discriminating enantiomers and quantifying their relative proportions. However, the relatively weak spectral separation of enantiomers (1H Δδiso(R, S)) in frequency units at low and moderate magnetic fields, as well as the lack of versatility of a majority of those agents with respect to different chemical functions, may limit the general use of this approach. In this article, we investigate the analytical potential of 19F NMR in anisotropic chiral media for the enantiomeric analysis of fluorinated active pharmaceutical ingredients (API) via two residual anisotropic NMR interactions: the chemical shift anisotropy (19F-RCSA) and dipolar coupling ((19F-19F)-RDC). Lyotropic chiral liquid crystals (CLC) based on poly-γ-benzyl-L-glutamate (PBLG) show an interesting versatility and adaptability to enantiodiscrimination as illustrated for two chiral drugs, Flurbiprofen® (FLU) and Efavirenz® (EFA), which have very different chemical functions. The approach has been tested on a routine 300 MHz NMR spectrometer equipped with a standard probe (5 mm BBFO probe) in a high-throughput context (i.e., ≈10 s of NMR experiments) while the performance for enantiomeric excess (ee) measurement is evaluated in terms of trueness and precision. The limits of detection (LOD) determined were 0.17 and 0.16 µmol ml-1 for FLU and EFA, respectively, allow working in dilute conditions even with such a short experimental duration. The enantiodiscrimination capabilities are also discussed with respect to experimental features such as CLC composition and temperature.

Superhydrophobic Metal-Organic Framework-Based Composite Featuring Removal of Hydrophobic Drugs and Pesticides and Antibacterial Activities.

The widespread use and contamination of natural sources by new-generation drugs and pesticides have enhanced concern about environmental pollution. Understanding the above importance, we developed a superhydrophobic metal-organic framework (MOF) (SHMOF': [Zr6O4(OH)4(BDC-NH-CO-R)2.4(BDC-NH2)0.6(CF3COO)6]·2.5H2O·4DMF) for ecological remediation via adsorption-based separation of hydrophobic drugs (flurbiprofen) and pesticides (fluazinam). The newly developed SHMOF' has a high adsorption capacity toward flurbiprofen and fluazinam, i.e., 435 and 575 mg/g, respectively. The adsorption equilibrium time of the MOF is very short (15 and 10 min for flurbiprofen and fluazinam, respectively). The outstanding superhydrophobic nature of the MOF was employed to separate flurbiprofen and fluazinam from highly alkaline and acidic media and environmental water samples. The SHMOF' has excellent selectivity toward the adsorption-based separation of flurbiprofen and fluazinam in the coexistence of common analytes. Again, we developed a polypropylene (PP) fabric-based composite of SHMOF' (SHMOF'@PP) to separate the hydrophobic targeted analytes by using a zero-energy-consuming filtration-based separation method, which made this separation process cost-efficient and user-friendly. Moreover, Ag nanoparticles were doped to the superhydrophobic composite. The Ag-doped reusable SHMOF'@PP@Ag composite exhibited excellent bacterial antiadhesion and antibacterial properties toward Staphylococcus aureus bacteria.

Determination of flurbiprofen in rat plasma using ultra-high performance liquid chromatography-tandem mass spectrometry and its application in a pharmacokinetic study.

A rapid and sensitive ultra-high performance liquid chromatography-tandem mass spectrometry method was developed to determine flurbiprofen in rat plasma. A triple quadrupole tandem mass spectrometer equipped with an electrospray ionization (ESI) source was used in negative ion mode. Acetonitrile precipitation was selected to prepare samples. Flurbiprofen and internal standard flurbiprofen-d5 were analyzed on an Acquity UPLC BEH C18 column with the mobile phase consisting of acetonitrile and water, and a gradient procedure was used for separation. The retention time of flurbiprofen was 0.67 min, and the whole running time was only 1.2 min. The detection was performed on a triple quadrupole tandem mass spectrometer using multiple reaction monitoring mode via an ESI source with optimized mass spectrometry parameters. The calibration curve was linear in the range of 25.0-1.00 × 104 ng/mL (r ≥ 0.99). The within-run and between-run relative standard deviations were not more than 13.9%. The within-run and between-run relative errors were from -9.0% to 3.4%. There was no significant matrix effect, and recovery was high. This method was fully validated, including whole blood stability in rat plasma, and successfully applied to the pharmacokinetic study in which 100% incurred sample reanalysis met the criteria.

Novel Flurbiprofen Derivatives as Antioxidant and Anti-Inflammatory Agents: Synthesis, In Silico, and In Vitro Biological Evaluation.

In this study, we present the synthesis of five novel compounds by combining flurbiprofen with various substituted 2-phenethylamines. The synthesized derivatives underwent comprehensive characterization using techniques such as 1H- and 13C-NMR spectroscopy, UV-Vis spectroscopy, and high-resolution mass spectrometry (HRMS). Detailed HRMS analysis was performed for each of these newly created molecules. The biological activities of these compounds were assessed through in vitro experiments to evaluate their potential as anti-inflammatory and antioxidant agents. Furthermore, the lipophilicity of these derivatives was determined, both theoretically using the cLogP method and experimentally through partition coefficient (RM) measurements. To gain insights into their binding affinity, we conducted an in silico analysis of the compounds' interactions with human serum albumin (HSA) using molecular docking studies. Our findings reveal that all of the newly synthesized compounds exhibit significant anti-inflammatory and antioxidant activities, with results statistically comparable to the reference compounds. Molecular docking studies further explain the observed in vitro results, shedding light on the molecular mechanisms behind their biological activities. Using in silico method, toxicity was calculated, resulting in LD50 values. Depending on the administration route, the novel flurbiprofen derivatives show lower toxicity compared to the standard flurbiprofen.

Defining the Conformational Ensembles Associated with Ligand Binding to Cyclooxygenase-2.

Cyclooxygenases (COX) catalyze the committed step in the production of prostaglandins responsible for the maintenance of physiological homeostasis. While crystal structures of COX in complex with substrates and inhibitors have provided insight into the molecular interactions governing their binding, they have not uncovered specific details related to the protein conformational motions responsible for important aspects of the COX function. We created a cysteine-free COX-2 construct and introduced a free cysteine at position-122 to enable labeling with 3-bromo-1,1,1-trifluoroacetone (BTFA). Placement of the label adjacent to the cyclooxygenase channel entrance permitted the detection of alterations upon ligand binding. 19F-nuclear magnetic resonance spectroscopy (19F-NMR) was then used to probe the conformational ensembles arising from BTFA-labeled COX-2 constructs in the presence and absence of ligands known to allosterically activate or inhibit COX-2. 19F-NMR analyses performed in the presence of the time-dependent inhibitor flurbiprofen, as well as Arg-120, Tyr-355, and Glu-524 mutations, led to the classification of two ensembles as representing the relaxed and tightened states of the cyclooxygenase channel entrance. A third ensemble, generated in the presence of arachidonic acid and the Y355F mutant and modulated by the allosteric potentiators palmitic acid and oleic acid and the nonallosteric substrates 2-arachidonoyl glycerol ether and anandamide, was classified as being related to the allosteric regulation of COX activity. The ensemble-based insight into COX function demonstrated here complements the static information derived from crystal structure analyses, collectively providing a more detailed framework of the dynamics involved in the regulation of COX catalysis and inhibition.

The Role of the Transient Atropisomerism and Chirality of Flurbiprofen Unveiled by Laser-Ablation Rotational Spectroscopy.

The combination of atropisomerism and chirality in flurbiprofen is shown to be relevant concerning its pharmacological activity. The two most stable conformers of a total of eight theoretically predicted for each R- or S- flurbiprofen enantiomers have been isolated in the cooling conditions of a supersonic jet and structurally characterized by laser ablation Fourier transform microwave spectroscopy. The detected conformers, whose structure is mainly defined by three dihedral angles, only differ in the sign of the phenyl torsion angle giving rise to Sa and Ra atropisomers. A comparison with the structures available for the R- and S- enantiomers complexed to COX isoforms reveals that the enzymes select only the Sa atropisomers, resulting in a diastereoisomer-specific recognition. The most stable gas phase conformer is exclusively selected when using the S- enantiomer while the second is recognized only for the R- enantiomer. These experimental results highlight the importance of atropisomerism in drug design.

Phenylalanine conjugated supramolecular hydrogels developed from the mafenide and flurbiprofen multidrug for biological applications.

A well-known nonsteroidal anti-inflammatory drug (NSAID), flurbiprofen (FLR), was first conjugated individually with two naturally occurring amino acids such as L-phenylalanine (PHE) and L-alanine (ALA). These covalent amidic bioconjugates were further reacted individually with mafenide (a drug for treating burn wounds) and amantadine (an antiviral drug) to develop primary ammonium monocarboxylate (PAM) salts. Interestingly, both the PHE-containing multidrug salts exhibited significant gelation ability with various solvents including biologically potent water or methyl salicylate (MS). The isolated hydrogel (HG) as well as all the organogels obtained from multidrug gelators were extensively characterized by dynamic rheology and rheoreversibility studies. The hydrogel of FLR·PHE·MAF and MS gels of FLR·PHE·AMN/FLR·AMN were also selectively characterized by table-top and FEG-TEM analyses. The temperature-dependent 1H-NMR spectroscopy of the selected HG further provided insights into the gelation mechanism and the only isolated single-crystal of the weakly diffracted gelator FLR·AMN also revealed the presence of 1D hydrogen-bonded networks. The pure hydrogelator FLR·PHE·MAF salt (which is also an ambidextrous gelator) was found to be promising in both mechanical (rheoreversible) and biological applications and was found to be effective in cytotoxicity, biocompatibility, anti-cancer activity (MTT and cell migration assay), antibacterial response (zone inhibition, turbidity, INT, and resazurin assay) and haemolysis studies.

Topological effects in ultrafast photoinduced processes between flurbiprofen and tryptophan in linked dyads and within human serum albumin.

The interaction dynamics between flurbiprofen (FBP) and tryptophan (Trp) has been studied in covalently linked dyads and within human serum albumin (HSA) by means of fluorescence and ultrafast transient absorption spectroscopy. The dyads have proven to be excellent models to investigate photoinduced processes such as energy and/or electron transfer that may occur in proteins and other biological media. Since the relative spatial arrangement of the interacting units may affect the yield and kinetics of the photoinduced processes, two spacers consisting of amino and carboxylic groups separated by a cyclic or a long linear hydrocarbon chain (1 and 2, respectively) have been used to link the (S)- or (R)-FBP with the (S)-Trp moieties. The main feature observed in the dyads was a strong intramolecular quenching of the fluorescence, which was more important for the (S,S)- than for the (R,S)- diastereomer in dyads 1, whereas the reverse was true for dyads 2. This was consistent with the results obtained by simple molecular modelling (PM3). The observed stereodifferentiation in (S,S)-1 and (R,S)-1 arises from the deactivation of 1Trp*, while in (S,S)-2 and (R,S)-2 it is associated with 1FBP*. The mechanistic nature of 1FBP* quenching is ascribed to energy transfer, while for 1Trp* it is attributed to electron transfer and/or exciplex formation. These results are consistent with those obtained by ultrafast transient absorption spectroscopy, where 1FBP* was detected as a band with a maximum at ca. 425 nm and a shoulder at ∼375 nm, whereas Trp did not give rise to any noticeable transient. Interestingly, similar photoprocesses were observed in the dyads and in the supramolecular FBP@HSA complexes. Overall, these results may aid to gain a deeper understanding of the photoinduced processes occurring in protein-bound drugs, which may shed light on the mechanistic pathways involved in photobiological damage.

Discovery of (S)-flurbiprofen-based novel azine derivatives as prostaglandin endoperoxide synthase-II inhibitors: Synthesis, in-vivo analgesic, anti-inflammatory activities, and their molecular docking.

The anti-inflammatory and analgesic drugs currently used are associated with several adverse effects and found to be highly unsafe for long-term use. Currently, nineteen novel bis-Schiff base derivatives (1-19) of flurbiprofen have been designed, prepared and assessed for in-vivo analgesic, anti-inflammatory and in vivo acute toxicity evaluation. The structures of the acquired compounds were deduced through modern spectroscopic techniques including HR-ESI-MS, 13C-, and 1H NMR. Amongst the series, compounds 7, 9, and 10 attributed potent activities with 93.89, 92.50, and 90.47% decreased edema, respectively compared to flurbiprofen (90.01%), however, compounds 11 and 15 exhibited significant activity of 90.00% decrease. Out of them, fourteen compounds (1-6, 8, 12-14, and 16-19) displayed good activity in the range of 68.96-86.95%. In case of an analgesic study, all the derivatives significantly (p 0.001) increased the pain threshold time particularly compound 7 had the best analgesic effect (24 ± 2.08 s) in comparison with flurbiprofen (21.66 ± 2.02 s) using hot plate test. Similarly, in the acetic acid-induced writhing test, compound 7 determined a potent inhibitory effect (60.47 %) close to flurbiprofen (59.28%). All the synthesized derivatives were found safe up to the dose of 30 mg/kg, in acute toxicity study. On a molecular scale, the synthesized compounds were modeled through a ligand-based pharmacophore study and molecular docking to have insight into the different possible interactions leading to high inhibition levels against the COX-2 enzyme.

Comparison of in vivo pharmacokinetic behaviors of R- and S-flurbiprofen after intravenous injection of flurbiprofen axetil.

Flurbiprofen axetil (FA) is a prodrug of flurbiprofen (FP), and it is hydrolyzed to the active FP by carboxylesterase in plasma after intravenous injection. The pharmacological action of FP is closely related to its chirality, and S-FP shows better analgesic effects than R-FP. Therefore, it is of great significance to compare the in vivo pharmacokinetic behaviors of R-FP and S-FP. In this study, we designed a sensitive high performance liquid chromatography-tandem mass spectrometry method and used CHIRALPAK-IG3 column for chiral separation to quantify the concentrations of R-FP and S-FP in rat plasma. The results show that this method can accurately and effectively analyze the contents of R-FP and S-FP in plasma. In addition, the systemic exposure was approximately 3.09-folds for the S-FP compared with the R-FP following intravenous administration of the FA to rats at a single dose of 4.5 mg/kg. More importantly, the clearance rate of S-FP is significantly smaller than that of R-FP. Therefore, the development of S-FA injectable emulsion for clinical treatment of postoperative pain is very necessary.

Preparation and chromatographic performance of chiral peptide-based stationary phases for enantiomeric separation.

This study presents the development of three new chiral stationary phases. They are based on silica modified with peptides containing phenylalanine and proline. Successful analyses and characterizations were conducted using Fourier transform infrared spectra, elemental analysis, and thermogravimetric analysis. After this, the enantioselective performance of the three chiral peptide-based columns was evaluated. The evaluation used 11 racemic compounds under normal-phase high performance liquid chromatography mode. Optimized enantiomeric separation conditions were established. Under these conditions, the enantiomers of flurbiprofen and naproxen were successfully separated on CSP-1 column: the separation factor of these was 1.27 and 1.21, respectively. In addition, the reproducibility of the CSP-1 column was also investigated. The results of the investigation illustrated that the stationary phases have good reproducibility (RSD = 0.73%, n = 5).

Analgesia with reduced incidence of adverse reactions using flurbiprofen axetil in combination with half standard-dose opioids in primary total knee arthroplasty.

OBJECTIVES: To determine the analgesic effect of flurbiprofen axetil (FBA) combined with half standard-dose opioids in patients undergoing primary unilateral total knee arthroplasty (TKA). MATERIALS AND METHODS: A total of 100 patients undergoing primary TKA were randomly divided into two groups, namely a control group and an experimental group, with 50 patients in each group. All patients received the same dose of FBA in the form of a patient-controlled intravenous analgesia but in the control group this was combined with a standard-dose of opioids and in the experimental group with a half standard-dose of opioids. RESULTS: A visual analogue scale, used to assess the level of pain 8 hours, 48 hours, and 5 days after TKA, showed that pain relief in the experimental group was equal to that in the control group (difference non-significant: p > 0.05). The knee flexion and extension activity in both groups reached target levels on the fifth day after TKA where differences were also not significant: p > 0.05. The incidence of nausea and vomiting after TKA in the experimental group was significantly less than in the control group (p < 0.05). CONCLUSION: The analgesic effect of FBA in combination with half standard-dose opioids was similar to that of FBA in combination with conventional standard-dose opioids, but the incidence of adverse effects involving nausea/vomiting in the experimental group were significantly reduced.

Contribution of prophylactic administration of flurbiprofen for mesenteric traction syndrome to postoperative leakage or bleeding in gastrointestinal surgery: a retrospective observational study.

PURPOSE: Mesenteric traction syndrome (MTS) sometimes occurs during abdominal surgery. Prophylactic administration of flurbiprofen, a non-steroidal anti-inflammatory drug, prevents the development of MTS. However, administration of non-steroidal anti-inflammatory drugs for postoperative pain increases the incidence of postoperative bleeding. Our aim was to examine the effect of prophylactic flurbiprofen administration on postoperative leakage or bleeding after gastrointestinal surgery. METHODS: A retrospective observational study on patients who underwent open or laparoscopic abdominal surgery was conducted. Perioperative, anesthesia and medical records were reviewed. Patients who did (Flurbio-Group) or did not receive (Control-Group) prophylactic flurbiprofen administration were compared. Then, the Flurbio-Group and Control-Group were each divided into two groups according to whether the patients did or did not develop MTS (Flurbio-MTS-Group and Flurbio-no-MTS-Group, respectively, Control-MTS-Group and Control-no-MTS-Group, respectively). RESULTS: This study included 188 patients (Flurbio-MTS-Group, 1 patient; Flurbio-no-MTS-Group, 31 patients; Control-MTS-Group, 59 patients; Control-no-MTS-Group, 97 patients). Seventeen patients developed postoperative leakage or bleeding. Eleven Flurbio-MTS-Group patients (18.6%), 4 Flurbio-no-MTS-Group patients (12.9%, 4/31), and only 2 Control-no-MTS-Group patients (2%, 2/97) developed postoperative leakage or bleeding. Multivariate logistic regression analysis demonstrated that there was a qualitative interaction effect between prophylactic administration of flurbiprofen and the development of MTS on postoperative leakage or bleeding. CONCLUSION: Prophylactic flurbiprofen administration increased the risk of postoperative leakage or bleeding among patients who did not develop MTS.

Ultrasound-guided pericapsular nerve group (PENG) block for early analgesia in elderly patients with hip fractures: a single-center prospective randomized controlled study.

BACKGROUND: The aim of this study was to compare the efficacy of ultrasound-guided PENG (pericapsular nerve group) block and drug therapy with intravenous flurbiprofen for early analgesia in elderly patients with hip fractures after hospitalization. METHODS: This is a single-center, observer-blinded, prospective, randomized, controlled trial. A total of 41 elderly patients (aged 60 or older) with hip fractures were enrolled in the current study. Patients were randomly assigned to two groups: Group P (ultrasound-guided PENG block, 20 mL of 0.375% ropivacaine) and Group F (intravenous flurbiprofen 50 mg). The primary outcome measure was the dynamic (passive straight leg raising 15°) NRS (numerical rating scale 0 to 10) pain scores at different time points. The secondary outcomes were the static NRS scores at different time points, the number of rescue analgesia sessions, patient satisfaction, and the incidence of complications. RESULTS: Patients in the two groups had comparable baseline characteristics. The group P had lower dynamic and static NRS scores at 15 min, 30 min, 6 h, and 12 h after intervention (P<0.05) than the group F. The highest NRS pain scores in the group P were still lower than the NRS scores in the group F at 30 min-12 h (Group F: 5.57±1.54 vs. Group P: 3.00±1.12, P<0.001), and there was no significant difference between the two groups at 12-24 h (Group F: 6.35±1.79 vs. Group P: 5.90±1.83, P>0.05). The group P had higher satisfaction scores (Group P: 9 (9,9) vs. Group F: 8 (7,8), P<0.001). There was no statistically significant difference in the number of rescue analgesics at 0-12 h or 12-24 h or the incidence of complications between the groups. CONCLUSIONS: Compared with intravenous flurbiprofen, ultrasound-guided PENG block provides better early analgesic effects in elderly patients with hip fractures, and a PENG block is safe for elderly patients with hip fractures after hospitalization. Trial registration This study was registered in the Chinese Clinical Trial Testing Center (ID: ChiCTR2200062400).

Effect of erector spinae plane block with different doses of dexmedetomidine as adjuvant for ropivacaine on the postoperative quality of recovery after video-assisted thoracoscopic lobectomy surgery: a randomized controlled trial.

BACKGROUND: Erector spinae plane block (ESPB) improves postoperative analgesia and significantly enhances the quality of recovery (QoR) after video-assisted thoracoscopic lobectomy surgery (VATLS). However, it is not known whether the use of dexmedetomidine (Dex) as an adjunct for ropivacaine to ESPB affects the QoR after VATLS. The purpose of this study was to explore the effects of different Dex dosages as an adjunct for ropivacaine in combination with ultrasound-guided ESPB on the quality of postoperative recovery in patients with VATLS. METHODS: In this single-center, double-blind, randomized study, 120 patients between the ages of 18 and 65 who were scheduled for VATLS from december 2021 and october 2022 in our hospital under general anesthesia were randomly divided into three groups: ultrasound-guided ESPB with 30 mL of 0.5% ropivacaine (Group R), ultrasound-guided ESPB 0.5% ropivacaine plus 0.5 µg/kg Dex (Group RD1), and ultrasound-guided ESPB 0.5% ropivacaine plus 1.0 µg/kg Dex (Group RD2), ultrasound-guided ESPB was administrated at the T5 vertebral level before surgery. The primary outcome was the QoR-15 score 24 h after the surgery. The secondary outcomes included the QoR-15 scores at 12 h, 48 h, and 72 h after the operation, visual analogue scale (VAS) scores at 8 h, 12 h, 24 h, and 48 h after surgery, cumulative flurbiprofen consumption, postoperative nausea and vomiting (PONV), postoperative bradycardia, and hypotension. RESULTS: The QoR-15 scores were higher in group RD2 than the R and RD1 groups on postoperative day 1 (P < 0.05), in addition, no significant difference was found in the QoR-15 scores between groups R and RD1 on postoperative day 1. The VAS scores were significantly lower in group RD2 than in groups RD1 and group R 12-24 h after surgery (P < 0.05). No significant differences were observed in the QoR-15 and VAS scores at 48 and 72 h after surgery between the three groups. The cumulative flurbiprofen consumption was markedly reduced during the 72 h after surgery in the RD2 group (P < 0.05). The incidence of postoperative nausea and vomiting was lower in the RD2 group (P < 0.05). CONCLUSIONS: The combination of 1 µg/kg dexmedetomidine as an adjunct with 0.5% ropivacaine 30 ml for erector spinae plane block significantly improved the postoperative quality of recovery and provided better postoperative analgesia on postoperative day 1 in patients undergoing Video-assisted thoracoscopic lobectomy surgery. However, dexmedetomidine (1 µg/kg) as an adjunct for ropivacaine combined with erector spinae plane block did not enhance the postoperative quality of recovery at 48 and 72 h postoperatively. TRIAL REGISTRY NUMBER: The number of this clinical trial registry is ChiCTR2100053230, date of registration: 16/11/ 2021).

QbD-based stability-indicating liquid chromatography (RP-HPLC) method for the determination of flurbiprofen in cataplasm.

A nonsteroidal drug called flurbiprofen (FBN) has analgesic, anti-inflammatory and antipyretic activity. Currently the determination of FBN in cataplasm does not have any pharmacopeial method. However, the drug substance, tablet and ophthalmic solution formulations do have pharmacopeial methods. The development and validation of an accurate, precise and stability-indicating analytical method for the determination of FBN in cataplasm formulations is reported. The gradient method was employed for the quantification of FBN in the presence of internal standards such as biphenyl. A nonpolar separation phase (C18 , 250 × 4.6 mm, 5 µm Inertsil column; GL Sciences) was used. The optimal flow rate, column oven temperature, injection volume and detector wavelengths were 1.0 ml/min, 40°C, 20 µl and 245 nm, respectively. Mobile phase A was a mixture of water and glacial acetic acid (30:1 v/v) pH adjusted to 2.20 with glacial acetic acid or 1 m NaOH; mobile phase B was methanol (100%). The gradient elution program was [time (min)/% B]: 5/60, 20/70, 25/70, 30/60 and 40/60. The obtained RSDs for the precision and intermediate precision were 0.7 and 0.5%. The percentage recovery ranged from 99.2 to 100.4%. The linear regression coefficient >0.9996 indicates that all peak responses were linear with the concentration. The sample and standard solutions were stable for up to 24 h on the benchtop and in the refrigerator. The critical peaks were well separated from the generated peaks owing to forced degradation, including diluent and placebo peaks. The method validation data and quality by design-based robustness study results indicate that the developed method is robust and fit for routine use in the quality control laboratory. The proposed method is specific, accurate and precise, and the quality by design utilized the first method for the determination of FBN in cataplasm formulations. Transdermal patches and gels have low extraction capacity and this method is applicable for quantification.

Masking the Taste of Fixed-Dose Combination Drugs: Particular NSAIDs Can Efficiently Mask the Bitterness of Famotidine.

This study aimed to evaluate the bitterness of famotidine (FAM) combined with each of three non-steroidal anti-inflammatory drugs (NSAIDs): ibuprofen (IBU), flurbiprofen (FLU), and naproxen (NAP), which have potential as fixed-dose combination (FDC) drugs. We evaluated the bitterness of FAM and each NSAID by taste sensor AN0 and C00, respectively. FAM showed high sensor output representing sensitivity to bitterness, whereas three NSAIDs did not show large sensor output, suggesting that the bitterness intensities of three NSAIDs were lower than that of FAM. The bitterness of FAM on sensor AN0 was suppressed in a concentration-dependent manner when mixed with IBU, FLU, or NAP. Among three NSAIDs, IBU most effectively inhibited bitterness on sensor output, and the gustatory sensation test confirmed that adding IBU to FAM reduced the bitterness of FAM in a concentration-dependent manner. MarvinSketch confirmed that the drugs were mostly present in an ionic solution when FAM was mixed with NSAIDs. The 1H-NMR spectroscopy analysis also revealed the presence of electrostatic interactions between FAM and NSAIDs, suggesting that the electrostatic interaction between FAM and NSAIDs might inhibit the adsorption of FAM on the bitter taste sensor membrane, thereby masking the bitter taste.