First derivative synchronous spectrofluorimetric method for the simultaneous determination of tramadol and celecoxib in their dosage forms and human plasma.

One of the most common features of many different clinical conditions is pain; hence, there is a crucial need for eliminating or reducing it to a tolerable level to retrieve physical, psychological and social functioning. A first derivative synchronous spectrofluorimetry technique is proposed for the simultaneous determination of celecoxib and tramadol HCl, a recent coformulation authorized for treating acute pain in adults. The method includes using synchronous spectrofluorimetry at ∆λ = 80 nm where tramadol HCl was determined using first derivative technique at λ = 230.2 nm, while celecoxib was determined at λ = 288.24 nm. The proposed method was successfully applied to their co-formulated dosage forms in addition to spiked human plasma and validated in agreement with the guidelines of the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH). The linear ranges were found to be 0.50-5.0 and 0.15-0.50, the limits of detection to be 0.088 and 0.011 and the limits of quantification to be 0.266 and 0.032 µg/ml for celecoxib and tramadol, respectively. Statistical analysis revealed no significant difference when compared with previously reported methods as evidenced by the values of the variance ratio F-test and Student t-test. The proposed method was successfully applied to commercial dosage forms and spiked human samples. Moreover, the greenness of the proposed method was investigated based on the analytical eco-scale approach, with the results showing an excellent green scale with a score of 95.

A Simple Bioanalytical Method for Simultaneous Estimation of Amlodipine and Celecoxib in Rat Plasma by High Performance Liquid Chromatography.

A simple, precise, rapid and accurate UFLC method has been developed with due validation for the simultaneous estimation of Amlodipine besylate and Celecoxib in rat plasma. The separation has been taken place by C18 Eclipse plus column at 1ml/min flow rate. The mobile phase comprises of 20 mM sodium acetate buffer of pH 4.5 adjusted with glacial acetic acid and methanol (30:70% v/v). The effluents were monitored at 228 nm with a total run time of 15min. The retention time of Amlodipine besylate and celecoxib were found to be 7.69 min and 10.69 min respectively. The extraction of drugs have been achieved by protein precipitation technique with methanol as a solvent. The detection concentration was linear over 60-420 ng/ml for Amlodipine besylate and 600-4200 ng/ml for Celecoxib. Regression equation of Amlodipine besylate and Celecoxib were found to be y = 30.996x + 520.29 & y = 39.722x + 23706 with regression coefficient 0.9944 & 0.9941 respectively using unweighted and weighted linear regression with a weighting factor of 1/x0, 1/x, 1/✓x and 1/x2. The percentage recoveries were found to be 88.52±1.276 to 93.06±2.872 for Amlodipine & 89.40±0.728 to 94.05±0.221 for Celecoxib. This liquid chromatography method was extensively validated for linearity, accuracy precision, and stability studies.

Interleukin-1ß, interleukin-6, and interleukin-17A as indicators reflecting clinical response to celecoxib in ankylosing spondylitis patients.

BACKGROUND: This study was to investigate the value of 10 serum inflammatory cytokines for predicting clinical response to celecoxib in ankylosing spondylitis (AS) patients. METHODS: Totally, 103 active AS patients who underwent celecoxib treatment for 12 weeks were enrolled. Then, pre-treatment serum TNF-α, IL-1ß, IL-6, IL-8, IL-17A, IL-21, IL-23, IL-32, ICAM-1, and VEGF were detected by enzyme-linked immunosorbent assay. Besides, the ASAS 20 response was assessed at week 2 (W2), week 6 (W6), and week 12 (W12). Based on the ASAS 20 response at W12, patients were divided into responders and non-responders. RESULTS: After celecoxib treatment, 53 (51.3%), 58 (56.3%), and 60 (58.3%) patients achieved ASAS 20 response at W2, W6, and W12, respectively. Furthermore, IL-1ß (P = 0.019), IL-6 (P = 0.004), and IL-17A (P = 0.007) levels were higher, while TNF-α (P = 0.086), IL-8 (P = 0.143), IL-21 (P = 0.687), IL-23 (P = 0.329), IL-32 (P = 0.216), ICAM-1 (P = 0.119), and VEGF (P = 0.732) levels were similar in responders compared with non-responders. Subsequent multivariate logistic regression analysis revealed that among these inflammatory cytokines, only IL-6 (P = 0.019) independently predicted higher ASAS 20 response to celecoxib at W12, and it had a fair value for predicting ASAS 20 response to celecoxib at W12 (area under the curve: 0.666, 95% confidence interval: 0.561-0.771) by receiver-operating characteristic curve analysis. CONCLUSION: Serum IL-1ß, IL-6, and IL-17A serve as indicators for predicting clinical response to celecoxib in AS patients, which may assist with the optimization of personalized treatment.

Liquid chromatographic method for simultaneous determination of alprazolam with NSAIDs in bulk drug, pharmaceutical formulation and human serum.

High performance liquid chromatography with UV/vis detection was optimized and validated for simultaneous quantification of alprazolam with celecoxib and diclofenac sodium in pharmaceutical formulation and human serum. Chromatographic separation was achieved at detection wavelength of 230 nm on Shimadzu Shim-pack CLC-ODS (M) 25M column employing 80:20 (v/v) methanol: water (pH 3.5) as mobile phase with elution rate 1.0mL min-1. Analytes were quantified in the ranges 0.2-15, 0.3-20 and 0.6-40 µg mL-1 with detection limits 19.76, 17.29 and 11.83ng mL-1 respectively. Recoveries were in the range 98.15-101.15, 99.24-99.90 and 98.87-101.19% in pharmaceutical formulation and 98.05-101.01, 98.72-99.49 and 98.25-99.47% in human serum respectively and precision ranged from 0.19-1.84%. The analytes were successfully detected without any observable interference commonly present in pharmaceutical formulation and human serum demonstrating applicability of method.

Effects of Celecoxib on the QTc Interval: A Thorough QT/QTc Study.

PURPOSE: Celecoxib is a selective cyclooxygenase-2 inhibitor widely used in patients with osteoarthritis and rheumatoid arthritis. Recently, nonclinical data on the inhibition of human ether-à-go-go-related gene potassium channels by celecoxib were reported, but there is no compelling evidence for this finding in humans. The aim of this study was to assess the potential effects of celecoxib on cardiac repolarization by conducting a thorough QT study, which was designed in compliance with the related guidelines. METHODS: This randomized, open-label, positive- and negative-controlled, crossover clinical study was conducted in healthy male and female subjects. Each subject received, in 1 of 4 randomly assigned sequences, all of the following 3 interventions: celecoxib 400 mg once daily for 6 days; a single dose of moxifloxacin 400 mg, which served as a positive control to assess the assay sensitivity; and water without any drug, which served as a negative control. Serial 12-lead ECG and blood samples for pharmacokinetic analysis were collected periodically over 24 h. Individually RR-corrected QT intervals (QTcI) and Fridericia method-corrected QT intervals (QTcF) were calculated and evaluated. FINDINGS: Twenty-eight subjects were allocated to 1 of the 4 intervention sequences. The largest time-matched mean effects of celecoxib on the QTcI and QTcF were <5 ms, and the upper bounds of the 1-sided 95% CIs of those values did not exceed 10 ms. Moreover, none of the subjects had an absolute QTcI value of >450 ms or a change from baseline in QTcI of >60 ms after multiple administrations of celecoxib. The QTcI did not show a positive correlation with celecoxib concentrations in the range up to ~2700 µg/L. The overall effects of moxifloxacin on the QTcI and QTcF were enough to establish assay sensitivity. No serious adverse events were reported, with a total of 11 AEs reported in 8 subjects. IMPLICATIONS: Celecoxib caused no clinically relevant increase in the QT/QTc interval at the maximum dose level used in current practice settings. ClinicalTrials.gov identifier: NCT03822520.

Overcoming the Charged Ion Competition in Triple Quad Chemical Ionization Ion Source for Estimation of Celecoxib in Biological Matrix and its Application to Bioequivalence Study.

The purpose of the study was to develop and validate a sensitive, selective and reproducible method for the estimation of Celecoxib in human plasma. During the development, ion competition phenomenon observed in electrospray ionization ion source of liquid chromatography mass spectrometer system and in order to overcome it, different approaches applied. The Celecoxib and Celecoxib D7 in plasma were extracted by liquid-liquid extraction and separated in less than 4.0 min on a reverse phase C18 column, using isocratic elution with a binary mobile phase in the ratio of 70:30 v/v (Acetonitrile: 0.1% Ammonia Solution). Mass spectrometer was used as detector to quantitate the analytes in positive ion mode, using Atmospheric Pressure Chemical Ionization mode. Since the method was developed to perform the pharmacokinetic end point study for United States and Europe market, the method was fully validated, complying Food and Drug Administration, European Medicines Agency guideline and recommendations of American Association of Pharmaceutical Scientists white papers.

Pharmacokinetics, metabolism and excretion of celecoxib, a selective cyclooxygenase-2 inhibitor, in horses.

Celecoxib, a nonsteroidal anti-inflammatory drug, is frequently used to treat arthritis in humans with minimal gastrointestinal side effect compared to traditional NSAIDs. The primary aim of this study was to determine the pharmacokinetic profile of celecoxib-a selective cyclooxygenase-2 (COX-2) inhibitor in horses. Six horses were administered a single oral dose of celecoxib at 2 mg/kg (body weight). After oral dosing, the drug reached a maximum concentration (mean ± SD) in blood of 1,088 ± 324 ng/ml in 4.58 hr. The elimination half-life was 13.60 ± 3.18 hr, and the area under the curve was 24,142 ± 1,096 ng hr ml-1 . The metabolism of celecoxib in horses was via a single oxidative pathway in which the methyl group of celecoxib is oxidized to a hydroxymethyl metabolite and is further oxidized to form a carboxylic acid metabolite. Celecoxib is eliminated mainly through faeces as unchanged drug and as metabolites in urine. Therefore, instructions for a detection time following therapeutic dosing of celecoxib can be set by the racing practitioner and veterinarians to control illegal use in horse racing based on the results of this study.

In Vivo Brain Imaging, Biodistribution, and Radiation Dosimetry Estimation of [11C]Celecoxib, a COX-2 PET Ligand, in Nonhuman Primates.

COX-2 selective inhibitors (COXIBs) are non-steroidal anti-inflammatory drugs (NSAIDs), with fewer side effects compared with non-selective NSAIDs, and are used for the treatment of arthritis, headaches, and other inflammatory diseases of the brain and peripheral tissues. Radiolabeled COXIBs may permit positron emission tomography (PET) imaging of COX-2 localization and activity in diseases, enable monitoring of inflammatory processes, and determine target occupancy of COX-2 activity by NSAIDs, thus, accelerating the development of novel CIXIBs. We synthesized [11C]celecoxib, one of the COXIBs and a prescription drug, and here report its in vivo uptake in the brain, whole body biodistribution, and radiation dosimetry in baboons using PET. Brain imaging experiments were performed in one baboon and whole body PET scans were performed in triplicates in two male baboons using an ECAT ACCEL (Siemens Medical Solutions, Inc. Knoxville) under anesthetic conditions. PET studies in baboons show that [11C]celecoxib penetrates the blood brain barrier (BBB) and accumulates in the brain, followed by a washout of radioactivity. The liver has the highest residence time and the gallbladder is the critical organ for [11C]celecoxib. Organ Level Internal Dose Assessment (OLINDA) estimates indicate that the maximum permissible single study dosage of [11C]celecoxib in humans is 1110 MBq (30 mCi) for both males and females under the 21 CFR 361.1 dose limit for research subjects.

The Effect of Food on Tramadol and Celecoxib Bioavailability Following Oral Administration of Co-Crystal of Tramadol-Celecoxib (CTC): A Randomised, Open-Label, Single-Dose, Crossover Study in Healthy Volunteers.

BACKGROUND AND OBJECTIVE: Co-Crystal of Tramadol-Celecoxib (CTC), in development for the treatment of moderate to severe acute pain, is a first-in-class co-crystal containing a 1:1 molecular ratio of two active pharmaceutical ingredients; rac-tramadol·HCl and celecoxib. This randomised, open-label, crossover study compared the bioavailability of both components after CTC administration under fed and fasting conditions. METHODS: Healthy adults received single doses of 200 mg CTC under both fed and fasting conditions (separated by a 7-day washout). Each dose of CTC was administered orally as two 100 mg tablets, each containing 44 mg tramadol·HCl and 56 mg celecoxib. In the fed condition, a high-fat, high-calorie meal [in line with recommendations by the US Food and Drug Administration (FDA)] was served 30 min before CTC administration. Tramadol, O-desmethyltramadol and celecoxib plasma concentrations were measured pre- and post-dose up to 48 h. Pharmacokinetic parameters were calculated using non-compartmental analysis. Safety was also assessed. RESULTS: Thirty-six subjects (18 female/18 male) received one or both doses of CTC; 33 provided evaluable pharmacokinetic data under fed and fasting conditions. For tramadol and O-desmethyltramadol, fed-to-fasting ratios of geometric least-squares means and corresponding 90% confidence interval (CI) values for maximum plasma concentration (Cmax) and extrapolated area under the plasma concentration-time curve to infinity (AUC∞) were within the pre-defined range for comparative bioavailability (80-125%). For celecoxib, Cmax and AUC∞ fed-to-fasting ratios (90% CIs) were outside this range, at 130.91% (116.98-146.49) and 129.34% (121.78-137.38), respectively. The safety profile of CTC was similar in fed and fasting conditions. CONCLUSIONS: As reported for standard-formulation celecoxib, food increased the bioavailability of celecoxib from single-dose CTC. Food had no effect on tramadol or O-desmethyltramadol bioavailability. CLINICAL TRIAL REGISTRATION NUMBER: 152052 (registered with the Therapeutic Products Directorate of Health Canada).

Silver-choline chloride modified graphene oxide: Novel nano-bioelectrochemical sensor for celecoxib detection and CCD-RSM model.

In this study, silver nanoparticles modified choline chloride functionalized graphene oxide (AgNPs-ChCl-GO) was synthesized using sonochemical method and utilized as a bioelectrochemical sensor for detection of celecoxib (CEL). The characterization studies were ultimately performed in order to acheive a more complete understanding of the morphological and structural features of the AgNPs-ChCl-GO using different techniques including FT-IR, AFM, FE-SEM, EDX, and XRD. AgNPs-ChCl-GO demonstrated a significant improvement in the reduction activity of CEL due to the enhancement in the current response compared to the bare carbon paste electrode (CPE). The optimum experimental conditions, were optimized using central composite design (CCD) methodology. The differential pulse voltammetry (DPVs) showed an expanded linear dynamic ranges of 9.6 × 10-9-7.4 × 10-7 M for celecoxib in Britton-Robinson buffer in pH 5.0 with. LOD (S/N = 3) and LOQ (S/N = 10) were obtained 2.51 × 10-9 M and 6.58 × 10-9 M respectively. AgNPs-ChCl-GO-carbon paste electrode exhibited suitable properties and high accuracy determination of celecoxib in the human plasma sample.

A molecularly imprinted dual-emission carbon dot-quantum dot mesoporous hybrid for ratiometric determination of anti-inflammatory drug celecoxib.

We report on a ratiometric fluorescent sensor based on dual-emission molecularly imprinted mesoporous silica embedded with carbon dots and CdTe quantum dots (mMIP@CDs/QDs) for celecoxib (CLX) as target molecule. The fluorescence of the embedded CDs is insensitive to the analyte while the green emissive QDs are selectively quenched by it. This effect is much stronger for the MIP than for the non-imprinted polymer, which indicates a good recognition ability of the mesoporous MIP. The hybrid sensor also exhibited good selectivity to CLX over other substances. The ratio of the intensity at two wavelengths (F550/F440) proportionally decreased with the increasing of CLX concentration in the range of 0.08-0.90µM. A detection limit as low as 57nM was achieved. Experimental results testified that this sensor was highly sensitive and selective for the detection of CLX in human serum samples.

A stratified randomized double-blind phase II trial of celecoxib for treating patients with cervical intraepithelial neoplasia: The potential predictive value of VEGF serum levels: An NRG Oncology/Gynecologic Oncology Group study.

PURPOSE: To examine the effect of celecoxib on cervical intraepithelial neoplasia 3 (CIN 3). This is a NRG Oncology/Gynecologic Oncology Group study with translational biomarkers. PATIENTS AND METHODS: Patients with CIN 3 were randomized to celecoxib 400mg once daily (67 patients) or placebo (63 patients) for 14-18weeks. The primary outcome measure was histologic regression. A test of equal probabilities of success between two therapies was conducted, using Fisher's Exact Test at alpha=10% and 90% power when the treatment arm boosted the probability of success by 30%. Translational analysis included cervical tissue HPV genotyping, COX-2 expression in biopsies, and serum celecoxib and VEGF levels. RESULTS: In primary analysis, histologic regression was not significantly higher in the celecoxib group (40%) than in the placebo group (34.1%). However, exploratory analyses suggest patients with high serum VEGF levels exhibited greater regression in the celecoxib arm (47.3%) than in the placebo arm (14.3%). Regression rates were similar by treatment group in patients with low VEGF. VEGF levels increased over time in the placebo group, but remained the same in the treatment group. COX-2 expression in cervical biopsies declined from pre-treatment to the end of treatment with celecoxib; it did not change with placebo. CONCLUSIONS: Celecoxib at 400mg once daily for 14-18weeks did not significantly decrease the severity of CIN 3 compared with placebo except, possibly, in subjects with high baseline VEGF. Therefore, serum VEGF levels might identify patients who may benefit from celecoxib or other therapies, personalizing future chemoprevention trials for CIN 3.

Celecoxib and 2,5-dimethylcelecoxib inhibit intestinal cancer growth by suppressing the Wnt/ß-catenin signaling pathway.

We previously reported that celecoxib, a selective COX-2 inhibitor, strongly inhibited human colon cancer cell proliferation by suppressing the Wnt/ß-catenin signaling pathway. 2,5-Dimethylcelecoxib (DM-celecoxib), a celecoxib analog that does not inhibit COX-2, has also been reported to have an antitumor effect. In the present study, we elucidated whether DM-celecoxib inhibits intestinal cancer growth, and its underlying mechanism of action. First, we compared the effect of DM-celecoxib with that of celecoxib on the human colon cancer cell lines HCT-116 and DLD-1. 2,5-Dimethylcelecoxib suppressed cell proliferation and inhibited T-cell factor 7-like 2 expression with almost the same strength as celecoxib. 2,5-Dimethylcelecoxib also inhibited the T-cell factor-dependent transcription activity and suppressed the expression of Wnt/ß-catenin target gene products cyclin D1 and survivin. Subsequently, we compared the in vivo effects of celecoxib and DM-celecoxib using the Mutyh-/- mouse model, in which oxidative stress induces multiple intestinal carcinomas. Serum concentrations of orally administered celecoxib and DM-celecoxib elevated to the levels enough to suppress cancer cell proliferation. Repeated treatment with celecoxib and DM-celecoxib markedly reduced the number and size of the carcinomas without showing toxicity. These results suggest that the central mechanism for the anticancer effect of celecoxib derivatives is the suppression of the Wnt/ß-catenin signaling pathway but not the inhibition of COX-2, and that DM-celecoxib might be a better lead compound candidate than celecoxib for the development of novel anticancer drugs.

Synthesis and application of molecularly imprinted nanoparticles combined ultrasonic assisted for highly selective solid phase extraction trace amount of celecoxib from human plasma samples using design expert (DXB) software.

In this work molecular imprinted nanoparticles (MINPs) was synthesized and applied for ultrasonic assisted solid phase extraction of celecoxib (CEL) from human plasma sample following its combination by HPLC-UV. The MINPs were prepared in a non-covalent approach using methacrylic acid as monomer, CEL as template, ethylene glycol dimethacrylate as cross-linker, and 2,2-azobisisobutyronitrile (AIBN) as the initiator of polymerization. pH, volume of rinsing and eluent solvent and amount of sorbent influence on response were investigated using factorial experimental design, while optimum point was achieved and set as 250mg sorbent, pH 7.0, 1.5mL washing solvent and 2mL eluent by analysis of results according to design expert (DX) software. At above specified conditions, CEL in human plasma with complicated matrices with acceptable high recoveries (96%) and RSD% lower than 10% was quantified and estimated. The proposed MISPE-HPLC-UV method has linear responses among peak area and concentrations of CEL in the range of 0.2-2000µgL(-1), with regression coefficient of 0.98. The limit of detection (LOD) and quantification (LOQ) based on three and ten times of the noise of HPLC peaks correspond to blank solution were 0.08 and 0.18µgL(-1), respectively.

Influence of Copolymer Composition on In Vitro and In Vivo Performance of Celecoxib-PVP/VA Amorphous Solid Dispersions.

Previous studies suggested that an amorphous solid dispersion with a copolymer consisting of both hydrophobic and hydrophilic monomers could improve the dissolution profile of a poorly water-soluble drug compared to the crystalline form. Therefore, this study investigated the influence of the copolymer composition of polyvinylpyrrolidone/vinyl acetate (PVP/VA) on the non-sink in vitro dissolution behavior and in vivo performance of celecoxib (CCX) amorphous solid dispersions. The study showed that the hydrophilic monomer vinylpyrrolidone (VP) was responsible for the generation of CCX supersaturation whereas the hydrophobic monomer vinyl acetate (VA) was responsible for the stabilization of the supersaturated solution. For CCX, there was an optimal copolymer composition around 50-60% VP content where further replacement of VP monomers with VA monomers did not have any biopharmaceutical advantages. A linear relationship was found between the in vitro AUC(0-4h) and in vivo AUC(0-24h) for the CCX:PVP/VA systems, indicating that the non-sink in vitro dissolution method applied in this study was useful in predicting the in vivo performance. These results indicated that when formulating a poorly water-soluble drug as an amorphous solid dispersion using a copolymer, the copolymer composition has a significant influence on the dissolution profile and in vivo performance. Thus, the dissolution profile of a drug can theoretically be tailored by changing the monomer ratio of a copolymer with respect to the required in vivo plasma-concentration profile. As this ratio is likely to be drug dependent, determining the optimal ratio between the hydrophilic (dissolution enhancing) and hydrophobic (crystallization inhibiting) monomers for a given drug is imperative.

Celecoxib interferes to a limited extent with aspirin-mediated inhibition of platelets aggregation.

AIMS: The aim of the study was to analyze the interaction between celecoxib and low dose aspirin for COX-1 binding and its consequences on the aspirin-mediated antiplatelet effects. METHODS: We investigated ex vivo the interaction between celecoxib and aspirin for COX-1 binding and measured the resulting antiplatelet effects. We applied mechanism-based pharmacokinetic-pharmacodynamic (PKPD) modelling to analyze these data and to predict in vivo platelet aggregation for different doses and administration schedules of aspirin and celecoxib. RESULTS: The predictions of the PK-PD model were consistent with results from previous studies that investigated interaction between aspirin and celecoxib. The modelling results indicate that celecoxib can attenuate to a limited extent the in vivo antiplatelet effects of low dose aspirin. The extent of this interaction can be substantial (up to 15% increase in platelet aggregation by 200 mg day(-1) celecoxib when combined with low dose aspirin) during the first days of aspirin administration in patients who are already treated with celecoxib, and it cannot be prevented by separate administration of the interacting drugs. CONCLUSIONS: At the recommended therapeutic doses, celecoxib can attenuate to a limited extent the in vivo antiplatelet effects of low dose aspirin. Patients receiving a combination of low dose aspirin and the recommended doses of celecoxib were not identified to have increased risk of cardiovascular and cerebrovascular events due to competition between these drugs for COX-1 binding. Interaction between low dose aspirin and other COX-2 inhibitors and its clinical consequences requires further investigation.

Pharmacodynamic comparison of LY3023703, a novel microsomal prostaglandin e synthase 1 inhibitor, with celecoxib.

To assess the safety, tolerability, and pharmacology of LY3023703, a microsomal prostaglandin E synthase 1 (mPGES1) inhibitor, a multiple ascending dose study was conducted. Forty-eight subjects received LY3023703, celecoxib (400 mg), or placebo once daily for 28 days. Compared with placebo, LY3023703 inhibited ex vivo lipopolysaccharide-stimulated prostaglandin E2 (PGE2 ) synthesis 91% and 97% on days 1 and 28, respectively, after 30-mg dosing, comparable to celecoxib's effect (82% inhibition compared to placebo). Unlike celecoxib, which also inhibited prostacyclin synthesis by 44%, LY3023703 demonstrated a maximal increase in prostacyclin synthesis of 115%. Transient elevations of serum aminotransferase were observed in one subject after 30-mg LY3023703 dosing (10× upper limit of normal (ULN)), and one subject after 15-mg dosing (about 1.5× ULN). Results from this study suggest that mPGES1 inhibits inducible PGE synthesis without suppressing prostacyclin generation and presents a novel target for inflammatory pain.

Influence of genetic polymorphisms on the pharmacokinetics of celecoxib and its two main metabolites in healthy Chinese subjects.

Celecoxib is a selective cyclooxygenase-2 inhibitor used extensively for the treatment of rheumatism and osteoarthritis. The aim of this study was to evaluate the influence of the genetic polymorphisms of CYP2C9, CYP2D6 and CYP3A4 on the pharmacokinetics (PK) of celecoxib and its two main metabolites, hydroxyl-celecoxib and carboxy-celecoxib, in healthy Chinese subjects, based on a bioequivalence study of celecoxib. This study was an open-label, two-period, crossover study. 52 healthy Chinese male subjects were recruited and were genotyped for CYP2C9*3, CYP2C9*13, CYP2D6*10 and CYP3A4*18 by using polymerase chain reactions (PCR). They were randomly divided into two groups and each group received either 200mg test formulation followed by reference formulation or vice versa with a one-week washout period. Safety and tolerability were monitored throughout the study and no severe adverse events were observed. Genotyping using PCR revealed that none of the subjects carried the CYP3A4*18 and CYP2C9*13. Therefore, the influence of the CYP2C9*3 and CYP2D6*10 on the PK of celecoxib and its metabolites in Chinese was studied. Compared with CYP2C9*1/*1 group, pharmacokinetic parameters of celecoxib such as AUC0-48 and Cmax was increased by 90.6% and 45.8%, the t1/2 was extended by 21.8% and the CL/F was decreased by 51.1% in CYP2C9*1/*3 group. In terms of hydroxy-celecoxib, compared with CYP2C9*1/*1 group, the Cmax was decreased by 17.2%, the t1/2 prolonged 42.1% in CYP2C9*1/*3 group. In terms of carboxy-celecoxib, the AUC0-48 was increased by 25.2%, the t1/2 prolonged 16.1% and the CL/F was decreased by 21.2% in CYP2C9*1/*3 group. Except for the t1/2 of hydroxy-celecoxib, no statistically significant difference was observed in other pharmacokinetic parameters of hydroxy-celecoxib and carboxy-celecoxib between the two CYP2C9 genotypic groups. This study revealed that there was no significant influence of CYP2D6*10 on the metabolism of celecoxib, and the expression of CYP2C9*3 led to increased drug exposure and slowed drug disposition in healthy Chinese male subjects.

Quantitation of celecoxib and four of its metabolites in rat blood by UPLC-MS/MS clarifies their blood distribution patterns and provides more accurate pharmacokinetics profiles.

A sensitive UPLC-MS/MS method was established and validated for the quantitation of celecoxib and its metabolites in rat blood. The analytes were extracted from rat blood samples by a salting-out liquid-liquid extraction method followed by the UPLC chromatography. The mass analysis of effluent was performed on an API 5500 Qtrap mass spectrometer via multiple reactions monitoring (MRM). The linear response ranges were 0.3-20000nM for celecoxib, and 1.2-20000nM, 0.3-20000nM, 2.0-2000nM, 1.5-6000nM for its metabolites carboxycelecoxib (M2), hydroxycelecoxib (M3), hydroxycelecoxib glucuronide (M1), and carboxycelecoxib glucuronide (M5), respectively. The inter-day and intra-day accuracies were within 85-115%, and the inter-day and intra-day precision were acceptable (<12%) for all analytes. Recoveries were above 70% and no obvious matrix effects were observed. The validated UPLC-MS/MS method was successfully applied to a pharmacokinetics study of oral celecoxib (20mg/kg) in Sprague-Dawley rats, and the rat blood concentrations (0-48h) of celecoxib and two of its metabolites M2 and M3 were successfully determined. Using the same method, we also showed preferential distributions of celecoxib, M2 and M3 in the blood cells as compared to the plasma. In conclusion, our results showed that our validated LC-MS/MS method can be successfully used for the pharmacokinetic studies of celecoxib and that the blood cells are a very important compartment for this drug such that profiles of celecoxib and its metabolites in whole blood will be more comprehensive and accurate representation of their profiles in vivo than the plasma.

Hot-melt extrusion of polyvinyl alcohol for oral immediate release applications.

The primary purpose of this study was to process partially hydrolyzed PVOH grades (degree of hydroxylation (DH): 33-88%) via HME and to evaluate them as carrier for oral immediate release dosage forms in order to improve the release rate of poorly water soluble drugs (i.e., HCT and CEL) via the formulation of solid dispersions. PVOH grades (DH >70%) were able to solubilize HCT and CEL up to 15%, but required higher extrusion temperature, due to the crystalline nature of PVOH. The highest drug release rate was observed from hot-melt extruded PVOH samples with a high DH. While drug release from extrudates consisting of PVOH with a low DH was affected by ionic strength, there was no influence of pH and ionic strength on HCT release from PVOH samples with a higher DH. However, PVOH (DH >70%) required higher extrusion temperatures, which could hamper its application for thermosensitive drugs. Therefore, the secondary purpose was to investigate the effect of sorbitol, a water-soluble plasticizer, on the thermal properties of hot-melt extruded PVOH (DH >70%). The melting of PVOH/sorbitol mixture was required to establish molecular interactions between PVOH and sorbitol. These molecular interactions were reflected in the HME behavior: whereas an extrusion temperature of 180 °C was necessary to process physical mixtures of PVOH (DH >70%) and sorbitol, only 140 °C was necessary during re-extrusion (after quench cooling and cryomilling) of the PVOH/sorbitol mixture. In addition, the in vitro and in vivo dug release of plasticized PVOH was examined; whereas the CEL/PVO/sorbitol system was able to maintain supersaturation during in vitro dissolution (0.1N HCl) compared to Celebrex(®), the in vivo pharmacokinetic parameters (AUC0-24h, Cmax and Tmax) were highly comparable.