Validation of an analytical method to quantify the permeation and penetration of flurbiprofen into human pharynx tissue

The aim of this investigation was to develop receiver and extraction fluids, and subsequently validate an analytical method to quantify the permeation and penetration of flurbiprofen into human pharynx tissue using a Franz diffusion cell. The solubility and stability of flurbiprofen in a suitable receiver fluid, and a suitable extraction method and fluid to recover and quantitate flurbiprofen from human pharynx tissue, were investigated using high‐performance liquid chromatography (HPLC). The potential interference of human pharynx tissue in the receiver fluid was also investigated. The HPLC analytical method was successfully validated according to current guidelines. The final receiver fluid demonstrated sufficient solubility and stability, and the extraction method and fluid resulted in >95% recovery of flurbiprofen following exposure to human pharynx tissue. The lower limit of quantitation of flurbiprofen was 0.045 μg/mL in both the receiver and extraction fluids. There was no interference of the human pharynx tissue with the HPLC method. This investigation validated an analytical method for quantitating flurbiprofen, and determined a suitable receiver fluid and extraction method and fluid, which can be used to investigate the permeation and penetration of flurbiprofen through human pharynx tissue using the Franz diffusion cell method.     

Development and validation of SPMMTE HPLC method for analysis of profens from human plasma

A fast, selective and reproducible solid‐phase membrane microtip extraction (SPMMTE) HPLC method has been developed and validated for the analyses of ibuprofen, ketoprofen, and flurbiprofen from human plasma. The analysis was carried out on a C₁₈ (150 × 4.6 mm; 5 μm) column. The mobile phase used was water–acetonitrile (55:45, v/v) adjusted to pH 3.0 using trifluoroacetic acid, at a flow rate 0.5 mL/min with a detection wavelength of 225 nm. The values for the capacity factors for the profen samples ranged from 0.47 to 1.50. The values for the selectivity factor (α) for ketoprofen–flurbiprofen, flurbiprofen–ibuprofen and ibuprofen–ketoprofen combinations from human plasma samples were 1.99, 1.00 and 2.10, respectively. The resolution factors (Rs) for ketoprofen–flurbiprofen, flurbiprofen–ibuprofen and ibuprofen–ketoprofen from plasma samples were 3.00, 1.50 and 4.10, respectively. The percentage recoveries of ibuprofen, ketoprofen, and flurbiprofen from human plasma were 75–85%. All of the profens were separated within 7.0 min, indicating a relatively fast method. During the development of the SPMMTE procedure the parameters of pH, contact time, desorption and types of solvents were optimized. The final method was also found to be efficient, effective and inexpensive. Copyright © 2016 John Wiley & Sons, Ltd.     

Thermo-reversible flurbiprofen liquid suppository with HP-β-CD as a solubility enhancer: improvement of rectal bioavailability

The purpose of this work was to develop a thermo-reversible flurbiprofen liquid suppository base composed of poloxamer and sodium alginate for the improvement of rectal bioavailability of flurbiprofen. Cyclodextrin derivatives such as α-, β-, γ-cyclodextrin and hydroxypropyl-β-cyclodextrin (HP-β-CD) were used to enhance the aqueous solubility of flurbiprofen. The effects of HP-β-CD and flurbiprofen on the physicochemical properties of liquid suppository were then investigated. Pharmacokinetic studies were performed after rectal administration of flurbiprofen liquid suppositories with and without HP-β-CD or after intravenous administration of commercial Lipfen^® (flurbiprofen axetil-loaded emulsion) to rats, and their pharmcokinetic parameters were compared. HP-β-CD decreased the gelation temperature and reinforced the gel strength and bioadhesive force of liquid suppository, while flurbiprofen was opposed to HP-β-CD. Thermo-reversible flurbiprofen liquid suppository showed the physicochemical properties suitable for rectal administration. The flurbiprofen liquid suppository with HP-β-CD showed significantly higher plasma levels, AUC and C_max of flurbiprofen than those of the liquid suppository without HP-β-CD, indicating that flurbiprofen could be well absorbed due to the enhanced solubility by formation of inclusion complex. Moreover, the flurbiprofen liquid suppository with HP-β-CD showed an excellent bioavailability in that the AUC of flurbiprofen after its rectal administration was not significantly different from that after intravenous administration of commercial Lipfen^®. It is concluded that HP-β-CD could be a preferable solubility enhancer for the development of liquid suppository containing poorly water-soluble drugs.     

Determination of flurbiprofen in pharmaceutical preparations by GC–MS

This article describes a gas chromatography–mass spectrometry (GC–MS) method for the determination of flurbiprofen in pharmaceutical preparations. The method is based on the derivatization of flurbiprofen with N-methyl-N-(trimethylsilyl)trifluoroacetamide (MSTFA). For GC–MS, electron ionization mode (EI = 70 eV) and selected ion monitoring (SIM) mode were used for quantitative analysis (m/z 180 for flurbiprofen). Calibration curve was linear between the concentration range of 0.25–5.0 μg/mL. Intra- and inter-day precision values for flurbiprofen were less than 3.64, and accuracy (relative error) was better than 2.67%. The mean recovery of flurbiprofen was 99.4% for pharmaceutical preparations. The limits of detection and quantification of flurbiprofen were 0.05 and 0.15 μg/mL, respectively. No interference was found from tablet excipients at the selected assay conditions. Also, the method was applied for the quality control of five commercial flurbiprofen dosage forms to quantify the drug and to check the formulation content uniformity.     

Combined use of l‐alanine tert butyl ester lactate and trimethyl‐β‐cyclodextrin for the enantiomeric separations of 2‐arylpropionic acids nonsteroidal anti‐inflammatory drugs

In this study, a new CE method, employing a binary system of trimethyl‐β‐CD (TM‐β‐CD) and a chiral amino acid ester‐based ionic liquid (AAIL), was developed for the chiral separation of seven 2‐arylpropionic acid nonsteroidal anti‐inflammatory drugs (NSAIDs). In particular, the enantioseparation of ibuprofen, ketoprofen, carprofen, indoprofen, flurbiprofen, naproxen, and fenoprofen was improved significantly by supporting the BGE with the chiral AAIL l ‐alanine tert butyl ester lactate (l ‐AlaC₄Lac). Parameters, such as concentrations of TM‐β‐CD and l ‐AlaC₄Lac, and buffer pH, were systematically examined in order to optimize the chiral separation of each NSAID. It was observed that the addition of the AAIL into the BGE improved both resolution and efficiency significantly. After optimization of separation conditions, baseline separation (R_s>1.5) of five of the analytes was achieved in less than 11 min, while the resolution of ibuprofen and flurbiprofen was approximately 1.2. The optimized enantioseparation conditions for all analytes involve a BGE of 5 mM sodium acetate/acetic acid (pH 5.0), an applied voltage of 30 kV, and a temperature of 20°C. In addition, the results obtained by computing the %‐RSD values of the EOF and the two enantiomer peaks, demonstrated excellent run‐to‐run, batch‐to‐batch, and day‐to‐day reproducibilities.     

Determination of pharmacokinetics of flurbiprofen in Pakistani population using modified HPLC method

Pharmacokinetics of flurbiprofen has been studied in different populations, especially in Caucasian. However, there are very few studies reported from Eastern part of world. Previous studies suggested that genetic and environmental factors may cause inter-individual differences in flurbiprofen disposition, so we investigated the pharmacokinetics of flurbiprofen in Pakistani subjects. A single oral dose of 100 mg of flurbiprofen was administered to 22 healthy male Pakistani adults after overnight fasting for 10 h. Periodical blood sampling was done at 0.25, 0.5, 0.75, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 7, 8, 10, 12, and 24 h after dosing. Plasma concentration of flurbiprofen was determined by a modified high-performance liquid chromatography method, which was simple, sensitive, less time consuming and economical with ordinary internal standard. The method was validated according to ICH guidelines and was found to be sensitive, accurate and precise. The pharmacokinetic parameters observed in Pakistani subjects when compared with other populations (USA, UK, Canadian, French, and Indian) did not show considerable ethnic differences. However, one subject's data was suggestive of being poor metabolizer of flurbiprofen which supports the presence of CYP2C9 polymorphism contributing to inter-individual differences in flurbiprofen disposition. Pharmacogenomic studies are needed to verify this hypothesis.     

荧光猝灭法研究氟比洛芬与DNA相互作用

采用荧光光谱法和紫外光谱法, 在生理条件下(pH=7.40)对氟比洛芬(FP)与脱氧核糖核酸(DNA)的作用方式进行了研究.证实了氟比洛芬通过沟槽结合方式与DNA发生相互作用.实验表明, DNA与氟比洛芬的相互作用为静态猝灭过程,测得结合常数为5.53×10~5 L·mol~(-1),结合位点数为1.12.     

Enantioselective,Potentiometric Memberane Electrodes Based on Different Cyclodextrins as Chiral Selectors for the Assay of S‐Flurbiprofen

Four enantioselective, potentiometric membrane electrodes (EPMEs) based on carbon paste impregnated with α‐, β‐, 2‐hydroxyl‐3‐trimethylammoniopropyl‐β‐(as chloride salt) and γ‐cyclodextrins, were proposed as a chiral selectors for assay of S‐flurbiprofen raw materials and in its pharmaceutical formulation Froben 100 tablets. The best response was obtained when β‐cyclodextrin was used for the electrode design. The four EPMEs showed very low detection limits (of 10^?8 to 10^?9 mol/L magnitude orders). The surfaces of the electrodes are easily renewable by simply polishing on an alumina paper.     

Simultaneous Quantitation of Captopril and NSAID's in API,Dosage Formulations and Human Serum by RP‐HPLC

An accurate, sensitive and least time consuming reverse phase high performance liquid chromatographic (RP‐HPLC) method for the estimation of captopril in the presence of non steroidal anti‐inflammatory drugs in formulation and human serum has been developed and validated. Chromatographic separation was conducted on prepacked Purospher star C18 (5 μm, 25 × 0.46 cm) column at room temperature using methanol:water (80:20 v/v) as a mobile phase, pH adjusted at 2.8 with o‐phosphoric acid and at a flow rate of 1.0 mL min⁻¹, while UV detection was performed at 227 nm. The limit of detection and quantification for captopril were 1 and 0.35 ng mL⁻¹, while that for (NSAID's) i.e. flurbiprofen, ibuprofen, diclofenac sodium and mefenamic acid LOD were 0.2, 1, 2 and 0.4 ng mL⁻¹ respectively and LOQ were 0.9, 2.9, 8 and 1 ng mL⁻¹ Analytical recovery was > 98.1%. The method used for the quantitative analysis of commonly administered non steroidal anti‐inflammatory drugs (NSAID's) i.e. ibuprofen, flurbiprofen, diclofenac sodium and mefenamic acid alone or in combination with captopril from API (active pharmaceutical ingredients), dosage formulations and in human serum. The established method is rapid (RT < 12 min), accurate (recovery > 98.1%), selective (no interference of excepients and other commonly used drugs and food) and sensitive (LOQ 3.5 ng mL^;‐1) and reproducible (SD ± 0.003).     

Improvement in bioavailability of transdermally applied flurbiprofen using tulsi (Ocimum sanctum) and turpentine oil

Penetration enhancing potential of tulsi and turpentine oil on transdermal delivery of flurbiprofen, a potent non-steroidal anti-inflammatory agent, was investigated. The transdermal permeation rate of flurbiprofen across the rat abdominal skin from binary solvent mixture composition of propylene glycol (PG):isopropyl alcohol (IPA) (30:70%, v/v) was 98.88 microg/cm(2)/h, significantly higher than other binary solvent mixtures. The corresponding steady state plasma concentration, 0.71 microg/ml, was much lower than required steady state plasma concentration of 3-5 microg/ml. Hence influence of tulsi and turpentine oil in the optimized binary solvent mixture along with the increased drug load on the flurbiprofen permeation was evaluated. The magnitude of the flux enhancement factor with turpentine oil and tulsi oil was 2.4 and 2.0 respectively at 5% (v/v) concentration beyond which there was no significant increase in the flux. Addition of 2% (w/v) hydroxypropyl methylcellulose (HPMC), as a thickening agent, resulted in desired consistency for the fabrication of patch with insignificant effect on permeation rate of flurbiprofen. The reservoir type of transdermal patch formulation, fabricated by encapsulating the flurbiprofen reservoir solution within a shallow compartment moulded from polyester backing film and microporous ethyl vinyl acetate membrane, did not modulate the skin permeation of flurbiprofen through rat skin in case of turpentine formulations whereas flux of formulations with tulsi oil was significantly altered. The influence of penetration enhancer and solvents on the anatomical structure of the rat skin was studied. Enhancement properties exhibited by turpentine oil and tulsi oil in optimized binary solvent mixture were superior as compared to solvent treated and normal control groups with negligible skin irritation. The fabricated transdermal patches were found to be stable. The bioavailability of flurbiprofen with reference to orally administered flurbiprofen in albino rats was found to increase by 2.97, 3.80 and 5.56 times with transdermal patch formulation without enhancer, tulsi and turpentine oil formulations, respectively. The results were confirmed by pharmacodynamic studies in rat edema inflammation model.     

HPLC microdetermination of flurbiprofen enantiomers in plasma with a glycopeptide-type chiral stationary phase column

A rapid and stereospecific HPLC micromethod to quantify flurbiprofen enantiomers was developed. Both flurbiprofen enantiomers and indomethacin, used as internal standard, were extracted with methylene chloride from 100 microL of acidified plasma. The resolution of the R- and S-forms was performed on a bonded vancomycin chiral stationary phase (Chirobiotic V) with 20% of tetrahydrofuran in ammonium nitrate (100 mM, pH 5) as mobile phase. Calibration curves were linear in the range 0.5-10 microg/mL for both enantiomers. A good accuracy (< or = 5%) was obtained for all quality controls, with intra-day and inter-day variation coefficients equal or less than 7.7%. Recovery of both enantiomers was found in the range 77.4-86.3%. The lower limit of quantitation was 0.25 microg/mL for both enantiomers, without interference of endogenous components. This validated micromethod has been successfully applied for quantifying R- flurbiprofen and S- flurbiprofen in rat plasma.     

Cotton thread modified with ionic liquid copolymerized polymer for online in‐tube solid‐phase microextraction and HPLC analysis of nonsteroidal anti‐inflammatory drugs

Cotton fiber is a biodegradable material that possesses properties such as high specific area, adjustable shape, and hygroscopicity. In this work, organic polymer was directly in situ grown on the surface of cotton thread and packed into a poly(ether ether ketone) tube for online in‐tube solid‐phase microextraction. The novel strategy solves the problems like high backpressure and tedious optimization process of normal monolithic polymer‐based in‐tube solid‐phase microextraction capillary. The quaternary ammonium typed ionic liquid of 1‐allyl‐methylimidazolium chloride, 4‐vinylbiphenyl, and ethylene dimethacrylate were co‐polymerized and in situ grown on the surface of cotton thread as extraction phase. The solid‐phase microextraction tube showed excellent performance for the extraction of three nonsteroidal anti‐inflammatory drugs including ketoprofen, naproxen, and flurbiprofen due to the strong ion exchange and hydrophobic interactions. After online coupling with a high‐performance liquid chromatography system by six‐port valve, the method was applied for the quantitative analysis of nonsteroidal anti‐inflammatory drugs in human plasma samples showing good enrichment performance (enrichment factor between 263 and 279), high sensitivity, good linearity, and good reproducibility.     

Effects of non-ionic surfactants on isotachophoretic separations of 2-arylpropionic acids

Non-ionic surfactant (Brij 35, Tween 20, Tween 80 and Tergitol NPX) modified capillary isotachophoresis was investigated for the separation of 2-arylpropionic acids (fenoprofen, flurbiprofen, ibuprofen, ketoprofen and naproxen) and benzoic acid and its derivatives (salicylic, acetylsalicylic and gallic acids). The relative step height (RSH) values of analytes were found to be dependent on the type and concentration of the surfactant. The strength of the affinity of the 2-arylpropionic acids to the non-ionic micelles was found to be as follows: flurbiprofen > fenoprofen > ibuprofen > naproxen > ketoprofen. In general, the RSH values of 2-arylpropionic acids increase with an increase in the concentration of surfactants. However, the RSHs of benzoic, salicylic and gallic acids are not considerably affected. Separation of all acids was obtained with the Tween 20 (1.5%, w/v) in the leading electrolyte 10 mmol L(-1) hydrochloric acid/L-histidine (pH 6.0). Changes in the fluorescence intensity of fenoprofen, flurbiprofen and naproxen were also investigated in micellar media (Tween 20, Tween 80 and Brij 35). The strength of the affinity of the 2-arylpropionic acids to the Tweens micelles was found to be as follows: flurbiprofen > fenoprofen > naproxen, which is consistent with the isotachophoretic results. On the contrary, the strength of the affinity to the Brij micelles was found to be as follows: fenoprofen > naproxen > flurbiprofen.     

Enantiomeric resolution of ibuprofen and flurbiprofen in human plasma by SPE-chiral HPLC methods

Chiral analysis of profens in human plasma is an important area of research due to different pharmaceutical activities of their enantiomers. The solid phase extraction of ibuprofen and flurbiprofen from human plasma was carried out on C18 cartridges by using phosphate buffer (50 mM, pH 6.0) followed by elution with methanol. Chiral-HPLC was performed on AmyCoat RP (150 mm x 46 mm, 3 μm particle size) column by using different combinations of water-acetonitrile-trifluoro acetic acid at 1.5 mLmin-1 flow rate. The detection was achieved at 236 and 254 nm for ibuprofen and flurbiprofen, respectively with 27±1°C as working temperature. The chromatographic parameters i.e. retention (k), separation (α) and resolution (Rs) factors ranged from 4.54-14.42, 1.10-1.30 and 1.01-1.49, respectively. The binding differences of enantiomers of ibuprofen and flurbiprofen were 4.4 and 5.2, respectively. These values suggest that S-(+)- enantiomer of flurbiprofen is more active than ibuprofen due to low enantiomeric difference of the later drug. The developed SPE-Chiral HPLC methods were validated, which are selective, efficient and reproducible.     

High Performance Liquid Chromatographic Determination of Flurbiprofen in Pharmaceutical Dosage Forms

Abstract

A rapid, specific and reliable high performance liquid chromatographic assay of flurbiprofen in dosage forms has been developed. Reversed-phase chromatography was conducted using a mobile phase of 0.05 M ammonium acetate and acetonitrile, (40% v/v) PH 5.2 and detection at λ 247 nm. The recovery and coefficient of variation from six placebo tablets spiked with 100 mg of flurbiprofen were 100.1% and 0.4% respectively. Replicate regression analyses of three standard plots in the concentration range 0.5 - 9 mcg/ml obtained on three different days gave a correlation coefficient (0.99996) and the coefficient of variation of the slopes 0.159%. The assay was precise within day and between days as indicated by ANOVA test. It is suggested that the proposed HPLC method should be used for routine quality control and dosage form assay of flurbiprofen.     

Biotransformation with whole microbial systems in a continuous flow reactor: resolution of (RS)-flurbiprofen using Aspergillus oryzae by direct esterification with ethanol in organic solvent

Cell-bound lipases of dry mycelium of Aspergillus oryzae were used in organic solvent for the resolution of racemic flurbiprofen by direct esterification with ethanol in a flow-chemistry reactor. Under flow conditions a significant reduction of the reaction time and an increase of the enantioselectivity were achieved compared to the batch mode. Moreover, the process was implemented by adding an in-line purification step integrated with the racemization of the unreacted flurbiprofen directly into a polymer-supported resin.     

Elimination profiles of flurbiprofen and its metabolites in equine urine for doping analysis

Flurbiprofen and its main acidic metabolites were detected in equine urine after a single-dose administration of 500 mg flurbiprofen to two 2.5–3.5-years-old mares, in order to be used in equine doping control routine analysis. The urine levels of the parent drug were determined using GC/MS. Five acidic metabolites were found in the urine. The structure of the proposed metabolites was confirmed by HRMS accurate mass measurements. The highest flurbiprofen concentration was 204 μg ml⁻¹ at 1–3 h post administration. Flurbiprofen could be detected for 24–37 h in urine using the standard screening procedure. All metabolites were present 25 h post administration, while 4′-hydroxyflurbiprofen could be traced for more than 48 h and it is regarded as the long-term metabolite of flurbiprofen in horse.     

氟比洛芬构象异构体的理论计算

用Hypercbem软件中构象搜寻模块,对氟比洛芬进行构象搜索,寻找分子低能构象．用B3LYP／6-31G（d）法优化计算22个低能构象,PCM溶剂模型用于水相计算,获得低能构象的优化几何结构、分子总能量和标准吉布斯自由能．结果表明,在气相和水相时,Z-型构象异构体稳定性最高．     

Characterization of interactions between methoxatin disodium salt and human serum albumin by pressure‐assisted capillary electrophoresis/frontal analysis and circular dichroism spectroscopy

Pressure‐assisted capillary electrophoresis (PACE)/frontal analysis (FA) and circular dichroism spectroscopy were utilized to investigate the interactions between methoxatin disodium salt (PQQ‐2Na) and human serum albumin (HSA). With the PACE/FA method, sodium phosphate buffer solution (67 mm , pH 7.4) was used as the background electrolyte. Hydrodynamic injection at 50 mbar for 50 s and external pressure of 50 mbar were applied. The binding constant and the number of primary binding sites to HSA were obtained under fixed concentration of PQQ‐2Na (100 µm ) and increasing HSA concentration (0~475 µm ). The thermodynamic parameters characterized the main acting forces of hydrophobic and electrostatic interactions. The displacement experiments using phenylbutazone and flurbiprofen as ligand markers suggested that the binding site was the Sudlow site I of the HSA molecule. Circular dichroism spectroscopy was further employed to evaluate the conformation changes of HSA under the interaction of PQQ‐2Na. This work provides comprehensive information for understanding the interactions between PQQ‐2Na and HSA. Copyright © 2014 John Wiley & Sons, Ltd.     

Utilization of Maltodextrin‐Based Enantioselective,Potentiometric Membrane Electrodes for the Enantioselective Assay of S‐Flurbiprofen

Abstract

Three enantioselective, potentiometric membrane electrodes (EPMEs) based on carbon paste impregnated with different maltodextrins [dextrose equivalent (DE) (DE 4.0–7.0 (I), 13–17 (II), 16.5–19.5 (III)], were proposed as chiral selectors for the assay of S‐flurbiprofen raw materials and from its pharmaceutical formulation, Froben 100^® tablets. The best response and enantioselectivity were obtained when maltodextrin with lower DE was used for the electrode design. The three EPMEs showed very low detection limits. The surfaces of the electrodes are easily renewable by simply polishing on an alumina paper.