Rapid Resolution RP-HPLC-DAD Method for Simultaneous Determination of Sildenafil,Vardenafil, and Tadalafil in Pharmaceutical Preparations and Counterfeit Drugs

A novel and Rapid Resolution Reversed-Phase High-Performance Liquid Chromatography-Diode Array Detector method has been developed and validated for the simultaneous determination of sildenafil, vardenafil, and tadalafil in pharmaceutical preparations and counterfeit drugs. An Agilent Zorbax SB C8 column (50 × 4.6 mm i.d., 1.8 μm particle size) was used. The mobile phase consisted of a mixture of 0.030 M of ammonium formate (adjusted to pH 3.0 with formic acid) and acetonitrile in the ratio 70:30. Ultraviolet (UV) detection was performed at 230 nm. Total run time was 7 min; these three drugs were eluted at the retention times of 1.654, 2.032, and 5.067 min for vardenafil, sildenafil, and tadalafil, respectively. The method was validated for accuracy, precision, linearity, specificity, and sensitivity. From the validation study, it was found that the method is specific, rapid, accurate, precise, and reproducible. Calibration curves were linear over the concentration ranges of 0.2–200 μg ml^?1 for sildenafil, vardenafil, and tadalafil. The limits of detection (LOD) values were 1.0, 1.1, and 1.0 ng and the limit of quantification (LOQ) values were 2.0, 2.1, and 2.0 ng for sildenafil, vardenafil, and tadalafil, respectively. The method is rapid both for routine quantitative analysis of sildenafil, vardenafil, and tadalafil in pharmaceutical preparations and screening their suspected counterfeit drugs.     

Sensitive and precise HPLC method with back‐extraction clean‐up step for the determination of sildenafil in rat plasma and its application to a pharmacokinetic study

A sensitive HPLC method was developed and validated for the determination of sildenafil concentrations in rat plasma (200 μL) using a liquid–liquid extraction procedure and paroxetine as an internal standard. In order to eliminate interferences and improve the peak shape, a back‐extraction into an acidic solution was utilized. Chromatographic separation was achieved on a cyanopropyl bonded‐phase column with a mobile phase composed of 50 m m potassium dihydrogen phosphate buffer (pH 4.5) and acetonitrile (75:25, v/v), pumped at the flow rate of 1 mL/min. A UV detector was set at 230 nm. A calibration curve was constructed within a concentration range from 10 to 1500 ng/mL. The limit of detection was 5 ng/mL. The inter‐ and intra‐day precisions of the assay were in the ranges 2.91–7.33 and 2.61–6.18%, respectively, and the accuracies for inter‐ and intra‐day runs were within 0.14–3.92 and 0.44–2.96%, respectively. The recovery of sildenafil was 85.22 ± 4.54%. Tests confirmed the stability of sildenafil in plasma during three freeze–thaw cycles and during long‐term storage at ?20 and ?80°C for up to 2 months. The proposed method was successfully applied to a pharmacokinetic study in rats. Copyright © 2015 John Wiley & Sons, Ltd.     

高效液相色谱-高分辨质谱快速筛查和确证保健品中非法添加的壮阳药物

采用高效液相色谱-四极杆/飞行时间质谱对中药保健品中红地那非、伐地那非、那红地那非、他达拉非、西地那非、豪莫西地那非、硫代艾地那非、伪伐地那非、羟基豪莫西地那非、育亨宾、达泊西汀等11种非法添加的壮阳类药物进行了快速筛查、确证和定性定量检测。样品经甲醇提取后,采用正离子扫描模式进行检测。结果表明,11种待测物的定量限除那红地那非为25.0 ng/mL外,其他10种壮阳类药物均为5.0 ng/mL,在5.0~200.0 ng/mL(那红地那非在25.0~500.0 ng/mL)范围内,线性相关性较好,相关系数均不小于0.9990。平均添加回收率为82.0%~105.9%,相对标准偏差为4.7%~16.5%。本方法利用准确质量数匹配和自建标准谱库,通过多级特征碎片离子的比对,实现快速筛查和确证,简单快速,结果可靠。     

Solid‐phase extraction and analysis of paroxetine in human plasma by ultra performance liquid chromatography–electrospray ionization mass spectrometry

A rapid, sensitive and rugged solid‐phase extraction ultra performance liquid chromatography tandem mass spectrometry (UPLC‐MS/MS) method was developed for determination of paroxetine in human plasma. The procedure for sample preparation includes simple SPE extraction procedure coupled with Hypersil Gold C₁₈ column (100 mm ? 2.1 mm, i.d., 1.9 μm) with isocratic elution at a flow‐rate of 0.350 mL/min and fluoxetine was used as the internal standard. The analysis was performed on a triple‐quadrupole tandem mass spectrometer by multiple reactions monitoring mode via electrospray ionization. Using 500 μL plasma, the methods were validated over the concentration range 0.050–16.710 ng/mL for paroxetine, with a lower limit of quantification of 0.050 ng/mL. The intra‐ and inter‐day precision and accuracy of the quality control samples were within 10.0%. The recovery was 69.2 and 74.4% for paroxetine and fluoxetine respectively. Total run time was only 1.9 min. The method was highly reproducible and gave peaks with excellent chromatography properties. Copyright © 2009 John Wiley & Sons, Ltd.     

Optimization of alcohol‐assisted dispersive liquid–liquid microextraction by experimental design for the rapid determination of fluoxetine in biological samples

A sensitive and rapid method based on alcohol‐assisted dispersive liquid–liquid microextraction followed by high‐performance liquid chromatography for the determination of fluoxetine in human plasma and urine samples was developed. The effects of six parameters on the extraction recovery were investigated and optimized utilizing Plackett–Burman design and Box–Benken design, respectively. According to the Plackett–Burman design results, the volume of disperser solvent, extraction time, and stirring speed had no effect on the recovery of fluoxetine. The optimized conditions included a mixture of 172 μL of 1‐octanol as extraction solvent and 400 μL of methanol as disperser solvent, pH of 11.3 and 0% w/v of salt in the sample solution. Replicating the experiment in optimized condition for five times, gave the average extraction recoveries equal to 90.15%. The detection limit of fluoxetine in human plasma was obtained 3 ng/mL, and the linearity was in the range of 10–1200 ng/mL. The corresponding values for human urine were 4.2 ng/mL with the linearity range from 10 to 2000 ng/mL. Relative standard deviations for intra and inter day extraction of fluoxetine were less than 7% in five measurements. The developed method was successfully applied for the determination of fluoxetine in human plasma and urine samples.     

A simple HPLC method for the simultaneous determination of two selective serotonin reuptake inhibitors and two serotonin-norepinephrine reuptake inhibitors in hair, nail clippings, and cerebrospinal fluid

A novel and simple high-performance liquid chromatography method has been developed for the simultaneous determination of two selective serotonin reuptake inhibitors (fluoxetine and paroxetine) and two serotonin-norepinephrine reuptake inhibitors (venlafaxine and duloxetine) in alternative samples of toxicological interest such as hair, nail clippings, and cerebrospinal fluid (CSF). The separation was achieved on a Hichrom Kromasil 100-5C(18) (250 × 4.6 mm) 5 μm column by using ammonium acetate (0.05 M)-acetonitrile (59:41% v/v) as the mobile phase, delivered isocratically at a flow rate of 1.3 mL/min, within ca. 10 min. Ultraviolet detection at 235 nm was used for monitoring the eluting analytes. Validation was performed in terms of linearity, selectivity, accuracy, precision, and stability. Correlation coefficients were greater than 0.9954. The limits of quantitation ranged between 0.3 and 2.1 ng/μL for all analytes in the liquid matrix (CSF), while the respective values were in the range of 0.3-3.6 ng/mg for solid matrices (hair and nail clippings), with an injection volume of 20 μL. Repeatability and intermediate precision (relative standard deviation, RSD%) were less than 16.6%. The method was successfully applied to actual hair and nail samples from a patient under fluoxetine treatment.     

Quantitative LC–MS/MS method in urine for the detection of drugs used to reverse the effects of chemical castration

The chemical castration law, which targets child molesters with recidivism, was introduced in Korea in 2011. For this, leuprolide, a gonadotropin-releasing hormone agonist, is used to decrease testosterone production and suppress libido. In order to achieve efficient law enforcement, it is necessary to monitor intentional ingestion of drugs that antagonize the effect of leuprolide. Therefore, an analytical method for the simultaneous detection of mirodenafil, sildenafil, tadalafil, udenafil, vardenafil, icariin, alprostadil, and yohimbine, which are the major impotence treatment drugs, legitimately or otherwise, in Korea, as well as their selected metabolites, in human urine was established and validated using liquid chromatography–tandem mass spectrometry (LC–MS/MS). First, different sample preparation methods, two solid-phase extractions with different cartridges and protein precipitation, were compared and protein precipitation was chosen for the entire study because it showed better matrix effects and recoveries. Thus, the drugs and metabolites in urine were extracted by protein precipitation and then filtered and analyzed by LC–MS/MS with polarity switching electrospray ionization. The validation results of selectivity, matrix effect, recovery, linearity, intra- and inter-assay precision and accuracy were satisfactory. The limits of detection ranged from 0.25 to 10 ng/mL, and the limits of quantification were 2.5 to 50 ng/mL. The drugs and metabolites in urine did not show any degradation under storage for 7 and 15 days at 4 and ?20 °C as well as after three freeze–thaw cycles. The developed method will be very useful for monitoring the illegal use of impotence treatment drugs.     

超高效液相色谱–串联质谱法同时测定露酒中伐地那非、西地那非和他达拉非含量

以甲醇提取样品,采用超高效液相色谱–串联质谱(UPLC–MS/MS)法同时测定露酒中西地那非、伐地那非和他达拉非。以甲醇–0.1%甲酸水溶液为流动相,质谱采用电喷雾ESI+扫描模式,通过多反应监测模式进行定性及定量分析。伐地那非、西地那非和他达拉非的线性范围均为5~1 000μg/L,检出限均为0.001 mg/kg,线性相关系数均大于0.999。实际样品中伐地那非、西地那非、他达拉非的加标回收率分别为91.0%~96.0%,92.0%~96.0%,89.5%~92.4%。测定结果的相对标准偏差均小于2%(n=6)。该方法操作简单、快捷,精密度、回收率高,适用于露酒中伐地那非、西地那非和他达拉非的含量分析。     

Chromatographic analysis of some drugs employed in erectile dysfunction therapy: Qualitative and quantitative studies using calixarene stationary phase

In this study, the effect of change in chromatographic process variables on the retention behavior of four drugs employed in erectile dysfunction therapy on a calixarene stationary phase is described. Three of these drugs are known to treat erectile dysfunction, namely, sildenafil citrate, tadalafil, and apomorphine hydrochloride, and one drug that is used as opioid analgesic, tramadol hydrochloride, which is quiet widely misused to treat premature ejaculation. The results indicate the importance of considering the structure and pK_a values of drugs to be separated along with mobile phase composition. A new optimized, rapid, and accurate liquid chromatography method is also established for simultaneous determination of sildenafil citrate, tadalafil, and apomorphine hydrochloride in pharmaceutical preparations and bulk powders. The chromatographic separation of the three pharmaceuticals was achieved on a calixarene column in less than 10 min using a binary mobile phase of 35% acetonitrile and 65% 50 mM sodium perchlorate pH2.5 at 1 mL/min flow rate. The method was validated for system efficiency, linearity, accuracy, precision, limits of detection and quantitation, specificity, stability, and robustness. Statistical analysis proved that the method enabled reproducible and selective quantification of all three analytes in bulk drugs and in pharmaceutical preparations.     

Simultaneous determination of sildenafil, vardenafil and tadalafil as forbidden components in natural dietary supplements for male sexual potency by high-performance liquid chromatography-electrospray ionization mass spectrometry

A high-performance liquid chromatographic method coupled with ultraviolet detection and electrospray ionization mass spectrometry (HPLC-UV-ESI-MS) was developed for simultaneous determination of banned additives-sildenafil, vardenafil and tadalafil in dietary supplements for male sexual potency. The separation was achieved on a C18 column with acetonitrile and aqueous solution (20 mmol ammonium acetate, 0.2% formic acid) as mobile phase at a flow rate of I ml/min with a linear gradient program. UV detection was at 292 nm. Identification of drugs was accomplished using ESI-MS. Good linearity between response (peak area) and concentration was found over a concentration range of 0.8-80 microg/ml for sildenafil; 2.25-225 microg/ml for vardenafil; and 1.1-110 microg/ml for tadalafil, with regression coefficient is better than 0.999. The recovery of the method ranged from 93.3 to 106.1%, and the relative standard deviation varied from 2.0 to 5.6% (n = 6). The method has been successfully applied to the analysis of practical samples of natural dietary supplements.     

Validated Method for the Simultaneous Determination of Gemifloxacin and H2‐receptor Antagonists in Bulk,Pharmaceutical Formulations and Human Serum by RP‐HPLC; In‐vitro Applications

Simple, isocratic and rapid RP‐HPLC method has been developed for the simultaneous analysis of gemifloxacin and H₂‐receptor antagonists i.e. Cimetidine, Famotidine and Ranitidine, in bulk, pharmaceutical formulation and human serum. Separation was achieved on the RP‐Mediterranea column [C18 (250 × 4.6 mm, 5 μ)] at ambient temperature using mobile phase consisting of acetonitrile: methanol: water (20:28:52 v/v/v pH 2.8 adjusted by phosphoric acid). Flow rate was 1.0 mL/min with an average operating pressure of 180 kg/cm². Gatifloxacin (GATI) was used as an internal standard (IS). Quantitation was achieved with UV detection at 221, 256 and 267 nm, respectively. Linear calibration curves, at concentration ranges of 0.05‐37.5 μgmL^‐L with a correlation coefficient of ±0.9994. The detection and quantification limits were in the ranges of 0.023‐0.250 μgmL^‐L and 0.071‐0.756 μgmL^‐L, respectively. Friedman's and Student's t‐test were applied to correlate these results. Method was validated in terms of selectivity, linearity, precision, robustness, recovery, limits of detection and quantitation and is applicable to the routine analysis of GFX and H₂‐receptor antagonists, alone or in combination.     

Development and validation studies for determination of phenylpropanoid‐substituted flavan‐3‐ols in semipurified extract of Trichilia catigua by high‐performance liquid chromatography with photodiode array detection

The phenolic compounds are the main phytochemical constituents of the bark of Trichilia catigua and are commonly used for medicinal purposes. An HPLC method for the simultaneous quantification of phenolic compounds (procyanidin B2 (PB2), epicatechin (EPC), chinchonains Ia, Ib, IIa, IIb, catechin, and chrologenic acid) in T. catigua extract was developed and validated. A suitable chromatographic system was selected, which uses a gradient elution with methanol/ACN (75:25), and water both with 0.05% TFA, as mobile phase, column Luna, 280 nm, and flow 0.4 mL/min. Validation of the analytical method was based on the parameters: linearity, precision, LODs and LOQs, accuracy, robustness, and stability. The method showed linearity for PB2 and EPC, in the range 10–120 μg/mL with good correlation coefficients (>0.996). For precision, the repeatability ranged from 1.89 to 3.23%, and the values for accuracy for PB2 and EPC were 95 and 89%, respectively. The LODs and LOQs for PB2 were 1.36 and 4.12 μg/mL, and for EPC were 2.18 and 6.61 μg/mL, respectively. The method was robust under the conditions employed. The proposed method could be employed for quality assessment of T. catigua, as well as pharmaceutical products.     

Simultaneous determination of synthetic phosphodiesterase-5 inhibitors found in a dietary supplement and pre-mixed bulk powders for dietary supplements using high-performance liquid chromatography with diode array detection and liquid chromatography-electrospray ionization tandem mass spectrometry

A high-performance liquid chromatography-diode array detection (HPLC-DAD) method and a liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) method were developed to screen for the presence of synthetic phosphodiesterase-5 (PDE-5) inhibitors and their analogues, namely sildenafil, vardenafil, tadalafil, homosildenafil, acetildenafil and hydroxyhomosildenafil. The methods were applied to pre-market samples submitted to the Health Sciences Authority of Singapore (HSA) for testing. One sample was in the form of capsules while six other samples were pre-mixed bulk powder samples for dietary supplements to be repackaged or formulated into the final dosage forms (usually capsules). Identification of PDE-5 inhibitors and their analogues was achieved by comparing individual peak retention times, UV spectra and mass spectra with those of reference standards. The seven samples were found to contain at least one of the following compounds: sildenafil, vardenafil, hydroxyhomosildenafil, homosildenafil and acetildenafil. The five compounds were simultaneously determined by LC-ESI-MS/MS in multiple reactions monitoring (MRM) scan mode. The method has been validated for accuracy, precision, linearity and sensitivity.     

Determination and validation of duloxetine hydrochloride in capsules by HPLC with pre-column derivatization and fluorescence detection

A high-performance liquid chromatographic (HPLC) method is described for the determination of duloxetine hydrochloride in capsules. The method was based on pre-column derivatization with 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole using the fluorimetric detection technique. Duloxetine hydrochloride was analyzed by HPLC using an Inertsil C18 column (5 μm, 150 × 4.6 mm) and mobile phase consisted of methanol and water (65:35, v/v). The fluorescence detector was adjusted at excitation and emission wavelengths of 461 and 521 nm, respectively. The linearity of the method was in the range of 10-600 ng/mL. Limits of detection and quantification were 0.51 and 1.53 ng/mL, respectively. The proposed method was successfully applied for determination of duloxetine hydrochloride in its pharmaceutical preparation. The results were in good agreement with those obtained using a reference method.     

保健食品中壮阳类西药成分的核磁共振氢谱定量分析

建立了保健食品中枸橼酸西地那非、他达拉非、伐地那非的核磁共振氢谱定量(1H q NMR)分析方法。采用布鲁克Avance DRX 500超导核磁共振波谱仪,以氘代二甲亚砜为溶剂,2,3,5-三碘苯甲酸为内标物,优化了仪器采集参数,并进行了方法验证。结果表明:当内标添加量为2 mg、内标与待测化合物摩尔比在1∶0.1~1∶1.2范围时,标准曲线线性良好,相关系数(r2)不小于0.999;枸橼酸西地那非、他达拉非、伐地那非的检出限分别为0.045,0.026,0.033 mg/m L,定量下限分别为0.218,0.128,0.159 mg/m L;日内精密度RSD值分别为0.38%,0.85%,0.34%;日间精密度RSD值分别为0.72%,1.2%,1.4%。利用所建立的方法对13种实际样品进行定量分析;并将测试结果与HPLC-DAD法测试结果进行比较,两种测试结果的RSD在1%~8%之间。     

High‐performance liquid chromatographic method for identification and quantification of three potent liver protective coumarinolignoids—cleomiscosin A,cleomiscosin B and cleomiscosin C—in extracts of Cleome viscosa

A simple, rapid, accurate and reproducible reverse‐phase HPLC method has been developed for simultaneous identification and quantification of three coumarinolignoids, cleomiscosin A (Cliv A), cleomiscosin B (Cliv B) and cleomiscosin C (Cliv C) in different extracts of the seeds of Cleome viscosa using photodiode array detection at 326 nm. Cliv A, B and C were separated on a Waters symmetry C₁₈ column (250 × 4.6 mm, 5 μm) using the solvent system consisting of a mixture of acetonitrile : methanol (1:2 v/v) and water : acetic acid (99.5:0.5 v/v) as a mobile phase in a gradient elution mode. The calibration curves were linear in the concentration ranges 15–200, 10–80 and 15–180 μg/mL for Cliv A, Cliv B and Cliv C, respectively. The limits of detection and quantification for Cliv A, Cliv B and Cliv C were 15 and 20 μg/mL, 10 and 15 μg/mL and 15 and 20 μg/mL, respectively. The intra‐day and inter‐day precisions were 2.08 and 0.93% for Cliv A , 1.22 and 0.39% for Cliv B and 1.29 and 0.23 for Cliv C respectively. The developed HPLC method was used to identify and quantify Cliv A, Cliv B and Cliv C in different extracts of seed of Cleome viscosa. Copyright © 2010 John Wiley & Sons, Ltd.     

Simultaneous determination of 10 kinds of biogenic amines in rat plasma using high‐performance liquid chromatography coupled with fluorescence detection

We describe a simple, rapid, selective and sensitive HPLC method coupled with fluorescence detection for simultaneous determination of 10 kinds of biogenic amines (BAs: tryptamine, 2‐phenethylamine, putrescine, cadaverine, histamine, 5‐hydroxytryptamine, tyramine, spermidine, dopamine and spermine). BAs and IS were derivated with dansyl chloride. Fluorescence detection (λ_ex/λ_em = 340/510 nm) was used. A satisfactory result for method validation was obtained. The assay was shown to be linear over the ranges 0.005–1.0 μg/mL for tryptamine, 2‐phenethylamine and spermidine, 0.025–1.0 μg/mL for putrescine, 0.001–1.0 μg/mL for cadaverine, 0.25–20 μg/mL for histamine, 0.25–10 μg/mL for 5–hydroxytryptamine and dopamine, and 0.01–1.0 μg/mL for tyramine and spermine. The limits of detection and the limits of quantification were 0.3–75.0 ng/mL and 1.0–250.0 ng/mL, respectively. Relative standard deviations were ≤5.14% for intra‐day and ≤6.58% for inter‐day precision. The recoveries of BAs ranged from 79.11 to 114.26% after spiking standard solutions of BAs into a sample at three levels. Seven kinds of BAs were found in rat plasma, and the mean values of tryptamine, 2‐phenethylamine, putrescine, cadaverine, histamine, spermidine and spermine determined were 52.72 ± 7.34, 11.45 ± 1.56, 162.56 ± 6.26, 312.75 ± 18.11, 1306.50 ± 116.16, 273.89 ± 26.41 and 41.51 ± 2.07 ng/mL, respectively.     

Simultaneous Determination of Ceftriaxone Sodium and Non Steroidal Anti‐Inflammatory Drugs in Pharmaceutical 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 ceftriaxone 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, 250 × 4.6 mm) column at room temperature using methanol:water:acetonitrile (80:15:5 v/v/v) as a mobile phase, pH adjusted at 2.8 with ortho‐phosphoric acid and at a flow rate of 1.0 mL/minute, while UV detection was performed at 270 nm. The results obtained showed a good agreement with the declared content. The method shows good linearity in the range of 2.5‐25 μg/mL ceftriaxone serum concentrations with a correlation coefficient 0.999 (inter‐ and intra‐day RSD < 2.0%). The limit of detection and quantification for ceftriaxone and NSAID's in pharmaceutical formulation and serum were in the range 0.51‐1.54 μg/mL. Analytical recovery was >98.1%. The proposed method may be used for the quantitative analysis of commonly administered non steroidal anti‐inflammatory drugs i.e. tiaprofenic acid, naproxen sodium, flurbiprofen, diclofenac acid and mefenamic acid alone or in combination with ceftriaxone from raw materials, dosage formulations and in serum. The established HPLC method is rapid, accurate and selective, because of its sensitivity and reproducibility.     

Simultaneous determination of yohimbine,sildenafil, vardenafil and tadalafil in dietary supplements using high‐performance liquid chromatography‐tandem mass spectrometry

A simple and sensitive method was developed for determination of illegal adulterants (yohimbine, sildenafil, vardenafil and tadalafil) in dietary supplements by HPLC‐MS/MS. The separation was achieved on a C₁₈ column with the mobile phase consisting of acetonitrile and 0.1% acetic acid aqueous solution with a gradient elution at a flow rate of 0.5 mL/min. The analytes were quantified and identified by two characteristic transitions using the multiple‐reaction monitoring mode. The recoveries of the analytes ranged from 77.5 to 109.3% with the RSD less than 8.1% (n=6). The method has been successfully applied to screen illegal adulterations of natural dietary supplements.     

Capillary electrophoresis separation of aminoalkanol derivatives of 1,7‐dimethyl‐8,9‐diphenyl‐4‐azatricyclo[5.2.1.02,6]dec‐8‐ene‐3,5,10‐trione as potential anticancer drugs

The purpose of this study, the direct separation of aminoalkanol derivatives I and II of 1,7‐dimethyl‐8,9‐diphenyl‐4‐azatricyclo[5.2.1.0^2,6]dec‐8‐ene‐3,5,10‐trione, which was found in earlier studies as potential anticancer drugs, were performed. Capillary electrophoresis offers the possibility of fast, cheap, and reproducible separations for compounds I and II . In this paper, the simultaneous separation of I and II by capillary zone electrophoresis has been achieved within 8 min by use of 50 mM phosphate buffer of pH 2.5. Analysis of the two compounds in the serum plasma standards was conducted. Limits of detection of I and II by UV absorbance at 200 nm were achieved in the range of 156.3–156.6 ng/mL. The method was validated for linearity, accuracy, precision, limits of detection, and quantification. The calibration equation revealed a good linear relationship (r² = 0.998–0.999). Sufficient recovery was observed in the range of 96.3–99.5%. The method showed good reproducibility with intra‐ and interday precision of 0.97 and 1.76%, respectively. The quantification limits for the compounds were in the range of 477.0–479.8 ng/mL. The proposed method was applied to the analysis of real serum samples.