HPLC–MS/MS studies of brimonidine in rabbit aqueous humor by microdialysis

Bioanalysis ◽  
2021 ◽  
Author(s):  
Zhan Tang ◽  
Xiumin Li ◽  
Hongyan Xu ◽  
Saizhen Chen ◽  
Binhui Wang ◽  
...  
Keyword(s):  
Pharmacokinetic Study ◽  
Mobile Phase ◽  
Internal Standard ◽  
In Situ Gel ◽  
Rabbit Eye ◽  
Relative Standard ◽  
Brimonidine Tartrate ◽  
Aqueous Formic Acid ◽  
Good Linear Correlation

Aim: The pharmacokinetic study of the brimonidine tartrate in situ gel in the anterior chamber of the rabbit eye was studied by microdialysis technique, and samples were analyzed by HPLC–MS/MS. Materials & methods: It was monitored in ESI mode at transition 291.9→212.0 and 296.0→216.0 for brimonidine and internal standard, respectively. Acetonitrile and 0.1% aqueous formic acid (50:50, v/v) were used as the mobile phase at 0.4 ml/min. Results & conclusion: It showed a good linear correlation between 5 and 5000 ng/ml in microdialysis solution, and the inter- and intra-day precision (relative standard deviation) was less than 4.0%. The pharmacokinetic study showed that the AUC(0-t) of in situ gel was 3.5-times than that of eyedrops, which significantly improve the bioavailability of brimonidine.

scholarly journals Quantitative Determination of Azithromycin in Human Plasma by Liquid Chromatography–Mass Spectrometry and its Application in Pharmackokinetic Study

2012 ◽  
Vol 11 (1) ◽  
pp. 55-63 ◽  
Author(s):  
Maizbha Uddin Ahmed ◽  
Mohammad Safiqul Islam ◽  
Tasmin Ara Sultana ◽  
AGM Mostofa ◽  
Muhammad Shahdaat Bin Sayeed ◽  
...  
Keyword(s):  
Mobile Phase ◽  
Solid Phase ◽  
Internal Standard ◽  
Extraction Process ◽  
Serum Samples ◽  
Limit Of Quantification ◽  
Relative Standard ◽  
Linear Concentration Range ◽  
Linear Concentration

Azithromycin is an effective and well-known antimicrobial agent. In the present study, a simple, sensitive and specific LC/MS/MS method has been developed and validated for the quantification of Azithromycin in  human serum samples using Clarithromycin as internal standard. Azithromycin was extracted from biological matrix  by using solid phase extraction process. The chromatographic separation was performed on Luna C18 (3 ?, 2x150   mm) column with a mobile phase consisting of 35 mM ammonium acetate buffer (mobile phase-A) and acetonitrile  and methanol in ratio of 90:10 ( as mobile phase-B) at a flow rate of 0.25 mL/min. The method was validated over a  linear concentration range of 0.5?50.0 ng/mL and limit of quantification (LOQ) was 0.5 ng/mL with a coefficient of  correlation (r2) = 0.9998. The intra-day and inter-day precision expressed as relative standard deviation were 1.64% – 8.43% and 2.32% – 9.92%, respectively. The average recovery of azithromycin from serum was 98.11%. The method  was successfully applied to a pharmacokinetic study after oral administration of Azithromycin 200 mg/5 ml suspension in healthy Bangladeshi volunteers. DOI: http://dx.doi.org/10.3329/dujps.v11i1.12488 Dhaka Univ. J. Pharm. Sci. 11(1): 55-63, 2012 (June)

scholarly journals DEVELOPMENT AND CHARACTERIZATION OF IN SITU GEL OF XANTHAN GUM FOR OPHTHALMIC FORMULATION CONTAINING BRIMONIDINE TARTRATE

2018 ◽  
Vol 11 (7) ◽  
pp. 277 ◽  
Author(s):  
Vazir Ashfaq Ahmed ◽  
Divakar Goli
Keyword(s):  
Drug Release ◽  
Xanthan Gum ◽  
Gelation Time ◽  
Gel Strength ◽  
Eye Drops ◽  
In Situ Gel ◽  
23 Factorial Design ◽  
Brimonidine Tartrate

Objective: The goal of this study was to develop and characterize an ion-activated in situ gel-forming brimonidine tartrate, solution eye drops containing xanthan gum as a mucoadhesive polymer.Method: Sol-gel formulation was prepared using gellan gum as an ion-activated gel-forming polymer, xanthan gum as mucoadhesive agent, and hydroxypropyl methyl cellulose (HPMC E50LV) as release retardant polymer. Phenylethyl alcohol is used as preservatives in borate buffer. The 23 factorial design was employed to optimize the formulation considering the concentration of gelrite, xanthan gum and HPMC as independent variables, gelation time, gel strength, and mucoadhesive force (N). Gelation time , gel strength, mucoadhesive force (N), viscosity (cP) and in vitro percentage drug release were chosen as dependent variables. The formulation was characteristics for pH, clarity, isotonicity, sterility, rheological behavior, and in vitro drug release, ocular irritation, and ocular visualization.Result: Based on desirability index of responses, the formulation containing a concentration of gelrite (0.4%), xanthan gum (0.21%), and HPMC (HPMC E50 (0.24%) was found to be the optimized formulation concentration developed by 23 factorial design. The solution eye drops resulted in an in situ phase change to gel-state when mixed with simulated tear fluid. The gel formation was also confirmed by viscoelastic measurements. Drug release from the gel followed non-fickian mechanism with 88% of drug released in 10 h, thus increased the residence time of the drug.Conclusion: An in situ gelling system is a valuable alternative to the conventional system with added benefits of sustained drug release which may ultimately result in improved patient compliance.

scholarly journals Determination of Fleroxacin in Pure and Tablet Forms by Liquid Chromatography and Derivative UV-Spectrophotometry

2003 ◽  
Vol 86 (2) ◽  
pp. 229-235 ◽  
Author(s):  
Dorota Kowalczuk ◽  
Hanna Hopkała
Keyword(s):  
Mobile Phase ◽  
Internal Standard ◽  
Spectrophotometric Assay ◽  
Uv Spectrophotometry ◽  
Aminobenzoic Acid ◽  
Tetrabutylammonium Hydroxide ◽  
Relative Standard ◽  
Liquid Chromatographic ◽  
Derivative Uv Spectrophotometry

Abstract Derivative UV-spectrophotometric and liquid chromatographic (LC) methods for fleroxacin determination were validated. In the spectrophotometric assay, first-, second-, third-, and fourth-order measurements were applied with the use of peak–zero and peak–peak techniques. The linear correlation between amplitude of the peak and concentration of the examined drug ranged from 2.0 to 12.0 μg/mL. An isocratic LC analysis was performed on a Purospher ODS column with an acidic mobile phase containing tetrabutylammonium hydroxide. Measurements were made at a wavelength of 285 nm with 4-aminobenzoic acid (PABA) as internal standard. The calibration curve was linear (r = 0.9999) in the studied range of concentration (1.0–10.0 μg/mL). The accuracy (mean recovery, about 100%), precision (relative standard deviation <1%), selectivity, and sensitivity of the elaborated methods were satisfactory.

scholarly journals Pharmacokinetics and bioavailability of liensinine in mouse blood by UPLC-MS/MS

2020 ◽  
Author(s):  
Shuhua Tong ◽  
Yuqi Zeng ◽  
Jianshe Ma ◽  
Congcong Wen
Keyword(s):  
Pharmacokinetic Study ◽  
Mobile Phase ◽  
Multiple Reaction Monitoring ◽  
Internal Standard ◽  
Quantitative Detection ◽  
Reaction Monitoring ◽  
Mouse Blood ◽  
Blood Samples ◽  
The Matrix ◽  
Better Than

AbstractLiensinine is a bisbenzyltetrahydroisoquinoline alkaloid extracted from lotus (Nelumbo nucifera GAERTNER., Nelumbonaceae), especially in its embryo loti “Lien Tze Hsin” (green embryo of mature seed). A rapid and simple UPLC-MS/MS method was developed to determine liensinine in mouse blood and its application to a pharmacokinetic study. The blood samples were preprocessed by protein precipitation using acetonitrile. Midazolam (internal standard, IS) and liensinine were gradient eluted by mobile phase of methanol and water (0.1% formic acid) in a Waters UPLC BEH C18 column. The multiple reaction monitoring of m/z 611.3 → 206.1 for liensinine and m/z 326.2 → 291.1 for IS with an electrospray ionization (ESI) source was used for quantitative detection. The calibration curve ranged from 0.5 to 400 ng/mL (r > 0.995). The accuracy ranged from 92.2 to 108.2%, the precision of intra-day and inter-day was less than 14%, and the matrix effect was between 100.0% and 109.6%, the recovery was better than 71.0%. The developed UPLC-MS/MS method was successfully used for a pharmacokinetic study of liensinine in mice after oral (5 mg/kg) and intravenous administration (1 mg/kg), and the absolute availability of liensinine was 1.8%.

Determination of Articaine in Human Blood by Gas and Liquid Chromatography and its Application in a Preliminary Pharmacokinetic Study

2015 ◽  
Vol 5 (2) ◽  
Author(s):  
Manda V. ◽  
Popescu M. ◽  
Baniceru M.
Keyword(s):  
Pharmacokinetic Study ◽  
Internal Standard ◽  
Isoamyl Alcohol ◽  
Buffer Solution ◽  
Flame Ionization ◽  
Detection Analysis ◽  
Gas And Liquid Chromatography ◽  
Relative Standard ◽  
External Standard ◽  
Liquid Chromatographic

Two simple, sensitive and specific gas and liquid chromatographic methods are developed and validated for quantification of articaine in human whole blood. Liquid-liquid extraction with n-hexane-isoamyl alcohol 90:10 (v/v) is used for sample preparation in both methods. GC-FID (gas chromatographic-flame ionization detection) analysis is performed with a gas chromatograph equipped with a split-splitless injector, flame-ionization detector and HP INNOwax capillary column. Reverse phase LC-PDA (liquid chromatographic-photo diode array detection) analysis is carried out using a C18 Hypersil GOLD column with two mobile phases: acetonitrile-water 10 mM ammonium acetate 50:50 (v/v), pH 7, and acetonitrile-buffer solution sodium acetate 10 mM and acetic acid 10 mM 50:50 (v/v), pH 4.7, respectively. A comparison between GC-FID and LC-PDA is performed, as well as between internal and external standard as quantification methods in LC. The best results in terms of accuracy (as recovery) and precision (as relative standard deviation) are obtained in GC (95-98% and 5.5-8.2%, respectively) with lidocaine internal standard and in LC (96-102% and 4.2-6.1%, respectively) with external standard and mobile phase pH 4.7. This method is applied in a preliminary pharmacokinetic study to three healthy volunteers to whom anesthesia with articaine is performed.

scholarly journals Validation and Optimization of a Simple RP-HPLC Method for the Determination of Paracetamol in Human Serum and its Application in a Pharmacokinetic Study with Healthy Bangladeshi Male Volunteers

2015 ◽  
Vol 13 (2) ◽  
pp. 125-131
Author(s):  
Anisa Alam Tanam ◽  
Mohammad Firoz Khan ◽  
Ridwan Bin Rashid ◽  
Md Zakir Sultan ◽  
Mohammad A Rashid
Keyword(s):  
Human Serum ◽  
Pharmacokinetic Study ◽  
Internal Standard ◽  
Immediate Release ◽  
Hplc Method ◽  
Serum Samples ◽  
Limit Of Quantification ◽  
Rp Hplc ◽  
Relative Standard

Acetaminophen (paracetamol) is an analgesic and antipyretic agent with minimum anti-inflammatory properties. In the present study a simple, fast, accurate, precise and reproducible RP-HPLC method has been developed and validated for the quantification of paracetamol in human serum samples using theophylline as internal standard. Protein precipitation with perchloric acid was employed in the extraction of paracetamol and theophylline from biological matrix. The chromatographic separation was accomplished on Phenomenex C18 column with a mobile phase comprising of 0.05 mM sodium sulfate buffer (pH 2.2 ± 0.02 adjusted with phosphoric acid) and acetonitrile at a ratio of 93:7 at a flow rate of 1.0 ml/min. The chromatogram was monitored by UV detection at a wavelength of 254 nm. The method was validated over a linear concentration range of 2-100 ?g/ml and limit of quantification (LOQ) was 1.61 ?g/ml with a correlation coefficient (r2) 0.997. The intra-day and inter-day precision expressed as relative standard deviation were found to be 0.49 - 2.68% and 0.36 - 3.44%, respectively. The average recovery of paracetamol from serum ranged from 99.0 - 106.4%. The method was successfully applied to a pharmacokinetic study after oral administration of immediate release paracetamol tablet (1000 mg) in four healthy Bangladeshi volunteers. The mean Cmax was found to be 11.03 ± 3.21 ?g/ml, which occurred at Tmax of 0.88 ± 0.14 hr. The half life, AUC0-8 and AUC0-? values were found to be 3.09 ± 0.71 hr, 31.06 ± 6.57 hr-?g/ml and 37.92 ± 9.51 hr- ?g/ml, respectively. DOI: http://dx.doi.org/10.3329/dujps.v13i2.21889 Dhaka Univ. J. Pharm. Sci. 13(2): 125-131, 2014 (December)

Isomer-Specific Assay of Ester and Salt Formulations of 2,4-Dichlorophenoxyacetic Acid by Automated High Pressure Liquid Chromatography

1977 ◽  
Vol 60 (4) ◽  
pp. 868-872
Author(s):  
Norman E Skelly ◽  
Timothy S Stevens ◽  
David A Mapes
Keyword(s):  
High Pressure ◽  
Internal Standard ◽  
Dichlorophenoxyacetic Acid ◽  
Precision Data ◽  
Liquid Chromatographic Method ◽  
Relative Standard ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Liquid Chromatographic ◽  
Better Than

Abstract An automated high pressure liquid chromatographic method is described for the assay of 2,4-dichlorophenoxyacetic acid (2,4-D) in either salt or ester herbicide formulations. The method is specific for the 2,4-D isomer, and resolves all known impurities from 2,4-D and the internal standard. Ester products are assayed similarly to salt formulations, following room temperature in situ saponification. Results are thus obtained for all products as a per cent 2,4-D acid equivalent. Compounds are separated on a reverse phase microparticulate column with acetonitrile-water (20+80), buffered at pH 3. Precision data indicate a relative standard deviation of better than 1%. The method was developed to replace the nonspecific total chlorine, titration, and saponification assay procedures.

Sign in / Sign up

Export Citation Format

Share Document