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Lacidipine: review of analytical methods developed for pharmaceutical dosage forms and biological fluids. Bioanalysis 2021; 13:1011-1024. [PMID: 34081530 DOI: 10.4155/bio-2021-0024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Lacidipine (LAC) is a calcium antagonist used in the treatment of hypertension. It is a lipophilic drug containing dihydropyridine ring that is responsible for the activity. This review article gives an overview of various analytical techniques proposed for the determination of LAC in pharmaceutical dosage forms, in pure form, in biological fluids and to determine characteristics of LAC in modified release dosage forms. Ultra violet/visible spectrophotometric, spectroflourimetric, high performance liquid chromatography, high performance thin layer chromatography, electro-analytical, bioanalytical and miscellaneous methods such as microbiological assay, X-ray diffraction, differential scanning calorimetry, were discussed. Various parameters such as system suitability, selectivity, linearity, precision, accuracy, limit of detection, limit of quantification and robustness have been discussed for the employed methods.
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Belal F, Sharaf EL-Din M, Tolba MM, Alaa H. Micelle-enhanced spectrofluorimetric method for determination of lacidipine in tablet form; application to content uniformity testing. LUMINESCENCE 2014; 30:805-11. [DOI: 10.1002/bio.2823] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Revised: 09/11/2014] [Accepted: 10/23/2014] [Indexed: 11/11/2022]
Affiliation(s)
- F. Belal
- Department of Analytical Chemistry, Faculty of Pharmacy; University of Mansoura; 35516 Mansoura Egypt
| | - M. Sharaf EL-Din
- Department of Analytical Chemistry, Faculty of Pharmacy; University of Mansoura; 35516 Mansoura Egypt
| | - M. M. Tolba
- Department of Analytical Chemistry, Faculty of Pharmacy; University of Mansoura; 35516 Mansoura Egypt
| | - H. Alaa
- Department of Analytical Chemistry, Faculty of Pharmacy; University of Mansoura; 35516 Mansoura Egypt
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Geng Y, Zhao L, Zhao J, Guo B, Ma P, Li Y, Zhang T. Development of a supercritical fluid chromatography–tandem mass spectrometry method for the determination of lacidipine in beagle dog plasma and its application to a bioavailability study. J Chromatogr B Analyt Technol Biomed Life Sci 2014; 945-946:121-6. [DOI: 10.1016/j.jchromb.2013.11.029] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Revised: 11/10/2013] [Accepted: 11/17/2013] [Indexed: 10/26/2022]
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Chatki PK, Hotha KK, Kolagatla PRR, Bharathi DV, Venkateswarulu V. LC-MS/MS determination and pharmacokinetic study of lacidipine in human plasma. Biomed Chromatogr 2013; 27:838-45. [DOI: 10.1002/bmc.2868] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Revised: 12/11/2012] [Accepted: 12/11/2012] [Indexed: 11/05/2022]
Affiliation(s)
- Pankaj Kisan Chatki
- Bioanalytical Department, Integrated Product Development, Dr Reddy's Laboratories Ltd, Bachupalli; Hyderabad 500 072 India
| | - Kishore Kumar Hotha
- Bioanalytical Department, Integrated Product Development, Dr Reddy's Laboratories Ltd, Bachupalli; Hyderabad 500 072 India
| | - Pandu Ranga Reddy Kolagatla
- Bioanalytical Department, Integrated Product Development, Dr Reddy's Laboratories Ltd, Bachupalli; Hyderabad 500 072 India
| | - D. Vijaya Bharathi
- Bioanalytical Department, Integrated Product Development, Dr Reddy's Laboratories Ltd, Bachupalli; Hyderabad 500 072 India
| | - V. Venkateswarulu
- Bioanalytical Department, Integrated Product Development, Dr Reddy's Laboratories Ltd, Bachupalli; Hyderabad 500 072 India
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Ramesh G, Vamshi Vishnu Y, Chinna Reddy P, Shravan Kumar Y, Madhusudan Rao Y. Development of high performance liquid chromatography method for lacidipine in rabbit serum: Application to pharmacokinetic study. Anal Chim Acta 2009; 632:278-83. [DOI: 10.1016/j.aca.2008.11.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2008] [Accepted: 11/03/2008] [Indexed: 10/21/2022]
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Ultra-performance liquid chromatography–tandem mass spectrometry for the determination of lacidipine in human plasma and its application in a pharmacokinetic study. J Pharm Biomed Anal 2008; 47:923-8. [DOI: 10.1016/j.jpba.2008.04.018] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2008] [Revised: 04/08/2008] [Accepted: 04/10/2008] [Indexed: 11/21/2022]
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Ziviani L, Da Ros L, Squassante L, Milleri S, Cugola M, Iavarone LE. The effects of lacidipine on the steady/state plasma concentrations of simvastatin in healthy subjects. Br J Clin Pharmacol 2008. [DOI: 10.1111/j.1365-2125.2001.bjcp119.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Wang H, Zhang L, Wang Q, Yuan Z, Li M. Validated LC–MS–MS method for determination of m-nisoldipine polymorphs in rat plasma and its application to pharmacokinetic studies. J Chromatogr B Analyt Technol Biomed Life Sci 2006; 835:71-6. [PMID: 16567136 DOI: 10.1016/j.jchromb.2006.03.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2005] [Revised: 01/27/2006] [Accepted: 03/05/2006] [Indexed: 11/15/2022]
Abstract
A sensitive and specific liquid chromatography-tandem mass spectrometric (LC-MS-MS) method has been developed to determine m-nisoldipine in rat plasma. Sample was pretreated by a single-step protein precipitation with acetonitrile, in contrast to the liquid-liquid procedure frequently used for the extraction of 1,4-dihydropyridines from biologic samples. Separation of analyte and internal standard (I.S.) was performed on a Symmetry RP-C(18) analytic column (50 mm x 4.6 mm, 3.5 microm) with a mobile phase consisting of acetonitrile-water (80:20, v/v) at a flow rate of 0.5 ml/min. The API 4000 triple quadrupole mass spectrometer was operated in multiple reaction monitoring (MRM) scan mode using TurboIonSpray ionization (ESI) source. The method was sensitive with a lower limit of quantification (LLOQ) of 0.2 ng/mL, with good linearity (r>or=0.9982) over the linear range of 0.2-20 ng/mL. All the validation data, such as accuracy, precision, and inter-day repeatability, were within the required limits. The method was successfully applied to pharmacokinetic and relative bioavailability studies of m-nisoldipine polymorphs in rats.
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Affiliation(s)
- Hairong Wang
- Department of Pharmaceutical Analysis, School of Pharmacy, Hebei Medical University, Shijiazhuang 050017, PR China
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Baranda AB, Mueller CA, Alonso RM, Jiménez RM, Weinmann W. Quantitative Determination of the Calcium Channel Antagonists Amlodipine, Lercanidipine, Nitrendipine, Felodipine, and Lacidipine in Human Plasma Using Liquid Chromatography-Tandem Mass Spectrometry. Ther Drug Monit 2005; 27:44-52. [PMID: 15665746 DOI: 10.1097/00007691-200502000-00010] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
A sensitive and specific liquid chromatography-tandem mass spectrometric method has been developed and validated for the quantification of the five 1,4-dihydropyridine calcium channel antagonists amlodipine, lercanidipine, nitrendipine, felodipine, and lacidipine in human plasma. Sample preparation involved solid-phase extraction on RP-C18 cartridges with good recovery for all the compounds. Sample analysis was performed on a Luna RP-C18 analytical column (15 mm x 2 mm ID, 3.0 microm) with a Sciex API 365 triple quadrupole mass spectrometer with turboionspray source and multiple reaction monitoring. The method is sensitive with a limit of detection below 1 ng/mL for each drug in plasma, with good linearity (r(2) > 0.998), over the therapeutic concentration range (1 to 40 ng/mL). All the validation data, such as accuracy, precision, and interday repeatability, were within the required limits. The method can be used for pharmacokinetic studies and therapeutic drug monitoring of the compounds in humans.
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Affiliation(s)
- Ana B Baranda
- Departamento de Química Analítica, Facultad de Ciencia y Tecnología, Universidad del País Vasco/EHU, Apdo. 644, E-48080 Bilbao, Spain.
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Baranda AB, Jiménez RM, Alonso RM. Simultaneous determination of five 1,4-dihydropyridines in pharmaceutical formulations by high-performance liquid chromatography–amperometric detection. J Chromatogr A 2004; 1031:275-80. [PMID: 15058593 DOI: 10.1016/j.chroma.2003.11.019] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A high-performance liquid chromatographic method with electrochemical detection was developed for the simultaneous determination of five 1,4-dihydropyridines: amlodipine, nitrendipine, felodipine, lacidipine and lercanidipine. These drugs are widely used in the treatment of hypertension, angina pectoris and the therapy of cerebrovascular spasms of various origins. The chromatographic separation was performed on a Supelcosil LC ABZ + Plus C18 column with a mobile phase consisting of acetonitrile-10 mM acetate buffer (72:28, v/v) at a flow rate of 1 ml/min. The temperature was set at 30 +/- 0.2 degrees C. The amperometric detector, equipped with a glassy carbon electrode was operated at +1100 mV versus Ag/AgCl in the direct current mode. Under these chromatographic conditions, the drugs eluted in less than 12 min. The method showed to be linear over the range 4.5-15 microg/ml with a within-day and day-to-day repeatabilities in terms of R.S.D. lower than 15%, an accuracy greater than 98% and detection limits varying from 90 ng/ml (amlodipine) to 1.55 microg/ml (nitrendipine). The method was successfully applied to commercially available pharmaceuticals with relative errors lower than 5%. The validity of the method was examined comparing the results obtained with those of HPLC with photometric detection.
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Affiliation(s)
- Ana B Baranda
- Departamento de Química Analítica, Facultad de Ciencias, Universidad del País Vasco/EHU, Apdo. 644, 48080 Bilbao, Spain
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Da Ros L, Squassante L, Milleri S. Dose linearity of lacidipine pharmacokinetics after single and repeated oral doses in healthy volunteers. Clin Pharmacokinet 2003; 42:99-106. [PMID: 12489980 DOI: 10.2165/00003088-200342010-00004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
OBJECTIVE To assess the dose proportionality of lacidipine after single and repeated oral doses, and to obtain new information on the pharmacokinetics of the compound since improvement of the plasma assay method. DESIGN Open, randomised, four-way cross-over trial. PARTICIPANTS 24 healthy male and female volunteers, aged 18-46 years. METHODS Lacidipine was administered as single doses of 2, 4, 6 and 8 mg, and as multiple doses of 2, 4 and 6 mg for 8 days. Pharmacokinetic evaluations were performed on study days 1 and 8. Plasma concentrations of lacidipine were determined by a validated high-performance liquid chromatography-radioimmunoassay method. The ratios of dose-normalised peak plasma concentration (C(max)) and area under the concentration-time curve (AUC) were calculated and then compared across dose groups by analysis of variance to assess dose linearity against a 4 mg reference dose. A power model was also applied as an alternative method for the evaluation of linearity. RESULTS After repeated 2, 4 and 6 mg doses of lacidipine, geometric least square mean values (95% CI) were 1.76 (1.46-2.12), 3.56 (2.96-4.29) and 5.23 (4.34--6.30) microg/L for C(max) and 5.29 (4.57-6.11), 11.42 (9.87-13.20) and 17.55 (15.18-20.29) microg x h/L for AUC over the administration interval at steady state (AUC(tau)), respectively. Mean half-life ranged between 13.2 hours and 18.7 hours. Precision of these estimates was limited by the small number of sampling timepoints collected in the final part of the curve. After administration of single doses, no statistically significant deviation from linearity was found except for the 8 mg dose, but a trend of greater than proportional exposure was evident with increasing dose. Following repeated administration, dose linearity over the therapeutic range was observed. No statistically significant difference was observed between AUC to infinity (AUC( infinity)) on day 1 and AUC(tau) on day 8, suggesting time-invariance of pharmacokinetics. CONCLUSIONS Lacidipine exhibited linear kinetics after repeated doses in the therapeutic range of 2-6 mg once daily. The two different methodologies for assessing linearity gave consistent results. Only the single 8 mg dose, which is outside the recommended therapeutic range, resulted in greater than predicted exposure. After low doses, the analytical method still does not allow complete characterisation of kinetics. Time-invariance of lacidipine kinetics is suggested.
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Affiliation(s)
- Lucio Da Ros
- GlaxoSmithKline Medicine Research Center, Verona, Italy
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Kharat VR, Verma KK, Dhake JD. Determination of lacidipine from urine by HPTLC using off-line SPE. J Pharm Biomed Anal 2002; 28:789-93. [PMID: 12008159 DOI: 10.1016/s0731-7085(01)00584-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A simple, rapid and sensitive high performance thin layer chromatographic method was developed and validated for the estimation of lacidipine. The sample preparation involved protein precipitation followed by an efficient solid phase extraction on C18 cartridge. The analytes were isolated from 1 ml of urine and recovered by pure ethyl acetate solution. The method employed TLC aluminium plate precoated with silica gel 60F254 as the stationary phase. The solvent system employed consists of toulene-ethyl acetate [6.5:3.5v/v]. This system gave a dense and compact spot of the drug at R(f) value of 0.45. The linear regression data for the calibration plots showed good linear relationship (r=0.999) over the concentration range 10-80 ng. Recovery studies were performed at two different levels. The recovery data reveals that the R.S.D. for intra-day and inter-day analysis at 10 ng was found to be 0.84 and 0.22%, respectively. The proposed method was found to be useful for the routine analysis of pharmaceuticals and pharmacokinetic studies in human urine samples.
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Affiliation(s)
- V R Kharat
- Department of Chemical Technology, Laxminarayan Institute of Technology, University of Nagpur, Nagpur 440010, India.
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Ziviani L, Da Ros L, Squassante L, Milleri S, Cugola M, Iavarone LE. The effects of lacidipine on the steady/state plasma concentrations of simvastatin in healthy subjects. Br J Clin Pharmacol 2001; 51:147-52. [PMID: 11259986 PMCID: PMC2014440 DOI: 10.1111/j.1365-2125.2001.bcp119.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
AIMS Lacidipine, a long acting 2, 4-dihydropyridine calcium channel antagonist is frequently administered with cholesterol lowering agents, particularly in elderly populations. The effects of lacidipine on the pharmacokinetics of simvastatin were investigated, since they share the CYP3A4 pathway for metabolism. METHODS The study was an open, randomised, two-way crossover design, with at least 7 days washout. Eighteen healthy subjects received simvastatin, 40 mg once daily, alone and together with lacidipine, 4 mg once daily, for 8 days. The pharmacokinetics of simvastatin were studied on the eighth day. Analysis was made of total simvastatin acid concentrations (naive simvastatin acid plus that derived from alkaline hydrolysis of the lactone). RESULTS Lacidipine increased the maximum concentration of simvastatin (Cmax) by approximately 70% (P=0.016) and the area under the plasma concentration-time curve AUC(0,24 h) by approximately 35% (P=0.001). The mean Cmax and AUC(0,24 h) of simvastatin (95% confidence interval) when given alone were 8.76 (6.72-11.41) ng ml(-1) and 60.36 (47.15-77.28) ng ml(-1) h. During treatment with lacidipine they were, respectively, 14.89 (10.77-20.58) ng ml(-1) and 80.96 (64.62-101.44) ng ml(-1) h. No significant differences were observed in either time to peak concentration (tmax was 1.0 h for simvastatin alone and 1.5 h for the combination) or in the half-life (t1/2,z was 8.5 h in both cases). The combination was safe and well tolerated. CONCLUSIONS The observed increased exposure to simvastatin 40 mg following coadministration of lacidipine is unlikely to be of clinical relevance.
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Affiliation(s)
- L Ziviani
- Glaxo Wellcome, Medicine Research Centre, Verona, Italy.
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Abstract
This paper reviews current trends and techniques in automated solid-phase extraction. The area has shown a dramatic growth the number of manuscripts published over the last 10 years, including applications in environmental science, food science, clinical chemistry, pharmaceutical bioanalysis, forensics, analytical biochemistry and organic synthesis. This dramatic increase of more that 100% per year can be attributed to the commercial availability of higher throughput 96-well workstations and extraction plates that allow numerous samples to be processed simultaneously. These so-called parallel-processing workstations represent the highest throughput systems currently available. The advantages and limitations of other types of systems, including discrete column systems and on-line solid-phase extraction are also discussed. Discussions of how automated solid-phase extractions can be developed, generic approaches to automated solid-phase extraction, and three noteworthy examples of automated extractions are given. The last part of the review suggests possible near- and long-term directions of automated solid-phase extraction.
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Affiliation(s)
- D T Rossi
- Department of Pharmacokinetics, Dynamics and Metabolism, Parke-Davis Pharmaceutical Research, Division of Warner-Lambert, Ann Arbor, MI 48105, USA.
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Dayton BD, Chiou WJ, Opgenorth TJ, Wu-Wong JR. Direct determination of endothelin receptor antagonist levels in plasma using a scintillation proximity assay. Life Sci 2000; 66:937-45. [PMID: 10714894 DOI: 10.1016/s0024-3205(99)00677-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An assay using scintillation proximity bead technology has been developed suitable for the quantitation of endothelin (ET) receptor antagonists in preclinical and clinical samples of plasma. The assay measures the competitive inhibition of radiolabelled ET-1 binding to ET(A) receptor membranes bound to wheat germ agglutinin (WGA)-coated scintillation proximity assay (SPA) beads in the presence of plasma containing A-127722, a potent orally active, ET(A) selective ET antagonist. The assay requires as little as 50 microl plasma and no extraction procedure is needed. The SPA methodology eliminates the need for the separation of bound from free ligand. Using this method, A-127722 could be directly quantified in rat plasma with a detection limit of 1 ng/ml.
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Affiliation(s)
- B D Dayton
- Metabolic Disease Research, Pharmaceutical Products Division, Abbott Laboratories, Abbott Park, Illinois 60064, USA.
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Kominami G, Nakamura M, Chomei N, Takada S. Radioimmunoassay for a novel benzodiazepine inverse agonist, S-8510, in human plasma and urine. J Pharm Biomed Anal 1999; 20:145-53. [PMID: 10704018 DOI: 10.1016/s0731-7085(99)00008-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
A radioimmunoassay (RIA) was developed for a new benzodiazepine inverse agonist, 2-(isoxazol-3-yl)-3,6,7,9-tetrahydroimidazo [4,5-d] pyrano [4,3-b] pyridine monophosphate monohydrate (S-8510), in human plasma and urine. For competitive RIA, three amino derivatives of S-8510 were labelled by the Bolton and Hunter method and rabbit antisera were prepared using three immunogens, conjugates of three carboxyl derivatives of S-8510 with bovine serum albumin. All combinations of the labelled antigens and antisera were examined and homologous combinations were selected for the competitive RIA. One of the three homologous combinations had the best selectivity after investigations of cross-reactivity using 12 related compounds and was very sensitive for S-8510. Next, a pretreatment for biological samples was developed using mixed mode solid-phase extraction (SPE) column followed by the RIA (SPE/RIA). The assay recoveries for human plasma and urine were both excellent and the limits of quantitation were extremely low, 80 and 200 pg ml(-1), respectively. Human plasma samples and urine samples after administration of this drug were successfully measured by the SPE/RIA. No cross-reactive metabolites were detected in any fractions after RP-HPLC separation of the plasma samples. The RIA using carefully selected antiserum and labelled antigen was highly specific for unchanged S-8510. To simplify the RIA procedure, a scintillation proximity assay (SPA) using the same labelled antigen and antiserum was developed for analyzing S-8510 in human plasma and found to be very promising.
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Affiliation(s)
- G Kominami
- Shionogi Research Laboratories, Toyonaka, Osaka, Japan.
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Kominami G, Ueda A, Sakai K, Misaki A. Radioimmunoassay for a novel lignan-related hypocholesterolemic agent, S-8921, in human plasma after high-performance liquid chromatography purification and in human urine after immunoaffinity extraction. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 1997; 704:243-50. [PMID: 9518156 DOI: 10.1016/s0378-4347(97)00466-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The novel compound methyl-1-(3,4-dimethoxyphenyl)-3-(3-ethylvaleryl)-4-hydroxy-6,7,8- trimethoxy-2-naphthoate (S-8921) has hypocholesterolemic activity in animals and is expected to exhibit a similar activity in human. Reversed-phase high-performance liquid chromatography (HPLC) separation followed by radioimmunoassay (RIA) for human plasma samples (HPLC-RIA) and immunoaffinity extraction (IAE) followed by RIA for human urine samples (IAE-RIA) were developed for investigation of S-8921 behavior in clinical studies. For the RIA, antisera from rabbit and a radioiodine-labelled S-8921 were prepared by immunizing a conjugate of S-8921 with bovine serum albumin and by the Bolton and Hunter method, respectively. HPLC-RIA using a semi-micro column was very sensitive, that is a 0.05 ng/ml limit of quantitation in human plasma, and specific for unchanged form of S-8921. IAE-RIA using a centrifugal filtration tube completely eliminated the matrix effect of human urine, and was very feasible. The limit of quantitation was 0.10 ng/ml. RIA detection following HPLC or IAE proved to be very useful for the pharmaceutical analysis of extremely low drug concentrations in body fluids.
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Affiliation(s)
- G Kominami
- Shionogi Research Laboratories, Shionogi and Co., Ltd., Osaka, Japan
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