Simultaneous determination of enalapril, felodipine and their degradation products in the dosage formulation by reversed-phase high-performance liquid chromatography using a Spherisorb C8 column

Qin, Xue-Zhi; DeMarco, Joe; Ip, Dominic P.

doi:10.1016/0021-9673(95)00349-r

Cited by 40 publications

(10 citation statements)

References 11 publications

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“…This ionization term is equal to 1 if the API is unionizable or is present in a buffered solution where ionization is minimal. Felodipine (pKa < 2) 51,52 and nifedipine (pKa < 3.5) 53 are unionized at pH 6.8 and thus this term reduces to 1 (for ionizable molecules or solute present at pH where it is ionized, this term is <1). The second term is calculated from the moisture sorption profile of the amorphous material and represents the reduction in the thermodynamic activity because of the presence of moisture.…”

Section: Amorphous Solubility Estimationsmentioning

confidence: 99%

Enhancements and Limits in Drug Membrane Transport Using Supersaturated Solutions of Poorly Water Soluble Drugs

Raina

Zhang

Alonzo

et al. 2014

Journal of Pharmaceutical Sciences

170

215

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Section: Amorphous Solubility Estimationsmentioning

confidence: 99%

Enhancements and Limits in Drug Membrane Transport Using Supersaturated Solutions of Poorly Water Soluble Drugs

Raina

Zhang

Alonzo

et al. 2014

Journal of Pharmaceutical Sciences

170

215

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“…These include spectrophotometric methods, [6][7][8][9] flow-injection spectrophotometric, 10 infrared method, 11 potentiometric selective membrane electrode methods, 12,13 NMR, 14 GC, 15 GCL/MS, 16 HPLC, [17][18][19][20][21][22][23][24][25][26][27] capillary electrophoresis, [28][29][30][31] radioenzymic 32 and radioimmunoassay. 33 Reviewing the literature revealed that up to the present time nothing has been published concerning the CL determination of enalapril maleate.…”

Section: Enalapril [(S)-1-(n-[1-(ethoxycarbonyl)-3-phenylpropyl]-lalamentioning

confidence: 99%

Flow-Injection Chemiluminescence Determination of Enalapril Maleate in Pharmaceuticals and Biological Fluids Using Tris(2,2′-bipyridyl)ruthenium(II)

Alarfaj

2003

ANAL. SCI.

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Enalapril maleate is a relatively new oral angiotensinconverting enzyme (ACE) inhibitor. Enalapril maleate, like its first-generation relative, captopril, has been shown to be effective in the treatment of hypertension and congestive heart failure. Enalapril [(S)-1-(N-[1-(ethoxycarbonyl)-3-phenylpropyl]-Lalanyl)-L-proline] is a prodrug which is de-esterified in the hepatic system to an active diacid form. 2 The drug is official in the USP 24. 3 The methods of analysis of the bulk drug and its tablets are high-performance liquid chromatography (HPLC) methods. It is also official in the European Pharmacopoeia 4 by a potentiometric titration method using sodium hydroxide.Other than the published analytical profile, 5 several methods have been reported for the analysis of enalapril maleate either in pure form, in pharmaceutical preparations, in biological fluids, or in mixture with other drugs. These include spectrophotometric methods, 33 Reviewing the literature revealed that up to the present time nothing has been published concerning the CL determination of enalapril maleate.Ru(bipy) 3 2+ is an extremely versatile base reactant for a variety of CL processes, and has also recently become a useful CL reagent. The process involves the oxidation of Ru(bipy)3 2+to Ru(bipy) 3 3+ , which is then followed by reduction with an analyte species to produce the emission of light. 34 There have been a variety of methods employed to obtain the active oxidized reagent Ru(bipy) 3 3+ .These include chemical, photochemical, electrochemical oxidation and in situ electrochemiluminescence.An analytical evaluation of commercially significant pharmaceutical drugs using Ru(bipy) 3 3+-CL detection has attracted considerable attention. A comprehensive review of the analytical applications of Ru(bipy) 3 3+ as a chemiluminescent reagent from 1978 to mid 1998 has been represented by Gerardi et al. 34The present paper describes the development of a simple flow-injection chemiluminometric method for the determination of enalapril maleate based on the chemical generation of Ru(bipy) 3 3+ by mixing two streams containing solutions of Ru(bipy) 3 2+ and acidic KMnO4. The experimental conditions for the reaction were optimized, and the final procedure allowed the successful determination of the studied drug in pharmaceuticals and biological fluids. Experimental Apparatus and manifoldThe flow system used for the determination and CL detection of enalapril maleate is shown schematically in Fig. 1. It consisted of a Gilson Minipuls 3MP4 peristaltic pump (two channels, variable speed) which was used to drive the carrier and the reagent streams through the flow system. Each stream was pumped at a constant flow rate using PTFE tubing (0.8 mm i.d.). The drug solution (250 µl) was injected through the sample injection valve, which allowed mixing of the sample with an acidified 1 × 10 -3 mol/l KMnO4 solution, and then combination with a 1 × 10 -2 mol/l Ru(bipy) 3 2+ solution in a Tshaped piece before entering the flow cell. The flow cell was a coil made of ...

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“…It is a rather inexpensive method and does not require special instrumentation. Extraction is performed with organic solvents (methanol [19][20][21][22], acetonitrile [23][24][25], ethanol [26,27], etc.) or their mixtures (e.g., methanol-acetonitrile (1 : 1) [28]) in the case of the subsequent determination by high-performance liquid chromatography (HPLC) with the corresponding mobile phase [29][30][31][32][33][34].…”

Section: Extraction Of Organic Impurities From Pharmaceutical Preparamentioning

confidence: 99%

Determination of organic impurities in pharmaceutical preparations

Glazkov

Bochkareva²,

Revel'skii

2005

J Anal Chem

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Simultaneous determination of enalapril, felodipine and their degradation products in the dosage formulation by reversed-phase high-performance liquid chromatography using a Spherisorb C8 column

Cited by 40 publications

References 11 publications

Enhancements and Limits in Drug Membrane Transport Using Supersaturated Solutions of Poorly Water Soluble Drugs

Enhancements and Limits in Drug Membrane Transport Using Supersaturated Solutions of Poorly Water Soluble Drugs

Flow-Injection Chemiluminescence Determination of Enalapril Maleate in Pharmaceuticals and Biological Fluids Using Tris(2,2′-bipyridyl)ruthenium(II)

Determination of organic impurities in pharmaceutical preparations

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