Determination of nicorandil concentrations in human plasma using liquid chromatography

Design and development of controlled release floating matrix tablet of Nicorandil using hydrophilic cellulose and pH-independent acrylic polymer: in-vitro and in-vivo evaluations

OBJECTIVES

The purpose of the study was to develop a floating matrix tablet of Nicorandil using blends of hydrophilic cellulose and pH-independent acrylic polymer to improve the therapeutic effectiveness of the drug in cardiovascular disease.

METHODS

Nicorandil tablets were prepared by direct compression and evaluated for drug-excipients compatibility, in-vitro buoyancy and in-vivo γ-scintigraphy study. The selected formulation (FT5) was also evaluated for stability study and the in-vivo absorption in rabbits to compare the pharmacokinetic parameters with the commercially available immediate release tablet of Nicorandil.

RESULTS

DSC and FT-IR studies confirmed the absence of incompatibility and were found stable at refrigerator temperature (2-8°C) and at 25ºC/60% RH. The in-vivo γ-scintigraphy studies revealed that the system was floated for a period of 6 -7 h in the stomach and in-vivo absorption study showed a significant difference (p < 0.05) in the pharmacokinetic parameters (AUC increased by 3 fold and MRT by 2.5 fold) as compared to the marketed formulation.

CONCLUSION

In conclusion, the developed Nicorandil floating matrix tablet improved the pharmacokinetics parameters (AUC and MRT) in rabbit plasma with expected lowering in side effects potential.

Simultaneous quantitation of nicorandil and its denitrated metabolite in plasma by LC-MS/MS: application for a pharmacokinetic study

A liquid chromatography-electrospray ionization tandem mass spectrometry method was developed and validated for the simultaneous quantitation of nicorandil and its denitrated metabolite, N-(2-hydroxyethyl)-nicotinamide, in rat plasma. After a liquid-liquid extraction step, chromatographic separation was performed on a ShinPack C(18) column with an isocratic mobile phase composed of methanol and 2 mM aqueous ammonium acetate containing 0.03% (v/v) formic acid (33:67 v/v). Procainamide was used as an internal standard (IS). Selected reaction monitoring was performed using the transitions m/z 212 → m/z 135, m/z 166 → m/z 106 and m/z 236 → m/z 163 to quantify nicorandil, its denitrated metabolite and IS, respectively. Calibration curves were constructed over the range of 5-15,000 ng.ml(-1) for both nicorandil and its metabolite. The mean relative standard deviation (RSD%) values for the intra-run precision were 5.4% and 7.3% and for the inter-run precision were 8.5% and 7.3% for nicorandil and its metabolite, respectively. The mean accuracy values were 100% and 95% for nicorandil and its metabolite, respectively. No matrix effect was detected in the samples. The validated method was successfully applied to a pharmacokinetic study after per os administration of nicorandil in rats.

Pharmacokinetics of nicorandil in dogs with mild mitral regurgitation

The aim of this study was to examine the pharmacokinetics of nicorandil, a hybrid of an adenosine triphosphate-sensitive potassium channel opener and a nitrate, and to estimate its clinical doses in dogs with mild mitral valve regurgitation (MR). Nicorandil (0.1, 0.3, and 1.0 mg/kg) was administered orally to normal dogs and those with experimentally-induced MR, and its plasma concentrations were analyzed using high-performance liquid chromatography. Plasma concentrations increased dose-dependently after the administration of nicorandil, and were not different between normal dogs and those with MR. Similar to the effective plasma values obtained in cardiac disease in humans, the findings of this pharmacokinetic study may indicate that a dose of 0.3-1.0 mg/kg has the same effectiveness in dogs with cardiac dysfunction.

Quantitation of Nicorandil in Pharmaceutical Formulations by Spectrophotometry Using N-(1-naphthyl) Ethylenediamine Dihydrochloride as Coupling Agent

A validated and sensitive spectrophotometric method is developed for the quantitation of nicorandil in pharmaceutical formulations. The method is based on the reduction of nitroxy ethyl group of nicorandil to carbonyl derivative and nitrite ion by Zn/NH4Cl. The nitrite ion undergoes diazotization with sulphanilamide in presence of HCl followed by coupling with N-(1-naphthyl) ethylenediamine dihydrochloride (NED) to form a colored product with lambda(max) at 525 nm. Under the optimized experimental condition, Beer's law is obeyed in the concentration range of 0.4-12.0 microg/ml with molar absorptivity of 1.92 x 10(4) l mol(-1) cm(-1). The statistical analysis of calibration data yields the linear regression equation: A = 6.304 x 10(-4)+9.13 x 10(-2) C with correlation coefficient of 0.9999. The limits of detection and quantification are 0.05 and 0.15 microg/ml, respectively. The results obtained by the proposed method are acceptable with average recoveries of 100.0-100.1%. The results of the proposed method are compared with those of the reference method by point and interval hypothesis tests, which showed excellent agreement and there is no significant difference in accuracy and precision of methods compared.

Determination of inorganic nitrate impurity from nicorandil and its tablet dosage form by simple reversed phase liquid chromatographic method

A simple, fast, precise, specific and economical reverse phase liquid chromatographic method was developed for determination of nitrate (NIT) impurity from nicorandil (NIC) and its tablet dosage form. NIT is process impurity as well as a degradation product of NIC. This article is based on application of amino propyl silane (APS) column for determination of NIT in presence of NIC and various excipients using potassium nitrate as a standard. The developed method was validated for its intended use by evaluating various important parameters like linearity, accuracy, recovery and specificity. The developed method was applied to evaluate the compatibility study of NIC with various excipients by monitoring the NIT content.

Rapid and sensitive liquid chromatography–tandem mass spectrometry method for the estimation of nicorandil in human plasma

A rapid and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed and validated for the estimation of nicorandil in human plasma. Nicorandil was extracted from human plasma using solid-phase extraction technique. Imipramine was used as the internal standard. A Betasil C18 column provided chromatographic separation of analytes followed by detection with mass spectrometry. The method involves a rapid solid-phase extraction from plasma, simple isocratic chromatography conditions and mass spectrometric detection that enables detection at nanogram levels. The proposed method has been validated for a linear range of 1.0-500.0 ng/mL with a correlation coefficient of > or =0.9993. The intra-run and inter-run precision and accuracy was within 10.0%. The overall recovery for nicorandil was 63.81%. The total run time was just 3.0 min.

Selective and validated spectrophotometric methods for the determination of nicorandil in pharmaceutical formulations

Two simple and sensitive validated spectrophotometric methods have been described for the assay of nicorandil in drug formulations. Method A is based on the reaction of the drug with phloroglucinol-sulfanilic acid reagent in sulfuric acid medium to give yellow-colored product, which absorbs maximally at 425 nm. Method B uses the oxidative coupling of 3-methyl-2-benzothiazolinone hydrazone hydrochloride (MBTH) with DL- 3,4 - dihydroxyphenylalanine (DL-dopa) in the presence of nicorandil as oxidant in sulfuric acid medium to form an intensely colored product having maximum absorbance at 530 nm. Beer's law is obeyed in the concentration range 2.5 to 50.0 and 1.0 to 15.0 microg mL(-1) with methods A and B, respectively. Both methods have been successfully applied for the analysis of drug in pharmaceutical formulations. The reliability and the performance of the proposed methods are established by point and interval hypothesis and through recovery studies. The experimental true bias of all samples is smaller than +/-2%.

Optimized and validated spectrophotometric methods for the determination of nicorandil in drug formulations and biological fluids

Two simple, sensitive and economical spectrophotometric methods have been developed for the determination of nicorandil in drug formulations and biological fluids. Method A is based on the reaction of the drug with brucine-sulphanilic acid reagent in sulphuric acid medium producing a yellow-coloured product, which absorbs maximally at 410 nm. Method B depends on the formation of the intensely blue-coloured product which results due to the interaction of an electrophilic intermediate of 3-methyl-2-benzothiazolinone hydrazone hydrochloride (MBTH) with oxidized product of 4-(methyl amino) phenol sulphate (metol) in the presence of nicorandil as an oxidizing agent in sulphuric acid medium. The coloured product shows absorbance maximum at 560 nm. Under the optimized experimental conditions, Beer's law is obeyed in the concentration range of 2.5-35.0 and 0.40-2.2 microg ml(-1) for Methods A and B, respectively. Both the methods have been successfully applied to the determination of nicorandil in drug formulations and biological fluids. The results are validated statistically and through recovery studies. In order to establish the bias and the performance of the proposed methods, the point and interval hypothesis tests have been performed. The experimental true bias of all samples is smaller than +/-2%.