RP-HPLC determination of atorvastatin calcium and amlodipine besylate combination in tablets

Development and validation of an eco-friendly HPLC-UV method for determination of atorvastatin and vitamin D3 in pure form and pharmaceutical formulation

Statin-associated muscle symptoms are considered as obvious adverse effects of prolonged statin therapy such as myopathy, myalgia, and rhabdomyolysis. These side effects are associated with vitamin D₃ deficiency and can be adjusted by amendment of serum vitamin D₃ level. Green chemistry aims to decrease the harmful effects of analytical procedures. Here we have developed a green and eco-friendly HPLC method for the determination of atorvastatin calcium and vitamin D₃. The two drugs were separated in less than 10 min on Symmetry column C₁₈ (100 × 4.6 mm, 3.5 µm) using a mixture consisting of 0.1% ortho-phosphoric acid (OPA) (pH = 2.16) and ethanol as the mobile phase in gradient manner. We have used Green Analytical Procedure Index (GAPI) tools and the Analytical GREEnness Metric Approach (AGREE) for assessment of the greenness of our proposed method. The method proved linearity over concentration ranges of (5-40) and (1-8) µg/ml with low limit of detection of 0.475 and 0.041 µg/ml for atorvastatin calcium and vitamin D₃ respectively. The method was successfully validated in accordance with ICH instructions and utilized for determination of the drugs of interest either in pure form or in their pharmaceuticals.

Determination of arsenic, cadmium, mercury, lead and nickel as elemental impurities in atorvastatin calcium by inductively coupled mass spectrometer

Atorvastatin calcium is employed as front-line treatment for cardiovascular diseases. According to the international conference on harmonization (ICH) guideline ICH Q3D, elemental impurities can come into drug products from various sources. These elemental impurities do not have any therapeutic benefit to the end-user. On the contrary, it harms the normal physiological system. Class 1 elements like arsenic, cadmium, mercury, and lead are inorganic impurities that can cause toxic effects on the human body. Nickel was used as a catalyst during the synthesis process of atorvastatin calcium. It comes under the Class-2A, can cause toxicity to humans, and must be quantified. A simple, fast, reliable inductively coupled plasma mass spectrometric method for the estimation of elemental impurities like arsenic, cadmium, mercury, lead, and nickel in atorvastatin calcium by open sample digestion technique was developed and validated in accordance with ICH Q3D and USP < 232 > and USP <233 > general chapter. Internal standards like indium, terbium, thallium, bismuth and yttrium were used to correct the non-spectral interferences that were generated during analysis. Gold was added to all solutions as it preserves mercury by amalgamation. The system performance was evaluated every time my performing system suitability parameters. The limits for all the elements were fixed in accordance with ICH Q3D. The limit of detection and the limit of quantification for all the five elements were estimated. Method specificity was proven by checking for interferences due to the sample matrix and other elements. Linearity of each element in standards was established from 25% to 200% of sample concentration, and correlation coefficients were found to be not less than 0.999. The accuracy of the method was demonstrated at three spiking levels at 50%, 100%, and 150% of the J-value for all the elements. The recoveries for all elements at each level were within the range of 90-120%. Method precision was proved at 100% J-value. The relative standard deviation of all elements was less than 5%. It concludes that this newly developed and validated reliable inductively coupled plasma mass spectrometric method for estimating of elemental impurities like arsenic, cadmium, mercury, lead, and nickel in atorvastatin calcium was within the permitted limit and suitable for routine use.

Analytical and Bioanalytical Techniques for the Quantification of the Calcium Channel Blocker - Amlodipine: A Critical Review

Hypertension is a condition in which blood pressure is elevated to an extent where benefit is obtained from blood pressure lowering. The risk of complications is proportional to the level that blood pressure raises. Calcium channel blockers are a class of compounds used in the treatment of hypertension. The dihydropyridine (DHP) group, a subclass of the calcium channel blocker works almost exclusively on L-type calcium channels in the peripheral arterioles and reduce blood pressure by reducing total peripheral resistant. Long acting DHP is preferred because they are more convenient for patients and avoid the large fluctuations in plasma drug concentration which are associated with side effects. Amlodipine is the most distinct DHP and the most popular. The drug was patented in the year 1986 and its commercial sale began by 1990. The current article provides a state of art about the analytical and bioanalytical techniques available for the quantification of drug as a single entity and in combined pharmaceutical formulations between 1989 and 2019.

Spray-Dried Amorphous Solid Dispersions of Atorvastatin Calcium for Improved Supersaturation and Oral Bioavailability

Over the past few decades, the amorphous solid dispersions (ASDs) technique has emerged as a promising strategy to enhance the in vitro/in vivo characteristic of hydrophobic drugs. The low aqueous solubility and poor bioavailability of atorvastatin calcium (ATO), a lipid-lowering drug, present challenges for effective drug delivery. The objective of this work was to improve the aqueous solubility, in vitro dissolution, and oral absorption of ATO with amorphous solid dispersion technique prepared by spray-drying method. The optimized ternary formulation comprising of ATO; hydroxypropyl methylcellulose (HPMC), as a hydrophilic polymer; and sodium lauryl sulfate (SLS), as a surfactant, at a weight ratio of 1/1/0.1, showed significant improvement in aqueous solubility by ~18-fold compared to that of the free drug, and a cumulative release of 94.09% compared to a release of 59.32% of the free drug. Further, physicochemical studies via scanning electron microscopy, differential scanning calorimetry, and powder X-ray diffraction revealed a change from the crystalline state of the free drug to its amorphous state in the ASD. Pharmacokinetic analysis in rats demonstrated 1.68- and 2.39-fold increments in AUC and Cmax, respectively, in the ASD over the free drug. Altogether, hydrophilic carrier-based ASDs prepared by the spray-drying technique represent a promising strategy to improve the biopharmaceutical performance of poorly soluble drugs.

Determination of amlodipine and atorvastatin mixture by different spectrophotometric methods with or without regression equations

Four new, simple, and reproducible spectrophotometric methods were developed and validated for the simultaneous determination of Amlodipine (AML) and Atorvastatin (AT) in bulk powder and pharmaceutical dosage form. The four methods include two progressive and two successive resolution techniques. The two progressive methods are Absorbance Subtraction (AS) and Amplitude Modulation (AM), while the two successive methods are Constant Value (CV) and Concentration Value. In the Concentration Value method, the concentration of the drugs is determined from the graphical representation without the use of regression equations. Linearity range for the two progressive methods was from 5 μg/mL-35 μg/mL while for the two successive methods was from 5 μg/mL-55 μg/mL. The four methods were validated according to the ICH guidelines and were found to be accurate, precise, and selective. The methods were also applied for determination of the mixture in the marketed pharmaceutical dosage form. Results obtained were compared with reported methods. Also, One-way ANOVA statistical test was done between all the proposed spectrophotometric methods where no significant differences were found.

Stability Indicating RP-HPLC Method for the Simultaneous Determination of Atorvastatin Calcium, Metformin Hydrochloride, and Glimepiride in Bulk and Combined Tablet Dosage Form

A simple, rapid, and precise RP-HPLC method for simultaneous analysis of atorvastatin calcium, metformin hydrochloride, and glimepiride in bulk and its pharmaceutical formulations has been developed and validated. These drugs were separated by using Grace Smart Altima C-8 column (250 × 4.6 mm, 5-μm) with a mobile phase consisting of acetonitrile : phosphate buffer (60 : 40 (v/v), pH 3.0) at a flow rate of 1 mL/min, injection volume 25 µL, and detection at 235 nm. Metformin, atorvastatin, and glimepiride were eluted with retention times of 2.57 min, 7.06 min, and 9.39 min, respectively. The method was validated for accuracy, precision, linearity, specificity, and sensitivity in accordance with ICH (Q2B) guidelines. The results of all the validation parameters were found to be within the acceptable limits. The calibration plots were linear over the concentration ranges from 10 to 150 µg/mL, 20 to 200 µg/mL, and 10 to 150 µg/mL for atorvastatin, metformin, and glimepiride, respectively. The accuracy and precision were found to be between 98.2%-105% and ≤2% for three drugs. Developed method was successfully applied for the determination of the drugs in tablet dosage form and recovery was found to be >98% for three drugs. The degradation products produced as a result of stress studies did not interfere with drug peaks.

An improved HPLC method with the aid of a chemometric protocol: simultaneous determination of atorvastatin and its metabolites in plasma

The aim of the present study was to optimize a chromatographic method for the analysis of atorvastatin (acid and lactone forms), ortho- and para-hydroxyatorvastatin by using an experimental design approach. Optimization experiments were conducted through a process of screening and optimization. The purpose of a screening design is to identify the factors that have significant effects on the selected chromatographic responses, and for this purpose a full 2³ factorial design was used. The location of the true optimum was established by applying Derringer’s desirability function, which provides simultaneously optimization of all seven responses. The ranges of the independent variables used for the optimization were content of acetonitrile in mobile phase (60–70%), temperature of column (30–40 °C) and flow rate (0.8–1.2 mL min⁻¹). The influences of these independent variables were evaluated for the output responses: retention time of first peak (p-hydroxyatorvastatin) and of last peak (atorvastatin, lactone form), symmetries of all four peaks and relative retention time of p-hydroxyatorvastatin. The primary goal of this investigation was establishing a new simple and sensitive method that could be used in analysis of biological samples. The method was validated and successfully applied for determination of atorvastatin (acid and lactone forms) and its metabolites in plasma.

Simultaneous Analysis of Losartan Potassium, Amlodipine Besylate, and Hydrochlorothiazide in Bulk and in Tablets by High-Performance Thin Layer Chromatography with UV-Absorption Densitometry

A Simple high-performance thin layer chromatography (HPTLC) method for separation and quantitative analysis of losartan potassium, amlodipine, and hydrochlorothiazide in bulk and in pharmaceutical formulations has been established and validated. After extraction with methanol, sample and standard solutions were applied to silica gel plates and developed with chloroform : methanol : acetone : formic acid 7.5 : 1.3 : 0.5 : 0.03 (v/v/v/v) as mobile phase. Zones were scanned densitometrically at 254 nm. The R(f) values of amlodipine besylate, hydrochlorothiazide, and losartan potassium were 0.35, 0.57, and 0.74, respectively. Calibration plots were linear in the ranges 500-3000 ng per spot for losartan potassium, amlodipine and hydrochlorothiazide, the correlation coefficients, r, were 0.998, 0.998, and 0.999, respectively. The suitability of this method for quantitative determination of these compounds was by validation in accordance with the requirements of pharmaceutical regulatory standards. The method can be used for routine analysis of these drugs in bulk and in formulation.

A novel use of oxidative coupling reactions for determination of some statins (cholesterol-lowering drugs) in pharmaceutical formulations

New, accurate and reliable spectrophotometric methods for the assay of three statin drugs, atorvastatin calcium (AVS), fluvastatin sodium (FVS) and pravastatin sodium (PVS) in pure form and pharmaceutical formulations have been described. All methods involve the oxidative coupling reaction of AVS, FVS and PVS with 3-methyl-2-benzothiazolinone hydrazone hydrochloride monohydrate (MBTH) in the presence of Ce(IV) in an acidic medium to form colored products with λ(max) at 566, 615 and 664 nm, respectively. Beer's law was obeyed in the ranges of 2.0-20.0, 4.9-35.4 and 7.0-30.0 μg mL(-1) for AVS-MBTH, FVS-MBTH and PVS-MBTH, respectively. Molar absorptivities for the above three methods were found to be 3.24×10(4), 1.05×10(4) and 0.68×10(4) L mol(-1) cm(-1), respectively. Statistical treatment of the experimental results indicates that the methods are precise and accurate. The proposed methods have been applied to the determination of the components in commercial forms with no interference from the excipients. A comparative study between the suggested procedures and the official methods for these compounds in the commercial forms showed no significant difference between the two methods.

HPLC method development for the simultaneous analysis of amlodipine and valsartan in combined dosage forms and in vitro dissolution studies

A simple, rapid and reproducible HPLC method was developed for the simultaneous determination of amlodipine and valsartan in their combined dosage forms, and for drug dissolution studies. A C18 column (ODS 2, 10 μm, 200 x 4.6 mm) and a mobile phase of phosphate buffer (pH 3.6 , 0.01 mol L-1):acetonitrile: methanol (46:44:10 v/v/v) mixture were used for separation and quantification. Analyses were run at a flow-rate of 1 mL min-1 and at ambient temperature. The injection volume was 20 μL and the ultraviolet detector was set at 240 nm. Under these conditions, amlodipine and valsartan were eluted at 7.1 min and 3.4 min, respectively. Total run time was shorter than 9 min. The developed method was validated according to the literature and found to be linear within the range 0.1 - 50 μg mL-1 for amlodipine, and 0.05 - 50 μg mL-1 for valsartan. The developed method was applied successfully for quality control assay of amlodipine and valsartan in their combination drug product and in vitro dissolution studies.