Atorvastatin: A Review on Analytical Method and Its Determination in Pharmaceuticals and Biological Matrix

Paras Virani^1,2*, Rajanit Sojitra², Hasumati Raj², Vineet Jain².

¹Research Scholar 2014, Gujarat Technological University, Gujarat

²Quality Assurance Department, Shree Dhanvantary Pharmacy College, Kim, Surat

*Corresponding Author E-mail: parasvirani@gmail.com

ABSTRACT:

Atorvastatin is the most efficacious of the currently available HMG-CoA Reductase inhibitors used in antilipidemic and also used in athresclerosis, stroke, cardiac risk. The clinical and pharmaceutical analysis of this drug requires effective analytical procedures for quality control and pharmacodynamic and pharmacokinetic studies as well as stability study. An extensive survey of the literature published in various analytical and pharmaceutical chemistry related journals has been conducted and the instrumental analytical methods which were developed and used for determination as single or combination with other drugs in bulk drugs, formulations and biological fluids have been reviewed. This review covers the most recent many analytical methods including spectrophotometric methods, chromatographic method including HPLC, HPTLC and RP HPLC, liquid chromatography tendam mass spectroscopy were reported.

KEYWORDS: Atorvastatin, Analytical Method, HPLC, Hmg-Coa Reductase Inhibitors, Antilipidemic.

INTRODUCTION:

Atorvastatin is a member of the drug class known as statins. Its mainly used in antilipidemic agent in cardiac risk condition. It is used for lowering cholesterol. Atorvastatin is a competitive inhibitor of hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase, the rate-determining enzyme in cholesterol biosynthesis via the mevalonate pathway (1). HMG-CoA reductase catalyzes the conversion of HMG-CoA to mevalonate. Atorvastatin acts primarily in the liver. Decreased hepatic cholesterol levels increases hepatic uptake of cholesterol and reduces plasma cholesterol levels.

Table : 1 Structural Identification Of ATORVASTATIN⁽¹⁾

Serial number	Class	Identification
1	Primary class	Organic compound
2	Superclass	Heterocyclic Compound
3	Class	Pyrroles
4	Subclass	Substituted Pyrroles
5	Direct parent	Diphenylpyrroles
6	Alternative parent	Secondary Alcohols; Enolates; Carboxylic Acids; Polyamines; Organofluoride

Figure:1 Structure of atorvastatin(2)

Appearance is white or almost white, crystalline powder. Solubility is given in practically insoluble in water, soluble in methanol, slightly soluble in methylene chloride.

Mechanism of Action:

Atorvastatin selectively and competitively inhibits the hepatic enzyme HMG-CoA reductase.(3) As HMG-CoA reductase is responsible for converting HMG-CoA to mevalonate in the cholesterol biosynthesis pathway, this results in a subsequent decrease in hepatic cholesterol levels. Decreased hepatic cholesterol levels stimulates upregulation of hepatic LDL-C receptors which increases hepatic uptake of LDL-C and reduces serum LDL-C concentrations. Atorvastatin, a selective, competitive HMG-CoA reductase inhibitor, is used to lower serum total and LDL cholesterol, apoB, and triglyceride levels while increasing HDL cholesterol. High LDL-C, low HDL-C and high TG concentrations in the plasma are associated with increased risk of atherosclerosis and cardiovascular disease. The total cholesterol to HDL-C ratio is a strong predictor of coronary artery disease and high ratios are associated with higher risk of disease. Increased levels of HDL-C are associated with lower cardiovascular risk. By decreasing LDL-C and TG and increasing HDL-C, atorvastatin reduces the risk of cardiovascular morbidity and mortality. Atorvastatin has a unique structure, long half-life, and hepatic selectivity, explaining its greater LDL-lowering potency compared to other HMG-CoA. Atorvastatin have been shown to decrease plasma LDL levels in patients with homozygous familial hypercholesterolemia (4), an effect that is proposed to result from their ability to produce a more significant decrease in the hepatic production of LDL cholesterol. Additionally, atorvastatin can produce a significant lowering in plasma triglycerides. Atorvastatin give effect has been attributed to its ability to produce an enhanced removal of triglyceride-rich VLDL.

Figure:2 Mechanism of atorvastatin(4)

Figure 3 : Chemical mechanism of action in atorvastatin(6)

The activity of HMGRIs is sensitive to the stereochemistry of the lactone ring (5), the ability of the lactone ring to be hydrolyzed, and the length of bridge connecting the two ring systems. Additionally, it was found that the bicyclic ring could be replaced with other lipophilic rings and that the size and shape of these other ring systems were. The ring system is a complex hydrophobic structure, covalently that is involved in the binding interactions to the HMG-CoA reductase. The binding interactions of the ring are able to reduce the competition for the binding site between the statin and the endoge nous HMG-CoA substrate because keeping the statin closed to the enzyme precludes the possibility of statin displacement by the endogenous substance.

Combination of Atorvastatin:

1. Atorvastatin + Hydrochlorthaizide

2. Atorvastatin + Irbesartan and other angiotensin receptor blocker

3. Atorvastatin + Ezetimibe

4. Atorvastatin + Amlodipine

5. Atorvastatin + Glimepiride and other Antidiabeti agent

6. Atorvastatin + Fenofibrate

7. Atorvastatin + Ramipril

8. Atorvastatin + B Group vitamin

9. Atorvastatin +Statin

10. Atorvastatin + Aspirin, Clopedogrel

11. Atorvastatin + Atenolol

12. Atorvastatin + Pioglitazone

Marketed Formulation of Atorvastatin(From Marketed) Atorvastatin Formulation :

• Lipitor, Acrostatin, Alip

• Atorvactor Irbesartan combination formulation :

• Alnavas –A, Amodart -E

• Atamra F, Atherochek -5

Analytical Method:

A. Compendial Method:

Atorvastatin is official in Indian Pharmacopoeia and United State Pharmacopoeia. (Table-2)

B. Reported Method:

1. Chromatographic methods:

The high-pressure liquid chromatography (HPLC)for residue determination and simultaneous estimation of single and combination drug and also used in impurity profiling. HPTLC method are widely used chromatographic method sin the analysis of atorvastatin in plasma and pharmaceutical dosage form. RP HPLC method also developed for determination of concentration of atorvastatin in human serum and also for simultaneous determination in synthetic mixture, combination dosage form like hydrochlorthaizide, losartan, valsartan etc. (Table-3)

Table No.2: Summary of Compendial Method of Atorvastatin (7,8)

Title	Pharmacopoeia	Method	Detail	Ref.
Identification	Indian Pharmacopoeia	Infrared Absorption Spectrophotometry	Compare with atorvastatin calcium RS	7
Assay	Indian Pharmacopoeia	High Performance Liquid Chromatography	acetonitrile and water(40:60 % v/v) column is (25mm x 4mm)	7
Identification	United State Pharmacopoeia	Infrared Absorption Spectrophotometry	I.R spectroscopy is perform with mixture dissolve in methanol	8
Assay	United State Pharmacopoeia	High Performance Liquid Chromatography	Acetonitrile, stabilizer-free tetrahydrofuran, and Buffer (21:12:67)column is (25mm x 4mm,2.5micron)	8

Table No.3: Summary of Chromatographic Method of Atorvastatin (9-53)

Drug and its combination	Method	Mobile phase	Wave length	Ref.
Atorvastatin and amlodipine	Rp-HPLC	0.03 M Potassium buffer: Acetonitrile in the ratio of 30:70, pH 2.5	237nm	9
	Rp-HPLC	Phosphate buffer: acetonitrile and methanol (53:43:4, v/v)	246nm	10
	Rp- HPLC	0.05 M Ammonium acetate solution and acetonitrile 55:45 (v/v)	238nm	11
	Rp-HPLC	0.05M Ammonium acetate buffer (pH-4) and acetonitrile in the ratio (40 + 60, v/v)	240nm	12
	Rp-HPLC	0.05M Ammonium acetate buffer (pH-4) and acetonitrile in the ratio (40 + 60, v/v).	238nm	13
	Rp-HPLC	Phosphate buffer (1ml ortho phosphoric acid in 1000 ml 0f water) acetonitrile and methanol (53:43:4,v/v)	246nm	14
	Rp-HPLC	0.05M Ammonium acetate buffer (pH-4) and acetonitrile (40 + 60 v/v).	240nm	15
Atorvastatin and amlodipine	HPLC	Acetonitrile : ammonium dihydrogen orthophosphate (40:60 v/v)	240nm	16
	HPTLC	Chloroform-methanol-acetic acid 85:10:5 (v/v)	247nm	17
	Rp UPLC	Acetonitrile and 0.02 M Potassium dihydrogen phosphate (55:45)	242nm	18
Atorvastatin + ezetimibe	Rp- HPLC	Methanol: water (75:25)	238nm	19
	Rp- HPLC	Methanol: Acetate Buffer I.P (70:30)	248nm	20
	Rp – HPLC	Acetonitrile: water (6: 4, v/v)	260nm	21
	HPTLC	Toluene–methanol 8:2 (v/v)	240nm	22
	HPTLC	BENZENE: methanol: Acetone: Triethylamine (7.2:1:0.2 v/v/v/v)	266nm	23
Atorvastatin +ramipril	Rp- HPLC	Acetonitrile: 0.02 M Potassium dihydrogen phosphate (pH 3.2) [80:20 %V/V]	217nm	24
	Rp – HPLC	Acetonitrile ,water and methanol (55:40:5)	237nm	25
	Rp - HPLC	Acetonitrile: 0.02 M Potassium dihydrogen phosphate (pH 3.2) [75: 25%v/v].	217nm	26
Atorvastatin + telmisartan	Rp- HPLC	Phosphate buffer (PH 3.0): Acetonitrile (40:60) %v/v	276nm	27
	Rp –HPLC	Acetonitrile: Buffer (0.01M Potassium dihydrogen phosphate) 65:35	250nm	28
	HPTLC	Chloroform : methanol(90:10)	291nm	29
Atorvastatin +Losartan	Rp- HPLC	Methanol and phosphate buffer (pH 6.8) (80:20)	238nm	30
	HPTLC	Toluene: Methanol (8:2 v/v)	260nm	31
Atorvastatin +Pioglitazone	HPLC	Tween-20 and n-Butanol Phosphate buffer, pH 4.2 (50:25:25v/v)	322nm	32
	HPTLC	Chloroform: methanol: toluene (6:3:4 v/v).	259nm	33
Atorvastatin +Clopidogrel bisulphate	Rp HPLC	Acetonitrile and 0.01M potassium dihydrogen phosphate (75:25 %v/v)	240nm	34
Atorvastatin +B groupvit.	Rp HPLC	Methanol :Phosphate Buffer (60 :40 %v/v)	265nm	35
Atorvastatin +Nicotinic acid	Rp HPLC	Acetonitrile: Ammonium Acetate buffer 0.02M (68:32) PH 4.5	245nm	36
Atorvastatin +Rosuvastatin	Rp HPLC	Methanol: water (68:32, v/v)	241nm	37
Atorvastatin +Aspirin	Rp HPLC	Acetonitrile: Ammonium Acetate buffer 0.02M (68:32) pH 4.5	245nm	38
Atorvastatin +Tercarnidipine	HPLC	Acetonitrile: 0.1M ammonium acetate buffer (pH 3.5)	235nm	39
Atorvastatin +Atenolol	Rp HPLC	Acetonitrile, and Phosphate buffer (pH 4.5±0.05)72:28 (v/v)	238nm	40
Atorvastatin +Fenofibrate	Rp HPLC	Methanol: Water 40:60v/v	274nm	41
Atorvastatin , Candesartan, olmesartan, chlorthelidon, HCTZ	Rp HPLC	0.05 M sodium dihydrogen phosphate buffer and acetonitrile (Gradient ratio)	265nm	42
Atorvastatin , Aspirin, clopedogrel	Rp UPLC	0.1% orthophosphoric acid and acetonitrile (55:45, v/v)	230nm	43
Atorvastatin , Ramipril, Aspirin	HPLC	Methanol and Acetate buffer (70:30v/v)	254nm	44
	HPTLC	benzene: ethyl acetate: toluene: methanol: glacial acetic acid (4.0:4.5:1.0:0.5:0.1 v/v/v/v/v).	220nm	45
Atorvastatin , Amlodipine, Ezetimibe	Rp HPLC	MeCN, MeOH, 20 mM K2HPO4 (pH 5.0 ) solution (36.74 : 20 : 43.26 v/v/v)	231nm	46
Atorvastatin , Metformin,glimepiride, pioglitazone	HPLC	methanol and phosphate buffer pH 3( 75:25)	230nm	47
Atorvastatin , Metformin, glimepiride	Rp UPLC	Phosphate buffer: acetonitrile (40:60v/v)	243nm	48
	HPTLC	Water: methanol: ammonium sulphate (3.5:3.5:12.6, v/v/v).	246nm	49
Atorvastatin , Aspirin,atenolol, losartan	Rp HPLC	Methanol : Acetonitrile : 0.02M KH2PO4 solution (50:20:30 v/v)	230nm	50
Atorvastatin , Enalpril, aspirin, hctz	Rp HPLC	Acetontrile, methanol and triethylammonium phosphate buffer (pH 2.5) 50:25:25 (v/v/v)	225nm	51
Atorvastatin , Pravastatin, simvastatin	Rp HPLC	Methanol and 0.1 % orthophosphoric acid in water	238nm	52
Atorvastatin , Ezitimibe, fenofibrate	Rp HPLC	Methanol/water (gradiant mixture)	240nm	53

2. UV SPECTROSCOPIC METHOD:

First order derivative spectroscopy and Ratio derivative spectroscopic technique, standard addition method, Q analysis method was developed for simultaneous determination ofatorvastatin and its combination with other anti hypertensive drug.

Table No.4:Summary of UV spectroscopic method of Atorvastatin (54-90)

Drug name	Method	Wavelength for Atorvastatin	Wavelength for other drug	Solvent	ref
Atorvastatin	Spectrophotometric Methods	240nm	280nm	Methanol	54
	Spectrophotometric Methods	290nm	566nm	Methanol	55
Atorvastatin + Amlodipine	Simultaneous estimation	242nm	364nm	Methanol	56
	Orthogonal spectroscopy	292nm,302nm 332nm,	251nm,255nm, 263nm	Methanol	57
	Simultaneous estimation	246nm	361nm	Methanol	58
	Simultaneous estimation	356nm,238.5nm	368nm, 352nm	Methanol	59
	Simultaneous estimation	257.6nm	360nm	Methanol	60
	Simultaneous estimation	245nm	336nm	Methanol	61
	Simultaneous equation method Q analysis	246nm	361nm	Methanol	62
		238.8nm
	H point addition method	278nm,305.6nm,	241nm, 252.4	Methanol	63
Atorvastatin + amlodipine	Simultaneous estimation	232nm	243nm	Methanol	64
	Derivative spectroscopy	250nm	241nm	Methanol :water (50-50)	65
Atorvastatin + Ezetimibe	Dual wavelength spectroscopy	228.8nm,240.8nm	232nm, 259.2nm	Methanol	66
	Simultaneous estimation	246.5nm	232.5nm	Methanol	67
	Simultaneous estimation	235nm	258.2nm	Methnol	68
	Biavariate calibration Second derivative	251nm 238.6nm	232.6nm 232.6nm	Methanol	69
	Second derivative	394nm	455nm	Methanol	70
Atorvastatin + Aspirin	Simultaneous estimation	242nm	222nm	Methanol	71
	Simultaneous estimation Q value method	240nm	230nm	0.1N NaOH	72
		150 – 290.5nm
Atorvastatin + Pioglitazone	Derivative spectroscopy	226nm	278nm	Water	73
	Simultaneous estimation	210nm	225nm	Eathanol	74
Atorvastatin + Losartan	Simultaneous estimation	207nm	246nm	Methanol	75
Atorvastatin + Glimepiride	Spectrometric method	241nm	231nm	0.1N NaOH	76
Atorvastatin + Fenofibrate	Spectrometric method	246nm	286nm	Methanol	77
	Simultaneous estimation	238nm, 256nm	259nm, 293nm	Methanol	78
Atorvastatin +fenofibrate	Simultaneous equation	245nm	285nm	Methanol	79
Atorvastatin + Ramipril	Derivative spectroscopy	294nm	229nm	Water : methanol (40:60)	80
Atorvastatin + Nicotinic acid	Simultaneous estimation	248nm	261.5nm	Methanol	81
Atorvastatin + Telmisartan	Simultaneous estimation	297nm	241.8nm	Water	82
	Simultaneous estimation	247nm	296nm	Methanol	83
Atorvastatin + Niacin	Simultaneous estimation	246nm	262nm	Methanol	84
Atorvastatin + Olmesartan	Ratio derivative spectroscopy	313nm	223nm	Methanol	85
	Simultaneous equation First order derivative	247nm 310nm	256.5 247nm	Methanol	86
Atorvastatin + Atenolol	Simultaneous estimation	241nm	225nm	Methanol	87
Atorvastatin ,Glimepiride, metformin	Multicomponent Simultaneous estimation	255nm	G 225nm M 285nm	Methanol	88
Atorvastatin , Ezetimibe, fenofibrate,	Simultaneous estimation	247nm	E 233nm F 287nm	Methanol	89
Atorvastatin , Ramipril, aspirin	Simultaneous estimation	246nm	R 206nm A 226nm	Methanol	90

3. STABILITY INDICATING METHOD:

Stability indicating method is used to checkout the stability of drug in various condition. Here Atorvastatin is studied by RP-HPLC, HPTLC, and also LC/MS/MS for stability study.

Table No.5 : Summary of Stability Indicating Method for Atorvastatin(91-99)

Drug name	Method	Mobile phase	Wave length	Ref.
Atorvastatin	Stability indicating HPLC	acetonitrile and 50 mM potassium dihydrogen phosphate buffer (60:40 v/v),	220nm	91
Atorvastatin	Stability indicating HPLC	Methanol: Acetonitrile: Phosphate Buffer (45:45:10).	246nm	92
Atorvastatin + Fenofibrate	Stability indicating HPLC	Acetonitrile - triethyl amine (95:5 v/v)	254nm	93
Atorvastatin + Amlodipine	Stability indicating HPLC	acetonitrile–0.025 M NaH2PO4 buffer (pH 4.5) (55:45, v/v)	237nm	94
Atorvastatin + Simvastatin	Stability indicating Rp HPLC	Acetonitrile – tetrahydrofuron (95:5v/v)	246nm	95
Atorvastatin + Valsartan	Stability indicating Rp HPLC	0.1% acetic acid and acetonitrile 50:50 v/v	225nm	96
Atorvastatin + Ezetimibe	Stability indicating Rp HPLC	acetonitrile and 0.4% v/v triethylamine 55:45, v/v	231nm	97
Atorvastatin + Amlodipine	Stability indicating Rp UPLC	acetonitrile and 0.1% v/v Triethyl amine buffer (pH 3 ± 0.05)	240nm	98
Atorvastatin + Ezetimibe	Stability Rp HPLC	0.02 M Potassium dihydrogen phosphate: Acetonitrile: Methanol (10:40:50, v/v/v)	236nm	99

4. Other Analytical Method for Atorvastatin:

Table No.6 : Other Method For Determination Of Atorvastatin (100-112)

Title	Method	Drug	Ref.
Development and validation of a simple, sensitive, and rapid method for simultaneous estimation of Atorvastatin and its active metabolites in human plasma by LC-ESI-MS/MS	Lc-esi-ms/ms method	Atorvastatin	100
Development and Validation of Analytical Methods for Simultaneous Estimation Of Atorvastatin Calcium and Ezetimibe in Combined Dosage Form	Simultaneous estimation ,hplc, hptlc method	Atorvastatin Calcium And Ezetimibe	101
Application of UV-Spectrophotometry and RP-HPLC for Simultaneous Determination of Atorvastatin Calcium and Ezetimibe in Pharmaceutical Dosage Form	Uv-spectrophotometry and rp-hplc	Atorvastatin Calcium And Ezetimibe	102
Development and validation of rp-hplc and spectrophotometric method for simultaneous estimation of atorvastatin and amlodipine in pharmaceutical dosage forms	Uv-spectrophotometry and rp-hplc	Atorvastatin And Amlodipine	103
Simultaneous determination of amlodipine besylate and atorvastatin calcium by using spectrophotometric method with multivariate calibration and hplc method implementing “design of experiment	Uv-spectrophotometry and hplc	Amlodipine Besylate And Atorvastatin Calcium	104
Simultaneous Estimation of Atorvastatin Calcium and Amlodipine besylate by UV Spectrophotometric method using hydrotropic solubilisation	Hydrotropic solubilization	Atorvastatin Calcium And Amlodipine Besylate	105
Simultaneous Determination of Atorvastatin and Glimepiride by LC-MS/MS in Human Plasma and Its Application to a Pharmacokinetic Study	Liquid- Chromatography-Tandem Mass Spectrometry	Atorvastatin And Glimepiride	106
Derivative- Ratio Spectrophotometric, Chemometric and hplc Validated methods for Simultaneous Determination of Amlodipine and Atorvastatin in Combined Dosage Form	Derivative- ratio spectrophotometric, chemometric and hplc	Atorvastatin And Amlodipine	107
Formulation, optimization and simultaneous determination of Atorvastatin calcium and losartan potassium in pure and bilayer tablets	Uplc, Hptlc	Atorvastatin Calcium And Losartan Potassium	108
Simultaneous Determination of Amlodipine Besylate and Atorvastatin Calcium in Binary Mixture by Spectrofluorimetry and HPLC Coupled with Fluorescence Detection	Septrofluorometric, spectrophotometric and hplc method	Atorvastatin And Amlodipine	109
RP-HPLC Estimation of Aspirin and Atorvastatin Calcium In Combined Dosage Forms	Spectrophotometric and rp hplc method	Aspirin And Atorvastatin Calcium	110
Simultaneous Determination of Atorvastatin and Aspirin in Human Plasma by LC–MS/MS: Its Pharmacokinetic Application	Liquid- Chromatography-Tandem Mass Spectrometry	Aspirin And Atorvastatin Calcium	111
Simultaneous Determination of Atorvastatin Calcium and Ezetimib by Ratio Spectra Derivative Spectrophotometry and Reverse Phase-High Performance Liquid Chromatography	Spectrophotometry and rp hplc	Atorvastatin Calcium And Ezetimib	112

CONCLUSION:

Presented systematic review covers the current analytical methods for the determination of Atorvastatin and its combination in pharmaceutical and biological samples like serum and plasma. HPLC method were found to be most widely use for Atorvastatin. The sensitivity, specificity, and better separation efficiency enable HPLC to be used frequently for simultaneous qualitative and quantitative determination of Atorvastatin. The other analytical method like RP-HPLC, HPTLC, LC/MS/MS, UV is also used for determination of Atorvastatin in blood, serum, pharmaceutical dosage form, synthetic mixture and also stability study. The presented information is useful for the future study for researcher involved in formulation development and quality control of Atorvastatin.

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Received on 08.06.2015 Accepted on 25.09.2015

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Asian J. Pharm. Ana. 5(3): July- Sept. 2015; Page 151-160

DOI: 10.5958/2231-5675.2015.00025.3