Vierodt’s and Q-Absorption Ratio Spectrophotometric Methods for Simultaneous Determination of Drotaverine Hydrochloride and Paracetamol in Tablet Dosage Form

A.J.Vyas¹*, J.K. Patel², J.R. Chavda³, A. Bhandari¹ and N.R. Seth⁴

¹Jodhpur National University, Jodhpur, India.

²Nootan College of Pharmacy, Visnagar, Gujarat, India.

³B.K. Mody Govt. Pharmacy College Rajkot, India.

⁴Department of Pharmaceutical Sceience, Saurastra University, Rajkot, India.

*Corresponding Author E-mail: amitvyas77@gmail.com

ABSTRACT:

Two simple, accurate, precise, sensitive and economical spectrophotometric methods; Vierodt’s method and Q Absorption ratio method have been described for the simultaneous estimation of drotaverine hydrochloride (DROT) and paracetamol (PCM) in combined tablet dosage form. Absorption maxima of drotaverine hydrochloride and paracetamol in 0.05 N NaOH was found to be 230.4 nm and 257 nm respectively. Drotaverine hydrochloride and Paracetamol obey Beer’s law in the concentration range 2-80 µgmL-1 (r2=0.9996) and 2-30 µgmL-1 (r2=0.9997) in 0.05 N NaOH and mean recovery for drotaverine hydrochloride and paracetamol were found to be 100.75±0.74% and 100.27 ±0.70%, respectively. Q absorption ratio method employs 238.8 nm as λ1 (Isobestic point) and 257 nm as λ2 (λmax of Paracetamol) for formation of equations. Drotaverine hydrochloride and paracetamol obey Beer’s law in the concentration range 2-80 µgmL-1 (r2=0.9993) and 2-30 µgmL-1 (r2=0.9997) in 0.05 N NaOH. The mean recovery for Drotaverine hydrochloride and Paracetamol were found to be 100.47 ± 0.10% and 100.006 ± 0.136%. The results of two methods were validated statistically and can be successfully applied for the routine analysis of drotaverine hydrochloride and paracetamol in bulk and combined tablet dosage form.

KEYWORDS: Drotaverine hydrochloride, paracetamol, vierodt’s method, Q Absorption ratio method, spectrophotometry.

INTRODUCTION:

Drotaverine hydrochloride (DROT) {1-[(3, 4-[diethoxyphenyl) methylene]-6, 7 diethoxy-1, 2, 3, 4 - tetrahydroisoquinolene hydrochloride; Figure 1 (structure 1)} is an analogue of papaver, generally acts as an antispasmodic agent by inhibiting phosphodiesterase IV enzyme [1]. It is not official in USP, BP and IP. Paracetamol (PCM) {N-(4-hydroxyphenyl) acetamide; Figure 1 (structure 2)} is amino phenol derivative, has analgesic and antipyretic activity [2]. Literature survey revealed that several spectrophotometric [3-8] and HPLC methods in urine and human plasma [9-11], and voltametry [12] had been reported for the determination of DROT. While spectrophometry [13-19], HPLC [20-30], LC-MS [31] and capillary electro- phoresis [32] had been reported for determination of PARA.

Tablet formulations containing the analgesic and antipyretic PCM along with the antispasmodic DROT are used in the therapy to treat spasm. To date, there is no reported method for the determination of drotaverine hydrochloride and paracetamol in combination in a pharmaceutical dosage form. Therefore, it was the purpose of this research to develop a simple, sensitive, reliable, and validated analytical method for the measurement of both drugs, which will be the first for their simultaneous analysis in API and tablet dosage form. The present RP-HPLC method was validated following the ICH guidelines [33].

MATERIAL AND METHOD:

Instrumentation:

A Shimadzu UV/Vis double beam spectrophotometer, model 1601, with matched quartz cells corresponding to 1 cm pathlength and spectral bandwidth of 2 nm was used for performing the analysis.

Chemicals and Reagent:

Sodium hydroxide AR grade and distilled water were used as solvents in the study. Standard gift samples of drotaverine hydrochloride and paracetamol were procured from Shree Pramukh Laboratories., Surendranagar. Combined drotaverine hydrochloride and paracetamol tablets (trade name-DROPAR, Label claim 80 mg DROT and 500 mg PCM) were purchased from local market.

Structure 1: Drotaverine hydrochloride

Structure 2: Paracetamol

Figure 1: Structure of Drotaverine hydrochloride and Paracetamol^{1, 2}

Preparation of Standard Stock Solutions and calibration Curve:

Standard stock solutions (100μg/ml) of DROT and PCM were prepared separately by dissolving accurately about 10 mg of each drug in 100 ml volumetric flasks by using 0.05 N NaOH (AR grade) as solvent. The standard solution (100 µ g mL-1) was further diluted with 0.05 N NaOH to obtain concentration range 2, 10, 20, 40, 60 and 80 µgmL -1 for DROT and 2, 5, 10,15, 20, 25 and 30 µgmL-1 for PCM. These solutions were scanned in the spectrum mode from 400.0 to 200.0 nm. The overlain spectra of the two were recorded (Fig 2).The overlain spectra exhibit major absorbance maxima at 230.4 nm and 257 nm for DROT and PCM, respectively, and at 238.8 nm as isoabsorptive point.

The linearity of DROT and PCM were found to be in the concentration ranges of 2-80 μg/ml and 2-30 μg/ml, respectively. The coefficients of correlation were found to be 0.9996 for DROT and 0.9997 for PCM.

Vierordt’s Method (Method I):

This method of analysis is based on the absorption of drugs (X and Y) at the wavelength having maximum absorbamce. The quantification analyses of DROT and PCM in a binary mixture were performed with the following equations:

C_DROT= (A2 ay1 –A1ay2)/ax2ay1–ax1ay2

C_PCM = (A1 ax2–A2ax1)/ax2ay1–ax1 ay2

where C_DROT and C_PCM are the concentrations of DROT and PCM respectively in the diluted sample, ax1 and ax2 are absorptivities of DROT at λ1 (230.4 nm, λmax of DROT) and λ2 (257 nm, λmax of PCM) , ay1 and ay2 are absorptivities of PCM at λ1 (230.4 nm, λmax of DROT) and λ2 (257 nm, λmax of DROT). The absorbance of the diluted samples at 230.4nm and 257nm are A1 (A1= ax1bcx+ay1bcy) and A2 (A2 = ax2 bcx+ay2bcy), respectively.

FIGURE 2: Overlain spectra showing isoabsorptive point and λmax of both the drugs

Absorbance Ratio Method (Method II):

In this method, the isoabsorptive points for both the drugs were determined from the spectra of standard drug solutions, The wavelengths selected were 238.8 nm as λ1 (Isoabsorptive point) and 257 nm (λmax for PCM) as λ2 for formation of equations as shown in Equation given below.

The concentration of individual components calculated by mathematical treatment of the simultaneous equations where Qm= A2/ A1, A1 is absorbance of sample at isoabsorptive point, A2 is absorbance of sample at λmax of PCM, Qx (1.760) = ax2/ax1, Qy (0.290) = ay2 /ay1, ax1 and ax2 represent absorptivities of PCM at λ1 (238.8nm, isoabsorptive point) and λ2 (257 nm, λmax of PCM) and ay1 and ay2 denote absorptivities of DROT at λ1 (238.8nm, isoabsorptive point) and λ2 (257 nm, λmax of PCM) respectively.

Table 1: Data of LOD and LOQ for DROT and PCM

DATA FOR VIERORDT’S METHOD
Parameters	DROT		PCM
Parameters	230.4 nm	257 nm	230.4 nm	257 nm
LOD (mg/ml)	0.1316	0.3223	0.2945	0.0961
LOQ (mg/ml)	0.3989	0.9769	0.8925	0.2913
DATA FOR Q ABSORPTION RATIO METHOD
	238.8 nm	257 nm	238.8 nm	257 nm
LOD (mg/ml)	0.128	0.321	0.291	0.142
LOQ (mg/ml)	0.389	0.973	0.883	0.432

Table 2: Data of recovery study of DROT and PCM

Drug	Amount taken (µg/ml)	Amount added (µg/ml)	Vierodt’s method	Q Absorbance ratio
Drug	Amount taken (µg/ml)	Amount added (µg/ml)	% Recovery ± S.D (n=3)	% Recovery ± S.D (n=3)
DROT	2	1	101.86 ± 1.61	101.37 ± 0.032
	2	2	101.38 ± 1.42	99.97 ± 0.115
	2	3	101.21 ± 1.20	100.09 ± 0.155
PCM	12.5	6.25	102.01 ± 0.01	98.65 ± 0.027
	12.5	12.5	101.63 ± 0.03	100.08 ± 0.158
	12.5	18.75	98.16 ± 0.18	101.29 ± 0.216

Table 3: Data of Analysis of Marketed Formulation

Formulations	Label claim (mg)		Amount found (mg)		*% Assay ± SD**
	DROT	PCM	DROT	PCM	DROT	PCM
Method I	80.0	500.0	81.11	500.1	101.39 ± 0.04	100.03 ± 0.07
Method II	80.0	500.0	80.79	498.26	100.98 ± 0.12	99.65± 0.39

* Average of five determination

Analysis of Marketed formulation:

Twenty tablets (trade name-DROPAR) were weighed and crushed separately to fine powder. A quantity of powder equivalent to 25 mg paracetamol (04 mg of drotaverine hydrochloride) was weighed and transferred to 100 ml volumetric flask and mixed with 0.05 M NaOH (70ml) and sonicated for 20 min. Allow solution to cool and then make up the volume with 0.05 M NaOH. The solution was filtered through whatmann filter paper No. 41. The above solution (5ml) was transferred in 100 ml volumetric flask and diluted to mark with 0.05 N NaOH and from above solution 5 ml was again diluted to 10 ml in 10 ml volumetric flask with 0.05 N NaOH obtain final solution with drotaverine hydrochloride (2 µg/ml) and paracetamol (12.5 µg/ml).

For this method, absorbance of the sample solution, i.e. A₁and A₂ were recorded at 238.8 nm and 257 nm for Q absorption ratio method, respectively where as for Simultaneous equation method A₁and A₂ were recorded at 230.4 nm and 257 nm, respectively.

RESULTS AND DISCUSSION:

In the present work, two methods, namely Vierordt’s method (simultaneous equation) and Q absorbance ratio method were developed for the simultaneous spectroscopic estimation of DROT and PCM in commercially available tablet dosage form using 0.05 N NaOH. From the overlain spectra of the two drugs wavelengths used for Q-absorbance ratio method is 238.8 nm (isoabsorptive point) and 257 nm (λmax of PCM) and for simultaneous equation method, 230.4 nm (λmax of DROT) and 257 nm (λmax of PCM) were selected to give optimum accuracy, precision, time, economy, and sensitivity. Linearity was found to be 2-80 µgmL-1 and 2-30 µgmL-1 in Method I and method II for drotaverine hydrochloride and paracetamol, reapectively. Data for LOD and LOQ were found to be good and as describe in Table 1. The mean percent label claims in tablet were found by the proposed methods were75±0.74% and100.27 ±0.70% (Method I) and 100.47 ± 0.100% and 100.006 ± 0.136% (Method II) for DROT and PCM respectively Tables-1. In order to demonstrate the validity and applicability recovery studies were performed by spiking of bulk drugs at 50, 100, 150 %, the percentage recoveries for DROT and PCM were found to be acceptable by methods I and Method II and the results presented in Table-2. Developed method was also applied to marketed formulation and results were found to be satisfactorily by both the method, as presented in Table-3.

CONCLUSION:

Both the developed methods were found to be simple, rapid, accurate and precise for routine simultaneous estimation of both drugs in tablet dosage form. The value of standard deviation was satisfactorily low and the recovery was close to 100% indicating the reproducibility and accuracy of the methods.

ACKNOWLEDGEMENT

The authors are thankful to Department of Pharmaceutical Sceience, Saurastra University, Rajkot for providing research facilities and also thankful to Shree Pramukh Laboratories for providing gift samples of drotaverine hydrochloride and paracetamol.

REFERENCES:

1) Oneil MJ, Smith A, Heckelman PE. The Merck Index, 13th ed, New Jersey: Merck, Whitehouse Station, 2001, 3489.

2) Indian Pharmacopoeia (4^th ed.), vol.-2, Govt. of India, Ministry of Health and Family Welfare, Controller of Publications, New Delhi, 1996, 554.

3) Shiekh RE, Fateh Z and Abou A, Spectrophotometric method for the determination of some anti-tussive and anti-spasmodic drugs through ion pair complex formation with thocynate and cobalt, Molecular and Biomolecular spectroscopy, 2007, 6(4), 1279-1287.

4) Chitlange SS, Ranjana S, Wankhede SB, Kulkarni AA. Spectrophotometric methods for simultaneous estimation of nimesulide and drotaverine. Intern. J of Chem Tech Research 2009; 1: 135-138.

5) Hisham E, Magdam A and Suzan M, Spectrophotometric and spectrodensitometric method for the determination of paracetamol and drotaverine hydrochloride in combination, Molecu-lar and Biomolecular Spectroscopy, 2007, 10(5), 1147-1151.

6) Metwally FH, Simultaneous determination of nifuroxazide and drotaverine hydrochloride in pharmaceutical preparations by bivariate and multivariate spectral analysis. Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy 2008; 69: 343-349.

7) Dahivelkar PP, Mahajan VK, Bari SB, Shirkhedkar AA, Fursule RA, Surana SJ, Simultaneous derivative and multi-component spectrophotometric determination of drotaverine hydrochloride and mefenamic acid in tablets, Indian J of Pharm Sci 2007; 69: 812-814.

8) Amin S, Sheikh ER and Fateh Z, Spectrophotometric method for the determination of pipazethate hydrochloride, dextromorphan hydrobromide, and drotaverine hydrochloride, Molecular and Biomolecular Spectroscopy, 2007, 3(4), 1088-1093.

9) Ayad MM, Youssef NF, Abdellatif HE, Soliman SM, A comparative study on various spectrometries with thin layer chromatography for simultaneous analysis of drotaverine and nifuroxazide in capsules. Chemical and Pharma Bull 2006; 54: 6807.

10) Bolaji OO, Onye JJ and Ogunbond FA, High performance liquid chromatographic method for the determination of drotaverine in human plasma and urine, J. Biomed. Applica- tion, 1993, 8(1), 93-97.

11) Lalla JK, Shah MU, Jain MB and Sharma AH, Modified high performance liquid chromatographic method for the determination of drotaverine in human plasma, J. Pharma. Biomed. Anal., 1993, 8(4), 385-388.

12) Mezei J, Kuttel S, Szentmiklosi P, Marton S, Racz I, A new method for high-performance liquid chromatographic determination of drotaverine in plasma, J. of Pharm Sci. 2006; 73: 1489 -1491.

13) Ziyatdinova GK, Samigullin AI, Budnikov GK., Voltammetric determination of papaverine and drotaverine, J. of Anal. Chem. 2007; 62: 773-776.

14) Kumar A, Anroop B and Vijay K S., Spectrophotometric method for the simultaneous estimation of nimesulide and paracetamol in tablet dosage form, Indian Drugs, 2003, 40(12), 727-729.

15) Szotak R and Mazurek s., Quantitative determination of acetylsalicylic acid and paracetamol in tablet dosage form, The Analyst, 2002, 127, 144-148.

16) Mahaparle PR, Sangshetti JN, Deshpande SV and Kasture PV., Simultaneous spectro-photometric estimation of aceclophenac and paracetamol in tablet dosage form, Indian J. Pharma.Educ. Res., 2007, 41(1), 42-45.

17) Ravishankar S, Vasudevan M and Mathew S., Spectrophotometric method for the simultaneous estimation of paracetamol and chlormezanone in formulations, Indian Drugs, 1998, 35(5), 12. 306- 308

18) Knochen M, Giglio J and Reis B F., Flow injection spectrophotometric determination of paracetamol in tablets and oral solutions, J. Pharma. Biomed. Anal., 2003, 33, 191-197.

19) Nagulwar, V., Dhurvey, Y., Despande S., Upadhye K., Bakhle, S. and Wadetwar R., UV Spectroscopic estimation of paracetamol and valdecoxib in tablet dosage form, Indian J. Pharm. Sci., 2006, 68 (5), 639-640..

20) Franeta JT, Agbaba D and Eric S., HPLC assay of acetylsalicylic acid, paracetamol, caffeine and phenobarbital, IL Pharmaco, 2002, 57, 709-713

21) Shinde VM and Raman R., Simultaneous method for the determination of paracetamol and chlormezanone in tablets by RP-HPLC, Indian Drugs, 1998, 35(8), 521-523.

22) Halkar UB, Analkope PB and Rane SH., High performance liquid chromatographic method for the determination of paracetamol, caffeine and propyphenazone in tablets, Indian Drugs, 2002, 39(5), 293-296.

23) Momin MY, Yeole PG and Puranik MP., RP-HPLC method for the determination of paracetamol and aceclophenac in tablet dosage form, Ind. J. Pharm. Sci., 2006, 68(3), 387-389.

24) Karthik A, Subramanian A, Udupa N., Simultaneous RP-HPLC estimation of Paracetamol and Domperidone in tablets, IndianJ.Pharm.Sci. 2007; 69(!): 142-143.

25) Natarajan S, Raman B, Stability indicating Isocratic HPLC method for simultaneous estimation of Ondasetron Hydrochloride and Paracetamol from tablets dosage, Indian Drug ;45(5): 2008.

26) Chouksey MK., Kandapur A., Tyagi N., Singh G., Simultaneous estimation of Paracetamol, Chlorzoxazone and Diclofenac sodium in solid dosage forms by RP-HPLC, Method Indian Drug;43(3):2006.

27) Nagaralli, BS, Seetharamappa J, Gowda BG and Melwanki MB., Liquid chromatographic determination of ceterizine hydrochloride and paracetamol in human plasma and pharmaceutical formulations, Journal of Chromatography B, 2003, 798 (1), 49–54.

28) Eswaraselvam A., Simultaneous estimation of paracetamol and ibuprofen by RP-HPLC by using same mobile phase for assay and dissolution in tablet dosage form, I.P.C. Abstracts. 2004, 83.

29) Subramanian G., Simultaneous RP-HPLC estimation of Tizanidine, Diclofenac potassium and Paracetamol in tablets. Indian J. Pharm. Sci., 2004, 66(5), 694-696.

30) Bhavsar AS, Talele GS, Fursule RA and Surana SJ., RP-HPLC estimation of paracetamol and valdecoxib in combined dosage form, 2006, 68(5), 675-677.

31) Celema C, Allue, JA, Prunonosa J, Peraire C. and Obach R., Simultaneous determination of Paracetamol and Chlorpheniramine in human plasma by liquid chromatography tandem mass spectrometery, Journal of Chromatography Analysis. 2000, 870(1-2), 77-86.

32) Azagvuel S and Sekar R., Method development and validation for the simultaneous determination of cetrizine dihydrochloride, paracetamol and phenylpropanolamine hydrochloride in tab- lets by capillary zone electrophoresis, J. Pharm. Biomed. Anal., 2006, 1-6.

33) Text on validation of analytical procedure, Q2 (R1) in ICH Harmonized Triplicate Guidelines, Nov.2005.

Received on 02.06.2011 Modified on 14.06.2011

Asian J. Research Chem. 4(8): August, 2011; Page 1258-1261