INTRODUCTION:
Tramadol is an orally administered non-steroidal anti-inflammatory drug1,2, which possesses good analgesic properties and good tolerability profile in a variety of painful conditions. The chemical name for tramadol hydrochloride is (±) cis-2-[(dimethylamino) methyl]-1-(3-methoxyphenyl cyclohexanol hydrochloride. Several methods have been reported for the assay of tramadol3-5.
The literature survey reveals that the methods available for estimation of Tramadol hydrochloride include LC-MS6,8 and Simultaneous UV Spectrophotometric7,9 methods. However, no UV spectrophotometric method is available for the quantitative determination of tramadol in tablet pharmaceutical dosage forms. In the present study a simple, sensitive, accurate and validated UV spectrophotometric method for the estimation of Tramadol hydrochloride in bulk and tablet dosage forms has been developed using 0.1 N HCl as solvent. HCl (0.1 N) has an advantage of being inexpensive, non-volatile and relatively less hazardous. Moreover the maximum wavelength for both the drugs remains stable by changing the concentration of the drugs.
This work was aimed to develop simple, rapid, accurate and specific UV spectrophotometric method for the estimation of tramadol in pharmaceutical dosage forms. The method was further validated for the parameters like precision, accuracy, sensitivity, and linearity.
The results of analysis were validated statistically and by recovery studies. This method of estimation of tramadol was found to be simple, precise and accurate.
MATERIALS AND METHOD:
Materials:
Tramadol was obtained as a gift sample from Lupin Ltd., Mumbai, India. Tramadol tablets were procured from local pharmacy. All the reagents were of analytical grade. Double distilled water was used throughout the experiment. A Shimadzu 1700 UV spectrophotometer with 1 cm matched couvettes was used for estimation.
Method:
Preparation of standard solution:
An accurately weighed 10 mg of tramadol was dissolved in and the volume was adjusted up to the mark with 0.1 N HCl prepared in distilled water in a 50 ml volumetric flask to obtain a stock solution of 200 µg/ml. Aliquots of 0.715 to 8.5 ml portions of standard solution were transferred to a series of 10 ml volumetric flasks and volume in each flask were adjusted to 10 ml with 0.1 N HCl to obtain concentration of range of 15-170 µg/ml.
One of the solutions was scanned in UV range using as a blank 0.1 N HCL and λmax was found to be 270.5 nm. The absorbance of solutions was measured at 270.5 nm against reagent blank and calibration curve was constructed (Fig.1). The optical characteristics are presented in Table 1.
Preparation of sample solution:
Ten tablets of tramadol were weighed and powered in glass mortar. Amount equivalent to 10 mg was transferred to 50 ml volumetric flask, dissolved in and made up the volume with to obtain a concentration of 200 µg/ml. The solution was filtered through Whatman filter paper No. 41 and filtrate was diluted to obtain concentration in between linearity range. The absorbance of sample solution was measured and amount of tramadol was determined by referring to the calibration curve. Recovery studies were carried out by adding a known quantity of pure drug to the preanalyzed formulation and the proposed method was followed. From the amount of drug found, percentage recovery was calculated. The results obtained are given in Table 2.
Table: 1 Optical Characteristics and Regression Equation for the Standard Tramadol
|
Parameters |
Values |
|
Absorption maxima (nm) |
270.5 |
|
Beer’s law limit (mcg/ml) |
15-170 |
|
Correlation coefficient |
0.9985 |
|
Molar absorptivity (lit/mole/cm) |
1.771×104 |
|
Sandell’s sensitivity(mcg/sqcm/0.001) |
0.16927 |
|
Regression equation : |
y = 0.005908x + 0.008368 |
|
Slope (m) |
0.005908 |
|
Intercept |
0.008368 |
|
% COV |
0.51005 |
|
LOD(mcg/ml) |
10.8 |
|
LOQ(mcg/ml) |
30.5 |
Figure 1: Calibration Curve for Tramadol hydrochloride
Table- 2: Results of analysis
|
Sr.No |
|
Label claim |
% Estimated |
% Recovery* |
|
1 |
Bestodol |
50 |
99.98 |
97.14 |
*= Mean of three reading
RESULTS AND DISSCUSION:
The proposed method of determination of tramadol showed molar absorptivity of 1.771×104l/mol/cm and Sandell’s sensitivity 0.16927mcg/Sq.cm/0.001-absorbance units. High Molar absorptivity and low Sandell’s sensitivity for the respective method reveals that all these methods are highly sensitive.
Linear regression of absorbance on concentration gave equation y = 0.005908 xs + 0.008368 with a correlation coefficient of 0.9985.Standard deviation of 0.510157 were observed for analysis of 3 replicate samples, indicating precision and reproducibility. Tramadol exhibits its maximum absorption at 270.5 nm and obeyed Beer’s law in the range of 15 - 170 µg/ml.
Table 3: Statistical analysis of results
|
Sr.No |
|
SD* |
COV (%)* |
SE* |
|
1 |
Bestodol |
0.510157 |
0.510005 |
0.294539 |
S.D.: Standard Deviation; S.E.: Standard Error; C.O.V.: Coefficient of Variation
The results of analysis and recovery studies10 are presented in the Table 2 and 3. The accuracy of the method was assessed by recovery studies at three different levels i.e. 50%, 100%, 150%. The percentage recovery value 97.14% indicates that there is no interference from the excipients present in formulation. The developed method was found to be sensitive, accurate, precise and reproducible and can be used for the routine quality control analysis of tramadol in bulk drugs and formulations.
ACKNOWLEDGEMENTS
We are grateful to Lupin Ltd., Mumbai, India, for providing gift sample of drug for research work. We are thankful to Principal, Govt. College of Pharmacy, Karad for providing laboratory facility and constant encouragement.
REFERENCES:
1. Gutstein HG, Akil H, Opioid analgesics, Goodman and Gillman's The Pharmacological basis of Therapeutics. 10 th ed. McGraw-Hill: London; 2001; 569-620.
2. Rang HP, Dale MM, Ritter JM, Moore RK, Antiinflammatory Agents: Rang and Dale's Pharmacology. 5 th ed. Church Livingstone: London; 2003; 580-5.
3. Meyyanathan SN, Pradeep K, Suresh B. Analysis of Tramadol in Pharmaceutical Preparations by High Performance Thin Layer Chromatography. J Separation Sci.2003; 26:1359-62.
4. Gan SH, Ismail R. Validation of a High Performance Liquid Chromatography Method for Tramadol and O-desmethyltramadol in Human Plasma using Solid-phase Extraction. J Chromatogr B Biomed Sci.2001; 759:325-35.
5. Ho ST, Wan JJ, Liaw WJ, Ho CM, Li JH. Determination of tramadol by capillary gas Chromatography with flame ionization detection. Application to human and rabbit pharmacokinetic studies. J Chromatogr B Biomed Sci. 1999; 89-96.
6. Patela BN, Sharmab N, Sanyal M and Shrivastav PS; Journal of An accurate, rapid and sensitive determination of tramadol and its active metabolite O-desmethyltramadol in human plasma by LC–MS/MS. Pharmaceutical and Biomedical Analysis, 2009;49:354-366.
7. Puranik M, Hirudkar A, Wadher SJ, Yeole PG; Development and validation of spectrophotometric methods for simultaneous estimation of tramadol hydrochloride and chlorzoxazone in tablet dosage form Indian Journal of Pharmaceutical Sciences.2006; 12:737-739.
8. Kachhadia PK, Doshi AS, Ram VR and Joshi HS. Validated LC. Method for Simultaneous Analysis of Tramadol Hydrochloride and Aceclofenac in a Commercial Tablet Chromatographia 2008; 68:997-999.
9. Srinivasan KK, Alex J, Shirwaikar A A, Jacob S, Sunil Kumar MR, Prabu SL. Simultaneous derivative spectrophotometric estimation of aceclofenac and tramadol with paracetamol in combination solid dosage forms.2007;540-545.
10. ICH–Q2B guidelines on Analytical Method Validation, International Convention on Quality for the Pharmaceutical Industry, Toronto, Canada, 2002.
Received on 02.03.2010 Modified on 03.04.2010
Accepted on 22.04.2010 © AJRC All right reserved
Asian J. Research Chem. 3(3): July- Sept. 2010; Page 714-715