UV Spectrophotometric Method for the Determination of Gemifloxacin in Bulk and Pharmaceutical Formulation
S. Ganapathy*, D.G. Sankar and Pettla Y. Naidu
Department of Pharmaceutical Sciences, Andhra University,Visakhapatnam-530003
*Corresponding Author E-mail: gadepalli_raj@yahoo.com
ABSTRACT:
A simple, sensitive and reproducible spectrophotometric method was developed for the determination of Gemifloxacin (GEMI) in pure and dosage forms. It has absorption maximum at 343nm and obeys beer’s law in the concentration range 2-20 µg mL-1 .Results of analysis were validated statistically and by recovery studies .The apparent molar absorptivity and sandell’s sensitivity were 1.3862 x 104 L mol-1 cm-1 and 2.809 x 10-2 µg cm-2, respectively. The slope and intercept of the equation of the regression line are 0.05370 and -0.00640 respectively. Correlation coefficient was found to be 0.999. This method is successfully employed for the determination of Gemifloxacin in pharmaceutical preparation.
Gemifloxacin mesylate is a synthetic broad-spectrum antibacterial agent for oral administration. Gemifloxacin, a compound related to the fluoroquinolone class of antibiotics, is available as the mesylate salt in the sesquihydrate form. Chemically, gemifloxacin is (R,S)-7- [(4Z)-3-(aminomethyl)-4-(methoxyimino)-1-pyrrolidinyl]-1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-1,8-aphthyridine -3-carboxylic acid.
The mesylate salt is a white to light brown solid with a molecular weight of 485.49. Gemifloxacin is considered freely soluble at neutral pH (350 µg/mL at 37şC, pH 7.0). Its empirical formula is C18H20FN5O4•CH4O3S and its chemical structure is1-6
It is not official in any pharmacopoeia and no UV spectrophotometric analytical reports are found in literature for its quantitative estimation in bulk and tablet dosage forms7-11. Literature survey reveals that the reported methods were HPLC and Visible Spectrophotometric method for determination of Gemifloxacin (GEMI)12-13 .Hence need arises to develop a simple, accurate UV method for routine analysis of Gemifloxacin (GEMI) in formulation .
EXPERIMENTAL:
Instrument: A Shimadzu UV-VIS Spectrophotometer was used for absorbance measurements
Reagents:
All the Chemicals used were of analytical grade
Diluent: Water
Preparation of Standard solution: A Standard stock solution of Gemifloxacin (500µg/mL) was prepared by dissolving 50mg of Gemifloxacin working standard in 100ml of diluent. It was further diluted to obtain 2, 4, 6, 8, 10, 15 and 20 µg mL-1 with water. The absorbance was measured at 343 nm against water as blank. The calibration curve was plotted in the concentration range of 2 to 20µg mL-1 of Gemifloxacin in water. Linearity graph is shown in Fig-1
Preparation of Test Solution: Twenty tablets were taken weighed and powdered. Sample equivalent to 50mg of Gemifloxacin was accurately weighed and transferred in to 100ml volumetric flask, 70ml of diluent was added sonicated for 20min and made up to volume with diluent. 10 ml was taken and centrifuged at 2500rpm. Further 3mL of the Resulting solution is taken into 100mL volumetric flask and made upto volume with diluent. The absorbance was measured at 343 nm against water as blank
Figure 1. Calibration Curve of Gemifloxacin in Water
Figure 2. UV Spectrum of Gemifloxacin in Water
The amount of Gemifloxacin(GEMI)present in the sample solutions(X) using the proposed method was calculated by formula given below and the results are given in Table-1
AT Ds Aw P
X = ------ X -------X ------- X ------- X 100
As DT L 100
AT = Absorbance of sample solution
As = Absorbance of standard solution
Ds= Dilution factor for Standard
DT = Dilution factor for Test Solution
Aw = Average weight of sample in mg
L = Label Claim
P =Potency of Standard on as is basis
RESULTS AND DISCUSSION:
The UV spectrum of standard solutions of Gemifloxacin (GEMI) in water was illustrated in Figure 2. The optical characteristics such as Beer’s law limits(µg/ml),Sandell’s sensitivity(µg/cm2/0.001 A.U), Correlation coefficient(r), % Relative standard deviation (Calculated from six determinations) , % Range of error (0.05 confidence limits and 0.01 confidence limits), Regression equation (I+ ac) for the proposed method is calculated and summarized in table-1.
|
Method Parameters |
Method A |
|
λmax |
343nm |
|
Beer’s law limits(µg/ml) |
2-20 |
|
Sand ell’s Sensitivity(µg/cm2/0.001 A.U) |
0.02809 |
|
Regression equation(I + ac) Slope (a) Intercept (I) |
0.05370 -0.00640 |
|
Correlation coefficient(r) |
0.999 |
|
%RSD |
0.7460 |
|
% Range of error Confidence limits with 0.05 level Confidence limits with 0.01 level |
0.517 0.765 |
* Mean of six determinations
The results obtained with the proposed methods for dosage forms is Compared with the results obtained with HPLC method and presented in Table-2.The Proposed method is Validated and found to be Specific, Accurate, Precise and Linear. Interference studies revealed that the common excipients used in the dosage forms do not interfere in the estimation of Gemifloxacin(GEMI)using the proposed method . To Check the recovery using the proposed method known amounts of pure drug was added to the Placebo used in the pharmaceutical preparation of Gemifloxacin and the mixtures were analyzed by the proposed method and the %Recoveries are given in the table-2 .In conclusion the proposed methods are simple, sensitive and accurate and can be used for the routine determination of Gemifloxacin (GEMI)in pharmaceutical preparations.
TABLE-2 Evaluation of Gemifloxacin in Pharmaceutical Preparations
|
Label Claim Mg/tablet |
Amount Obtained(mg)* |
Reference Method (HPLC) |
% Recovery** |
|
320 |
319.4 ± 1.961 |
319.7 ± 0.314 |
99.8 ± 0.613 |
*Mean ±SD of six determinations.** Mean ±SD of six determinations (100mg of Gemifloxacin was added and recovered)
ACKNOWLEDGEMENTS:
The authors wish to thank the Orchid Healthcare for providing the samples of Gemifloxacin.
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Received on 17.04.2010 Modified on 09.05.2010
Accepted on 22.05.2010 © AJRC All right reserved
Asian J. Research Chem. 3(3): July- Sept. 2010; Page 745-746