An isocratic, reversed phase-liquid-chromatographic assay method was developed for the quantitative determination of ibuprofen and famotidine in combined-dosage form. A Brownlee C18, 5
Ibuprofen (IBU) is chemically (RS)-2-(4-(2-methylpropyl) phenyl) propanoic acid [
Structure of ibuprofen.
Structure of famotidine.
A literature survey regarding quantitative analysis of these drugs revealed that attempts have been made to develop analytical methods for the estimation of ibuprofen alone and in combination with other drugs by liquid chromatographic (LC) [
There is no method reported for the estimation of IBU and FAM in combined dosage form. The present study involves development and validation of liquid chromatographic method for the estimation of IBU and FAM in combined dosage form.
The liquid chromatographic system consists of PerkinElmer series 200 LC (Shelton, USA) equipped with a series 200 UV detector, series 200 quaternary gradient pump, and manual injector rheodyne valve with 20
Analytically pure FAM and IBU were obtained as gift samples from Blue Cross Laboratory limited, Mumbai, India, and Mercury Laboratories Limited, Vadodara, India, respectively. HPLC grade acetonitrile, methanol, and water were obtained from E. Merck Ltd., Mumbai, India. Tablet formulation (DUEXIS, Horizon Pharma, USA) containing labeled amount of 800 mg of ibuprofen and 26.6 mg of famotidine was used for the study.
The Brownlee C18 column equilibrated with mobile phase water : methanol : acetonitrile (30 : 60 : 10, v/v/v) was used. The flow rate was maintained at 1 mL/min, eluent was monitored with UV detector at 264 nm, and the injection volume was 20
IBU and FAM were weighed (25 mg each) and transferred to two separate 25 mL volumetric flasks and dissolved in few mL of mobile phase. Volumes were made up to the mark with mobile phase to yield a solution containing 1000
The method was validated for accuracy, precision, linearity, detection limit, quantitation limit, and robustness.
Appropriate aliquots of IBU and FAM working standard solutions were taken in different 10 mL volumetric flasks and diluted up to the mark with mobile phase to obtain final concentrations of 2, 5, 10, 15, 20
The repeatability studies were carried out by estimating response of IBU (10
The accuracy of the method was determined by calculating recoveries of IBU and FAM by method of standard additions. Known amount of IBU (0, 4, 8, 12
The limit of detection (LOD) is defined as the lowest concentration of an analyte that can reliably be differentiated from background levels. Limit of quantification (LOQ) of an individual analytical procedure is the lowest amount of analyte that can be quantitatively determined with suitable precision and accuracy. LOD and LOQ were calculated using following equation as per ICH guidelines:
Robustness of the method was studied by deliberately changing the experimental conditions like flow rate and percentage of organic phase.
Stability of sample solutions was studied at
A system suitability test was an integral part of the method development to verify that the system is adequate for the analysis of IBU and FAM to be performed. System suitability test of the chromatography system was performed before each validation run. Five replicate injections of a system suitability standard and one injection of a check standard were made. Area, retention time (RT), tailing factor, asymmetry factor, and theoretical plates for the five suitability injections were determined.
Twenty tablets were weighed accurately and finely powdered. Tablet powder equivalent to 800 mg IBU and 26.6 mg of FAM was taken in 100 mL volumetric flask. Methanol (50 mL) was added to the above flask, and the flask was sonicated for 15 minutes. The solution was filtered using whatman filter paper no. 41, and volume was made up to the mark with the mobile phase.
Appropriate volume of the aliquot was transferred to a 10 mL volumetric flask, and the volume was made up to the mark with the mobile phase to obtain a solution containing 12
The objective of the method development was to resolve chromatographic peaks for active drug ingredients with less asymmetric factor.
The mobile phase water : methanol : acetonitrile (30 : 60 : 10, v/v/v) was found to be satisfactory which gave two symmetric and well-resolved peaks for IBU and FAM. The retention time for IBU and FAM were 4.9 min and 6.8 min, respectively (Figure
Liquid chromatogram of IBU and FAM.
The calibration curve for IBU was found to be linear in the range of 2–20
Regression analysis of calibration curve.
Parameter | IBU | FAM |
---|---|---|
Linearity ( | 2–20 | 0.1–10 |
Correlation coefficient ( | 0.998 | 0.997 |
Slope of regression | 1973.26 | 25880.80 |
Standard deviation of slope | 14.97 | 29.47 |
Intercept of regression | 535.06 | 7544.28 |
Standard deviation of intercept | 2.96 | 0.30 |
Summary of validation parameters.
Parameters | IBU | FAM |
---|---|---|
Retention time (min) | 4.9 | 6.8 |
Detection limit ( | 0.65 | 0.033 |
Quantitation limit ( | 2 | 0.1 |
Accuracy (%) | 97.60–100.42% | 99.85–101.47% |
Precision (RSDa, %) | ||
Intraday precision | 0.75–0.93% | 0.72–0.94% |
Interday precision | 0.92–1.51% | |
Instrument precision (RSDa) | 0.58% | 0.47% |
aRSD is relative standard deviation, and ‘‘
The accuracy of the method was determined by calculating recoveries of IBU and FAM by method of standard addition. The recoveries were found to be 97.60–100.42% and 99.85–101.47% for IBU and FAM, respectively (Table
The detection limits for IBU and FAM were found to be 0.65
System suitability test was carried out, and the results are summarized in Table
System suitability parameter for the proposed method.
Parameter | IBU | FAM |
---|---|---|
Retention time (min) | 4.9 | 6.8 |
Theoretical plates | 4560 | 6400 |
Tailing factor | 1.3 | 0.8 |
Base width (sec) | 29.49 | 42.22 |
Stability of standard and sample solution of IBU and FAM were evaluated at room temperature for 24 hr. Both the drugs were found to be stable with a recovery of more than 97%.
The proposed method was successfully applied to the determination of IBU and FAM in their combined dosage form. The % recovery was found to be 100.01
Analysis of marketed formulation.
Formulations | Labelled | % Recoveryb | ||
Amount (mg) | ||||
IBU | FAM | IBU | FAM | |
A | 800 | 26.6 |
bmean value
The proposed study describes stability indicating LC method for the estimation of IBU and FAM combination in mixture. The method was validated and found to be simple, sensitive, accurate, and precise. The method was successfully used for determination of drugs in their pharmaceutical formulation.
The authors are thankful to Mercury pharmaceuticals Ltd., Baroda and Blue Cross Laboratory, Mumbai, India, for providing a gift sample of IBU and FAM, respectively. The authors are very thankful to Principal, Indukaka Ipcowala College of Pharmacy, New Vallabh, Vidyanagar, for providing necessary facilities to carry out research work.