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Simultaneous determination of pioglitazone and glimepiride in bulk drug and pharmaceutical dosage form by RP-HPLC method


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A simple, fast, and precise reverse phase, isocratic HPLC method was developed for the separation and quantification of pioglitazone and glimepiride in bulk drug and pharmaceutical dosage form. The quantification was carried out using Inertsil ODS (250 +/- 4.6 mm, 5 micro) column and mobile phase comprised of acetonitrile and ammonium acetate (pH 4.5; 20mM) in proportion of 60:40 (v/v). The flow rate was 1.0 ml/min and the effluent was monitored at 230 nm. The retention time of pioglitazone and glimepiride were 7.0+/-0.1 and 10.2+/-0.1 min respectively. The method was validated in terms of linearity, precision, accuracy, and specificity, limit of detection and limit of quantitation. Linearity of pioglitazone and glimepiride were in the range of 2.0 to 200.0 microg/ ml and 0.5-50microg/ ml respectively. The percentage recoveries of both the drugs were 99.85% and 102.06% for pioglitazone and glimepiride respectively from the tablet formulation. The proposed method is suitable for simultaneous determination of pioglitazone and glimepiride in pharmaceutical dosage form and bulk drug.
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Pak. J. Pharm. Sci., Vol.21, No.4, October 2008, pp.421-425 421
Department of Pharmaceutical Quality Assurance, Manipal College of Pharmaceutical Sciences, Manipal, India
A simple, fast, and precise reverse phase, isocratic HPLC method was developed for the separation and
quantification of pioglitazone and glimepiride in bulk drug and pharmaceutical dosage form. The quantification
was carried out using Inertsil ODS (250 × 4.6 mm, 5µ) column and mobile phase comprised of acetonitrile and
ammonium acetate (pH 4.5; 20mM) in proportion of 60:40 (v/v). The flow rate was 1.0 ml/min and the effluent
was monitored at 230 nm. The retention time of pioglitazone and glimepiride were 7.0±0.1 and 10.2±0.1 min
respectively. The method was validated in terms of linearity, precision, accuracy, and specificity, limit of
detection and limit of quantitation. Linearity of pioglitazone and glimepiride were in the range of 2.0 to
200.0µg/ml and 0.5-50µg/ml respectively. The percentage recoveries of both the drugs were 99.85% and
102.06% for pioglitazone and glimepiride respectively from the tablet formulation. The proposed method is
suitable for simultaneous determination of pioglitazone and glimepiride in pharmaceutical dosage form and
bulk drug.
Keywords: Pioglitazone, Glimepride, HPLC, method validation.
Pioglitazone is a thiazolidine Dione derivative. It is one of
the PPAR-alpha agonist, insulin sensitizer used to reduce
the insulin resistance. Pioglitazone (fig. 1) is chemically
[(±)-5-[[4-[2-[5-ethyl -2- pyridinyl) ethoxy] phenyl]-
methyl]-2,4-]thiazolidinedionemonohydro-chloride. Gli-
mepiride is a sulfonylurea urea derivative chemically-[[p-
phenyl] sulfonyl]-3-(trans-4-methylcyclohexyl) urea,
widely used in patients with type 2 diabetes (non-insulin-
dependent diabetes). The drugs are prescribed
individually as well as multi component dosage forms
available in the market. A number of methods have been
published for the estimation of the above said analytes.
Pioglitazone in human plasma (Venkatesh et al., 2007;
Xue et al., 2006 and Sripalakit et al., 2006) and HPLC
method for antidiabetic drugs (Yao et al., 2006; Jedlicka
et al., 2004 and Kolte et al., 2004) were reported. Method
for estimation of glimepiride in human plasma
(Chakradhar et al., 2007; Saleem et al., 2004) was
published. HPLC method for estimation of glimepiride
and related substances (Deep et al., 2005; Kovarikova et
al., 2004; Khan et al., 2005) were also reported in the
literature. Even though various methods were reported in
the literature for estimation of glimepiride and
pioglitazone individually or in combination with other
drugs no method had been reported for simultaneous
estimation of these two drugs using HPLC in bulk drug
and pharmaceutical dosage forms. The present study was
aimed at the simultaneous estimation of pioglitazone and
glimepiride by reverse phase HPLC method. The method
was validated according to the ICH (Q2A 1995)
Materials, reagents and chemicals
Pioglitazone and Glimepiride were obtained as gift
samples from Dr. Reddys Laboratories, Hyderabad.
Ammonium acetate and glacial acetic acid were A.R
grade from SD fine chemicals Mumbai. acetonitrile
HPLC grade from Merck chemicals, Mumbai.
Chromatographic condition: Water alliance 2695-
separation module with waters 2487 dual UV detector
was used. Millennium software version 4.0 s used for
Data acquisition .Inertsil ODS (25 cm × 4.6 mm, 5µ)
column was used as a stationary phase. Mobile phase
comprised of acetonitrile and 20mM ammonium acetate
buffer (60; 40 v/v) with pH adjusted to 4.5±0.2 was used.
Injection volume was 10µl and run time was 12min and
flow rate 1.0ml/min. The column was maintained at
ambient temperature and the eluent was detected at 230
Standard solutions
Standard stock solution (1000 µg/ml) of pioglitazone,
glimepiride were prepared separately in methanol. The
*Corresponding author: Fax: +91-820-2571998, e-mail:
Simultaneous determination of pioglitazone and glimepiride in bulk
Pak. J. Pharm. Sci., Vol.21, No.4, October 2008, pp.421-425
working standard solutions were prepared and further
diluted in mobile phase to contain a mixture of
pioglitazone and glimepiride in over the linearity range
from 2-200 µg/ml and 0.5-50 µg/ml respectively.
Assay in formulations
Twenty tablets, Pioryl, (Panacea Biotech), each
containing 15mg of pioglitazone and 2mg of glimepiride
were weighed and finely powdered. A quantity of powder
equivalent to 15mg of pioglitazone and 2mg of
glimepiride was weighed and transferred to a Standard
flask. The drug was diluted using methanol to get a
concentration of 10µg/ml of pioglitazone, 1µg/ml of
glimepiride. The contents were mixed thoroughly and
filtered through a 0.45 µ filter. 10µ of the sample was
injected in to HPLC system.
The proposed HPLC method required fewer reagents and
materials, and it is simple and less time consuming. This
method could be used in quality control test in
pharmaceutical industries. The chromatograms of
pioglitazone and glimepiride were shown in (fig. 4).
There was clear resolution between pioglitazone and
glimepiride with retention time of 7.0 and 10.2 minutes
Validation of the method
The response for the detector was determined to be linear
over the range of 2 to 200µg/ml (2, 5, 10, 25, 50, 100,
200) for pioglitazone and 0.5-50µg/ml (0.5, 1, 2, 5, 10,
25, 50) for glimepiride. Each of the concentration was
injected in duplicate to get reproducible response. The
calibration curve was plotted as concentration of the
respective drug versus the response at each level. The
proposed method was evaluated by its correlation
coefficient and intercept value calculated in the statistical
study. They were represented by the linear regression
equation (figs. 2, 3).
Y Pioglitazone = 27494X+32335, ‘r’ value= 0.9995
Y Glimepiride = 37719X-3261, ‘r’ value= 0.9987
Slopes and intercepts were obtained by using regression
equation (y=mx+c) and least square treatment of the
results used to confirm linearity of the method developed.
Precision and accuracy
The accuracy of the method was determined by recovery
experiments. The recovery studies were carried out 6
times and the percentage recovery and % relative standard
deviation was calculated. From the data obtained,
recoveries of standard drugs were found to be accurate
(table 1).
The %CV of interday and intraday precision obtained was
less than 1% for both the drugs. The intraday and interday
precision of pioglitazone was 0.47 and 0.86 and
glimepiride was 0.76 and 0.94 respectively. From the data
obtained, the developed HPLC method was found to be
precise and accurate.
Specificity of the method
The PDA chromatograms of the pioglitazone and
glimepiride in standard and sample were recorded. In the
chromatograms of the formulations, some additional
peaks were observed which may be due to excipients
present in the formulations. These peaks however did not
interfere with the standard peaks, which demonstrate that
the assay method is specific. Furthermore, the purity of
the peaks was studied by peak purity studies. The results
revealed that the peak is free from interferences, which
shows that the HPLC method is specific.
Quantification limit
The limit of detection (LOD) and limit of quantification
(LOQ) of the developed method determined by injecting
progressively low concentrations of the standard solutions
using the developed methods. The LOD is the lowest
concentration of the analyte that can be detected with
signal to noise ratio (1:3) and LOQ is the lowest
concentration that can be quantified with acceptable
precision and accuracy with signal to noise ratio (1:10).
The LOD of pioglitazone and glimepiride found to be
0.2µg/ml and 0.1µg/ml respectively. The LOQ of
pioglitazone and glimepiride found to be 2µg/ml and
0.5µg/ml respectively
Table 1: Recovery studies
Name of the Drug Spiking level
(%) Amount added
(µg/ml) n=3
80 8 7.89 98.63
100 10 10.21 102.1
Pioglitazone 120 12 11.86 98.83
80 0.8 0.82 102.5
100 1 1.02 102
Glimepiride 120 1.2 1.22 101.67
Karthik A et al.
Pak. J. Pharm. Sci., Vol.21, No.4, October 2008, pp.421-425 423
The robustness of the method was studied by deliberate
changes in the method like alteration in pH of the mobile
phase, percentage organic content, changes in the
wavelength. It was observed that there was no marked
changes in the chromatograms demonstrate that the HPLC
methods have developed are robust.
Solution Stability
In this study, the mobile phase, the standard solutions, and
the sample solution were subjected to long term (3 days)
stability studies. The stability of these solutions was
studied by performing the experiment and looking for
changes in separation, retention, and asymmetry of the
peaks which were then compared with the pattern of the
chromatogram of freshly prepared solutions.
System suitability
The resolution, capacity factor, theoretical plates/meter,
Rt values and peak symmetry were calculated for the
standard solutions. The values obtained demonstrated the
suitability of the system for the analysis of the above drug
combinations System suitability parameters might be fall
within ± 3% standard deviation range during routine
performance of the method. The summary of the method
validation results were showed in the (table 2).
Table 2: Summary of analytical method validation
Validation parameters Pioglitazone Glimepiride
Recovery (%) 99.85 102.06
Intraday precision (%CV) 0.47 0.76
Interday precision (%CV) 0.86 0.94
Linearity (r2) 0.9995 0.9987
Robustness (%CV) 0.66 0.82
LOD(µg/ml) 0.2 0.1
LOQ ( µg/ml) 2 0.5
Specificity Passed Passed
Fig. 1: Chemical structures of (a) Pioglitazone (b) Glimepiride
0 50 100 150 200 250
Fig. 2: Calibration curve of pioglitazone
Simultaneous determination of pioglitazone and glimepiride in bulk
Pak. J. Pharm. Sci., Vol.21, No.4, October 2008, pp.421-425
This method is simple, specific and easy to perform and
requires short time to analyze the samples. Low limit of
quantification and limit of detection makes this method
suitable for use in quality control. This method enables
simultaneous determination of Pioglitazone and
Glimepiride because of good separation and resolution of
the chromatographic peaks. The method was found to be
accurate, precise, linear, robust and rugged.
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Conc ( µg/mL)
Fig. 3: Calibration curve of glimepiride.
1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 12.0
Piogli - 7.029
Glimi - 10.171
Fig. 4: Typical chromatogram of pioglitazone and glimepiride
Karthik A et al.
Pak. J. Pharm. Sci., Vol.21, No.4, October 2008, pp.421-425 425
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... Studies demonstrated that the combination treatment of pioglitazone with glimepiride can have a dual action of glycemic control and improving the body's lipid profile and lowering cardiovascular risk [20]. Literature data reported a fewer number of analytical methods for quantitative analysis of PIO and GLM involving spectrophotometric methods (oxidative coupling and chemometric techniques) [21,22], native spectrofluorimetry [23], LC/ tandem mass in human plasma [24] and RP-HPLC [25][26][27][28][29]. ...
... No interference from excipients was observed which proved the applicability of the proposed method as shown in Figs. 2, 3, 4, 5 and 6. The results of the analysis of pharmaceutical tablets were compared to the results of the reported methods [18,27,43,44] by statistical tests which showed no significant difference as shown in Table 6. ...
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A novel, sensitive, and green micellar UPLC method was proposed and validated for the simultaneous determination of four hypoglycemic agents used in type II diabetes mellitus treatment namely, pioglitazone, alogliptin, glimepiride, and vildagliptin. The developed UPLC method was successfully applied for quantitative analysis of these drugs in bulk, in pharmaceutical formulations, and in spiked human plasma. Chromatographic separation was carried out on a Kinetex® 1.7 μm XB-C18 100 Å (50 × 2.1 mm) column, using a degassed and filtered mixture of (0.1 M SDS- 0.3% triethyl amine- 0.1% phosphoric acid (pH 6)) and n-propanol (85:15 v/v), at a flow rate of 0.2 mL/min. The experimental conditions of the suggested method were well investigated and optimized. The newly developed micellar UPLC method is capable of determining different dosage forms at the same time with the same solvents, saving time and effort. The method was found to be efficiently applicable in spiked human plasma and could be extended to study the pharmacokinetics of the cited drugs in real human plasma samples. The greenness of the developed method was evaluated by applying the Eco-scale scoring tool, which verified the excellent greenness of the analytical method.
... Similarly, a DoE-based simultaneous estimation method available for anti-diabetic drugs including MET, PIO, glibenclamide, and repaglinide on the C 8 column [17]. In connection with literature and our previous experience, developing simultaneous HPLC methods for anti-diabetic drugs involve numerous trials in optimization of method variables such as buffer type, pH, column, and mobile phase composition [18]. Overall, from the literature, we found that C 18 column is most suitable for all diabetic drugs except for metformin. ...
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This work emphasized the use of the quantitative structure–retention relationship (QSRR) approach in the prediction retention time of anti-diabetic drugs on C18 column in the HPLC method development process. This in silico QSRR study utilized a data set from literature and in-house studies for the development of better predictive model. A total of 11 QSRR models were developed and narrowed to 5 candidate models using a mobile phase composition range. The candidate models 1, 2, 3, 4, and 5 showed R² scores of 0.8844, 0.8968, 0.8996, 0.9769, and 0.9916, respectively. The model validation data revealed that support vector model (SVM)-based models 4 and 5 showed better predictive ability (> 99%) than the random forest model. The R² value for capacity factor prediction for models 4 and 5 was 0.862 and 0.881, respectively. Accordingly, the experimental retention time of pioglitazone, glimepiride, gliclazide, glyburide, and metformin was experimentally verified. Accordingly, we demonstrated good correlation (R² > 0.9) between experimental and predictive retention time on C18 column. Based on prediction, a new HPLC method was optimized for the simultaneous analysis of pioglitazone (3.6 ± 0.2 min) and glimepiride (6.1 ± 0.2 min) on C18 column using a mobile phase consisting of methanol and 0.1% ortho phosphoric acid (pH 2.7) with detection at 227 nm. The respective % retention prediction error was 0.2% and 6.3% for pioglitazone and glimepiride. The method demonstrated the linearity with regression coefficients of 0.9985 and 0.9998, respectively, for pioglitazone (15–75 µg/mL) and glimepiride (2–10 µg/mL). The % RSD (0.77–1.43%) and % accuracy (98.01–102.39%) of the method were acceptable. The method has proven specificity in the presence of degradation products and demonstrated robustness (< 2%RSD) to critical method parameters.
... A review of the literature revealed that the pharmaceutical drugs under investigation were officially listed in both the BP and the USP [15,16]. Furthermore, numerous reports using RP-HPLC to analyze these drugs separately or in combination have been published [17,18,[27][28][29][30][31][19][20][21][22][23][24][25][26]. ...
Various antidiabetic combinations have recently been used to improve the management of type II diabetes mellitus. The first time a totally green mixed micellar LC method was used to analyze the biguanide metformin (MET) in a mixture with two sulfonylurea antidiabetics, glipizide (GPZ) and glimepiride (GLM), as well as pioglitazone (PGZ) as a thiazolidinedione derivative antidiabetic and repaglinide (RPG) as an insulin secretagogue antidiabetic. Response surface methodology (RSM) was used to optimize the method by using central composite design (CCD). The design space that represents the robustness zone was identified. Analytes were separated by elution of an aqueous mobile phase containing Brij-35 (12.05 mM) and SDS (76.25 mM) at pH 3.72 on a Symmetry C18 column (75*4.6 mm, 3.5 m) at a flow rate of 1 mL/min and UV detection at 225 nm and 210 nm, respectively, for MET and the other analytes. The laboratory mixtures and pharmaceutical products of the examined drugs were successfully determined using the established method. Using the Green Analytical Procedure Index (GAPI) and Analytical Greenness Metric (AGREE) principles, the greenness of the created method was analyzed and compared to previously reported methods. In comparison to previous methods, the new method was shown to be more efficient and effective.
... A review of the literature revealed that the pharmaceutical drugs under investigation were officially listed in both the BP and the USP [15,16]. Furthermore, numerous reports using RP-HPLC to analyze these drugs separately or in combination have been published [17,18,[27][28][29][30][31][19][20][21][22][23][24][25][26]. ...
A simple, specific, and quantitative high-performance thin-layer chromatography method has been developed for the simultaneous determination of Glimepiride and 3-acetyl-11-keto-beta-boswellic acidin the formulation. Chromatographic development was performed using n-hexane: Ethyl acetate: Toluene: Glacial acetic acid (4:2:4:0.2, % v/v/v/v) as optimized mobile phase on TLC aluminum plate precoated withsilica gel 60 F254 and further densitometric measurement at 242nm.The drugs were satisfactorily resolved with Rfvalues of 0.38±0.02, 0.65±0.02, for Glimepiride and 3-acetyl-11-keto-beta-boswellic acid, respectively. The linear ranges were found to be 100-600 and 4000-24000ng/band for Glimepiride and 3-acetyl-11-keto-beta-boswellic acid. The accuracy and precision measured were less than 2% relative standard deviation for both drugs. The sensitivity of the method in terms of limit of detection and limit of quantitation were found to be 11.22 and 34ng/band for Glimepiride and 439.92 and 1333.102ng/band for 3-acetyl-11-keto-beta-boswellic acid respectively. 24-1 fractional factorial design was applied for robustness study to evaluate the small difference in independent variables. Among four factors, the significant factor found was the volume of n-hexane that resulted in a change in the Rf of drugs. The proposed method was found to be accurate, precise, reproducible, robust, and specific.
Among special therapeutic options, anti-inflammatory treatment using topical glucocorticosteroids (TCS) or topical calcineurin inhibitors (TCI) are core elements. Antimicrobial therapy using preferably antiseptics can help against microbial colonization or infection. Antipruritic therapy includes also systemic antihistamines although with limited evidence. New topical substances include phosphodiesterase inhibitors and opioid receptor antagonists.Phototherapy with UVB or UVA1 is often used. Allergen-specific immunotherapy (ASIT) has no routine place however has been tried successfully in some studies.Greatest progress has been made in new immunomodulatory therapy already beyond immunosuppressives like ciclosporin A, methotrexate, azathioprine, or mycophenolate.Inhibitors of the janus kinase (JAK) are registered, as well as specific biologics like anti-interleukin 4/interleukin 13 (Dupilumab) or interleukin 13 (Tralokinumab). With anti-interleukin 31 (Nemolizumab), new antipruriginous strategies may be possible. Besides pharmacotherapy, also psychosomatic counseling and behavioral therapy have been proven helpful. Few diseases are characterized by the use of so many unconventional procedures like atopic eczema. Most of them have limited or no proven efficacy, but are very popular with the patients. Among “alternative” strategies for phytotherapeutic approaches, acupuncture may be tried. There was no effect in several controlled trials for bioresonance, homeopathy, or kinesiology. There is a high degree of placebo responders in controlled clinical trials in atopic eczema possibly due to a high suggestibility in this disease.KeywordsAnti-inflammatory treatmentTopical glucocorticoidsTopical calcineurin inhibitorsSystemic immunomodulatorsJAK inhibitorsBiologicsDupilumabTralokinumabUnconventional procedures
An assortment of lifestyle and genetic characteristics contribute to the eventual appearance of type 2 diabetes. Diabetes can be triggered by a variety of drugs and other health issues. Five anti�diabetic medications, Metformin, Glimepiride, Canagliflozin, Pioglitazone, and Sitagliptin, were identified for simultaneous evaluation in their synthetic mixtures applying multivariate calibra�tion models Principal Component Regression (PCR) and Partial Least Square (PLS-2) to resolve the extensively overlapping spectrum. For extracting important information and enhancing the accuracy of the techniques, both techniques were used for deciding on the variables. The most beneficial spectral ranges and com�binations were identified by considering the least values of the Correlation Coefficient (R2 ≥ 0.9998), the Root Mean Square Error of Prediction (RMSEP) values between (0.02782–0.08277), and the Relative Error of Prediction (SEC) values between (0.20693–0.90161). The two multivariate calibration approaches were successful in determining all five compo�nents in their quinary mixture simultaneously. As a result, the suggested techniques can easily be employed without a separation stage and effectively implemented in pharmaceutical formulation evaluation. In addition, statistical assessments between the suggested chemometric techniques and the reference revealed no significant differences. Furthermore, the suggested techniques succeeded in the guidelines of green analytical chem�istry, and their eco-friendliness was assessed using four tools, namely, the Analytical Eco-Scale, the National Environmental Methods Index (NEMI), the Green Analytical Procedure Index (GAPI), and the Analytical Greenness Metric (AGREE), which confirmed the proposed methods' eco-friendliness. In addition, the newly generated Red-Green-Blue (RGB12 paradigm) was em�ployed to investigate the whiteness properties. The suggested methods' acceptable observations, as well as their long-term sustainability, straightforwardness, cost-effectiveness, and inexpensive cost, stimulate adoption in quality control laboratories
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Objective: An efficient, high performance liquid chromatographic method has been developed and validated for the quantification of related substances in pioglitazone hydrochloride drug substance. Methods: This method includes the determination of three related substances in pioglitazone hydrochloride. The mobile phase A is 0.1% w/v triethylamine in water with pH 2.5 adjusted by dilute phosphoric acid. The mobile phase B is premixed and degassed mixtures of acetonitrile and methanol. The flow rate was 1 ml/min. The elution used was gradient mode. The HPLC column used for the analysis was symmetry C18 with a length of 250 mm, internal diameter of 4.6 mm and particle size of 5.0 microns. Results: The developed method was found to be linear with the range of 0.006-250% with a coefficient of correlation 0.99. The precision study revealed that the percentage relative standard deviation was within the acceptable limit. The limit of detection and limit of quantitation of the impurities was less than 0.002%and 0.006% with respect to pioglitazone hydrochloride test concentration of 2000 µg/ml respectively. This method has been validated as per ICH guidelines Q2 (R1). The specificity, solution stability and robustness of the method show that the impurity PGR-II and PIO-II were process related impurities and N-oxide was degradation impurity. This indicates that the equipment was suitable, accurate, precise, sensitive and fit for study. Conclusion: A reliable, economical HPLC method was magnificently established for quantitative analysis of related substances of pioglitazone hydrochloride drug substance.
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A high percentage of marketed drugs suffer from poor water solubility and require an appropriate technique to increase their solubility. This study aims to compare physically modified and unmodified gum polymers extracted from Ziziphus spina-christi fruits as solid dispersion carriers for some drugs. Taguchi Orthogonal Design (L9) was chosen for the screening and optimization of the solid dispersions. The design has four factors: type of drug, type of polymer, type of solid dispersion process, and drug to polymer ratio. Each factor was varied in three stages and the total number of runs was 9 in triplicate. The polymer was physically modified by heating (M1ZG) or freeze-drying (M2ZG). The drugs were selected according to the biopharmaceutical classification system, namely loratadine and glimepiride (class II) and furosemide (class IV). Drugs were dispersed in the polymer in three different ratios 1: 1, 1: 2, and 1: 3. Solid dispersions were made by co-grinding, solvent evaporation, and kneading methods. Modified and unmodified polymers were characterized in terms of their organoleptic properties, solubility, powder flowability, density, viscosity, swelling index, and water retention capacity. Solid dispersions were characterized in terms of percentage practical yield, solubility improvement, and drug compatibility. The results showed that the organoleptic properties of polymers were not changed by the gum modification. The swelling index of the polymer was doubled in M1ZG. The viscosity and water retention capacity of the polymer was increased in both modified polymers. All solid dispersions showed a high practical percentage yield of more than 93%, the higher values being more associated with loratadine and furosemide than with glimepiride. The improvement in solubility was observed in all solid dispersions prepared, the values varying with the pH of the medium and the method of modification. The FTIR results indicated that there was no chemical interaction between these drugs and the polymer used. Analysis of the results according to the Taguchi orthogonal design indicated 51 folds aqueous solubility enhancement for loratadine using M2ZG polymer at a ratio of 1: 3 of Drug: polymer. This study showed the possibility of improving the solubility of other poorly soluble drugs.
Simple, accurate, and precise four spectrophotometric methods were developed and validated for simultaneous determination of glimepiride and pioglitazone hydrochloride in their pharmaceutical formulation. The first spectrophotometric method was the dual-wavelength which determined glimepiride at 219.0 and 228.0 nm and pioglitazone hydrochloride at 268.0 nm. The second one is the first derivative of ratio spectra (DD1) spectrophotometry in which the peak amplitudes were used at 238.0 nm and 268.0 nm for glimepiride and pioglitazone hydrochloride, respectively. The third method is ratio subtraction in which glimepiride was determined at 228.0 nm in the presence of pioglitazone hydrochloride which was determined by extended ratio subtraction at 268.0 nm. The fourth method was the ratio difference to determine glimepiride and pioglitazone hydrochloride. Beer’s law was confirmed in the concentration range 2.50–15.00 µg mL-1, and 10.00–50.00 µg mL-1 for glimepiride and pioglitazone respectively for the four methods. The proposed methods were used to determine both drugs in their pure powdered form with mean percentage recoveries of 99.91 ± 1.117% for glimepiride and 99.76 ± 0.911% for pioglitazone hydrochloride in method (A). In method (B), the mean percentage recoveries were 100.12 ± 0.89% for glimepiride and 100.02 ± 1.06% for pioglitazone hydrochloride. In method (C) glimepiride was 100.01 ± 0.592% and 99.85 ± 0.845% for pioglitazone hydrochloride by extended ratio subtraction. And finally, in method (D) the mean percentage recoveries were 100.66 ± 0.670% for glimepiride and 99.92 ± 0.988% for pioglitazone hydrochloride. The developed methods were successfully applied for the determination of glimepiride and pioglitazone hydrochloride in pure powder and dosage form. The suggested methods were also used to determine both compounds in laboratory-prepared mixtures. The accuracy, precision, and linearity ranges of the developed methods were determined. The results obtained were compared statistically with the official method, and there was no significant difference between the proposed methods and the official method for accuracy and precision.
A simple, high throughput, direct-injection high-performance liquid chromatography tandem mass spectrometry method (LC/MS/MS) has been developed and validated for the quantitation of pioglitazone in human serum. After mixing the internal standard with a sample, a 10 microl portion of the mixture was directly injected into a high-flow LC/MS/MS system, which included an extraction column, an analytical column and a six-port switching valve. The on-line extraction was achieved on an Oasis HLB column (1 mm x 50 mm, 30 microm) with a 100% aqueous loading mobile phase containing 5 mM ammonium acetate (pH 4.0) at a flow rate of 4 ml/min. The extracted analyte was eluted by a mobile phase which contained 5 mM ammonium acetate and acetonitrile. The analytical column was a Luna C18 column (4.6 mm x 50 mm, 5 microm). Detection was achieved by positive ion electrospray tandem mass spectrometry. The lower limit of quantitation of the method was 9 ng/ml. The standard curve, which ranged from 9 to 1350 ng/ml, was fitted by a weighted (1/x2) quadratic regression model. The validation results demonstrated that this method had satisfactory precision and accuracy across the calibration range. There was no evidence of instability of the analyte in human serum following three freeze-thaw cycles, and samples could be stored for at least 2 weeks at -30 degrees C. This method was used to analyze pioglitazone concentrations in human serum samples from a bioequivalence study of a blinded Actos formulation (encapsulated 15 mg tablet) and an Actos 15 mg tablet. The blinded formulation was shown to be bioequivalent to an Actos 15 mg tablet.
A simple, rapid, and precise method is developed for the quantitative simultaneous determination of metformin and pioglitazone in a combined pharmaceutical-dosage form. Separation is achieved with a Zorbax XDB C(18), 15-cm analytical column using buffer-acetonitrile (66:34, v/v) of pH 7.1, adjusted with orthophosphoric acid as the mobile phase. The buffer used in the mobile phase contains 10mM disodium hydrogen phosphate and 5mM sodium dodecyl sulphate in double-distilled water. The instrumental settings are flow rate of 1 mL/min, column temperature at 40 degrees C, and detector wavelength of 226 nm. The internal standard method is used for the quantitation of the ingredients of this combination. Methylparaben is used as an internal standard. The method is validated and shown to be linear for metformin and pioglitazone. The correlation coefficients for metformin and pioglitazone are 0.9991 and 0.9999, respectively. The relative standard deviations for six replicate measurements in two sets of each drug in the tablets are always less than 2%.
A reversed-phase gradient HPLC method was developed for the evaluation of pioglitazone hydrochloride (PG-HCl) in tablets. Limit of detection for PG-HCl was found to be 42 ng/ml. Analyses were performed on a C18 column (Symmetry C18, 5 microm, 250 x 4.6 mm), mobile phase was a mixture of ammonium formate buffer adjusted with formic acid to pH 4.1 and acetonitrile. Shortened purity method was used as the assay method. Methods were validated.
Glimepiride is a modern hypoglycaemic agent, which belongs to the group of sulfonylurea derivates. In this paper, simple, specific and accurate RP-HPLC method was developed in order to study decomposition of glimepiride under the hydrolytic stress conditions (acid, neutral, alkaline and oxidative). The best separation of glimepiride and its degradation products was achieved on reverse phase C18 column. The mobile phase was composed of acetonitrile-phosphate buffer (pH 3.5, 0.03 M) (48:52, v/v). Employing RP-HPLC method, five main degradation products were detected in the exposed samples. It was found that the susceptibility of glimepiride to hydrolytic decomposition increased in following manner: neutral condition < alkaline condition < acid condition < oxidative condition.
Five impurities in glimepiride drug substance were detected and quantified using a simple isocratic reverse phase HPLC method. For the identification and characterization purpose these impurities were isolated from a crude reaction mixture of glimepiride using a normal phase HPLC system. Based on the spectroscopic data like NMR, FTIR, UV and MS these impurities were characterized and used as impurity standards for determining the relative response factor during the validation of the proposed isocratic reverse phase HPLC method. The chromatographic separation was achieved on a Phenomenex Luna C8 (2) 100 A, 5 microm, 250 mm x 4.6 mm using a mobile phase consisting of phosphate buffer (pH 7.0)-acetonitrile-tetrahydrofuran (73:18:09, v/v/v) with UV detection at 228 nm and a flow rate of 1 ml/min. The column temperature was maintained at 35 degrees C through out the analysis. The method has been validated as per international guidelines on method validation and can be used for the routine quality control analysis of glimepiride as active pharmaceutical ingredient (API).
This paper describes a convenient method for the separation and simultaneous determination of six anti-diabetic drugs viz., glibenclamide (GLB), gliclazide (GLC), glipizide (GLZ), pioglitazone (PGL), repaglinide (RPG) and rosiglitazone (RGL) in pharmaceutical formulations. Also, the assay has been shown applied to support quantification of the six anti-diabetic drugs in human plasma. The analytes were either injected directly onto the column after suitable dilution (pharmaceutical formulation analysis) or a simple extraction procedure, using acetonitrile, from human plasma spiked with anti-diabetic drugs and internal standard (IS). Ternary gradient elution at a flow rate of 1 mL/min was employed on an Intertisl ODS 3V column (4.6 x 250 mm, 5 microm) at ambient temperature. The mobile phase consisted of 0.01 m formic acid (pH 3.0), acetonitrile, Milli Q water and methanol. Celecoxib was used as an IS. The six anti-diabetic drugs were monitored at a wavelength of 260 nm. The nominal retention times of RGL, PGL, GLZ, GLC, GLB, IS and RGL were 11.4, 13.3, 14.8, 17.6, 20.78, 22.1 and 25.4 min, respectively. The assay developed for formulation analysis was found to be accurate and precise. The calibration curves ranged from 0.1 to 100 microg/mL for all analytes with the exception of GLB, where the range was 0.3-100 microg/mL. The plasma assay was validated for parameters such as specificity, accuracy and extraction recovery. The proposed method is simple, selective and can be extended for routine analysis of anti-diabetics in pharmaceutical preparations and in biological matrices.
An analytical method based on high-performance liquid chromatography (HPLC) with ultraviolet detection (269 nm) was developed for the determination of pioglitazone in human plasma. Rosiglitazone was used as an internal standard. Chromatographic separation was achieved with a reversed-phase Apollo C18 column and a mobile phase of methanol-acetonitrile-mixed phosphate buffer (pH 2.6; 10mM) (40:12:48, v/v/v) with a flow rate of 1.2 ml/min. The calibration curve was linear over the range of 50-2000 ng/ml (r(2)>0.9987) and the lower limit of quantification was 50 ng/ml. The method was validated with excellent sensitivity, accuracy, precision, recovery and stability. The assay has been applied successfully to a pharmacokinetic study with human volunteers.
This work presents a fast method for the simultaneous separation and determination of glimepiride, glibenclamide, and two related substances by RP LC. The separation was performed on a Chromolith Performance (RP-18e, 100 mm x 4.6 mm) column. As mobile phase, a mixture of phosphate buffer pH 3, 7.4 mM, and ACN (55:45 v/v) was used. Column oven temperature was set to 30 degrees C. The total chromatographic run time was 80 s. This was achieved using a flow program from 5 to 9.9 mL/min. Precisions of the interday and the intraday assay for both retention times and peak areas for the four analyzed compounds were less than 1.2%. The method showed good linearity and recovery. The short analysis time makes the method very valuable for quality control and stability testing of drugs and their pharmaceutical preparations.
Pharmaceutical counterfeiting is becoming a serious problem in the world, especially in developing countries including China. Herein an isocratic reversed-phase high performance liquid chromatography (RP-HPLC) method was developed for screening counterfeit medicines and adulterated dietary supplement products. The developed method could be employed to separate and determine simultaneously six anti-diabetic drugs (glipizide, gliclazide, glibenclamide, glimepiride, gliquidone, repaglinide) on an isocratic solvent system using an Alltima C18 column (5 microm, 150 mmx4.6 mm) with an isocratic mobile phase of methanol-phosphate buffer (pH 3.0; 0.01 mol/L) (70:30, v/v), at a flow rate of 1.0 mL/min and at a wavelength of 230 nm. The proposed method was successfully applied to the analysis of medicinal and dietary supplement samples purchased from the local market in China.
A sensitive and specific liquid chromatography-positive electrospray ionization-tandem mass spectrometry method has been developed and validated for the determination of glimepiride (GPD) in human plasma. GPD and the internal standard (IS, glibenclamide) were extracted from a small aliquot of human plasma (200 microL) by a simple liquid-liquid extraction technique using ethyl acetate as extraction solvent. The compounds were separated on a YMC Propack, C18, 4.6x50 mm column using a mixture of ammonium acetate buffer, acetonitrile and methanol (30:60:10, v/v) as mobile phase at 0.5 mL/min on an API 4000 Sciex mass spectrometer connected to an Agilent HPLC system. Method validation and pre-clinical sample analysis was performed as per FDA guidelines and the results met the acceptance criteria. GPD and IS were detected without any interference from human plasma matrix. The method was proved to be accurate and precise at linearity range of 0.02-100.00 ng/mL with a correlation coefficient of 0.999. The method was robust with a lower limit of quantitation of 0.02 ng/mL. Intra- and inter-day accuracies for GPD were 88.60-113.50 and 96.82-103.93%, respectively. The inter-day precision was better than 12.21%. This method enabled faster and reliable determination of GPD in a pre-clinical study.