Development and Validation of Four Spectrophotometric Methods for Assay of Rebamipide and its Impurity: Application to Tablet Dosage Form.

BACKGROUND: Rebamipide (REB) is quinolinone derivative compound, which is used for the treatment of stomach ulcers. OBJECTIVE: The development of four spectrophotometric methods for quantification of REB and its impurity and degradation product: the debenzoylated isomer of REB (DER). METHODS: Method A is ratio difference spectrophotometry where 254 and 291 nm were selected for REB and 320 and 355 nm were selected for DER, allowing spectral discrimination for both. Method B is derivative ratio spectrophotometry, where the peak amplitudes of the first derivative of ratio spectra at 261 and 350.2 nm for REB and DER, respectively, are determined. Method C is a second derivative approach, which allows quantification of both REB and DER at 337 and 340 nm, respectively. Method D is mean centering of ratio spectra, where electronic absorption spectra of REB and DER were recorded and divided by a suitable divisor from DER and REB, respectively, and then the mean center is represented by the ratio spectrum so obtained. RESULTS: The proposed methods are simple, selective, and sensitive in the quantification of REB and DER. These methods were validated according to International Conference on Harmonization guidelines. Statistical analyses performed on the findings from the suggested methods and those obtained from reported methods revealed high accuracy and good precision. CONCLUSION: The developed and validated methods are useful for quality control assay in routine analyses. HIGHLIGHTS: First derivative, second derivative, derivative ratio, and mean centering methods for quantification of REM and DER. These methods are useful for analysis of REB in pharmaceutical dosage form.

Separation and Determination of Diflunisal and its Impurity by Two Chromatographic Methods: TLC-Densitometry and HPLC.

BACKGROUND: Diflunisal (DIF) has analgesic and anti-inflammatory activity. It is a pharmacopeial drug found in the British Pharmacopoeia (BP), and its major pharmacopeial impurity is biphenyl-4-ol (BPL). OBJECTIVE: DIF has not previously been determined together with BPL. The presence of BPL could significantly affect the dose of DIF in its dosage forms; hence it is crucial to determine DIF and BPL in each other's presence. METHODS: TLC is the first proposed method, where DIF and BPL were separated on silica gel TLC F254 plates. The eluent was toluene-acetone-acetic acid solution (3.5:6.5:1, v/v). Reversed-phase (RP) HPLC is the second suggested method, where a mixture of DIF and BPL was separated on a C18 (5 µm ps, 250 mm and 4.6 id) column using phosphate buffer pH 4 (0.05 M)-acetonitrile (40:60, v/v). Detection was carried out at 254 nm in both methods. RESULTS: For the TLC method, concentration ranges of 0.5-3 and 0.3-1.7 µg/band were used, with mean percentage recoveries of 100.22% (SD 0.893) and 100.52% (SD 0.952) for DIF and BPL, respectively. The RP-HPLC method was carried out over a concentration range of 5-30 and 2-9 µg/mL, with mean percentage recoveries of 100.10% (SD 1.259) and 98.88% (SD 0.822) for DIF and BPL, respectively. CONCLUSION: The TLC and RP-HPLC methods were successfully applied for the determination of DIF and BPL, quantitatively, whether in bulk powder or in pharmaceutical formulations. HIGHLIGHTS: Two chromatographic methods were developed and validated according to International Council on Harmonization guidelines for the assay of DIF and its pharmacopeial impurity.

Development and validation of a stability indicating RP-HPLC-DAD method for the determination of bromazepam.

A reliable, selective and sensitive stability-indicating RP-HPLC assay was established for the quantitation of bromazepam (BMZ) and one of the degradant and stated potential impurities; 2-(2-amino-5-bromobenzoyl) pyridine (ABP). The assay was accomplished on a C18 column (250 mm × 4.6 mm i.d., 5 µm particle size), and utilizing methanol-water (70: 30, v/v) as the mobile phase, at a flow rate of 1.0 ml min-1. HPLC detection of elute was obtained by a photodiode array detector (DAD) which was set at 230 nm. ICH guidelines were adhered for validation of proposed method regarding specificity, sensitivity, precision, linearity, accuracy, system suitability and robustness. Calibration curves of BMZ and ABP were created in the range of 1-16 µg mL-1 with mean recovery percentage of 100.02 ± 1.245 and 99.74 ± 1.124, and detection limit of 0.20 µg mL-1 and 0.24 µg mL-1 respectively. BMZ stability was inspected under various ICH forced degradation conditions and it was found to be easily degraded in acidic and alkaline conditions. The results revealed the suitability of the described methodology for the quantitation of the impurity (ABP) in a BMZ pure sample. The determination of BMZ in pharmaceutical dosage forms was conducted with the described method and showed mean percentage recovery of 99.39 ± 1.401 and 98.72 ± 1.795 (n = 6), respectively. When comparing the described procedure to a reference HPLC method statistically, no significant differences between the two methods in regard to both accuracy and precision were found.

Does Intra-Articular Injection of Platelet-Rich Plasma Have an Effect on Cartilage Thickness in Patients with Primary Knee Osteoarthritis?

OBJECTIVES: To determine the effect of intra-articular injection of platelet-rich plasma (PRP) in patients with primary knee osteoarthritis (OA) by clinical evaluation and ultrasonographic (US) assessment of cartilage thickness. PATIENTS AND METHODS: A total of 100 patients with mild to severe primary knee OA using the Kellgren- Lawrence (K-L) grading scale were included and divided into two groups. Group I included 50 patients who were given two intra-articular knee injections of PRP, 1 week apart; Group II included 50 patients who received non-steroidal anti-inflammatory drugs (NSAIDs) and chondroprotective drugs. Functional assessment of all OA patients was done using the basal WOMAC score, at 2 and 6 months. US assessment of femoral condylar cartilage thickness was conducted basally and at 6 months. RESULTS: Improvement of WOMAC score was observed at 2 and 6 months in Group I following PRP injection compared to Group II (p values < 0.001), The improvement of WOMAC in Group I occurred in all severity degrees of OA (p < 0.001). Moreover, a significant increase in cartilage thickness was found at the intercondylar area (ICA) at 6 months relative to baseline assessment by US in Group I (p = 0.041). CONCLUSION: Treatment with PRP injections can reduce pain and improve knee function in patients with various degrees of articular degeneration. Further studies are needed to clarify the anabolic effect of PRP on the articular cartilage.

Ecologically evaluated and FDA-validated HPTLC method for assay of pregabalin and tramadol in human biological fluids.

The introduced research presents a novel in vivo quantitative method for assay of mixtures of pregabalin and tramadol as a common combinations approved for treatment of neuropathic pain. Green analytical chemistry is a recently emerging science concerned with control of the use of chemicals harmful to the environment in various analytical methods. Consequently, a green high-performance thin layer chromatography (HPTLC) method was achieved for determination of the mixture in human plasma and urine satisfying both analytical and environmental standards. The separation was achieved on HPTLC sheets using a separating mixture of ethanol-ethyl acetate-acetone-ammonia solution (8:2:1:0.05, by volume) as a mobile phase. The sheets were dried in air then scanned at two wavelengths. For tramadol, 220 nm was chosen; however, pregabalin is an unconjugated drug, so its determination was a challenge. Hence for pregabalin, the plates were sprayed with ethanolic solution of ninhydrin (3%, w/v), to obtain a conjugated complex, which could be assessed at 550 nm. Furthermore, the developed method fulfilled the US Food and Drug Administration validation guidelines, and proved to be useful in therapeutic drug monitoring of this combination. The Eco-scale assessment protocol was implemented to determine the greenness profile of the applied method.

US FDA-validated green GC-MS method for analysis of gabapentin, tramadol and/or amitriptyline mixtures in biological fluids.

Background: Mixtures of gabapentin, tramadol and/or amitriptyline are usually recommended for treatment of neuropathic pain. Materials & methods/results: A novel GC-MS/MS method was developed to assess the studied mixture whether in pure forms or human biological fluids (plasma/urine). The chromatographic detection was performed using MS detector applying the selected ion-monitoring mode. An (Agilent, CA, USA) GC-MS with triple axis single quadrupole detector unit was used for the analysis equipped with HP-5MS (5% phenyl methyl siloxane) column. Helium was the carrier gas and positive electron impact ionization mode was applied. Conclusion: The developed method was able to assess the mixture components simultaneously within six minutes. Validation of the method was assured according to US FDA guidelines and Eco-Scale assessment.

Stability indicating spectrophotometric methods for quantitative determination of bromazepam and its degradation product.

Four simple, sensitive and selective stability indicating spectrophotometric methods are presented for quantitative determination of the benzodiazepine drug; bromazepam (BMZ) and one of its reported potential impurities and degradation product; 2-(2-amino-5-bromobenzoyl) pyridine (ABP) in methanol. Method A, is isoabsorptive point coupled with D0 method, where good linearity was obtained by measuring the absorbance of BMZ at 264 nm (Aiso) in the concentration range of 2-25 µg mL-1, and the absorbance of ABP at its λmax 396 nm in concentration range of 0.5-24 µg mL-1. Method B, is ratio subtraction; the absorbance was measured at 233 nm for BMZ using 20 µg mL-1 of ABP, while ABP was determined directly at its λmax 396 nm using methanol as a solvent. Method C, was based on measuring the total peak amplitude of the first derivative of the ratio spectra (DD1) of BMZ from 301 to 326 nm using 10 µg mL-1 of ABP as a divisor and determination of ABP at peak amplitude of 293 nm using 5 µg mL-1 of BMZ as a divisor. In method D, ratio difference method, good linearity was achieved for determination of BMZ and ABP by measuring the differences between the amplitudes of ratio spectra at 312 nm and 274 nm and differences between the amplitudes of ratio spectra at 274 nm and 312 nm, respectively. The stability of BMZ was investigated under different ICH recommended forced degradation conditions. The suggested methods were then successfully applied for determination of BMZ in its pharmaceutical formulations.

Stability indicating spectrophotometric methods for quantitative determination of carbamazepine and its degradation product, iminostilbene, in pure form and pharmaceutical formulations.

A stressed study on the stability and degradation behavior under ICH forced degradation conditions of most widely used antiepileptic drug; carbamazepine (CMZ) is presented in this work. The research also includes studying spectrophotometric nature of CMZ and assaying it with mostly used spectrophotometric techniques. Six simple and sensitive spectrophotometric methods are introduced as stability indicating methods for quantitative determination of CMZ and its degradation product, one of its reported potential impurities; iminostilbene (IMS). Dual wavelength is method I where two wavelengths (215 and 270 nm for CMZ and 258 and 307 nm for IMS) were chosen for each component while absorbance difference is zero for the second one. Method II is isoabsorptive point method where the absorbance of CMZ at A225 nm was measured in the range of 0.5-20 µg mL-1. Method III is second derivative method which allows simultaneous determination of CMZ at 247 nm and IMS at 273 nm without any interference. Method IV based on measuring the peak amplitude of first derivative of ratio spectra (1DD) at 280.5 and 253 nm for determination of CMZ and IMS, respectively. Method V is mean centering of the ratio spectra with good linearity for CMZ and IMS over 200-330 nm. Ratio difference method is method VI where good linearity was achieved for determination of CMZ and IMS by measuring differences in the amplitude of ratio spectra at 285, 258 nm and 258, 285 nm, respectively. The proposed methods show successful application in CMZ's pharmaceutical formulations.

Coinciding Changes in B Lines Patterns, Haemoglobin and Hematocrit Values Can Predict Outcomes of Weaning from Mechanical Ventilation.

BACKGROUND: Weaning from invasive mechanical ventilation (MV) is considered as a daily challenging practice in the management of critically ill patients. The use of lung ultrasound and change in haemoglobin and hematocrit during weaning may help to predict weaning outcomes. AIM: We aim to study the impact of weaning induced pulmonary edema on outcomes of weaning from mechanical ventilation. PATIENTS AND METHODS: Sixty patients who fulfilled readiness criteria for weaning from MV. Spontaneous breathing trial (SBT) on T-piece for 120 minutes was performed under close hemodynamic monitoring. Lung ultrasound was performed using eight lung zones protocol to detect both the presence and the trend of change in B lines before and after SBT. For all the studied patients, haemoglobin and hematocrit values were checked just before and at the end of SBT. RESULTS: Patient who failed to pass SBT showed significant increase in lung segments showing B pattern, haemoglobin and hematocrit levels (p-value < 0.001 for all) also those patients had significantly higher duration of ICU stay (p-value < 0.001) Despite mortality rate was higher among patients who failed SBT yet it was statistically insignificant (p-value 0.104). CONCLUSION: lung ultrasound and both haemoglobin and hematocrit levels correlate with weaning outcomes.

Stability-Indicating HPLC and HPTLC Methods for Determination of Agomelatine and its Degradation Products.

Two accurate, sensitive and highly selective stability-indicating methods are developed and validated for simultaneous determination of Agomelatine (AGM) and its forced degradation products (Deg I and II). The first method is High-Performance Liquid Chromatography for separation and quantitation of AGM, Deg I and II on a C18 column (250 mm × 4.6 mm, 5 µm p.s) in isocratic mode by using a binary mixture of Potassium dihydrogen phosphate (0.05 M, pH adjusted to 2.9 with orthophosphoric acid): acetonitrile (60:40, v/v) at a flow rate of 2 mL/min. The components were detected at 230 nm over a concentration range of 0.5-10 µg/mL for AGM and 0.5-5 µg/mL for both Deg I and II. The second method is High-Performance Thin-Layer Chromatography, where AGM, Deg I and II were separated on silica gel HPTLC F254 plates using chloroform:methanol:ammonia solution (9:1:0.1, by volume) as a developing system. The separated bands were scanned at 230 nm over the concentration range of 0.2-1.2 µg/band for AGM in pure form and human plasma and 0.1-1 µg/band for both Deg I and II. The proposed methods were successfully applied for analysis of AGM in pharmaceutical formulations. The results obtained by the proposed methods were statistically compared to the reported HPLC method revealing high accuracy and good precision.

Application of normal fluorescence and stability-indicating derivative synchronous fluorescence spectroscopy for the determination of gliquidone in presence of its fluorescent alkaline degradation product.

Simple, smart and sensitive normal fluorescence and stability-indicating derivative synchronous spectrofluorimetric methods have been developed and validated for the determination of gliquidone in the drug substance and drug product. Normal spectrofluorimetric method of gliquidone was established in methanol at λ excitation 225nm and λ emission 400nm in concentration range 0.2-3µg/ml with LOD equal 0.028. The fluorescence quantum yield of gliquidone was calculated using quinine sulfate as a reference and found to be 0.542. Stability-indicating first and third derivative synchronous fluorescence spectroscopy were successfully utilized to overcome the overlapped spectra in normal fluorescence of gliquidone and its alkaline degradation product. Derivative synchronous methods are based on using the synchronous fluorescence of gliquidone and its degradation product in methanol at Δ λ50nm. Peak amplitude in the first derivative of synchronous fluorescence spectra was measured at 309nm where degradation product showed zero-crossing without interference. The peak amplitudes in the third derivative of synchronous fluorescence spectra, peak to trough were measured at 316,329nm where degradation product showed zero-crossing. The different experimental parameters affecting the normal and synchronous fluorescence intensity of gliquidone were studied and optimized. Moreover, the cited methods have been validated as per ICH guidelines. The peak amplitude-concentration plots of the derivative synchronous fluorescence were linear over the concentration range 0.05-2µg/ml for gliquidone. Limits of detection were 0.020 and 0.022 in first and third derivative synchronous spectra, respectively. The adopted methods were successfully applied to commercial tablets and the results demonstrated that the derivative synchronous fluorescence spectroscopy is a powerful stability-indicating method, suitable for routine use with a short analysis time. Statistical comparison between the results obtained by normal fluorescence and derivative synchronous methods and the official one using student's t-test and F-ratio showed no significant difference regarding accuracy and precision.

Forced degradation of gliquidone and development of validated stability-indicating HPLC and TLC methods

Forced degradation studies of gliquidone were conducted under different stress conditions. Three degradates were observed upon using HPLC and TLC and elucidated by LC-MS and IR. HPLC method was performed on C18 column using methanol-water (85:15 v/v) pH 3.5 as a mobile phase with isocratic mode at 1 mL.min-1 and detection at 225 nm. HPLC analysis was applied in range of 0.5-20 µg.mL-1 (r =1) with limit of detection (LOD) 0.177 µg.mL-1. TLC method was based on the separation of gliquidone from degradation products on silica gel TLC F254 plates using chloroform-cyclohexane-glacial acetic acid (6:3:1v/v) as a developing system with relative retardation 1.15±0.01. Densitometric measurements were achieved in range of 2 -20 µg /band at 254 nm (r = 0.9999) with LOD of 0.26 µg /band. Least squares regression analysis was applied to provide mathematical estimates of the degree of linearity. The analysis revealed a linear calibration for HPLC where a binomial relationship for TLC. Stability testing and methods validation have been evaluated according to International Conference on Harmonization guidelines. Moreover, the proposed methods were applied for the analysis of tablets and the results obtained were statistically compared with those of pharmacopeial method revealing no significant difference about accuracy and precision.

TLC-Densitometric and RP-HPLC Methods for Simultaneous Determination of Dexamethasone and Chlorpheniramine Maleate in the Presence of Methylparaben and Propylparaben.

Validated simple, sensitive, and highly selective methods are applied for the quantitative determination of dexamethasone and chlorpheniramine maleate in the presence of their reported preservatives (methylparaben and propylparaben), whether in pure forms or in pharmaceutical formulation. TLC is the first method, in which dexamethasone, chlorpheniramine maleate, methylparaben, and propylparaben are separated on silica gel TLC F254 plates using hexane-acetone-ammonia (5.5 + 4.5 + 0.5, v/v/v) as the developing phase. Separated bands are scanned at 254 nm over a concentration range of 0.1-1.7 and 0.4-2.8 µg/band, with mean ± SD recoveries of 99.12 ± 0.964 and 100.14 ± 0.962%, for dexamethasone and chlorpheniramine maleate, respectively. Reversed-phase HPLC is the second method, in which a mixture of dexamethasone and chlorpheniramine maleate, methylparaben, and propylparaben is separated on a reversed-phase silica C18 (5 µm particle size, 250 mm, 4.6 mm id) column using 0.1 M ammonium acetate buffer-acetonitrile (60 + 40, v/v, pH 3) as the mobile phase. The drugs were detected at 220 nm over a concentration range of 5-50 µg/mL, 2-90 µg/mL, 4-100 µg/mL, and 7-50 µg/mL, with mean ± SD recoveries of 100.85 ± 0.905, 99.67 ± 1.281, 100.20 ± 0.906, and 99.81 ± 0.954%, for dexamethasone, chlorpheniramine maleate, methylparaben paraben, and propylparaben, respectively. The advantages of the suggested methods over previously reported methods are the ability to detect lower concentrations of the main drugs and to show better resolution of interfering preservatives; hence, these methods could be more reliable for routine QC analyses.

Spectrophotometric Methods for Simultaneous Determination of Sofosbuvir and Ledipasvir (HARVONI Tablet): Comparative Study with Two Generic Products.

Sofosbuvir and ledipasvir are the first drugs in a combination pill to treat chronic hepatitis C virus. Simple, sensitive, and rapid spectrophotometric methods are presented for the determination of sofosbuvir and ledipasvir in their combined dosage form. These methods were based on direct measurement of ledipasvir at 333 nm (due to the lack of interference of sofosbuvir) over a concentration range of 4.0-14.0 µg/mL, with a mean recovery of 100.78 ± 0.64%. Sofosbuvir was determined, without prior separation, by third-derivative values at 281 nm; derivative ratio values at 265.8 nm utilizing 5.0 µg/mL ledipasvir as a divisor; the ratio difference method using values at 270 and 250 nm using 5.0 µg/mL ledipasvir as a divisor; and the ratio subtraction method using values at 261 nm. These methods were found to be linear for sofosbuvir over a concentration range of 5.0-35.0 µg/mL. The suggested methods were validated according to International Conference on Harmonization guidelines. Statistical analysis of the results showed no significant difference between the proposed methods and the manufacturer's LC method of determination with respect to accuracy and precision. These methods were used to compare the equivalence of an innovator drug dosage form and two generic drug dosage forms of the same strength.

Least-Squares Regression and Spectral Residual Augmented Classical Least-Squares Chemometric Models for Stability-Indicating Analysis of Agomelatine and Its Degradation Products: A Comparative Study.

Two accurate, sensitive, and selective stability-indicating methods are developed and validated for simultaneous quantitative determination of agomelatine (AGM) and its forced degradation products (Deg I and Deg II), whether in pure forms or in pharmaceutical formulations. Partial least-squares regression (PLSR) and spectral residual augmented classical least-squares (SRACLS) are two chemometric models that are being subjected to a comparative study through handling UV spectral data in range (215-350 nm). For proper analysis, a three-factor, four-level experimental design was established, resulting in a training set consisting of 16 mixtures containing different ratios of interfering species. An independent test set consisting of eight mixtures was used to validate the prediction ability of the suggested models. The results presented indicate the ability of mentioned multivariate calibration models to analyze AGM, Deg I, and Deg II with high selectivity and accuracy. The analysis results of the pharmaceutical formulations were statistically compared to the reference HPLC method, with no significant differences observed regarding accuracy and precision. The SRACLS model gives comparable results to the PLSR model; however, it keeps the qualitative spectral information of the classical least-squares algorithm for analyzed components.

Novel ratio difference at coabsorptive point spectrophotometric method for determination of components with wide variation in their absorptivities.

Different methods have been introduced to enhance selectivity of UV-spectrophotometry thus enabling accurate determination of co-formulated components, however mixtures whose components exhibit wide variation in absorptivities has been an obstacle against application of UV-spectrophotometry. The developed ratio difference at coabsorptive point method (RDC) represents a simple effective solution for the mentioned problem, where the additive property of light absorbance enabled the consideration of the two components as multiples of the lower absorptivity component at certain wavelength (coabsorptive point), at which their total concentration multiples could be determined, whereas the other component was selectively determined by applying the ratio difference method in a single step. Mixture of perindopril arginine (PA) and amlodipine besylate (AM) figures that problem, where the low absorptivity of PA relative to AM hinders selective spectrophotometric determination of PA. The developed method successfully determined both components in the overlapped region of their spectra with accuracy 99.39±1.60 and 100.51±1.21, for PA and AM, respectively. The method was validated as per the USP guidelines and showed no significant difference upon statistical comparison with reported chromatographic method.

HPTLC Method for Quantitative Determination of Zopiclone and Its Impurity.

This study was designed to establish, optimize and validate a sensitive, selective and accurate high-performance thin layer chromatographic (HPTLC) method for determination of zopiclone (ZPC) and its main impurity, 2-amino-5-chloropyridine, one of its degradation products, in raw material and pharmaceutical formulation. The proposed method was applied for analysis of ZPC and its impurity over the concentration range of 0.3-1.4 and 0.05-0.8 µg/band with accuracy of mean percentage recovery 99.92% ± 1.521 and 99.28% ± 2.296, respectively. The method is based on the separation of two components followed by densitometric measurement of the separated peaks at 305 nm. The separation was carried out on silica gel HPTLC F254 plates, using chloroform-methanol-glacial acetic acid (9:1:0.1, by volume) as a developing system. The suggested method was validated according to International Conference on Harmonization guidelines and can be applied for routine analysis in quality control laboratories. The results obtained by the proposed method were statistically compared with the reported method revealing high accuracy and good precision.

Quantitative determination of zopiclone and its impurity by four different spectrophotometric methods.

Four simple, sensitive and selective spectrophotometric methods are presented for determination of Zopiclone (ZPC) and its impurity, one of its degradation products, namely; 2-amino-5-chloropyridine (ACP). Method A is a dual wavelength spectrophotometry; where two wavelengths (252 and 301 nm for ZPC, and 238 and 261 nm for ACP) were selected for each component in such a way that difference in absorbance is zero for the second one. Method B is isoabsorptive ratio method by combining the isoabsorptive point (259.8 nm) in the ratio spectrum using ACP as a divisor and the ratio difference for a single step determination of both components. Method C is third derivative (D(3)) spectrophotometric method which allows determination of both ZPC at 283.6 nm and ACP at 251.6 nm without interference of each other. Method D is based on measuring the peak amplitude of the first derivative of the ratio spectra (DD(1)) at 263.2 nm for ZPC and 252 nm for ACP. The suggested methods were validated according to ICH guidelines and can be applied for routine analysis in quality control laboratories. Statistical analysis of the results obtained from the proposed methods and those obtained from the reported method has been carried out revealing high accuracy and good precision.

Simultaneous determination of metformin hydrochloride and pioglitazone hydrochloride in binary mixture and in their ternary mixture with pioglitazone acid degradate using spectrophotometric and chemometric methods.

In this work two well known oral hypoglycemic drugs that are administered in combination for patients with type-II diabetes were simultaneously determined. Several spectrophotometric methods were developed and validated for the determination of metformin hydrochloride (MET), pioglitazone hydrochloride (PIO) and pioglitazone acid degradate (PIO Deg). Derivative, ratio derivative, isosbestic and chemometric-assisted spectrophotometric methods were developed. The first derivative (D(1)) method was used for the determination of MET in the range of 5-30 microg x mL(-1) and PIO in the range of 10-90 microg x mL(-1) by measuring the peak amplitude at 247 nm and 280 nm, respectively. The concentration of PIO was calculated directly at 268 nm. The first derivative of ratio spectra (DD(1)) method used the peak amplitudes at 238 nm and 248.6 nm for the determination of MET in the range of 5-30 microg x mL(-1). In the isosbestic point method (ISO), the total mixture concentration was calculated by measuring the absorbance at 254.6 nm. Classical least squares (CLS), principal component regression (PCR) and partial least squares (PLS-2) were used for the quantitative determination of MET, PIO and PIO Deg. The methods developed have the advantage of simultaneous determination of the cited components without any pre-treatment. Resolution and quantitative determination of PIO degradate with a minimum concentration of 3 microg x mL(-1) in drug samples was done. The proposed methods were successfully used to determine each drug and the acid degradate in a laboratory-prepared mixture and pharmaceutical preparations. The results were statistically compared using one-way analysis of variance (ANOVA). The methods developed were satisfactorily applied to the analysis of the two drugs in pharmaceutical formulations.