Novel Validated Stability-Indicating UPLC Method for the Estimation of Naproxen and its Impurities in Bulk Drugs and Pharmaceutical Dosage Form

A novel, reversed-phase ultra-performance liquid chromatographic method was developed and validated for the determination of related substances in Naproxen (NAP) bulk drugs and dosage forms. The related substances included degradation and process-related impurities. The method was developed using the Waters Acquity BEH C18 column using the gradient program with mobile phase A of a pH 7.0 phosphate buffer and methanol in the ratio of 90: 10 (v/v) and mobile phase B as methanol and acetonitrile in the ratio of 50:50 (v/v). Naproxen and its impurities were monitored at 260 nm. Naproxen was subjected to the stress conditions of oxidative, acid, base, hydrolytic, thermal, humidity, and photolytic degradations. The degradation products were well-resolved from the main peak and its impurities, proving the stability-indicating power of the method. The performance of the method was validated according to the present ICH guidelines for specificity, limit of detection, limit of quantification, linearity, accuracy, precision, ruggedness, and robustness.

Development and validation of a stability indicating RP-HPLC method for the determination of Rufinamide

A stability-indicating RP-HPLC method was developed and validated for the determination of Rufinamide in tablet dosage forms using C 18 column (250 mm×4.6 mm, 5 μm) with mobile phase consisting of water–acetonitrile (40:60, v/v) with a flow rate of 0.8 mL/min (UV detection 215 nm). Linearity was observed over the concentration range 1.0–200 μg/mL (R²=0.9997) with regression equation y=113190 x+63053. Rufinamide was subjected to stress conditions including acidic, alkaline, oxidation, photolysis and thermal degradation. Rufinamide is more sensitive towards acidic degradation. The method was validated as per ICH guidelines.

A Validation of the Inventory of Callous-Unemotional Traits in a Community Sample of Young Adult Males

Callous-unemotional (CU) traits have been shown to delineate a subgroup of individuals at high risk for exhibiting severe and persistent criminal behavior. The Inventory of Callous-Unemotional Traits (ICU; Frick 2004) was recently developed as a comprehensive rating scale designed to measure multiple facets of CU traits. However, validation of this measure has been limited to youth in adolescence and emerging adulthood (age range=12-20), leaving questions about the utility of this measure in early adulthood unanswered. The current study evaluated the factor structure of the ICU within a racially diverse and well characterized community sample of adult males (n=425) using exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). While results found the best fitting model to be the three-bifactor structure that has been previously reported in adolescent samples, the fit indices were only marginally acceptable and suggest the need for scale refinement. Total and subscales scores demonstrated significant and distinct associations with relevant external criteria (e.g., delinquency, psychopathy, psychopathology, psychosocial functioning). Implications and directions for future research are discussed.

What symptoms are more important for korean patients in knee osteoarthritis? Development and validation of the korean knee score

PURPOSE

The purpose of this study was to develop and validate a novel knee evaluation instrument, the Korean Knee Score (KKS), to reflect a floor life style with high knee flexion. In addition, we aimed to assess the importance of high knee flexion activity for Korean patients.

MATERIALS AND METHODS

The KKS was developed following the guidelines of the International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine. During development step, generated items were asked to 50 patients to determine importance and obtain an impact score for each item. A total of 634 patients were included in the validation survey.

RESULTS

Forty one items were generated and impact scores of each item about floor life style were higher than other items. The KKS exhibited excellent reliability (intraclass correlation coefficient=0.931) and strong internal consistency (Cronbach's α=0.973). The content validity was good, with no ceiling or floor effect. The construct, convergent, and divergent validities were good. Moderate responsiveness was evident, with a standardized response mean of 0.74.

CONCLUSIONS

The KKS, has good validity, reliability, and responsiveness. The KKS includes items for floor life style, which are thought more important for Korean patients. The KKS can be used as a good evaluation questionnaire for Korean knee osteoarthritis patients.

Translation, cross-cultural adaptation and validation of the Danish version of the Oxford hip score: Assessed against generic and disease-specific questionnaires

OBJECTIVES

The Oxford hip score (OHS) is a 12-item questionnaire designed and developed to assess function and pain from the perspective of patients who are undergoing total hip replacement (THR). The OHS has been shown to be consistent, reliable, valid and sensitive to clinical change following THR. It has been translated into different languages, but no adequately translated, adapted and validated Danish language version exists.

METHODS

The OHS was translated and cross-culturally adapted into Danish from the original English version, using methods based on best-practice guidelines. The translation was tested for psychometric quality in patients drawn from a cohort from the Danish Hip Arthroplasty Register (DHR).

RESULTS

The Danish OHS had a response rate of 87.4%, no floor effect and a 19.9% ceiling effect (as expected in post-operative patients). Only 1.2% of patients had too many items missing to calculate a sum score. Construct validity was adequate and 80% of our predefined hypotheses regarding the correlation between scores on the Danish OHS and the other questionnaires were confirmed. The intraclass correlation (ICC) of the different items ranged from 0.80 to 0.95 and the average limits of agreement (LOA) ranged from -0.05 to 0.06. The Danish OHS had a high internal consistency with a Cronbach's alpha of 0.99 and an average inter-item correlation of 0.88.

CONCLUSIONS

This Danish version of the OHS is a valid and reliable patient-reported outcome measurement instrument (PROM) with similar qualities to the original English language version.

Reliability and Validity of the OMNI-Vibration Exercise Scale of Perceived Exertion

This study examined reliability and concurrent validity of the newly developed OMNI-vibration exercise scale (OMNI-VIBRO) to measure Ratings of Perceived Exertion (RPE) during vibration exercise in twenty recreationally active students (12 males and 8 females). The criterion variables were muscle activity of the Vastus Medialis (VM), Vastus Lateralis (VL), Biceps Femoris (BF), and Medial Gastrocnemius (MG) muscles, as well as accelerations (12.5, 20.2, 30.9, 36.3, 60.1, and 88.4 m·s(-2)). RPE was registered during the final of each 30 s condition. Each participant attended two laboratory testing sessions. Positive linear regression coefficients (p < 0.001) were found between RPE (OMNI-VIBRO) and acceleration (r = 0.976) and muscle activity of lower-body muscles (r = 0.942). Between session (test-retest), reliability of RPE (OMNI-VIBRO) was good (ICC: 0.790. 95% CI: 0.699-0.854).

CONCLUSIONS

findings provided concurrent validation of the OMNI-VIBRO to measure RPE for the active muscle and overall body in recreationally active students performing lower-body vibration exercise. Key pointsThe pictorial-verbal category scale of perception of exertion (OMNI-VIBRO) during lower body vibration exercise on a vibration platform showed good concurrent validity.The OMNI-VIBRO method in conjunction with WBV exercise would allow coaches, fitness professionals, or health-care personnel to assess the intensity that corresponds to the level of the vibratory stimulus.The OMNI-VIBRO could be a useful tool of measuring the different intensities of a vibratory-training session and altering the vibratory stimulus in a periodized fashion.

Identification and Characterization of an Oxidative Degradation Product of Fexofenadine, Development and Validation of a Stability-Indicating RP-UPLC Method for the Estimation of Process Related Impurities and Degradation Products of Fexofenadine in Pharmaceutical Formulations

A novel stability-indicating gradient RP-UPLC method was developed for the quantitative determination of process related impurities and forced degradation products of fexofenadine HCl in pharmaceutical formulations. The method was developed by using Waters Aquity BEH C18 (100 mm x 2.1 mm) 1.7 μm column with mobile phase containing a gradient mixture of solvent A (0.05% triethyl amine, pH adjusted to 7.0 with ortho-phosphoric acid) and B (10:90 v/v mixture of water and acetonitrile). The flow rate of mobile phase was 0.4 mL/min with column temperature of 30°C and detection wavelength at 220nm. Fexofenadine HCl was subjected to the stress conditions including oxidative, acid, base, hydrolytic, thermal and photolytic degradation. Fexofenadine HCl was found to degrade significantly in oxidative stress conditions, and degradation product was identified and characterized by ESI-MS/MS, (1)H and (13)C NMR spectroscopic method as the N-oxide 2-[4-(1-hydroxy-4-{4-[hydroxy(diphenyl)methyl]-1-oxido-piperidin-1-yl}butyl)phenyl]-2-methylpropanoic acid. The degradation products were well resolved from fexofenadine and its impurities. The mass balance was found to be satisfactory in all the stress conditions, thus proving the stability-indicating capability of the method. The developed method was validated as per ICH guidelines with respect to specificity, linearity, limit of detection and quantification, accuracy, precision and robustness.

Stress Degradation Behavior of Abacavir Sulfate and Development of a Suitable Stability-Indicating UHPLC Method for the Determination of Abacavir, its Related Substances, and Degradation Products

A novel, stability-indicating UHPLC method was developed for the quantitative determination of Abacavir sulfate, its related substances, and forced degradation impurities in bulk drugs. The chromatographic separation was achieved on a Waters Acquity BEH C₈, 50 mm × 2.1 mm, 1.7 μm particle size column with a mobile containing a gradient mixture of solution A (0.10 % v/v o-phosphoric acid in water) and solution B (0.10% v/v o-phosphoric acid in methanol). The flow rate was set at 0.40 mL/min and the run time was 6.0 min. The drug substance was subjected to the stress studies of hydrolysis, oxidation, photolysis, and thermal degradation. Abacavir sulfate was found to degrade significantly under acidic hydrolysis and oxidative stress conditions. The formed degradation products were reported and were well-resolved from Abacavir and its related substances. The mass balance was found to be satisfactory in all of the stress conditions, thus proving the stability-indicating capability of the method. The developed UHPLC method was validated to be in agreement with ICH requirements and found to be rapid, accurate, precise, linear, specific, and suitable for the quantitative determination of related substances and degradants in the bulk drug samples of Abacavir sulfate.

Development and validation of a simple UV spectrophotometric method for the determination of levofloxacin both in bulk and marketed dosage formulations

A rapid, specific and economic UV spectrophotometric method has been developed using a solvent composed of water:methanol:acetonitrile (9:0.5:0.5) to determine the levofloxacin content in bulk and pharmaceutical dosage formulations. At a pre-determined λ_max of 292 nm, it was proved linear in the range of 1.0-12.0 μg/mL, and exhibited good correlation coefficient (R²=0.9998) and excellent mean recovery (99.00-100.07%). This method was successfully applied to the determination of levofloxacin content in five marketed brands from Bangladesh and the results were in good agreement with the label claims. The method was validated statistically and by recovery studies for linearity, precision, repeatability, and reproducibility. The obtained results proved that the method can be employed for the routine analysis of levofloxacin in bulks as well as in the commercial formulations.

Development and validation of the stability-indicating LC-UV method for the determination of Cefditoren pivoxil

An isocratic RP-HPLC method was developed for the determination of Cefditoren pivoxil in pharmaceutical formulations using a C-18 column with water–acetonitrile (50:50, v/v) as mobile phase and flow rate 1.2 mL/min (UV detection at 218 nm). Linearity was observed in the concentration range 1.0–250 μg/mL (R²=0.999) with regression equation y=24194x+10749. The forced degradation studies were performed by using HCl, NaOH, and H₂O₂, and thermal and UV radiation. Cefditoren pivoxil is more sensitive towards oxidation and alkaline conditions and resistant towards acidic and photolytic degradations. The method was validated as per ICH guidelines.

A validated stability-indicating liquid chromatographic method for determination of degradation impurities and diastereomers in voriconazole tablets

A reversed-phase gradient liquid chromatographic method has been developed for the quantitative determination of Voriconazole, along with its degradation and diastereomeric impurities in tablet dosage form. Chromatographic separation has been achieved on an Inertsil ODS 3V, 150 × 4.6 mm, 5 μm column. The mobile phase consisting of solvent A 0.05 molar (M) potassium dihydrogen phosphate (pH 2.5 buffer) and solvent B (mixture of acetonitrile and methanol in the ratio 90:10 (v/v)), was delivered at a flow rate of 1.2 mL min⁻¹ with the detection wavelength at 256 nm. Resolution of Voriconazole and all five potential impurities was achieved at greater than 2.0 for all pairs of compounds. The drug was subjected to stress conditions such as oxidative, acid and base hydrolysis, and thermal and photolytic degradation. Voriconazole was found to degrade significantly under base hydrolysis stress conditions compared to acid hydrolysis stress conditions. The degradation products were well-resolved from the main peak and its impurities, thus proving the stability-indicating power of the method. The stressed samples were assayed against a reference standard and the mass balance was found to be close to 99.0%. The developed method was validated as per ICH guidelines with respect to specificity, linearity, limit of detection, limit of quantification, accuracy, precision, and robustness.

Development and validation of an HPLC method for the analysis of sirolimus in drug products

PURPOSE

The aim of this study was to develop a simple, rapid and sensitive reverse phase high performance liquid chromatography (RP-HPLC) method for quantification of sirolimus (SRL) in pharmaceutical dosage forms.

METHODS

The chromatographic system employs isocratic elution using a Knauer- C18, 5 mm, 4.6 × 150 mm. Mobile phase consisting of acetonitril and ammonium acetate buffer set at flow rate 1.5 ml/min. The analyte was detected and quantified at 278nm using ultraviolet detector. The method was validated as per ICH guidelines.

RESULTS

The standard curve was found to have a linear relationship (r(2) > 0.99) over the analytical range of 125-2000ng/ml. For all quality control (QC) standards in intraday and interday assay, accuracy and precision range were -0.96 to 6.30 and 0.86 to 13.74 respectively, demonstrating the precision and accuracy over the analytical range. Samples were stable during preparation and analysis procedure.

CONCLUSION

Therefore the rapid and sensitive developed method can be used for the routine analysis of sirolimus such as dissolution and stability assays of pre- and post-marketed dosage forms.

Simultaneous Estimation of Amlodipine Besylate and Indapamide in a Pharmaceutical Formulation by a High Performance Liquid Chromatographic (RP-HPLC) Method

An isocratic reversed-phase liquid chromatograpic assay method was developed for the quantitative determination of amlodipine besylate (AML) and indapamide (IND) in combined dosage form. A Brownlee C-18, 5 μm column with a mobile phase containing 0.02 M potassium dihydrogen phosphate-methanol (30+70, v/v) total pH-adjusted to 3 using o-phosphoric acid was used. The flow rate was 1.0 mL min(-1) and effluents were monitored at 242 nm. The retention times of amlodipine besylate and indapamide were 5.9 min and 3.6 min, respectively. The proposed method was validated with respect to linearity, accuracy, precision, and robustness. The method was successfully applied to the estimation of amlodipine besylate and indapamide in combined tablet dosage forms.

Novel and validated titrimetric method for determination of selected angiotensin-II-receptor antagonists in pharmaceutical preparations and its comparison with UV spectrophotometric determination

A novel and simple titrimetric method for determination of commonly used angiotensin-II-receptor antagonists (ARA-IIs) is developed and validated. The direct acid base titration of four ARA-IIs, namely eprosartan mesylate, irbesartan, telmisartan and valsartan, was carried out in the mixture of ethanol:water (1:1) as solvent using standardized sodium hydroxide aqueous solution as titrant, either visually using phenolphthalein as an indicator or potentiometrically using combined pH electrode. The method was found to be accurate and precise, having relative standard deviation of less than 2% for all ARA-IIs studied. Also, it was shown that the method could be successfully applied to the assay of commercial pharmaceuticals containing the above-mentioned ARA-IIs. The validity of the method was tested by the recovery studies of standard addition to pharmaceuticals and the results were found to be satisfactory. Results obtained by this method were found to be in good agreement with those obtained by UV spectrophotometric method. For UV spectrophotometric analysis ethanol was used as a solvent and wavelength of 233 nm, 246 nm, 296 nm, and 250 nm was selected for determination of eprosartan mesylate, irbesartan, telmisartan, and valsartan respectively. The proposed titrimetric method is simple, rapid, convenient and sufficiently precise for quality control purposes.

Development and validation of RP-HPLC and RP-UPLC methods for quantification of parathyroid hormones (1-34) in medicinal product formulated with meta-cresol

Rapid and sensitive reversed phase high performance liquid chromatography (RP-HPLC) and ultra performance liquid chromatography (RP-UPLC) method with UV detection has been developed and validated for quantification of parathyroid hormone (PTH) in presence of meta-cresol as a stabilizer in a pharmaceutical formulation. Chromatography was performed with mobile phase containing 0.1% Trifluoroacetic acid (TFA) in MilliQ water and 0.1% TFA in acetonitrile with gradient program and flow rate at 0.3 mL/min for HPLC and 0.4 mL/min for UPLC. Quantification was accomplished with internal reference standard (qualified against innovator product and National Institute for Biological Standards and Control (NIBSC) standard). The methods were validated for linearity (correlation coefficient=0.99), range, accuracy, precision and robustness. Robustness was confirmed by considering three factors; mobile phase composition, column temperature and flow rate/age of mobile phase. Intermediate precision was confirmed on different equipments, different columns and on different days. The relative standard deviation (RSD) (<2% for RP-HPLC and <1% for UPLC, n=30) indicated a good precision. Retention time was found about 17 min and 2 min by HPLC and UPLC methods, respectively. Both methods are simple, highly sensitive, precise and accurate and have the potential of being useful for routine quality control.

Stability-indicating liquid chromatographic method for the quantification of the new antipsychotic agent asenapine in bulk and in pharmaceutical formulation

A simple, specific and stability-indicating reversed phase high performance liquid chromatographic method was developed for the quantitative determination of asenapine in tablet dosage form. A SunFire C₁₈, 5 μm column having 250×4.6 mm i.d. in isocratic mode, with mobile phase containing 0.02 M potassium dihydrogen phosphate: acetonitrile (95:05, v/v, pH 3.5 adjusted with 1% o-phosphoric acid) was used. The flow rate was 1.0 mL min⁻¹ and effluents were monitored at 232 nm. The retention time of asenapine was 5.51 min. The linearity for asenapine was in the range of 0.1–20 μg/ml. The recoveries obtained for asenapine were 98.31–101.51%. Asenapine stock solutions were subjected to acid and alkali hydrolysis, chemical oxidation, sunlight and dry heat degradation. The degraded product peaks were well resolved from the pure drug peak with significant difference in their retention time values. Stressed samples were assayed using developed LC method. The proposed method was validated with respect to linearity, accuracy, precision and robustness. The method was successfully applied to the estimation of asenapine in tablet dosage form.

A validated stability-indicating LC method for the separation of enantiomer and potential impurities of Linezolid using polar organic mode

Although a number of methods are available for evaluating Linezolid and its possible impurities, a common method for separation if its potential impurities, degradants and enantiomer in a single method with good efficiency remain unavailable. With the objective of developing an advanced method with shorter runtimes, a simple, precise, accurate stability-indicating LC method was developed for the determination of purity of Linezolid drug substance and drug products in bulk samples and pharmaceutical dosage forms in the presence of its impurities and degradation products. This method is capable of separating all the related substances of Linezolid along with the chiral impurity. This method can also be used for the estimation of assay of Linezolid in drug substance as well as in drug product. The method was developed using Chiralpak IA (250 mm×4.6 mm, 5 μm) column. A mixture of acetonitrile, ethanol, n-butyl amine and trifluoro acetic acid in 96:4:0.10:0.16 (v/v/v/v) ratio was used as a mobile phase. The eluted compounds were monitored at 254 nm. Linezolid was subjected to the stress conditions of oxidative, acid, base, hydrolytic, thermal and photolytic degradation. The degradation products were well resolved from main peak and its impurities, proving the stability-indicating power of the method. The developed method was validated as per International Conference on Harmonization (ICH) guidelines with respect to specificity, limit of detection, limit of quantification, precision, linearity, accuracy, robustness and system suitability.

LC-UV and LC-MS evaluation of stress degradation behavior of desvenlafaxine

The objective of current study was to develop a validated specific stability indicating reversed-phase liquid chromatographic method for the quantitative determination of desvenlafaxine in bulk sample and pharmaceutical dosage form in the presence of degradation products. Forced degradation studies were performed on bulk sample of desvenlafaxine as per ICH prescribed stress conditions using acid, base, oxidative and photolytic degradation to show the stability indicating power of the method. Significant degradation was observed under acidic stress condition and the degradation product formed was identified by LC–MS and a degradation pathway for drug has been proposed. Successful separation of drug from degradation products formed under stress conditions was achieved on a SymmetryShield column C₁₈ (5 μm, 250 mm×4.6 mm, i.d.) using the mobile phase consisting of a mixture of 0.2% (v/v) triethylamine in ammonium acetate (0.05 M; pH 6.5) and methanol using isocratic gradient.

Stress degradation studies on varenicline tartrate and development of a validated stability-indicating HPLC method

A simple, rapid and stability-indicating reversed-phase liquid chromatographic method was developed for the assay of varenicline tartrate (VRT) in the presence of its degradation products generated from forced decomposition studies. The HPLC separation was achieved on a C18 Inertsil column (250 mm × 4.6 mm i.d. particle size is 5 μm) employing a mobile phase consisting of ammonium acetate buffer containing trifluoroacetic acid (0.02M; pH 4) and acetonitrile in gradient program mode with a flow rate of 1.0 mL min(-1). The UV detector was operated at 237 nm while column temperature was maintained at 40 °C. The developed method was validated as per ICH guidelines with respect to specificity, linearity, precision, accuracy, robustness and limit of quantification. The method was found to be simple, specific, precise and accurate. Selectivity of the proposed method was validated by subjecting the stock solution of VRT to acidic, basic, photolysis, oxidative and thermal degradation. The calibration curve was found to be linear in the concentration range of 0.1-192 μg mL(-1) (R(2) = 0.9994). The peaks of degradation products did not interfere with that of pure VRT. The utility of the developed method was examined by analyzing the tablets containing VRT. The results of analysis were subjected to statistical analysis.

Stability-Indicating RP-HPLC Method for Determination of Tamsulosin HCL in Pharmaceutical Dosage Form

A selective, specific and sensitive stability-indicating high-performance liquid chromatographic method was developed and validated for the determination of Tamsulosin in in pharmaceutical dosage forms. Celecoxib was used as Internal Standard (IS). The chromatographic conditions comprised of a reversed-phase Lichrocart / Lichrosphere C18 column (250 × 4.0 mm packed with 5) with mobile phase consisting of a mixture of Acetonitrile: T.D.W. in the ratio (40: 60). Flow rate was 0.8 mL / min. Detection was carried out at 275 nm. The retention time of Tamsulosin HCl and Celecoxib were found to be 1.608 and 2.767min respectively and the linear regression analysis data for the calibration plots showed good linear relationship in the concentration range 1 - 200 g/mL. The value of correlation coefficient, slope and intercept were, 0.9995, 0.7453 and 0.4584, respectively. Tamsulosin HCl was subjected to stress conditions of degradation in aqueous solutions including acidic, alkaline, oxidation, photolysis and thermal degradation. The developed method was validated with regard to linearity, accuracy, precision, selectivity and robustness and the method was found to be precise, accurate, linear and specific. The method was employed successfully for identification and determination of Tamsulosin in pharmaceutical preparations.

Application of HPLC for the simultaneous determination of aceclofenac, paracetamol and tramadol hydrochloride in pharmaceutical dosage form

A simple, precise and accurate reversed-phase liquid chromatographic method has been developed for the simultaneous estimation of aceclofenac (ACF), paracetamol (PCM) and tramadol hydrochloride (TRM) in pharmaceutical dosage form. The chromatographic separation was achieved on a HiQ-Sil™ HS C18 column (250×4.6 mm i.d., 5 μm particle size), kromatek analytical column at ambient temperature. The mobile phase consisted of 40: 60 (v/v); phosphate buffer (pH 6.0): methanol. The flow rate was set to 1.0 mL min⁻¹ and UV detection was carried out at 270 nm. The retention time (t_R) for ACF, PCM and TRM were found to be 14.567 ± 0.02, 3.133 ± 0.01 and 7.858 ± 0.02 min, respectively. The validation of the proposed method was carried out for linearity, precision, robustness, limit of detection, limit of quantitation, speci city, accuracy and system suitability. The linear dynamic ranges were from 40–160 μg mL⁻¹ for ACF, 130–520 μg mL⁻¹ for PCM and 15–60 μg mL⁻¹ for TRM. The developed method can be used for routine quality control analysis of titled drugs in pharmaceutical dosage form.

Development and Validation of a Terbium-Sensitized LuminescenceAnalytical Method for Deferiprone

A sensitive fluorometric method for the determination of deferiprone (DFP) based on the formation of a luminescent complex with Tb(3+) ions in aqueous solutions is reported. The maximum excitation and emission wavelengths were 295 and 545 nm, respectively. The effects of various factors on the luminescence intensity of the system were investigated and optimized, then under the optimum conditions, the method was validated. The method validation results indicated that the relative intensity at 545 nm has a linear relationship with the concentration of DFP in aqueous solutions at the range of 7.2 × 10(-9) to 1.4 × 10(-5) M, the detection and quantification limits were calculated respectively as 6.3 × 10(-9) and 2.1 × 10(-8) M, precision and accuracy of the method were lower than 5% and the recovery was between 100.1% and 102.3%. The results indicated that this method was simple, time saving, specific, accurate and precise for the determination of DFP in aqueous solutions. After optimization and validation, the method successfully applied for determination of DFP in tablet dosage forms. The stoichiometry of the Tb(3+)-DFP complex was found as 1:3 and the complex formation constant was 1.6 × 10(16).

Validation of DRAMMS among 12 Popular Methods in Cross-Subject Cardiac MRI Registration

Cross-subject image registration is the building block for many cardiac studies. In the literature, it is often handled by voxel-wise registration methods. However, studies are lacking to show which methods are more accurate and stable in this context. Aiming at answering this question, this paper evaluates 12 popular registration methods and validates a recently developed method DRAMMS [16] in the context of cross-subject cardiac registration. Our dataset consists of short-axis end-diastole cardiac MR images from 24 subjects, in which non-cardiac structures are removed. Each registration method was applied to all 552 image pairs. Registration accuracy is approximated by Jaccard overlap between deformed expert annotation of source image and the corresponding expert annotation of target image. This accuracy surrogate is further correlated with deformation aggressiveness, which is reflected by minimum, maximum and range of Jacobian determinants. Our study shows that DRAMMS [16] scores high in accuracy and well balances accuracy and aggressiveness in this dataset, followed by ANTs [13], MI-FFD [14], Demons [15], and ART [12]. Our findings in cross-subject cardiac registrations echo those findings in brain image registrations [7].

Validation of a Finnish version of the Fibromyalgia Impact Questionnaire (Finn-FIQ)

Background and purpose Fibromyalgia (FM) is a chronic pain syndrome, which affects up to 5% of the general population. The aetiology of FM is unclear. The lack of specific diagnostic laboratory tests or imaging options combined with the severe burden on both patients and society caused by the FM syndrome demands the development of valid instruments able to measure the current health status of the FM patients. The Fibromyalgia Impact Questionnaire (FIQ) is the most widely used of these instruments. Our objective was to translate the Fibromyalgia Impact Questionnaire (FIQ) into Finnish and evaluate its validity in Finnish speaking FM patients. Methods FIQ was translated by two bilingual researchers into the Finnish version (Finn-FIQ) and linked to the categories of International Classification of Functioning, Disability and Health (ICF). Finn-FIQ was administered to 162 patients who had prior fibromyalgia diagnoses M79.0 according to ICD-10 year 2006 version. They also filled in the Health Assessment Questionnaire (HAQ), the Rand 36-item Health Survey (RAND-36), the Beck Depression Inventory IA (BDIIA), the Chronic Pain Acceptance Questionnaire (CPAQ), the International Physical Activity Questionnaire Short Form (IPAQ), and they assessed their general well-being on a 0-100 mm visual analogue scale while attending a clinical check-up visit. Internal consistency was estimated according to Cronbach's alpha internal consistency. An exploratory factor analysis was performed to identify related items and to show construct validity. Correlation coefficients were calculated by the Spearman method. Results From the 162 participants 153 were female and 9 male, 119 (73%) had an active job or were students, 21 (13%) were unemployed, 16 (10%) were retired and 6 (4%) were on sick leave. The mean age was 47 years. The internal consistency value (95% CI) was 0.90 for the overall Finn-FIQ. The factor analysis performed for construct analysis showed that Finn-FIQ was loaded on 4 factors. These factors were loaded on components of ICF and explained 69% of total variance. Significant correlations were obtained between patients own assessments of general well-being and Finn-FIQ total score (r = 0.64 [95% CI 0.53-0.73]) and also between Finn-FIQ total score and HAQ total score (r = 0.56 [95% CI 0.44-0.66]). Finn-FIQ questions had significant correlations with RAND-36 domains. Conclusion Finn-FIQ is a valid and feasible instrument to mirror the functioning of FM patients according to its internal consistency, correlation to general well-being, convergent validity and response rate. It covers the main components of the ICF framework hence reflecting the whole spectrum of functioning. Implications In our study Finn-FIQ was proven as a valid instrument with Finnish speaking FM patients. Original FIQ and other validated translations have already confirmed their place in fibromyalgia research. After this study Finnish fibromyalgia research can be included in those using the best-known instrument in validated form and native language. Current study showed also Finn-FIQ's ability to measure functioning of the FM patients, and it had good applicability among Finnish speaking patients. Therefore it can be recommended also for monitoring individual FM patients and their functioning for example during different treatment trials.

Comparative interrater reliability of Asian Stroke Disability Scale, modified Rankin Scale and Barthel Index in patients with brain infarction

BACKGROUND

This study tried to develop an Asian Stroke Disability Scale (ASDS) and compared its interrater reliability with modified Rankin Scale (mRS) and Barthel Index (BI).

METHODS

Three items including self-care, mobility, and daily activities were selected as variables for development of the ASDS. The variables were provisionally graded on a 2- to 4-point scale based on the importance of each item. Each of the variables was categorized into 3 categories. Afterward, 125 rater-patient assessments for each scale (mRS, BI, and ASDS) were performed on 25 stroke patients by 5 raters. For categorization of functional impairment as minor or major, the scores of mRS, BI and ASDS were categorized as ≤ 2 and > 2, < 90 and ≥ 90, and < 3 and ≥ 3, respectively.125 rater-patient assessments for each of the mRS, BI, and ASDS were performed on 25 stroke patients by five raters.

RESULTS

The quantitative variability of BI, mRS, and ASDS scores was not significant (P = 0.379; P = 0.780; and P = 0.835, respectively). Interrater variability of mRS, BI, and ASDS scores based on qualitative categorization was not significant (P = 1.000; P = 0.978; and P = 0.901, respectively). Paired interrater variability of mRS, BI, and ASDS scores based on qualitative categorization was not significant (P > 0.05).

CONCLUSION

The ASDS is easy to use, requires less than 1 minute to complete and is as valid as mRS and BI in assessment of functional impairment of patients with stroke.

A survey validation and analysis of undergraduate medical biochemistry practical curriculum in maharashtra, India

In order to review the strengths and weaknesses of medical biochemistry practical curriculum for undergraduates and to generate ideas to improve it, a questionnaire was sent to 50 biochemistry faculty members selected (through simple random sampling method) from 42 medical colleges of Maharashtra, India. 39 responded to the questionnaire, representing a 78% response rate. The internal consistency of the questionnaire sections was found to be satisfactory (>0.7). The respondents did not agree that the ongoing curriculum was in alignment with learning outcomes (8%), that it encouraged active learning (28%), helped to apply knowledge to clinical situations (18%) and promoted critical thinking and problem solving skills (28%). There were a number of qualitative experiments that were rated 'irrelevant'. Qualitative and quantitative experiments related to recent advances were suggested to be introduced by the respondents. Checklists for the practicals and new curriculum objectives provided in the questionnaire were also approved. The results of the curriculum evaluation suggest a need for re-structuring of practical biochemistry curriculum and introduction of a modified curriculum with more clinical relevance.

A Validated Stability-Indicating RP-UPLC Method for Simultaneous Determination of Desloratadine and Sodium Benzoate in Oral Liquid Pharmaceutical Formulations

A novel, sensitive and selective stability-indicating gradient reverse phase ultra performance liquid chromatographic method was developed and validated for the quantitative determination of desloratadine and sodium benzoate in pharmaceutical oral liquid formulation. The chromatographic separation was achieved on Acquity BEH C8 (100 mm × 2.1 mm) 1.7 μm column by using mobile phase containing a gradient mixture of solvent A (0.05 M KH(2)PO(4) and 0.07 M triethylamine, pH 3.0) and B (50:25:25 v/v/v mixture of acetonitrile, methanol and water) at flow rate of 0.4 mL/min. Column temperature was maintained at 40°C and detection was carried out at a wavelength of 272 nm. The described method shows excellent linearity over a range of 0.254 μg/mL to 76.194 μg/mL for desloratadine and 1.006 μg/mL to 301.67 μg/mL for sodium benzoate. The correlation coefficient for desloratadine and sodium benzoate was more than 0.999. To establish stability-indicating capability of the method, drug product was subjected to the stress conditions of acid, base, oxidative, hydrolytic, thermal and photolytic degradation. The degradation products were well resolved from desloratadine and sodium benzoate. The developed method was validated as per international ICH guidelines with respect to specificity, linearity, LOD, LOQ, accuracy, precision and robustness.

Performance and robustness of a multi-user, multi-spectrometer system for INAA

The laboratory for instrumental neutron activation analysis at the Reactor Institute Delft, Delft University of Technology uses a network of 3 gamma-ray spectrometers with well-type detectors and 2 gamma-ray spectrometers with coaxial detectors, all equipped with modern sample changers, as well as 2 spectrometers with coaxial detectors at the two fast rabbit systems. A wide variety of samples is processed through the system, all at specific optimized (and thus different) analytical protocols, and using different combination of the spectrometer systems. The gamma-ray spectra are analyzed by several qualified operators. The laboratory therefore needs to anticipate on the occurrence of random and systematic inconsistencies in the results (such as bias, non-linearity or wrong assignments due to spectral interferences) resulting from differences in operator performance, selection of analytical protocol and experimental conditions. This has been accomplished by taking advantage of the systematic processing of internal quality control samples such as certified reference materials and blanks in each test run. The data from these internal quality control analyses have been stored in a databank since 1991, and are now used to assess the various method performance indicators as indicators for the method’s robustness.

Predicting tumor response after preoperative chemoradiation using clinical parameters in rectal cancer

AIM: To evaluate the clinical parameters and identify a better method of predicting pathological complete response (pCR).

METHODS: We enrolled 249 patients from a database of 544 consecutive rectal cancer patients who underwent surgical resection after preoperative chemoradiation therapy (PCRT). A retrospective review of morphological characteristics was then performed to collect data regarding rectal examination findings. A scoring model to predict pCR was then created. To validate the ability of the scoring model to predict complete regression.

RESULTS: Seventy patients (12.9%) achieved a pCR. A multivariate analysis found that pre-CRT movability (P = 0.024), post-CRT size (P = 0.018), post-CRT morphology (P = 0.023), and gross change (P = 0.009) were independent predictors of pCR. The accuracy of the scoring model was 76.8% for predicting pCR with the threshold set at 4.5. In the validation set, the accuracy was 86.7%.

CONCLUSION: Gross changes and morphological findings are important predictors of pathological response. Accordingly, PCRT response is best predicted by a combination of clinical, laboratory and metabolic information.

Simultaneous Determination of Sitagliptin Phosphate Monohydrate and Metformin Hydrochloride in Tablets by a Validated UPLC Method

A novel approach was used to develop and validate a rapid, specific, accurate and precise reverse phase ultra performance liquid chromatographic (UPLC) method for the simultaneous determination of Sitagliptin phosphate monohydrate and Metformin hydrochloride in pharmaceutical dosage forms. The chromatographic separation was achieved on Aquity UPLC BEH C8 100 × 2.1 mm, 1.7 μm, column using a buffer consisting of 10 mM potassium dihydrogen phosphate and 2 mM hexane-1-sulfonic acid sodium salt (pH adjusted to 5.50 with diluted phosphoric acid) and acetonitrile as organic solvent in a gradient program. The flow rate was 0.2 mL min⁻¹ and the detection wavelength was 210 nm. The limit of detection (LOD) for Sitagliptin phosphate monohydrate and Metformin hydrochloride was 0.2 and 0.06 μg mL⁻¹, respectively. The limit of quantification (LOQ) for Sitagliptin phosphate monohydrate and Metformin hydrochloride was 0.7 and 0.2 μg mL⁻¹, respectively. This method was validated with respect to linearity, accuracy, precision, specificity and robustness. The method was also found to be stability-indicating.

New Stability Indicating RP-HPLC Method for the Estimation of Cefpirome Sulphate in Bulk and Pharmaceutical Dosage Forms

A simple stability indicating reversed-phase HPLC method was developed and subsequently validated for estimation of Cefpirome sulphate (CPS) present in pharmaceutical dosage forms. The proposed RP-HPLC method utilizes a LiChroCART-Lichrosphere100, C18 RP column (250 mm × 4mm × 5 μm) in an isocratic separation mode with mobile phase consisting of methanol and water in the proportion of 50:50 % (v/v), at a flow rate 1ml/min, and the effluent was monitored at 270 nm. The retention time of CPS was 2.733 min and its formulation was exposed to acidic, alkaline, photolytic, thermal and oxidative stress conditions, and the stressed samples were analyzed by the proposed method. The described method was linear over a range of 0.5-200μg/ml. The percentage recovery was 99.46. F-test and t-test at 95% confidence level were used to check the intermediate precision data obtained under different experimental setups; the calculated value was found to be less than the critical value.

Box-Behnken supported validation of stability-indicating high performance thin-layer chromatography (HPTLC) method: An application in degradation kinetic profiling of ropinirole

Stability-indicating high-performance thin-layer chromatographic (HPTLC) method for the analysis of ropinirole HCl was developed and validated as per the ICH guidelines. The method employed the mobile phase and toluene-ethyl acetate-6 M ammonia solution (5:6:0.5, v/v/v) was optimized with the help of a design expert. Densitometric analysis of ropinirole HCl was carried out in the absorbance mode at 250 and 254 nm. Compact spots for ropinirole HCl were found at R f value of 0.58 ± 0.02. The linear regression analysis data for the calibration plots showed R (2) = 0.9989 ± 0.0053 with a concentration range of 100-3000 ng spot(-1). The method was validated for precision, accuracy, ruggedness, robustness, specificity, recovery, limit of detection (LOD) and limit of quantitation (LOQ). The LOD and LOQ were 12.95 and 39.25 ng spot(-1) respectively. Drug was subjected to acidic, alkaline, oxidative, dry heat, wet heat and photo degradation stress. All the peaks of degradation products were well resolved from the standard drug peak with significant difference of R f. The acidic and alkaline stress degradation kinetics of ropinirole, were found to be in first order, showing high stability (t 1/2, 146.37 h(-1); t 0.9, 39.11 h(-1)) in the acidic medium and low stability (t 1/2, 97.67 h(-1); t 0.9, 14.87 h(-1)) in the alkaline environment.

Development and validation of a reversed-phase HPLC method for analysis of tetrahydrozoline hydrochloride in eye drop formulations

A simple, precise, accurate, and stability-indicating method is developed and validated for analysis of tetrahydrozoline hydrochloride in eye drop formulations. Separation was achieved on a reversed-phase C₈ column (125 mm×4.6 mm i.d., 5 μm) using a mobile phase consisting of acetonitrile/phosphate buffer of pH 3.0 (20:80, v/v) at a flow rate of 1.0 mL/min and UV detection at 240 nm. This method is validated according to United States Pharmacopeia requirements for new methods, which include accuracy, precision, selectivity, robustness, and linearity and range. This method shows enough selectivity, accuracy, precision, and linearity and range to satisfy Federal Drug Administration/International Conference on Harmonization regulatory requirements. The current method demonstrates good linearity over the range of 0.025-0.075 mg/mL of tetrahydrozoline with r² 0.999. The average recovery of the method is 100.8% with a relative standard deviation of 0.47%. The degree of reproducibility of the results obtained as a result of small deliberate variations in the method parameters and by changing analytical operators has proven that the method is robust and rugged.

Development and validation of RP-HPLC and RP-UPLC methods for quantification of erythropoietin formulated with human serum albumin

Rapid and sensitive reverse phase high performance liquid chromatography (RP–HPLC) and ultra performance liquid chromatography (UPLC) methods with UV detection for quantification of erythropoietin (EPO) in presence of human serum albumin (HSA) as a stabilizer in a pharmaceutical formulation of EPO have been developed and validated. Chromatography was performed with mobile phase containing 0.1% Trifluoroacetic acid (TFA) in MilliQ water and 0.1% TFA in acetonitrile with gradient program and a flow rate of 1.5 mL/min for HPLC and 0.35 mL/min for UPLC. Quantification was accomplished with internal reference standard (qualified using EP reference standard). The methods were validated for linearity (correlation coefficient=0.99), accuracy, precision and robustness. Robustness was confirmed by considering three factors; percentages of TFA in mobile phase, age of test sample and mobile phase and column temperature. Intermediate precision was confirmed by different analysts, different equipments and on different days. The relative standard deviation (RSD) value (<2%, n=30) indicated good precision of the developed method. The proposed RP-HPLC method had retention time less than 20 min while the developed UPLC method had retention time less than 4 min. Both the RP-HPLC and UPLC methods were simple, highly sensitive, precise and accurate, suggesting that the developed methods are useful for routine quality control.

Alternative methods in toxicology: pre-validated and validated methods

The development of alternative methods to animal experimentation has progressed rapidly over the last 20 years. Today, in vitro and in silico methods have an important role in the hazard identification and assessment of toxicology profile of compounds. Advanced alternative methods and their combinations are also used for safety assessment of final products. Several alternative methods, which were scientifically validated and accepted by competent regulatory bodies, can be used for regulatory toxicology purposes, thus reducing or fully replacing living animals in toxicology experimentation. The acceptance of the alternative methods as valuable tools of modern toxicology has been recognized by regulators, including OECD, FDA and EPA.This paper provides a brief overview of the topic "alternative methods in toxicology" and focuses on pre-validated and validated alternative methods and their position in the modern toxicology.

Rapid determination of anti-estrogens by gas chromatography/mass spectrometry in urine: Method validation and application to real samples

A fast screening protocol was developed for the simultaneous determination of nine anti-estrogenic agents (aminoglutethimide, anastrozole, clomiphene, drostanolone, formestane, letrozole, mesterolone, tamoxifen, testolactone) plus five of their metabolites in human urine. After an enzymatic hydrolysis, these compounds can be extracted simultaneously from urine with a simple liquid-liquid extraction at alkaline conditions. The analytes were subsequently analyzed by fast-gas chromatography/mass spectrometry (fast-GC/MS) after derivatization. The use of a short column, high-flow carrier gas velocity and fast temperature ramping produced an efficient separation of all analytes in about 4 min, allowing a processing rate of 10 samples/h. The present analytical method was validated according to UNI EN ISO/IEC 17025 guidelines for qualitative methods. The range of investigated parameters included the limit of detection, selectivity, linearity, repeatability, robustness and extraction efficiency. High MS-sampling rate, using a benchtop quadrupole mass analyzer, resulted in accurate peak shape definition under both scan and selected ion monitoring modes, and high sensitivity in the latter mode. Therefore, the performances of the method are comparable to the ones obtainable from traditional GC/MS analysis. The method was successfully tested on real samples arising from clinical treatments of hospitalized patients and could profitably be used for clinical studies on anti-estrogenic drug administration.

Validated HPLC Method for Concurrent Determination of Antipyrine, Carbamazepine, Furosemide and Phenytoin and its Application in Assessment of Drug Permeability through Caco-2 Cell Monolayers

The present work explains the development and validation of a simple, rapid and sensitive liquid chromatographic method for the simultaneous determination of antipyrine (ANT), carbamazepine (CBZ), furosemide (FSD) and phenytoin (PHTN). Chromatographic analysis was carried out by a reversed phase technique on a C18 column, using water pH 3.0 and 50:50 mixtures of methanol and acetonitrile (58:42 v/v) as the mobile phase, at a flow-rate of 1.0 ml/min and a column temperature of 40°C. Detection was carried out at 205 nm for CBZ and PHTN and at 230 nm for ANT and FSD. The proposed method was evaluated for validation parameters including linearity, range, accuracy, precision, limit of detection (LOD), limit of quantification (LOQ) and specificity. Elution of drugs ANT, FSD, PHTN, and CBZ was observed at 4.1, 5.1, 12.3 and 13.5 min, respectively. The method was found to be linear (R² ≥ 0.999) in the concentration range of 5–100 μM, with an acceptable accuracy and relative standard deviation. Results of intra- and inter-day validation (n=3) showed the method to be efficient for routine determination of these permeability markers in Caco-2 cell monolayer permeability studies. The method was successfully utilized for determination of standard compounds in Caco-2 permeability experiments.

Simple and sensitive stability-indicating ion chromatography method for the determination of cyclopropylamine in nevirapine and moxifloxacin hydrochloride drug substances

A simple and sensitive ion chromatography method has been developed for the determination of cyclopropylamine (CPA) in nevirapine (NEV) and moxifloxacin HCl (MOX) pharmaceutical drug substances. Efficient chromatographic separation was achieved on a Metrosep C4, 5 μm (250 mm × 4.0 mm) column. The mobile phase consists of 5 mM hydrochloric acid containing 10% (v/v) acetonitrile and was delivered in an isocratic mode at a flow rate of 0.9 mL min⁻¹ at 27°C. A conductometric detector was used for the detection of the analyte. The drug substances were subjected to stress conditions including oxidation, thermal, photolytic and humidity for the evaluation of the stability-indicating nature of the method. The method was validated for specificity, precision, linearity, accuracy and solution stability. The limit of detection (LOD) and limit of quantification (LOQ) values are 0.10 μg mL⁻¹ and 0.37 μg mL⁻¹ respectively. The linearity range of the method is between 0.37 μg mL⁻¹ and 1.5 μg mL⁻¹ and the correlation coefficient is found to be 0.9971. The average recoveries of CPA in NEV and MOX are 97.0% and 98.0%, respectively.

A Sensitive and Simple HPLC-UV Method for Trace Level Quantification of Ethyl p-Toluenesulfonate and Methyl p-Toluenesulfonate, Two Potential Genotoxins in Active Pharmaceutical Ingredients

A sensitive and simple HPLC/UV method has been developed and validated for the determination of two potential genotoxic impurities, namely methyl p-toluenesulfonate (MPTS) and ethyl p-toluenesulfonate (EPTS) at trace levels in Pemetrexed sodium API. Applying the concept of threshold of toxicological concern (TTC), a limit of 3 ppm each for both genotoxins was calculated based on the maximum daily dose of API. A reversed phase LC method using UV detection was developed and validated. The method was found to be specific and selective for the application. The limit of detection (LOD) and limit of quantitation (LOQ) for both MPTS and EPTS was found to be 0.15 ppm (0.009 μg mL(-1)) and 0.5 ppm (0.03 μg mL(-1)), respectively, with respect to sample concentration. The calibration curves of MPTS and EPTS were linear over the concentration range from LOQ to 6 μg/mL. The method was found to be specific, precise, linear and accurate and has been successfully applied to determine the two genotoxins in commercial batches of the API.

Validated RP-HPLC Method for Simultaneous Quantitation of Losartan Potassium and Metolazone in Bulk Drug and Formulation

A HPLC method has been described for simultaneous determination of Losartan potassium and Metolazone in formulation. This method is based on a HPLC separation of the two drugs on the Thermo Hypersil BDS–C₁₈ (250 mm × 4.6 mm, 5.0 μm) with isocratic conditions and a simple mobile phase containing acetonitrile:water (60:40) at a flow rate of 0.8 mL/min using UV detection at 237 nm. This method has been applied to a marketed formulation without interference of excipients. The linear regression analysis data for the calibration plots showed a good linear relationship over the concentration range of 2–12 μg/mL for Losartan potassium and 0.2–1.2 μg/mL for Metolazone, respectively. The method was validated for precision, robustness and recovery. Statistical analysis showed that the method is repeatable and selective for the estimation of Losartan potassium and Metolazone.

Evaluation of the rubella surveillance system in Quebec

OBJECTIVE

To evaluate the validity of information in the rubella surveillance system in Quebec.

DATA AND METHODS

Cases of rubella in the provincial registry of notifiable diseases, "Maladies à declaration obligatoire" (MADO), from 1994 to 1996 were matched with laboratory-identified cases and with cases in a reference file created from all case investigation records of regional departments of public health for the same period. Sensitivity and the proportion of cases in agreement were calculated.

RESULTS

Compared with laboratories, the sensitivity of the provincial registry was 56%. Compared with the reference file, global sensitivity (confirmed cases plus clinical cases) was 58% and the positive predictive value was 50%. Of the 356 cases reported to regional public health departments, 65% were classified in the same diagnostic category (confirmed case, clinical case, excluded case) by public health professionals and a group of experts (weighted kappa=0.32). Information on rubella vaccination status was missing in 25% of cases in the MADO file for rubella.

CONCLUSIONS

Notification of positive results for immunoglobulin M antibodies and viral cultures should be required of all laboratories. Uniform procedures should be adopted and applied for the validation of cases that are reported to regional departments of public health. In the context of the rarefaction of rubella, any immunoglobulin M-positive result should be interpreted using all available epidemiological information.

Stability indicating LC-method for estimation of paracetamol and lornoxicam in combined dosage form

A simple, specific and stability indicating reversed phase high performance liquid chromatographic method was developed for the simultaneous determination of paracetamol and lornoxicam in tablet dosage form. A Brownlee C-18, 5 μm column having 250×4.6 mm i.d. in isocratic mode, with mobile phase containing 0.05 M potassium dihydrogen phosphate:methanol (40:60, v/v) was used. The flow rate was 1.0 ml/min and effluents were monitored at 266 nm. The retention times of paracetamol and lornoxicam were 2.7 min and 5.1 min, respectively. The linearity for paracetamol and lornoxicam were in the range of 5–200 μg/ml and 0.08–20 μg/ml, respectively. Paracetamol and lornoxicam stock solutions were subjected to acid and alkali hydrolysis, chemical oxidation and dry heat degradation. The proposed method was validated and successfully applied to the estimation of paracetamol and lornoxicam in combined tablet dosage form.

Development and validation of an HPLC-UV method for the quantification of carbamazepine in rabbit plasma

An isocratic simple rapid assay has been developed and validated for the determination of carbamazepine (CBZ) in both solution form and rabbit plasma using propylparaben as an internal standard. The assay was performed using a μ-Bondapak C18 (150 mm × 4.6 mm i.d) with a mobile phase consisting of methanol and water (50:50), the flow rate was 1 ml/min and UV detection at 285 nm. The method was found to be specific for CBZ, no interfering peaks were observed with an overall analytical run time of 15 min. Accuracy reported as % recovery were found to be 98.37-100.45% and 97.53-103.58% for inter-day and intra-day accuracies, respectively. Inter-day precision (reproducibility) was found to be 0.53-2.75% RSD, while intra-day precision (repeatability) was found to be 1.06-3.7% RSD for the samples studied. The calibration curve was found to be linear with the equation y = 0.2847x + 0.0138, with a correlation coefficient of 0.9999 (R (2)) over a concentration range of 0.5-40 μg/ml. The limit of quantitation was the lowest concentration. The method is simple and rapid and does not require any preliminary treatment of the sample. The method was fully validated.

Homology modeling of Ferredoxin-nitrite reductase from Arabidopsis thaliana

Nitrogen is one of the major growth-limiting nutrients for plants: The main source of nitrogen in most of the higher plants is nitrate taken up through roots. Nitrate can be reduced both in the chloroplasts (photosynthetic tissues) and in proplastes (nonphotosynthetic tissues) such as roots. Ferredoxin-nitrite reductase (NiR) catalyses the reduction of nitrite to ammonium in the second step of the nitrate- assimilation pathway. Homology model of Ferredoxin-nitrite reductase has been constructed using the X-ray structure (PDB code: 2akj) a s a template and MODELLER 9v5 software. The resulting model assessed by PROCHECK, PROSAII and RMSD that showed the final refined model is reliable: has 81% of amino acid sequence identity with template, 0.2Å as RMSD and has (-10.37) as Z-scores, the Ramachandran plot analysis showed that conformations for 99.5 % of amino acid residues are within the most favored regions. The model could prove useful in further functional characterization of this protein.

ABBREVIATIONS

PDB - Protein Data Bank, NMR - Nuclear Magnetic Resonance, NiR - Nitrite Reductase, RMSD - Root Mean Squared Deviation, Fd - ferredoxin.

Validation and reliability of distress thermometer in chinese cancer patients

OBJECTIVE

To examine the validation and reliability of the distress thermometer (DT) recommended by National Comprehensive Cancer Network (NCCN) in Chinese cancer patients.

METHODS

A total of 574 Chinese cancer patients from Beijing Cancer Hospital completed the detection of DT, the Hospital Anxiety and Depression Scale (HADS) and Symptom Checklist 90 (SCL-90), Receiver Operating Characteristic (ROC) curve and Area Under the Curve (AUC) were used to analyze the validation relative to HADS and SCL-90. The patients with DT≥4 and whose distress caused by emotional problems were interviewed with the MiNi International Neuro-psychiatric Interview (MINI) (Chinese Version 5.0). This version was used to analyze cancer patients' psychological and Psychiatric symptoms during the cancer process; 3. Another 106 cancer patients in rehabilitation stage and stable condition were asked to fill in DT two times, at the base time and after 7-10 days.

RESULTS

Data of ROC indicates that a DT cutoff score of 4 yielded AUC of 0.80 with a optimal sensitivity (0.80) and specificity (0.70) relative to HADS, and AUC of 0.83 with the greatest sensitivity (0.87) and specificity (0.72) against SCL-90. The DT also has acceptable test-retest reliability (r=0.800, P=0.000); According to the interview results, the most common psychiatric problems cancer patients have adjustment disorder, depression, and anxiety.

CONCLUSION

The data suggest that DT has acceptable overall accuracy and reliability as a screening tool for testing distress severity and specific problems causing distress in Chinese cancer patients. It is worth being used in oncology clinic, the rapid screening and interview could help caregivers to identify psychological and psychiatric problems of cancer patients and provide useful information for further treatment.

Validation Protocol: First Step of a Lean-Total Quality Management Principle in a New Laboratory Set-up in a Tertiary Care Hospital in India

Method validation is pursued as the first step in establishing Lean-Total Quality Management in a new clinical laboratory, in order to eliminate error in test results. Validation of all the new tests were done (with particular reference to alkaline phosphatase) by verifying reference intervals, analytical accuracy and precision, inter-assay and intra-assay variations, analytical sensitivity, limit of detection, linearity and reportable range, i.e. (i) Analytical measurement range (AMR) and (ii) Clinically reportable range (CRR). Our obtained reference range was within that of the manufacturer's and showed high degree of analytical accuracy between two laboratories (r(2) = 0.99). Precision was comparable with the manufacturer's claim with inter-assay variation CV 1.04% and intra-assay variation CV 1.54%. Lowest limit of detection was 1.0324 ± 0.007 with CV 0.34%. AMR was also verified with CV 1.26 and 0.69%, for level 1 and level 2 control sera, respectively. The assay was linear with different dilutions. Lean concept was also verified with high recovery percentage. Validation ensures that accurate and precise results are reported in a clinically relevant turn around time.

A new validated liquid chromatographic method for the determination of loratadine and its impurities

An improved gradient, reversed-phase liquid chromatographic (RP-LC) method was developed and subsequently validated for the determination of Loratadine and its impurities/degradation products in pharmaceutical drug substance. Separation was achieved with Inertsil ODS-3V, 250 × 4.6 mm, 5μ column with gradient elution at a flow rate of 1.0 mL min⁻¹. UV detection was performed at 220 nm. The described method is linear over a range of LOQ (0.044, 0.088, 0.084, and 0.072 μg mL⁻¹ for impurity-B, impurity-C, impurity-D, and impurity-E respectively) to 1.2 μg mL⁻¹ (0.6 μg mL⁻¹ of the specification limit) for all the impurities and degradation products. The recovery of impurities were found to be in the range of 85–115 %. The method is simple, selective, and accurate for the quantification of impurities and degradation products of Loratadine in its bulk drug samples.

Optimization of forced degradation using experimental design and development of a stability-indicating liquid chromatographic assay method for rebamipide in bulk and tablet dosage form

A novel stability-indicating RP-HPLC assay method was developed and validated for quantitative determination of rebamipide in bulk and tablet dosage form. Rebamipide (drug and drug product) solutions were exposed to acid and alkali hydrolysis, thermal stress, oxidation by hydrogen peroxide and photodegradation. Experimental design has been used during forced degradation to determine significant factors responsible for degradation and to obtain optimal degradation conditions. In addition, acid and alkali hydrolysis was performed using a microwave oven. The chromatographic method employed the HiQ sil C-18HS (250 × 4.6 mm; 5 μm) column with mobile phase consisting of 0.02 M potassium phosphate (pH adjusted to 6.8) and methanol (40:60, v/v) and the detection was performed at 230 nm. The procedure was validated for specificity, linearity, accuracy, precision and robustness. There was no interference observed of excipients and degradation products in the determination of the active pharmaceutical ingredient. The method showed good accuracy and precision (intra and inter day) and the response was linear in a range from 0.5 to 5 μg mL(-1). The method was found to be simple and fast with less trial and error experimentation by making use of experimental design. Also, it proved that microwave energy can be used to expedite hydrolysis of rebamipide.

Rapid simultaneous determination of telmisartan, amlodipine besylate and hydrochlorothiazide in a combined poly pill dosage form by stability-indicating ultra performance liquid chromatography

A simple, precise and rapid stability-indicating ultra-performance liquid chromatography (UPLC) method is developed for the simultaneous quantitative determination of Telmisartan, Amlodipine besylate and Hydrochlorothiazide from their innovative poly pill combination drug product in the presence of degradation products. It involves a 100 mm x 2.1 mm, 1.7 μm C-18 column. The separation is achieved on a simple gradient method. The mobile phase A contains a mixture of sodium perchlorate buffer pH 3.2 (0.053M): acetonitrile in the ratio 90:10, v/v, and mobile B contains a mixture of sodium perchlorate buffer pH 3.2 (0.053M): acetonitrile in the ratio 20:80, v/v. The flow rate is 0.6 mL min(-1) and the column temperature is maintained at 55°C.The gradient program (T/%B) is set as 0/5, 1.2/5, 1.6/40, 4/40, 4.1/5 and 4.5/5. The detector wavelength is 271 nm for Hydrochlorothiazide and Telmisartan and 237 nm for Amlodipine. The retention times of Telmisartan, Amlodipine, and Hydrochlorothiazide are 3.6 minutes, 3.2 minutes and 0.9 minutes; respectively. The total runtime for the separation of the three active compounds and their degradation products is 4.5 minutes. The described method is validated with respect to system suitability, specificity, linearity, precision and accuracy. The precision of the assay method is evaluated by carrying out six independent assays of T, A and H (0.032 mg mL(-1) of T, 0.004 mg mL(-1) of A, 0.01 mg mL(-1) of H). The accuracy of the method is evaluated in triplicate at three concentration levels, i.e. 50%, 100% and 150% of target test concentration (0.64 mg mL(-1) of T, 0.08 mg mL(-1) of A, 0.2 mg mL(-1) of H). The described method is linear over the range, 16 to 48 μg mL(-1) for T, 2 to 6 μg mL(-1)A and 5 to 15 μg mL(-1) for H. The method is fast and suitable for high-throughput analysis allowing the analysis of about 250 samples per working day.

Development and validation of a rapid HPLC method for simultaneous analysis of budesonide and its novel synthesized hemiesters in colon specific formulations

A simple and reliable reversed-phase high performance liquid chromatographic (HPLC) method was developed, validated and applied for determination of budesonide and its novel synthesized hemiesters in colon specific formulations and dissolution media. The method was employed on a μ-Bondapak C(18) column (250 mm × 4.6 mm, 5 μm) at ambient temperature. The mobile phase consisted of acetonitrile: monobasic potassium phosphate containing orthophosphoric acid (55:45, pH 3.2) at a flow rate of 1 ml/min. The UV detection wavelength was set at 244 nm and 50 μL of sample was injected into the HPLC system. Dexamethasone was used as the internal standard. The retention times for internal standard and budesonide were 4.5 and 7.2 min, respectively. The method was linear in the concentration range of 1-20 μg/ml of budesonide (R(2)>0.999). Limit of detection and limit of quantitation were 0.05 and 0.5 μg/ml, respectively. The method presented the requisite accuracy, selectivity, sensitivity and precision and showed good resolution for separation of the drug and related derivatives in the presence of excipients. The proposed method was successfully used for analysis of the drug and its derivatives in dissolution media and oral colon specific formulations prepared in our laboratory with enough reproducibility.