A simple HPLC assay for determining eltrombopag concentration in human serum.

Eltrombopag, a thrombopoietin receptor agonist, is used for the treatment of idiopathic thrombocytopenic purpura (ITP) and aplastic anemia. We developed a HPLC assay for the determination of serum eltrombopag concentration in ITP patients. An aliquot of a serum sample spiked with diclofenac as the internal standard (IS) was treated with acetonitrile to precipitate the proteins. Eltrombopag and the IS were separated on an octadecylsilyl silica-gel column using a mobile phase consisting of 10 mM 1-pentanesulfonic acid sodium salt, acetonitrile, and acetic acid. The detection wavelength was set at 265 nm. The calibration curve was linear at the concentration range of 0.15-12.5 µg/mL for eltrombopag (r = 0.9987). The recoveries of eltrombopag from the serum samples were greater than 95.9% with coefficients of variation (CVs) being less than 2.8%. The CVs for the intra-day and inter-day assays were 1.9-11.8% and 1.0-11.8%, respectively. This assay method could be used for therapeutic drug monitoring of eltrombopag in ITP patients.

Process analytical technology for continuous manufacturing tableting processing: A case study.

The use of Near Infrared Spectroscopy (NIRS) as a fast and non-destructive technique was employed for the control and monitoring of the tableting step during a continuous manufacturing process. Two NIRS methods were optimized in order to in-line control the blend uniformity in the tablet feed frame and the API concentration of freshly pressed tablets prior the ejection. The novelty of this work first lies in the acquisition speed of NIR spectra reaching up to 70,000 tablets/h. Partial Least Square (PLS) regression was used as chemometric tool for the computation that resulted in excellent predictive calibration results. A coefficient of correlation (r) value of 0.99 was obtained for both probes. The root mean square error of calibration (RMSEC) and the root mean square error of prediction (RMSEP) were respectively 1.8% and 1.8% for active content in the tablet feeder and 2.2% and 2.3% for the tablet content. In addition, calibration performance and robustness of the methods were evaluated. Moreover several qualitative methods were proposed to monitor the tableting process in different stages of development (single wavelength, Principal Component Analysis, and Independent Component Analysis). In early phase development, the requirement/quality of the input material is not established yet; hence the use of a qualitative approach allows to confirm the suitability of the PAT methodology for in-process material monitoring & control. Later, the qualitative approach constitutes the foundation for the quantitative approach when input materials are fixed and larger production size occurs. The proposed strategy is a performant PAT tool for continuous manufacturing and a step forward to real time release.

Quality surveillance of immediate release aceclofenac tablets (100 mg) available in local market.

Aceclofenac is considered to be an effective drug that has been widely prescribed for multi-medical complaints globally. Owing to high demand many generic counterpart of aceclofenac tablets are now available in the commercial market. The aim of the present work is to evaluate and compare the quality attributes of various national/local brands of aceclofenac immediate release tablets (100mg) with the standard multi-national brand available in Pakistan. Physico-chemical evaluation was performed by determining the average tablet weight, thickness, hardness, disintegration time, percent dissolution and assay. Moreover, brands and reference formulation were exposed to multipoint dissolution. The in vitro drug release pattern was examined in various pH environment (1.2, 4.5 and 6.8) using USP dissolution apparatus 2 (paddle) at 50 rpm. The data was then analyzed by model dependent (Zero-order, first-order, Higuchi, Hixson-Crowell, Korsmeyer & Peppas, and Weibull model), pair wise procedure (f1 & f2) and one-way ANOVA methods. Results showed that the all aceclofenac brands and the reference tablets followed Weibull kinetics at pH 6.8. f1 & f2 were also found to be within the acceptable FDA limits. Furthermore, the values of One-way ANOVA also confirmed the absence of any significant difference among various aceclofenac brands.

Quality evaluation and in vitro interaction studies between levofloxacin 250mg and diclofenac sodium 50mg tablets.

Fluoroquinolones are broad-spectrum antibiotics, work against Gram-positive and Gram-negative bacteria and are a clinically proven option for many resistant infections. Among fluoroquinolones Levofloxacin works best against acute sinusitis, inflammation of the lower airways, acute exacerbation of chronic bronchitis, community acquired pneumonia, complicated urinary tract infection including Pyelonephritis, chronic bacterial prostatitis and skin and soft tissue infection. Levofloxacin is a frequently prescribed antibacterial agent with Diclofenac Sodium for pain management in infectious conditions. The objective of the present work is to evaluate the level of interaction between Levofloxacin and Diclofenac Sodium. In this work market available brands of both drugs were also evaluated for quality.The physiochemical parameters like weight variation, thickness variation, and mechanical strength were determined. Similarly the percentage drug release and content uniformity test were also analyzed; the tested quality attributes were found within the recommended pharmacopeia ranges except brand L(6) that had high drug content 124.629±3.614 while brand L(4) and L(5) were not found similar in pH 1.2. When subjected to model dependent analysis Levofloxacin showed compliance with (first order, Higuchi, Hixson Crowell and Weibull) at pH (1.2, 4.5 and 6.8). However Diclofenac Sodium showed adherence with (first order, Hixson Crowell and Weibull) at pH (1.2, 4.5 and 6.8) but following Higuchi at pH 1.2 and 4.5 only. The interaction studies were also performed spectrophotometrically and simultaneous equation was used to estimate the percentage availability of both the drugs at pH 4.5, 6.8, FaSSGF and FaSSIF. The studies showed that the percent availability of Levofloxacin was increased significantly in FaSSIF i.e. 129.173±0.323 at 45 minutes in the presence of Diclofenac Sodium.

Simultaneous determination of diclofenac, its human metabolites and microbial nitration/nitrosation transformation products in wastewaters by liquid chromatography/quadrupole-linear ion trap mass spectrometry.

An analytical method was developed and validated for the first determination of five major human metabolites of the non-steroidal anti-inflammatory drug diclofenac as well as two microbial transformation products in wastewater. The method was based on the extraction of diclofenac and the chemically synthetized compounds by solid-phase extraction (SPE), using a hydrophilic-lipophilic balanced polymer followed by liquid chromatography (LC) coupled to hybrid quadrupole-linear ion trap mass spectrometry (QqLIT-MS). Quantitation was performed by the internal standard approach, to correct for matrix effects. The accuracy of the method was generally higher than 40% for raw and treated wastewater with a precision below 12%. In wastewater influent and effluent samples the detection limits for the majority of target compounds were 0.3-2.5ngL(-1) and 0.1-3.1ngL(-1), respectively. The method was applied to the analysis of influent and effluent wastewater samples from urban wastewater treatment plants. Moreover, to obtain an extra tool for confirmation and identification of the studied diclofenac-derived compounds, Information-Dependent Acquisition (IDA) experiments were performed, with selected reaction monitoring (SRM) as the survey scan and an enhanced product ion (EPI) scan as the dependent scan. Diclofenac and its major human metabolite, 4'-hydroxydiclofenac were detected in all samples at concentrations of 331-1150ngL(-1) and 585-6000ngL(-1), respectively. Neither microbial transformation product of diclofenac was detected in any of the influent samples analyzed, but in effluents, their concentrations ranged from 4 to 105ngL(-1).

Exploring the perspectives of potential consumers and healthcare professionals on the readability of a package insert: a case study of an over-the-counter medicine.

PURPOSE: To explore and compare the opinions of physicians, pharmacists and potential users on the readability of a package insert of an over-the-counter medicine. METHODS: Exploratory study based on the administration of a semi-open questionnaire. This instrument was developed according to the readability guideline of the European Medicine Agency (EMA) and used to evaluate participants' accessibility to, and comprehensibility of, the package insert for diclofenac 12.5 mg tablets. Sixty-three participants were recruited from the Lisbon region and enrolled in three groups: physicians (Dg), pharmacists (Pg) and potential consumers (PCg), with a minimum of 20 participants each. RESULTS: Almost all (85 %) of the 20 PCg participants were educated above the 9th grade, although the majority of them (95 %) referred to, at least, one package insert interpretation issue, mainly related to the comprehension of technical terms. Amongst other differences between the groups, the Pg participants (n = 22) obtained a significantly less favourable opinion regarding the layout of the titles. Furthermore, the Pg and Dg (n = 21) participants proposed technical enhancements, such as the use of a table to explain the posology, precautions in case of renal failure, or the recommendation to take the tablets with meals. CONCLUSIONS: Differences in the way of using the diclofenac tablets are expected, considering the comprehension dissimilarities between health professionals and potential consumers. The package insert of diclofenac 12.5 mg could be enhanced for safer use. Regarding the readability assessment of this package insert, the method proposed in the EMA guidelines might not be as effective as expected. Future research is advisable.

Effects of material properties and speed of compression on microbial survival and tensile strength in diclofenac tablet formulations.

A work has been done to study the effects of material properties and compression speed on microbial survival and tensile strength in diclofenac tablet formulations. Tablets were produced from three formulations containing diclofenac and different excipients (DC, DL and DDCP). Two types of machines (Hydraulic hand press and single punch press), which compress the tablets at different speeds, were used. The compression properties of the tablets were analyzed using Heckel and Kawakita equations. A 3-dimensional plot was produced to determine the relationship between the tensile strength, compression speed and percentage survival of Bacillus subtilis in the diclofenac tablets. The mode of consolidation of diclofenac was found to depends on the excipient used in the formulation. DC deformed mainly by plastic flow with the lowest Py and Pk values. DL deformed plastically at the initial stage, followed by fragmentation at the later stage of compression, whereas DDCP deformed mainly by fragmentation with the highest Py and Pk values. The ranking of the percentage survival of B. subtilis in the formulations was DDCP > DL > DC, whereas the ranking of the tensile strength of the tablets was DDCP > DL > DC. Tablets produced on a hydraulic hand press with a lower compression speed had a lower percentage survival of microbial contaminants than those produced on a single punch press, which compressed the tablets at a much higher speed. The mode of consolidation of the materials and the speed at which tablet compression is carried out have effects on both the tensile strength of the tablets and the extent of destruction of microbial contaminants in diclofenac tablet formulations.

Isotope pattern deconvolution-tandem mass spectrometry for the determination and confirmation of diclofenac in wastewaters.

Isotope dilution mass spectrometry (IDMS) based on isotope pattern deconvolution (IPD) has been applied here to MS/MS (QqQ) in order to carry out the quantification and confirmation of organic compounds in complex matrix water samples without the use of a methodological IDMS calibration graph. In this alternative approach, the isotope composition of the spiked sample is measured after fragmentation by SRM and deconvoluted into its constituting components (molar fractions of natural abundance and labeled compound) by multiple linear regression (IPD). The procedure has been evaluated for the determination of the pharmaceutical diclofenac in effluent and influent urban wastewaters and fortified surface waters by UHPLC (ESI) MS/MS using diclofenac-d(4) as labeled compound. Calculations were performed acquiring a part and the whole fragment cluster ion, achieving in all cases recoveries within 90-110% and coefficients of variation below 5% for all water samples tested. In addition, potential false negatives arising from the presence of diclofenac-d(2) impurities in the labeled compound were avoided when the proposed approach was used instead of the most usual IDMS calibration procedure. The number of SRM transitions measured was minimized to three to make possible the application of this alternative technique in routine multi-residue analysis.

Development of a new sodium diclofenac certified reference material using the mass balance approach and ¹H qNMR to determine the certified property value.

Certified reference materials (CRMs) are essential tools to guarantee the metrological traceability of measurement results to the International System of Units (SI), which means the accuracy and comparability of results over time and space. In the pharmaceutical area, only a few CRMs are available and the use of (non-certified) reference materials is a much more common practice. In this paper, the studies on a new candidate CRM of sodium diclofenac based on the ISO Guides 34:2009 and 35:2005 are described. The project steps included characterization, homogeneity test, stability studies, and uncertainties estimation. In the characterization, the mass fractions of organic, inorganic, and volatile impurities were determined, and the results were cross-checked by independent reference methods or interlaboratorial study. The API mass fraction was calculated by mass balance and cross-checked by quantitative proton nuclear magnetic resonance (¹H qNMR). The paper also presents a Monte Carlo simulation to estimate the measurement uncertainty as an approach to validate the GUM results in ¹H qNMR. The homogeneity between batch units was verified, and the candidate CRM stability under transport and storage conditions was evaluated in short- and long-term stability studies. The CRM certified property value and corresponding expanded uncertainty, obtained from the combined standard uncertainty multiplied by the coverage factor (k=2), for a confidence level of 95%, was (999.76+0.10) mg g⁻¹.

Mathematical evaluation of similarity factor using various weighing approaches on aceclofenac marketed formulations by model-independent method.

The US Food and Drug Administration's (FDA's) guidance for industry on dissolution testing of immediate-release solid oral dosage forms describes that drug dissolution may be the rate limiting step for drug absorption in the case of low solubility/high permeability drugs (BCS class II drugs). US FDA Guidance describes the model-independent mathematical approach proposed by Moore and Flanner for calculating a similarity factor (f2) of dissolution across a suitable time interval. In the present study, the similarity factor was calculated on dissolution data of two marketed aceclofenac tablets (a BCS class II drug) using various weighing approaches proposed by Gohel et al. The proposed approaches were compared with a conventional approach (W = 1). On the basis of consideration of variability, preference is given in the order of approach 3 > approach 2 > approach 1 as approach 3 considers batch-to-batch as well as within-samples variability and shows best similarity profile. Approach 2 considers batch-to batch variability with higher specificity than approach 1.

Polarographic behaviour of Aceclofenac, Tenoxicam and Droxicam in a methanol-water mixture.

A polarographic study about how three anti-inflammatories, such as Aceclofenac, Tenoxicam and Droxicam behave, using tast polarography (TP) and differential pulse polarography (DPP) was carried out. These studies were always carried out in a media formed by Methanol-Britton-Robinson aqueous buffer (0.1M) (4:96 (v/v)) due to the low solubility of these drugs in water. A strong influence of pH on analytical signals was observed, showing that the optimal pH values were between 4 and 5. Using DPP in the optimal experimental conditions, a detection limit of 10 ppb for Tenoxicam and Droxicam and 52 ppb for Aceclofenac was reached. The DPP proposed method was successfully applied to the determination of the active compounds in commercial drugs.

A study to determine the efficacy and safety of tenoxicam versus piroxicam, diclofenac and indomethacin in patients with osteoarthritis: a meta-analysis.

OBJECTIVE: To obtain a better quantitative and qualitative estimate of the effect of tenoxicam (Tx) compared to piroxicam (Px), diclofenac (Dcl) and indomethacin (Ind) in the treatment of osteoarthritis (OA). METHODS: Relevant studies were identified using computerized Medline search, manual search of cited references and correspondence with investigators, colleagues and the manufacturer of Tx. Once the studies were selected and chosen on the basis of predetermined methodologic criteria, the required data were extracted by 2 authors, independently. Eighteen studies met the required eligibility criteria. Meta-analyses were undertaken on 12 studies of Tx vs Px, 3 studies of Tx vs Dcl, and 2 studies of Tx vs Ind. Efficacy was measured in 2 ways: (1) physician global rating scale and (2) pain scale. Safety was measured in 3 ways: (1) physician global rating scale, (2) number of patients with adverse events, and (3) dropouts due to adverse events. RESULTS: The following findings of the meta-analysis were statistically significant: In Tx vs Px comparisons, efficacy-(1), safety-(1) and safety-(3) were all better with Tx; in Tx vs Ind comparisons, safety-(1) and safety-(2) were better with Tx. All other findings showed no statistically significant differences between Tx and the comparison drug. CONCLUSIONS: Compared to Px, Tx performs better on physician assessment of efficacy and tolerability, but the other comparisons remain inconclusive. Compared to Dcl, there appears not to be a difference. Compared to Ind, Tx is safer.

A two-year, placebo-controlled trial of non-steroidal anti-inflammatory therapy in osteoarthritis of the knee joint.

Eighty-nine patients with established OA of the knee joint, already on regular NSAIDs for joint pain, were randomly allocated to receive 100 mg/day of slow release diclofenac (45 patients) or matching placebo (44), in place of their NSAID, for 2 years. Thirty-eight patients withdrew or dropped out of the study. The major causes for withdrawal were lack of efficacy (three active, 12 placebo, P < 0.01) or side effects (six active, five placebo), and most withdrawals occurred within the first 6 months. Long term follow up of these patients was not possible. Fifty-one patients completed the study (31 active, 20 placebo), 35 of whom reported that they were the same or better at the end of the 2-year period than at the beginning. Most of the recorded clinical parameters showed little or no change over 2 years in these 51 subjects, and in 70% there was no detectable change in the radiographs. We conclude that long term placebo-controlled trials are both feasible and ethical in knee OA, but that conventional clinical and radiographic techniques detect very little change in joint structure or function over a 2-year time period. This may reflect the insensitivity of the methods used to assess progression rather than absence of change. The fact that 20 of 44 patients changed from an NSAID to placebo completed the 2-year study without any symptomatic penalty indicates that not all patients entered needed or responded to NSAIDs.

Arthrotec: a therapeutic option in the management of arthritis.

Arthrotec (Searle) is a new concept in NSAID therapy that provides powerful anti-inflammatory efficacy with enhanced upper GI safety. Arthrotec comprises an enteric-coated core of diclofenac sodium (50 mg) surrounded by a mantle of misoprostol (200 mcg). Two multicentre trials evaluated the efficacy of Arthrotec in rheumatoid arthritis (RA) and osteoarthritis (OA) patients who were randomised to receive either Arthrotec or diclofenac. The results of all arthritis assessments showed Arthrotec to be as effective as diclofenac in treating the signs and symptoms of RA and OA. Two endoscopic studies compared the antiarthritic efficacy and gastroduodenal safety of Arthrotec and diclofenac. In a 12-week study of RA patients, the antiarthritic efficacy of Arthrotec was equivalent to diclofenac; in addition, 60% fewer patients taking Arthrotec experienced ulcers than did those taking diclofenac (4.4% Arthrotec vs 11.1% diclofenac: P = 0.034). In a 4-week study of OA patients, Arthrotec's efficacy was equivalent to that of diclofenac and the Arthrotec group developed no ulcers, while 3.6% of the diclofenac group had ulcers (P = 0.015). In a trial conducted to compare the efficacy and upper gastroduodenal safety of Arthrotec with those of piroxicam and naproxen, patients with OA received either Arthrotec BID piroxicam 10 mg BID, or naproxen 375 BID for 4 weeks. Arthritis assessments showed Arthrotec to be at least as effective as piroxicam and naproxen in treating OA. Post-treatment endoscopy data indicated that gastroduodenal ulcers developed in 1.5% of patients receiving Arthrotec, 10.3% of patients receiving piroxicam, and 8.6% patients in the naproxen group.(ABSTRACT TRUNCATED AT 250 WORDS)

Meta-analysis of three double-blind comparative trials with sustained-release etodolac in the treatment of osteoarthritis of the knee.

A meta-analysis was done with the final data from three trials that provided the first results relating to efficacy and safety of the new sustained-release (SR) formulation of etodolac versus established nonsteroidal anti-inflammatory drugs (NSAIDs) in the treatment of osteoarthritis (OA) of the knee. The studies were 4-week, double-blind, randomized, parallel-group comparisons of etodolac SR 600 mg (119 patients) against diclofenac SR 100 mg (54 patients), tenoxicam 20 mg (46 patients), or piroxicam 20 mg (18 patients). The primary efficacy parameters (assessed after 2 and 4 weeks of treatment) were physicians' and patients' overall assessments of patients' condition, night pain, and pain intensity. All patients had radiographic and clinical evidence of OA of the knee. For the meta-analysis, the data from the individual etodolac SR studies were pooled and compared with the pooled data for diclofenac SR, tenoxicam, and piroxicam. The homogeneity of the treatments across studies and the changes from baseline between groups were tested using a Cochran-Mantel-Haenszel test and an analysis of variance, including "study," "treatment," and "center within treatment" effects and their interaction. The analysis for the efficacy parameters was based on the final assessment during therapy (last visit). At baseline, the two treatment groups were comparable. Improvement rates were high in both groups (range, 68-81%), indicating that treatments were effective for most patients. No significant treatment difference was observed for the patients' overall assessment, night pain, or pain intensity. Both etodolac SR and the reference preparations were well tolerated. No clinically significant changes were noted in the laboratory data.(ABSTRACT TRUNCATED AT 250 WORDS)

Worldwide experience with etodolac (Lodine) 300 mg b.i.d. in the treatment of osteoarthritis.

Worldwide experience with the conventional formulation of etodolac (300 mg b.i.d.) was reviewed in 12 randomized, double-blind, parallel-group studies in patients with osteoarthritis (OA) of the hip or knee. The studies were conducted in 13 countries at 59 sites, and 1289 patients were enrolled. The results of 9 comparative and 3 placebo-controlled clinical studies were examined to compare the efficacy and safety of etodolac versus piroxicam, naproxen, indomethacin, indomethacin sustained-release (SR), and diclofenac SR. Efficacy assessments were made at pretreatment screening, baseline, and every 2 weeks thereafter during treatment until study completion up to 4, 6, or 8 weeks. The primary efficacy assessments were the patient's and physician's global evaluations, pain intensity and night pain, or joint tenderness and walking pain. Safety was assessed with reference to study events, reports of laboratory results, and vital signs measurements. Patients in all active treatment groups showed prompt response to therapy. According to the physicians' global evaluation, at least 64% of all etodolac-treated patients and 62% of all active-reference preparation-treated patients had improved by the end of the study. Similar results were seen in the patients' global evaluation. All of the study drugs were well tolerated. Eight (8%) percent of the etodolac-treated patients withdrew because of study events. The proportions of patients treated with active reference preparations and placebos who withdrew because of study events ranged from 3% to 18%.(ABSTRACT TRUNCATED AT 250 WORDS)

The efficacy of Arthrotec in the treatment of osteoarthritis.

In a double-blind study, 455 patients with osteoarthritis were randomly assigned to receive a combination of Arthrotec, 50 mg of diclofenac and 200 micrograms of misoprostol, or 50 mg of diclofenac; the drugs were given two or three times daily for 4 weeks. At weeks 2 and 4 of treatment, no significant differences between the treatment groups were noted in changes from baseline on the physicians' and patients' global assessment of osteoarthritis. On a measure of arthritis severity, patients with both arthritis of the hip and knee showed improvement from week 2 to week 4, with no significant differences between treatment groups.

Efficacy of Arthrotec in the treatment of rheumatoid arthritis.

In a double-blind study, 346 patients with active rheumatoid arthritis were randomly assigned to receive Arthrotec, a combination of 50 mg of diclofenac and 200 *g of misoprostol, or 50 mg of diclofenac; the drugs were given two or three times daily for 12 weeks. At weeks 4, 8, and 12 of treatment, no clinically significant differences between the two treatment groups were noted on measures of joint tenderness, pain, and swelling or on physicians' and patients' assessments of disease severity.

A double-blind comparison of the gastroduodenal safety and efficacy of diclofenac and a fixed dose combination of diclofenac and misoprostol in the treatment of rheumatoid arthritis.

This double-blind, parallel group study was conducted to evaluate the gastroduodenal safety and antiarthritic efficacy of a fixed combination of diclofenac sodium 50 mg and misoprostol 200 mcg, compared with a combination of diclofenac 50 mg and placebo. Three hundred and thirty-nine patients with rheumatoid arthritis and no significant gastric or duodenal mucosal damage were enrolled and received study medication (diclofenac/misoprostol, 164; diclofenac/placebo, 175) BID or TID for 12 weeks. Posttreatment gastroduodenal endoscopic examinations revealed ulcers in 11% of the diclofenac/placebo group, compared with only 4% of the diclofenac/misoprostol group (p = 0.034). Four-weekly assessments of arthritic condition revealed no clinically or statistically significant treatment differences. It was concluded that diclofenac/misoprostol caused significantly less gastroduodenal damage than diclofenac, but was as effective as diclofenac alone in the treatment of rheumatoid arthritis.