Bioequivalence Study of Capsules versus Film Tablets Containing Rivaroxaban in Healthy Caucasian Subjects under Fasting and Fed Conditions.

The bioequivalence (BE) of orally administered capsules versus film tablets containing 20  and 10 mg of rivaroxaban was assessed in 2 single-dose, open-label, randomized 2-way crossover trials with a washout period of at least 1 week. The study for the 10 mg strength was conducted under fasting conditions (n = 68) and the study for the 20 mg strength under fed conditions (n = 52). Blood samples were collected over a 36-hour period and concentrations were assayed using a liquid chromatography tandem mass spectrometry method. Pharmacokinetic (PK) evaluation was performed with the program Phoenix WinNonlin, for non-compartmental assessment of data. After administration of 10 mg rivaroxaban under fasting conditions, mean Area Under the time - concentration Curve until the last blood sampling point (AUCt ), Area Under the time - concentration Curve until infinity (AUC∞ ), and maximum plasma concentration (Cmax ) were comparable (972 ng/mL*h, 1048 ng/mL*h, and 111 ng/mL, respectively, for the test and 1013 ng/mL*h, 1070 ng/mL*h and 130 ng/mL, respectively, for the reference formulation). Mean AUCt , AUC∞ , and Cmax were also comparable under fed conditions after administration of 20 mg rivaroxaban (2145 ng/mL*h, 2198 ng/mL*h and 275 ng/mL, respectively, for the test and 1856 ng/mL*h, 1916 ng/mL*h and 240 ng/mL, respectively, for the reference formulation). The 90% confidence intervals for all PK parameters were within the acceptance range of 80%-125%, suggesting BE between the generic product and the innovator product in healthy Caucasian male subjects. A clinically relevant difference in the tolerability and safety of the treatments was not detected. Study results indicated that the capsule formulations were bioequivalent with the film tablet formulations.

Brace-Free Rehabilitation after Isolated Anterior Cruciate Ligament Reconstruction with Hamstring Tendon Autograft Is Not Inferior to Brace-Based Rehabilitation-A Randomised Controlled Trial.

PURPOSE: The postoperative use of a rehabilitative knee brace after isolated primary anterior cruciate ligament (ACL) reconstruction (ACLR) using a hamstring tendon (HT) autograft is controversial. A knee brace may provide subjective safety but can cause damage if applied incorrectly. The aim of this study is to evaluate the effect of a knee brace on clinical outcomes following isolated ACLR using HT autograft. METHODS: In this prospective randomised trial, 114 adults (32.4 ± 11.5 years, 35.1% women) underwent isolated ACLR using HT autograft after primary ACL rupture. Patients were randomly assigned to wear either a knee brace (n = 58) or no brace (n = 56) for 6 weeks postoperatively. An initial examination was performed preoperatively, and at 6 weeks and 4, 6, and 12 months. The primary endpoint was the subjective International Knee Documentation Committee (IKDC) score to measure participants' subjective perceptions. Secondary endpoints included objective knee function assessed by IKDC, instrumented knee laxity measurements, isokinetic strength tests of the knee extensors and flexors, Lysholm Knee Score, Tegner Activity Score, Anterior Cruciate Ligament-Return to Sport after Injury Score, and quality of life determined by Short Form-36 (SF36). RESULTS: There were no statistically significant or clinically meaningful differences in IKDC scores between the two study groups (3.29, 95% confidence interval (CI) -1.39 to 7.97, p = 0.03 for evidence of non-inferiority of brace-free compared with brace-based rehabilitation). The difference in Lysholm score was 3.20 (95% CI -2.47 to 8.87); the difference in SF36 physical component score 0.09 (95% CI -1.93 to 3.03). In addition, isokinetic testing did not reveal any clinically relevant differences between the groups (n.s.). CONCLUSIONS: Brace-free rehabilitation is non-inferior to a brace-based protocol regarding physical recovery 1 year after isolated ACLR using HT autograft. Consequently, the use of a knee brace might be avoided after such a procedure. LEVEL OF EVIDENCE: Level I, therapeutic study.

C-Nail versus plate osteosynthesis in displaced intra-articular calcaneal fractures-a comparative retrospective study.

BACKGROUND: Locking plate osteosynthesis via an L-shaped lateral approach is the gold standard in treating displaced intra-articular calcaneal fractures. High complication rates are known for this approach. The most frequent complications are wound edge necrosis and superficial wound infections. To reduce complication rates, a locking intramedullary nail (C-Nail) was developed that can be implanted minimally invasively via a sinus tarsi approach. We compared the postoperative complication rate and the outcome of plate osteosynthesis versus C-Nail in displaced intra-articular calcaneal fractures. METHODS: All patients with calcaneal fractures who received osteosynthesis with either plate or C-Nail between January 2016 and October 2019 in our institution were retrospectively analyzed. A subgroup analysis was performed with matched pairs (matching Sanders type, age, Böhler's angle postoperative in normal range, 33 pairs). Endpoints were postoperative complication rate, bone healing, full weight-bearing and functional outcome. Treatment groups were compared using Fisher's exact test for binary data, and Mann-Whitney U-test for continuous data. A p-value < 0.05 was considered statistically significant. RESULTS: One hundred and one calcaneal fractures were included (C-Nail n = 52, plate n = 49). Patients with C-Nail developed significantly less postoperative complications (p = 0.008), especially wound edge necrosis (p < 0.001). Screw malposition was found more often in the C-Nail group. The rates of achieving full weight-bearing as well as bone healing were comparable in both groups, but in each case significant faster in the C-nail subgroup. The results of the matched-pairs analysis were comparable. CONCLUSIONS: The postoperative complication rate was significantly lower in the C-Nail group. The C-Nail appears to be a successful alternative in the treatment of calcaneal fractures, even in Sanders IV fractures because of the minimal-invasive implantation as well as the high primary stability. Long-term analysis of this new implant including elaboration on functional outcome is planned. TRIAL REGISTRATION: Deutsches Register Klinischer Studien (DRKS) DRKS00020395 . Date of registration 3 January 2020.

Dark Matter Annihilation Can Produce a Detectable Antihelium Flux through Λ[over ¯]_{b} Decays.

Recent observations by the Alpha Magnetic Spectrometer (AMS-02) have tentatively detected a handful of cosmic-ray antihelium events. Such events have long been considered as smoking-gun evidence for new physics, because astrophysical antihelium production is expected to be negligible. However, the dark-matter-induced antihelium flux is also expected to fall below current sensitivities, particularly in light of existing antiproton constraints. Here, we demonstrate that a previously neglected standard model process-the production of antihelium through the displaced-vertex decay of Λ[over ¯]_{b}-baryons-can significantly boost the dark matter induced antihelium flux. This process can entirely dominate the production of high-energy antihelium nuclei, increasing the rate of detectable AMS-02 events by 2 orders of magnitude.

The role of recipient myosteatosis in graft and patient survival after deceased donor liver transplantation.

BACKGROUND: Myosteatosis is associated with perioperative outcomes in orthotopic liver transplantation (OLT). Here, we investigated the effects of body composition and myosteatosis on long-term graft and patient survival following OLT. METHODS: Clinical data from 225 consecutive OLT recipients from a prospective database were retrospectively analysed (May 2010 to December 2017). Computed tomography-based lumbar skeletal muscle index (SMI) (muscle mass) and mean skeletal muscle radiation attenuation (SM-RA) (myosteatosis) were calculated using a segmentation tool (3D Slicer). Patients with low skeletal muscle mass (low SMI) and myosteatosis (low SM-RA) were identified using predefined and validated cut-off values. RESULTS: The mean donor and recipient age was 55 ± 16 and 54 ± 12 years, respectively. Some 67% of the recipients were male. The probability of graft and patient survival was significantly lower in patients with myosteatosis compared with patients with higher SM-RA values (P = 0.011 and P = 0.001, respectively). Low skeletal muscle mass alone was not associated with graft and patient survival (P = 0.273 and P = 0.278, respectively). Dividing the cohort into quartiles, based on the values of SMI and SM-RA, resulted in significant differences in patient but not in graft survival (P = 0.011). Even though multivariable analysis identified low SM-RA as an important prognostic marker (hazard ratio: 2.260, 95% confidence interval: 1.177-4.340, P = 0.014), myosteatosis lost its significance when early mortality (90 days) was excluded from the final multivariable model. Patients with myosteatosis showed significantly higher all-cause mortality and in particular higher rates of deaths due to respiratory and septic complication (P = 0.002, P = 0.022, and P = 0.049, respectively). CONCLUSIONS: Preoperative myosteatosis may be an important prognostic marker in patients undergoing deceased donor liver transplantation. The prognostic value of myosteatosis seems to be particularly important in the early post-operative phase. Validation in prospective clinical trials is warranted.

Can CSF spectrophotometry for "Xanthochromia" be used to detect leaking subarachnoid aneurysms in patients with sickle cell anemia with negative MRI or CT angiogram despite hyperbilirubinemia?

CSF (Cerebrospinal Fluid) xanthochromia by spectroscopy should not be dismissed in the context of hyperbilirubinemia in a patient with sickle cell anemia. Xanthochromia detected by spectrophotometry offers a vital clue that further invasive diagnosis is required.

Blocking representation in the ERA-Interim driven EURO-CORDEX RCMs.

While Regional Climate Models (RCMs) have been shown to yield improved simulations compared to General Circulation Model (GCM), their representation of large-scale phenomena like atmospheric blocking has been hardly addressed. Here, we evaluate the ability of RCMs to simulate blocking situations present in their reanalysis driving data and analyse the associated impacts on anomalies and biases of European 2-m air temperature (TAS) and precipitation rate (PR). Five RCM runs stem from the EURO-CORDEX ensemble while three RCMs are WRF models with different nudging realizations, all of them driven by ERA-Interim for the period 1981-2010. The detected blocking systems are allocated to three sectors of the Euro-Atlantic region, allowing for a characterization of distinctive blocking-related TAS and PR anomalies. Our results indicate some misrepresentation of atmospheric blocking over the EURO-CORDEX domain, as compared to the driving reanalysis. Most of the RCMs showed fewer blocks than the driving data, while the blocking misdetection was negligible for RCMs strongly conditioned to the driving data. A higher resolution of the RCMs did not improve the representation of atmospheric blocking. However, all RCMs are able to reproduce the basic anomaly structure of TAS and PR connected to blocking. Moreover, the associated anomalies do not change substantially after correcting for the misrepresentation of blocking in RCMs. The overall model bias is mainly determined by pattern biases in the representations of surface parameters during non-blocking situations. Biases in blocking detections tend to have a secondary influence in the overall bias due to compensatory effects of missed blockings and non-blockings. However, they can lead to measurable effects in the presence of a strong blocking underestimation.

A randomised, two-period, cross-over, open-label study to evaluate the pharmacokinetic profiles of single doses of two different flurbiprofen 8.75-mg lozenges in healthy volunteers.

AIMS: To compare the bioavailability of a new oromucosal formulation of flurbiprofen 8.75-mg lozenges, developed by Alfa Wassermann S.p.A. (test drug) to that of marketed flurbiprofen 8.75-mg lozenges (Benactiv Gola®, reference drug). METHODS: This was an open, randomised, two-period, crossover, pharmacokinetic (PK) study in which flurbiprofen plasma levels were compared in 12 healthy volunteers after the administration of single doses (8.75 mg × 2) of two different oromucosal lozenges to be sucked and slowly dissolved in the mouth. A wash-out period of at least 7 days separated the two study periods. Blood samples were collected prior to dosing and at predefined intervals for 24 h after dose. Flurbiprofen plasma concentrations were determined by liquid chromatography/tandem mass spectrometry. PK parameters maximum plasma concentration (C(max)), time to maximum plasma concentration (T(max)), area under the plasma concentration-time curve from time zero to 24 hours (AUC(0-t)), area under the plasma concentration-time curve from time zero to infinity (AUC(0-)∞) and half-life were calculated and compared by analysis of variance using treatment, period and sequence as sources of variation. Bioequivalence between the two formulations was based on 90% confidence intervals of the ratio of the geometric means of C(max) and AUC falling within the 0.80-1.25 range as defined in bioequivalence guidelines by regulators. Tolerability of the two formulations was assessed by adverse event monitoring, routine laboratory tests, physical examination, electrocardiographic tracing and vital sign measurements. RESULTS: All enrolled subjects completed the study. Bioequivalence without significant treatment effect was demonstrated between the test drug/reference drug ratios of mean C(max) and AUCs. Moreover, mean T(max) was superimposable. No safety parameter presented a clinically relevant variation after administration of either formulation that were therefore well tolerated. CONCLUSION: The new formulation of flurbiprofen 8.75-mg compressed lozenges developed by Alfa Wassermann S.p.A. is bioequivalent to the reference product flurbiprofen 8.75-mg lozenges (Benactiv Gola) in healthy volunteers.

Alterations of atrial electrophysiology related to hemodialysis session: insights from a multiscale computer model.

BACKGROUND: The prevalence of atrial fibrillation is increased in patients with end-stage renal disease. Previous studies suggested that extracellular electrolyte alterations caused by hemodialysis (HD) therapy could be proarrhythmic. METHODS: Multiscale models were used for a consequent analysis of the effects of extracellular ion concentration changes on atrial electrophysiology. Simulations were based on measured electrolyte concentrations from patients with end-stage renal disease. RESULTS: Simulated conduction velocity and effective refractory period are decreased at the end of an HD session, with potassium having the strongest influence. P-wave is prolonged in patients undergoing HD therapy in the simulation as in measurements. CONCLUSIONS: Electrolyte concentration alterations impact atrial electrophysiology from the action potential level to the P-wave and can be proarrhythmic, especially because of induced hypokalemia. Analysis of blood electrolytes enables patient-specific electrophysiology modeling. We are providing a tool to investigate atrial arrhythmias associated with HD therapy, which, in the future, can be used to prevent such complications.

A new topical formulation enhances relative diclofenac bioavailability in healthy male subjects.

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT: • Therapy with topical non-steroidal anti-inflammatory drugs (NSAIDs) relies on the ability of the active drug to penetrate the skin in sufficiently high amounts to exert a clinical effect, which is linked to the specific galenic properties of the formulation. WHAT THIS STUDY ADDS: • This phase 1 study characterizes the transdermal penetration and plasma exposure of different dose levels with galenic differences of a novel topical diclofenac formulation under development and indicates greater diclofenac penetration through the skin when compared with a commercially available formulation. AIMS: To evaluate the relative plasma and tissue availability of diclofenac after repeated topical administration of a novel diclofenac acid-based delivery system under development (DCF100C). METHODS: This was a single-centre, open-label, three-period, crossover clinical trial of five discrete diclofenac formulations. Test preparations comprised two concentrations (1.0% and 2.5%) of DCF100C, with and without menthol and eucalyptus oil (total daily doses of 5 mg and 12.5 mg). Voltaren Emulgel gel (1.0%) was the commercially available comparator (total daily dose of 40 mg). Topical application was performed onto the thigh of 20 male healthy subjects for 3 days. Applying a Youden square design, each drug was evaluated in 12 subjects, with each subject receiving three test preparations. Blood sampling and in vivo microdialysis in subcutaneous adipose and skeletal muscle tissues were performed for 10 h after additional final doses on the morning of day 4. RESULTS: All four DCF100C formulations demonstrated a three- to fivefold, dose-dependent increase in systemic diclofenac availability compared with Voltaren Emulgel and were approximately 30-40 times more effective at facilitating diclofenac penetration through the skin, taking different dose levels into account. Tissue concentrations were low and highly variable. The 2.5% DCF100C formulation without sensory excipients reached the highest tissue concentrations. AUC(0,10 h) was 2.71 times greater than for Voltaren Emulgel (90% CI 99.27, 737.46%). Mild erythema at the application site was the most frequent adverse event associated with DCF100C. There were no local symptoms after treatment with the reference formulation. CONCLUSION: DCF100C formulations were safe and facilitated greater diclofenac penetration through the skin compared with the commercial comparator. DCF100C represents a promising alternative to oral and topical diclofenac treatments that warrants further development.

Pharmacokinetics and bioequivalence study of a generic amlodipine tablet formulation in healthy male volunteers.

Two different tablets containing amlodipine besylate (CAS 111470-99-6) (Vazkor 10 mg tablet as test preparation and 10 mg tablet of the originator product as reference preparation) were investigated in 18 healthy male volunteers in order to compare the bioavailability and prove the bioequivalence between both treatments after oral single dose administration. The study was performed according to an open-label, randomized, two-period cross-over design with a wash-out phase of 21 days. Blood samples for pharmacokinetic profiling were taken up to 144 h post-dose, and amlodipine plasma concentrations were determined with a validated LC-MS/MS method. Maximum plasma concentrations (Cmax) of 6,183.7 pg/ml (test) and 5,366.7 pg/ml (reference) were achieved. Areas under the plasma concentration-time curve (AUC(0-infinity)) of 267,231.0 pg x h/ml (test) and 266,061.7 ng x h/ml (reference) were calculated. The median tmax was 5.6 h (test) and 6.1 h (reference). Plasma elimination half-lives (t 1/2) were 46.46 h (test) and 45.34 h (reference). Both primary target parameters AUC(0-infinity) and Cmax were tested parametrically by analysis of variance (ANOVA); 90% confidence intervals were between 93.20%-107.16% (AUC(0-infinity) and 103.36%-123.13% (Cmax). Bioequivalence between test and reference preparation was demonstrated since for both parameters AUC and Cmax the 90% confidence intervals of the T/R-ratios of logarithmically transformed data were in the generally accepted range of 80%-125%.

Validation of a "new" short tandem repeat (STR) fluorescent multiplex system and report of population genetic data.

The Humantype Chimera PCR Amplification Kit contains 12 polymorphic loci (ACTBP2 (= SE33), D18S51, D4S2366, D6S474, D8S1132, D12S391, D2S1360, D3S1744, D5S2500, D7S1517, D10S2325, D21S2055), of which the latter 10 loci have not been used extensively for human identity testing. The sex determinant locus amelogenin is also included in the kit. Amplification was successful on a variety of thermal cyclers and the amplicons could be analyzed on both the ABI PRISM 310 and 3100 Genetic Analyzers. Complete genotyping results from single source samples were possible between 0.25 and 2 ng of DNA template. Heterozygote imbalance (< 60% peak height balance) caused by stochastic effects was observed at a rate of around 5%. No deviations from the Hardy-Weinberg equilibrium were observed. Thus, there were no detectable significant deviations from the expected genetic independence of alleles.

Pharmacokinetics and bioequivalence study of ranitidine film tablets in healthy male subjects.

The aim of the present study was to compare the bioavailability of ranitidine (CAS 66357-35-5) from two different ranitidine hydrochloride (CAS 66357-59-3) film tablets (Ranitab 150 mg film tablets as test preparation and 150 mg film tablets of the originator product as reference preparation). The study was conducted according to an open-label, randomised two-period cross-over design with a wash-out phase of 9 days. Blood samples for pharmacokinetic profiling were taken up to 24 h post-dose, and ranitidine plasma concentrations were determined with a validated HPLC method with UV-detection. Maximum plasma concentrations (Cmax) of 461.8 ng/ml (test) and 450.6 ng/ ml (reference) were achieved. Areas under the plasma concentration-time curve (AUC (0-infinity) of 2,488.6 ng . h/ml (test) and 2,528.8 ng . h/ml (reference) were calculated. The median tmax was 2.83 h (test) and 3.04 h (reference). Plasma elimination half-lives (t1/2) of 2.78 h (test) and 2.89 h (reference) were determined. Both primary target parameters AUC(0-infinity) and Cmax were tested parametrically by analysis of variance (ANOVA) and the 90% confidence intervals were between 91.93 %-106.98 % (AUC (0-infinity) and 92.34%-118.85% (Cmax). Bioequivalence between test and reference preparation was demonstrated since for both parameters AUC and Cmax the 90 % confidence intervals of the T/R ratios of logarithmically transformed data were in the generally accepted range of 80 %-125 %.

Pharmacokinetics and bioequivalence study of doxycycline capsules in healthy male subjects.

The aim of the present study was to compare the bioavailability of doxycycline (CAS 564-25-0) from two different doxycycline hyclate (CAS 24390-14-5) capsules (Monodoks 100 mg capsule as test preparation and 100 mg capsule of the originator product as reference preparation) in 24 healthy male subjects. The study was conducted according to an open-label, randomised two-period cross-over design with a wash-out phase of 16 days. Blood samples for pharmacokinetic profiling were taken up to 72 h post-dose, and doxycycline plasma concentrations were determined with a validated HPLC method with UV-detection. Maximum plasma concentrations (Cmax) of 1,715.1 ng/ml (test) and 1,613.3 ng/ml (reference) were achieved. Areas under the plasma concentration-time curve (AUC(0-infinity)) of 28,586.5 ng x h/ml (test) and 29,047.5 ng x h/ml (reference) were calculated. The median tmax was 1.88 h (test) and 2.00 h (reference). Plasma elimination half-lives (t1/2) of 16.49 h (test) and 16.75 h (reference) were determined. Both primary target parameters AUC(0-infinity) and Cmax were tested parametrically by analysis of variance (ANOVA) and the 92.39 %-103.53% (AUC(0-infinity)) and 98.45%-111.74% (Cmax). Bioequivalence between test and reference preparation was demonstrated since for both parameters AUC and Cmax the 90% confidence intervals of the T/R ratios of logarithmically transformed data were in the generally accepted range of 80 0%-125%.

Pharmacokinetic and bioequivalence study of meloxicam tablets in healthy male subjects.

Meloxicam (CAS 71125-38-7), a non-steroidal anti-inflammatory drug (NSAID), is used for the treatment of osteoarthritis and rheumatic arthritis. In the present study, two different oral meloxicam formulations (Melcam 15 mg tablets as test preparation and tablets of a reference preparation) were investigated in 24 healthy male subjects in order to prove bioequivalence between both preparations. A single 15 mg oral dose was administered according to an open, randomised, two-period cross-over design in the fasted state. Blood samples for the determination of meloxicam plasma concentrations were collected at pre-defined time points up to 96 h following drug administration. A wash-out period of 7-8 days separated both treatment periods. Meloxicam plasma concentrations were determined by means of a validated HPLC method with UV-detection. Maximum plasma concentrations (C(max)) of 1,146.9 ng/ml (test) and 1,064.8 ng/ml (reference) were achieved. Areas under the plasma concentration-time curve (AUC(0-infinity) of 34,499.0 ng x h/ml (test) and 33,784.3 ng x h/ml (reference) were determined. The results showed nearly identical rate and extent of drug absorption. Also further pharmacokinetic parameters were well comparable. Thus, t(max) showed values of 5.00 h for both test and reference. The plasma elimination half-life (t1/2) was 18.29 h (test) und 18.94 h (reference). Both primary target parameters C(max). and AUC(0-infinity, were tested parametrically by analysis of variance (ANOVA) and the 90% confidence intervals were between 99.46%-105.24% (AUC0-infinity)) and 103.37%-112.46% (C(max)). Bioequivalence between test and reference preparation was demonstrated since for both parameters AUC and C(max) the 90% confidence intervals of the T/R ratios of logarithmically transformed data were in the generally accepted range of 80%-125%.

Comparative pharmacokinetics of two tablet formulations of amoxicillin: bioequivalence assessment.

The aim of the present study was to compare the bioavailability of amoxicillin (CAS 26787-78-0) from two different amoxicillin tablets (Demoksil 1 g tablet as test preparation and 1 g tablet of the originator product as reference preparation). The study was conducted according to an open-label, randomised two-period cross-over design with a wash-out phase of 4-7 days. Blood samples for pharmacokinetic profiling were taken up to 10 h post-dose, and amoxicillin plasma concentrations were determined with a validated LC-MS/ MS method. Maximum plasma concentrations (C(max)) of 13,296.4 ng/ml (test) and 12,797.7 ng/ml (reference) were achieved. Areas under the plasma concentration-time curve (AUC(0-infinity)) of 39,556.7 ng x h/ml (test) and 38,599.1 ng x h/ml (reference) were calculated. The median t(max) was 1.62 h (test) and 1.54 h (reference). Plasma elimination half-lives (t(1/2)) of 1.64 h (test) and 1.65 h (reference) were determined. Both primary target parameters, AUC(0-infinity) and C(max) were tested parametrically by analysis of variance (ANOVA) and the 90% confidence intervals were between 96.76%-108.46% (AUC(0-infinity)) and 97.80%-111.98% (C(max)). Bioequivalence between test and reference preparation was demonstrated since for both parameters, AUC and C(max) the 90% confidence intervals of the T/R-ratios of logarithmically transformed data were in the generally accepted range of 80%-125%.

Bioequivalence study of sultamicillin suspensions.

Sultamicillin (CAS 76497-13-7) is a prodrug combination of ampicillin (CAS 69-53-4) and sulbactam (CAS 68373-14-8), with the antibiotic ampicillin and the beta-lactamase inhibitor sulbactam chemically linked as double ester. The present study was performed to investigate the relative bioavailability and to assess the bioequivalence of two different sultamicillin suspensions (Devasid 250 mg/5 ml as test preparation and 375 mg/7.5 ml of the originator product as reference preparation). Twenty-four healthy male volunteers received equal doses of the sultamicillin preparations according to an open, randomised, single-dose, two-period cross-over design with a wash-out phase of 7 days. Blood samples for pharmacokinetic profiling were taken up to 8 h post-dose, and ampicillin and sulbactam plasma concentrations were determined with a validated LC-MS/MS method. Maximum plasma concentrations (C(max)) of 11,267.4 ng/ml (ampicillin, test), 10,864.4 ng/ml (ampicillin, reference), 6,360.6 ng/ml (sulbactam, test and 6,410.7 ng/ml (sulbactam, reference) were achieved. Areas under the plasma concentration-time curve (AUC(0-infinity) of 17,512.9 ng x h/ml (ampicillin, test), 18,388.0 ng x h/ml (ampicillin, reference), 10,971.7 ng ng x h/ml (sulbactam, test) and 11,181.2 ng x h/ml (sulbactam, reference) were calculated. The median t(max) was 0.69 h (ampicillin, test), 0.85 h (ampicillin, reference), 0.72 h (sulbactam, Devasid) and 0.83 h (sulbactam, reference). Plasma elimination half-lives (t(1/2)) of 1.04 h (ampicillin, test), 1.03 h (ampicillin, reference), 1.26 h (sulbactam, Devasid) and 1.00 h (sulbactam, reference) were determined. Both primary target parameters AUC(0-infinity) and C(max) of ampicillin and sulbactam were tested parametrically by analysis of variance (ANOVA) and the 90% confidence intervals were between 84.58%-117.80% (AUC(0-infinity), ampicillin), 92.37%-119.93% (C(max), ampicillin), 85.81%-120.50% (AUC(0-infinity), sulbactam) and 88.41%-117.57% (C(max), sulbactam). Bioequivalence between test and reference preparation was demonstrated since for both parameters AUC and C(max) the 90% confidence intervals of the T/R-ratios of logarithmically transformed data were in the generally accepted range of 80%-125%.

Favourable dermal penetration of diclofenac after administration to the skin using a novel spray gel formulation.

AIMS: The study was designed to evaluate the relative bioavailability of diclofenac in plasma, subcutaneous adipose and skeletal muscle tissue after repeated topical administration using MIKA Diclofenac Spray Gel (4%), a novel formulation, and after oral dosing using VOLTAREN 50 mg enteric coated tablets. METHODS: Diclofenac (48 mg) was administered topically three times daily for 3 days onto a defined area of the thigh of 12 healthy males. After a 14-day wash out period, subjects were orally treated with 50 mg diclofenac three times daily for 3 days. In vivo microdialysis in subcutaneous and muscle tissues was performed immediately after the final doses from both treatments on day 4, and 48 h later. Plasma samples were taken simultaneously. RESULTS: The relative bioavailability of diclofenac in subcutaneous adipose and skeletal muscle tissue was substantially higher after topical compared with oral dosing (324% and 209%, respectively) whereas relative plasma bioavailability was 50-fold lower. Plasma C(max) values were approximately 250-fold lower after topical compared with oral drug administration (i.e. median values = 4.89 ng mL(-1); 95% CI: 3.37-7.68 and 1240 ng mL(-1); 95% CI: 787-1389 ng mL(-1)). Both treatments were well tolerated. CONCLUSIONS: Owing to its favourable penetration characteristics and low systemic availability, MIKA Diclofenac Spray Gel 4% is a rational alternative to oral diclofenac formulations for the treatment of inflammatory soft tissue conditions.

Determination of the transdermal bioavailability of a newly developed diclofenac sodium patch in comparison with a reference preparation.

Two different transdermal diclofenac (CAS 15307-86-5) formulations (Olfen Patch 140 mg diclofenac sodium as test preparation and 180 mg diclofenac epolamine plaster, equivalent to 140 mg diclofenac sodium, as reference preparation) were investigated in 24 healthy male and female volunteers in order to compare the transdermal bioavailability between both treatments following topical multiple dose administration. Subjects were applied 2 plasters of test and reference formulation at a dose interval of 12 h for 4 consecutive days. Test and reference preparation were administered in randomised sequence at a marked spot at the left upper arm under non-fasting conditions. For determination of diclofenac concentrations, pre-dose (trough) values were taken during steady-state build-up and during the period of switch-over between both preparations on days 1-3 and 5-7. Blood samples for pharmacokinetic profiling were taken on days 4 and 8 at pre-defined time points up to 24 h following drug administration (after the 7th resp. 15th dose). Treatments were not separated by a wash-out phase. Considering the short half-life of diclofenac, it was appropriate that a switch-over design was chosen without wash-out periods between treatments. Diclofenac plasma concentrations were determined by means of a validated LC-MS/MS method (limit of detection: 0.06 ng/ml; lower limit of quantification: 0.15 ng/ml). For the test preparation, maximum plasma concentrations of 3.36 ng/ml (C(max, 0-12)), 3.73 ng/ml (C(max, 12-24)) and 3.84 ng/ml (C(max, 0-24)) as well as areas under the plasma concentration-time curve (AUC) of 31.11 ng x h/ml (AUC(0-12), 34.83 ng x h/ml (AUC(12.24)) and 65.94 ng x h/ml (AUC(0-24)) were determined. For the reference preparation, these values were 1.55 ng/ml (C(max, 0-12)), 1.45 ng/ml (C(max, 12-24) and 1.57 ng/ml (C(max, 0-24)) as well as 13.28 ng x h/ml (AUC(0-12)), 12.68 ng x h/ml (AUC(12-24)) and 25.96 ng x h/ml (AUC(0-24)). For the test preparation, peak-to-trough fluctuations (% PTF) of 34.78% (% PTF(0-12)), 38.50% (% PTF(12-24)) and 43.68% (% PTF(0-24)) were observed. Corresponding values for the reference preparation were 35.82% (% PTF(0-12), 31.36% (% PTF(12-24)) and 40.55% (% PTF(0-24)). In order to evaluate comparable bioavailability of both preparations, 90% confidence intervals of the test/reference ratios were determined. Thereby, for all dose intervals considered and all AUC parameters calculated, the extent of diclofenac absorption from the test preparation markedly exceeds those values obtained for the reference preparation. Likewise, maximum plasma concentrations, as a measure for the rate of absorption, were higher after the test preparation. With respect to peak-to-trough fluctuation of plasma diclofenac levels, both plaster preparations were comparable for the morning dose interval 0-12 h as well as for the 0-24 h period.

Bioavailability investigation of two different oral formulations of citalopram, a so-called 'second generation' antidepressant drug.

Citalopram (CAS 59729-33-8) belongs to the so-called 'second generation' antidepressant drugs and is used for the treatment of patients with major depression or other depressive disorders. In the present study, two different oral citalopram formulations (Citalopram-ratiopharm film-coated tablets as test preparation and tablets of a reference preparation distributed in Germany) were investigated in 20 healthy volunteers in order to prove bioequivalence between both preparations. A single 40 mg oral dose was administered according to an open, randomised, two-period cross-over design in the fasted state. Blood samples for determination of citalopram plasma concentrations were collected at pre-defined time points up to 168 h following drug administration. A wash-out period of 21 days separated both treatment periods. Citalopram plasma concentrations were determined by means of a validated HPLC method with fluorescence detection. Maximum plasma concentrations (Cmax), of 34.77 ng/ml (test) and 34.42 ng/ml (reference) were achieved. Areas under the plasma concentration-time curve (AUC0-infinity) of 1,719.69 ng*h/ml (test) and 1,725.71 ng*h/ml (reference) were determined. The results showed nearly identical rate and extent of drug absorption. Also further pharmacokinetic parameters were well comparable with each other. Thus, tmax showed values of 3.29 h (test) and 3.77 h (reference). The plasma elimination half-life (t1/2) was 42.50 h (test) und 44.46 h (reference). Both primary target parameters Cmax and AUC0-infinity were tested parametrically by analysis of variance (ANOVA). Bioequivalence between test and reference preparation was demonstrated since for both parameters AUC and Cmax the 90 % confidence intervals of the T/R-ratios of logarithmically transformed data were in the generally accepted range of 80 %-125 %.