Bioequivalence of two oral formulations of clopidogrel tablets in healthy male volunteers.

A randomized, two-way, crossover, bioequivalence study in 32 fasting, healthy, male volunteers was conducted to compare two brands of clopidogrel 75 mg tablets, Thrombo (EIPICO, Egypt) as test and Plavix (Sanofi Pharma/Bristol-Myers Squibb, Paris, France) as reference. The study was performed in a Pharmaceutical Research Unit (PRU) using HPLC/ MS-MS. Arithmetic means for clopidogrel test versus reference formulation, respectively were for Cmax (4.39 +/- 2.58 vs. 4.30 +/- 2.65) ng/ml, AUC0-t (11.98 +/- 9.82 vs. 12.01 +/- 9.46) ng.h/ml, AUC0- yen (12.43 +/- 9.94 vs. 12.49 +/- 9.58) ng.h/ml, t1/2 (6.06 +/- 3.87 vs. 5.87 +/- 2.47) h and the medians for tmax (1 h vs. 0.75 h). Arithmetic means for clopidogrel carboxylic acid metabolite were Cmax (3.75 +/- 1.19 vs. 3.51 +/- 0.97) microg/ml AUC0-t (9.18 +/- 2.36 vs. 9.17 +/- 2.06) microg.h/ml, AUC0- yen (9.72 +/- 2.4 vs. 9.80 +/- 2.21) microg.h/ml , and t1/2 (6.43 +/- 3.52 vs. 6.33 +/- 1.71) h for test versus reference formulation respectively and there was no difference in the medians for tmax (0.75 h). The parametric 90% confidence intervals for the mean of the difference between log-transformed values were within the accepted range for bioequivalence of 80 - 125% as proposed by the US-FDA , namely for clopidogrel (90.66% - 109.66%), (90.63% - 109.73%), and (93.19% - 115.37%) for AUC0-t, AUC0- yen, and Cmax, respectively and also for clopidogrel carboxylic acid metabolite (94.90 - 104.19) , (94.04 - 103.86) and (96.47 - 114.79) for AUC0-t , AUC0- yen, and Cmax, respectively. Thus there was no significant difference between these values and therefore the two products can be considered bioequivalent.

Immunosuppression: evolution in practice and trends, 1994-2004.

Over the last 10 years, there have been important changes in immunosuppression management and strategies for solid-organ transplantation, characterized by the use of new immunosuppressive agents and regimens. An organ-by-organ review of OPTN/SRTR data showed several important trends in immunosuppression practice. There is an increasing trend toward the use of induction therapy with antibodies, which was used for most kidney, pancreas after kidney (PAK), simultaneous pancreas-kidney (SPK) and pancreas transplant alone (PTA) recipients in 2004 (72-81%) and for approximately half of all intestine, heart and lung recipients. The highest usage of the tacrolimus/mycophenolate mofetil combination as discharge regimen was reported for SPK (72%) and PAK (64%) recipients. Maintenance of the original discharge regimen through the first 3 years following transplantation varied significantly by organ and drug. The usage of calcineurin inhibitors for maintenance therapy was characterized by a clear transition from cyclosporine to tacrolimus. Corticosteroids were administered to the majority of patients; however, steroid-avoidance and steroid-withdrawal protocols have become increasingly common. The percentage of patients treated for acute rejection during the first year following transplantation has continued to decline, reaching 13% for those who received a kidney in 2003, 48% of which cases were treated with antibodies.

Development of the new lung allocation system in the United States.

This article reviews the development of the new U.S. lung allocation system that took effect in spring 2005. In 1998, the Health Resources and Services Administration of the U.S. Department of Health and Human Services published the Organ Procurement and Transplantation Network (OPTN) Final Rule. Under the rule, which became effective in 2000, the OPTN had to demonstrate that existing allocation policies met certain conditions or change the policies to meet a range of criteria, including broader geographic sharing of organs, reducing the use of waiting time as an allocation criterion and creating equitable organ allocation systems using objective medical criteria and medical urgency to allocate donor organs for transplant. This mandate resulted in reviews of all organ allocation policies, and led to the creation of the Lung Allocation Subcommittee of the OPTN Thoracic Organ Transplantation Committee. This paper reviews the deliberations of the Subcommittee in identifying priorities for a new lung allocation system, the analyses undertaken by the OPTN and the Scientific Registry for Transplant Recipients and the evolution of a new lung allocation system that ranks candidates for lungs based on a Lung Allocation Score, incorporating waiting list and posttransplant survival probabilities.

Estimating the impact of renal replacement therapy choice on outcome in severe acute renal failure.

BACKGROUND: Mortality in severe acute renal failure (ARF) requiring renal replacement therapy (RRT) approximates 50% and varies with clinical severity. Continuous RRT (CRRT) has theoretical advantages over intermittent hemodialysis (IHD) for critical patients, but a survival advantage with CRRT is yet to be clearly demonstrated. To date, no prospective controlled trial has sufficiently answered this question, and the present prospective outcome study attempts to compare survival with CRRT versus that with IHD. METHODS: Multivariable Cox-proportional hazards regression was used to analyze the impact of RRT modality choice (CRRT vs. IHD) on in-hospital and 100-day mortality among ARF patients receiving RRT during 2000 and 2001 at University of Michigan, using an "intent-to-treat" analysis adjusted for multiple comorbidity and severity factors. RESULTS: Overall in-hospital mortality before adjustment was 52%. Triage to CRRT (vs IHD) was associated with higher severity and unadjusted relative rate (RR) of in-hospital death (RR = 1.62, p = 0.001, n = 383). Adjustment for comorbidity and severity of illness reduced the RR of death for patients triaged to CRRT and suggested a possible survival advantage (RR = 0.81, p = 0.32). Analysis restricted to patients in intensive care for more than five days who received at least 48 hours of total RRT, showed the RR of in-hospital mortality with CRRT to be nearly 45% lower than IHD (RR = 0.56, n = 222), a difference in RR that indicates a strong trend for in-hospital mortality with borderline statistical significance (p = 0.069). Analysis of 100-day mortality also suggested a potential survival advantage for CRRT in all cohorts, particularly among patients in intensive care for more than five days who received at least 48 h of RRT (RR = 0.60, p = 0.062, n = 222). CONCLUSION: Applying the present methodology to outcomes at a single tertiary medical center, CRRT may appear to afford a survival advantage for patients with severe ARF treated in the ICU. Unless and until a prospective controlled trial is realized, the present data suggest potential survival advantages of CRRT and support broader application of CRRT among such critically ill patients.

Generation of micro-particles of proteins for aerosol delivery using high pressure modified carbon dioxide.

PURPOSE: To investigate the feasibility of using the Aerosol Solvent Extraction System (ASES) to generate microparticles of proteins suitable for aerosol delivery from aqueous-based solutions. METHODS: The ASES technique using high-pressure carbon dioxide modified with ethanol was utilised for the generation of microparticles of proteins (lysozyme, albumin, insulin and recombinant human deoxyribonuclease (rhDNase)) from aqueous solutions. Particle size, morphology, size distributions and powder aerosol performance were examined. The biochemical integrity of the processed proteins was assessed by testing the level of molecular aggregation using size exclusion chromatography and by bioassay technique for lysozyme. RESULTS: Proteins were precipitated as spherical particles ranging in size from 100 to 500 nm. The primary nano-sized particles agglomerated to form micron-sized particles during the precipitation process. The median size of the particles was a function of the operating conditions. In-vitro aerosol performance tests showed that the percent fine particle mass (< 5 microm) was approximately 65%, 40% and 20% for lysozyme, albumin and insulin, respectively. Negligible loss in the monomer content or biological activity was observed for lysozyme. Insulin exhibited slight aggregation and 93% of the monomer was retained after processing. Albumin was affected by processing and only 50-75% of the monomer was retained compared with 86% in the original material. However, rhDNase was substantially denatured during processing as shown by the significantly reduced monomer content. CONCLUSIONS: Micron-sized particles of lysozyme, albumin and insulin with satisfactory inhalation performance were successfully generated from aqueous solutions using the modified ASES technique. The biochemical integrity of the processed proteins was a function of the operating conditions and the nature of the individual protein.