Biological Efficacy (biological + efficacy)

Distribution by Scientific Domains


Selected Abstracts


Bioavailability and Biological Efficacy of a New Oral Formulation of Salmon Calcitonin in Healthy Volunteers,

JOURNAL OF BONE AND MINERAL RESEARCH, Issue 8 2002
Thierry Buclin
Abstract Salmon calcitonin (SCT) is a well-tolerated peptide drug with a wide therapeutic margin and is administered parenterally for long-term treatments of bone diseases. Its clinical usefulness would be enhanced by the development of an orally active formulation. In this randomized crossover double-blinded phase I trial, controlled by both a placebo and a parenteral verum, we have tested a new oral formulation of SCT associated with a caprylic acid derivative as carrier. Eight healthy volunteers received single doses of 400, 800, and 1200 ,g of SCT orally, a placebo, and a 10-,g (50 IU) SCT intravenous infusion. SCT was reliably absorbed from the oral formulation, with an absolute bioavailability of 0.5,1.4%, depending on the dose. It induced a marked, dose-dependent drop in blood and urine C-terminal telopeptide of type I collagen (CTX), a sensitive and specific bone resorption marker, with the effects of 1200 ,g exceeding those of 10 ,g intravenously. It also decreased blood calcium and phosphate, and increased the circulating levels of parathyroid hormone (PTH) and, transiently, the urinary excretion of calcium. It was well-tolerated, with some subjects presenting mild and transient nausea, abdominal cramps, diarrheic stools, and headaches. This study shows that oral delivery of SCT is feasible with reproducible absorption and systemic biological efficacy. Such an oral formulation could facilitate the use of SCT in the treatment of osteoporosis and other bone diseases. [source]


Enhancement of haemostatic efficacy of plasma-derived FVIII by formulation with PEGylated liposomes

HAEMOPHILIA, Issue 5 2009
I. DAYAN
Summary., We have shown previously that PEGylated liposomes (PEGLip) bind recombinant FVIII (rFVIII) with high affinity and specificity. This binding resulted in a significant extension of the biological activity of rFVIII as demonstrated in animal models and in clinical trials. In the present study we found that PEGLip bind plasma-derived factor VIII (pdFVIII). PEGLip binding did not affect potency or stability in vitro and did not alter levels of FVIII activity in vivo immediately after injection. However, formulation of pdFVIII with PEGLip led to several important improvements. Twenty-four and 30 hours after injection, FVIII activity levels were significantly higher in haemophilic mice injected with PEGLip-pdFVIII than in mice injected with standard pdFVIII. Half life, area under the curve and mean residence time were increased while clearance was decreased. In vivo efficacy was evaluated in a tail vein transection assay performed in haemophilic mice. Prophylactic treatment with PEGLip-pdFVIII was much more effective in prolonging survival in this assay than similar treatment with standard pdFVIII. These results suggest that formulation of pdFVIII with PEGLip has the potential to improve patient care by prolonging the biological efficacy of pdFVIII and reducing the frequency of FVIII infusions. [source]


Bioavailability and Biological Efficacy of a New Oral Formulation of Salmon Calcitonin in Healthy Volunteers,

JOURNAL OF BONE AND MINERAL RESEARCH, Issue 8 2002
Thierry Buclin
Abstract Salmon calcitonin (SCT) is a well-tolerated peptide drug with a wide therapeutic margin and is administered parenterally for long-term treatments of bone diseases. Its clinical usefulness would be enhanced by the development of an orally active formulation. In this randomized crossover double-blinded phase I trial, controlled by both a placebo and a parenteral verum, we have tested a new oral formulation of SCT associated with a caprylic acid derivative as carrier. Eight healthy volunteers received single doses of 400, 800, and 1200 ,g of SCT orally, a placebo, and a 10-,g (50 IU) SCT intravenous infusion. SCT was reliably absorbed from the oral formulation, with an absolute bioavailability of 0.5,1.4%, depending on the dose. It induced a marked, dose-dependent drop in blood and urine C-terminal telopeptide of type I collagen (CTX), a sensitive and specific bone resorption marker, with the effects of 1200 ,g exceeding those of 10 ,g intravenously. It also decreased blood calcium and phosphate, and increased the circulating levels of parathyroid hormone (PTH) and, transiently, the urinary excretion of calcium. It was well-tolerated, with some subjects presenting mild and transient nausea, abdominal cramps, diarrheic stools, and headaches. This study shows that oral delivery of SCT is feasible with reproducible absorption and systemic biological efficacy. Such an oral formulation could facilitate the use of SCT in the treatment of osteoporosis and other bone diseases. [source]


An analysis of the persistence and potency of film-coated seed protectant as influenced by various storage parameters

PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 7 2009
Sherry Rachel Jacob
Abstract BACKGROUND: An efficient delivery system for seed-protectant chemicals is needed in light of several disadvantages of conventional seed treatment methods. This study evaluates the efficacy of film-coat application in maintaining the persistence and potency of imidacloprid on Lycopersicon esculentum (L.) Mill. seeds after simultaneous storage under ambient and regulated environment in paper and aluminium packages. RESULTS: High-performance liquid chromatography (HPLC) revealed 0.135 mg kg,1 of herbage material to be the threshold value beyond which absolute control was obtained, and with film coating the latter was achieved even with half-dosage seed treatment, irrespective of the storage condition. The technique provided early protection to the crop and also nullified the deleterious effects of ambient storage on the persistence and potency of the pesticide. CONCLUSION: Film coating enabled superior pesticide dosage as well as higher biological efficacy to be achieved. Hence, in addition to being an ecofriendly alternative, the technique would be a more economically viable option for storage of treated seeds. Copyright © 2009 Society of Chemical Industry [source]


A First Comparative Study of Purpurinimide-based Fluorinated vs.

PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 5 2002
Nonfluorinated Photosensitizers for Photodynamic Therapy
ABSTRACT A first report on the synthesis and comparative in vitro,in vivo photosensitizing efficacy of various fluorinated and the corresponding nonfluorinated, purpurinimide-based photosensitizers is discussed. In preliminary in vivo screening, compared with the nonfluorinated analogs, purpurinimides bearing trifluoromethyl substituents showed enhanced photosensitizing efficacy. Among compounds (isomers) with similar lipophilicity, the position of the substituents was found to play a decisive role in biological efficacy. [source]


Administration of Cyperus rotundus tubers extract prevents weight gain in obese Zucker rats

PHYTOTHERAPY RESEARCH, Issue 8 2007
Bernard Lemaure
Abstract Cyperus rotundus L. (Cyperaceae; C. rotundus) is an Indian medicinal plant demonstrated to exert multiple health benefits. The purpose of the present study was to test the biological efficacy of C. rotundus tubers extract on weight control in obese Zucker rats. It was demonstrated that administration of 45 or 220 mg/kg/day of C. rotundus tubers hexane extract for 60 days in Zucker rats induced a significant reduction in weight gain without affecting food consumption or inducing toxicity. In vitro, 250 µg/mL of this extract was able to stimulate lipolysis in 3T3-F442 adipocytes suggesting that this medicinal plant contains activators of , -adrenoreceptors (AR). The binding assay performed on the rat ,3-AR isoform, known to induce thermogenesis, demonstrated that C. rotundus tubers extract can consistently and effectively bind to this receptor. These data suggest that the effect on weight gain exerted by C. rotundus tubers extract may be mediated, at least partially, through the activation of the ,3-AR. In conclusion, C. rotundus tubers extract prove to be a new herbal supplement for controlling body weight preferentially in ,3-AR sensitive species. Copyright © 2007 John Wiley & Sons, Ltd. [source]


Can we face the challenge of expanding use of intravenous immunoglobulin in neurology?

ACTA NEUROLOGICA SCANDINAVICA, Issue 5 2010
I. Elovaara
Elovaara I, Hietaharju A. Can we face the challenge of expanding use of intravenous immunoglobulin in neurology? Acta Neurol Scand: 2010: 122: 309,315. © 2010 The Authors Journal compilation © 2010 Blackwell Munksgaard. The use of high-dose polyclonal intravenous immunoglobulin (IVIG) in the treatment of autoimmune neurological diseases has expanded over the last decade. Based on controlled clinical trials IVIG can be considered currently as the first-line treatment in Guillain-Barré syndrome, chronic inflammatory demyelinating polyneuropathy and multifocal motor neuropathy, and it may be used as a rescue therapy in worsening myasthenia gravis. IVIG is a second-line therapy in dermatomyositis, stiff-person syndrome and pregnancy-associated or postpartum relapses of multiple sclerosis. Although the biological efficacy of IVIG is due to multiple effects on the immune system, many mechanisms are still unknown. The awareness of risks and complications of IVIG therapy has increased, but severe side effects are still considered rare. Due to increasing costs of this treatment, careful selection of patients who will benefit from IVIG is extremely important. [source]