Pharmacokinetics of Ferrous Sulphate (Tardyferon®) after Single Oral Dose Administration in Women with Iron Deficiency Anaemia.

Iron-containing preparations available on the market vary in dosage, salt, and chemical state of iron contained in the preparation, as well as in the iron delivery process (immediate or prolonged-release). The present study aimed at characterizing the serum pharmacokinetics of iron in non pregnant women with iron deficiency anaemia (IDA) following a single oral administration of a prolonged-release ferrous sulphate tablet. This multicenter, single dose, open-label study was conducted in 30 women aged between 18 and 45 years with IDA. A single 160 mg oral dose of ferrous sulphate was given as 2 tablets of 80 mg of Tardyferon(®) under fasting conditions. Blood samples were collected before dosing and until 24 h post-dosing. Serum iron concentrations were determined using a routine colorimetric analytical method. Pharmacokinetic parameters were determined from the serum concentration profiles using a non compartmental approach. Serum profiles showed elevated levels of iron up to 12 h after drug intake. The median time to maximum serum concentrations (Tmax) occurred 4 h post-dosing. Between 2 and 8 h post-dosing, mean serum iron concentrations fluctuated by only 20%. Additionally, C8h and C12h represented on average 78.6% and 47.5% of the Cmax, respectively. This study demonstrates that a single oral dose of 160 mg Tardyferon(®) administered under fasting condition to 30 women with IDA leads to an optimal long-lasting release of iron in the gastrointestinal tract in the targeted population. This allows the attainment and maintenance of elevated serum iron levels for up to 12 h after administration.

Improved training of neural networks for the nonlinear active control of sound and vibration.

Active control of sound and vibration has been the subject of a lot of research in recent years, and examples of applications are now numerous. However, few practical implementations of nonlinear active controllers have been realized. Nonlinear active controllers may be required in cases where the actuators used in active control systems exhibit nonlinear characteristics, or in cases when the structure to be controlled exhibits a nonlinear behavior. A multilayer perceptron neural-network based control structure was previously introduced as a nonlinear active controller, with a training algorithm based on an extended backpropagation scheme. This paper introduces new heuristical training algorithms for the same neural-network control structure. The objective is to develop new algorithms with faster convergence speed (by using nonlinear recursive-least-squares algorithms) and/or lower computational loads (by using an alternative approach to compute the instantaneous gradient of the cost function). Experimental results of active sound control using a nonlinear actuator with linear and nonlinear controllers are presented. The results show that some of the new algorithms can greatly improve the learning rate of the neural-network control structure, and that for the considered experimental setup a neural-network controller can outperform linear controllers.

Insolubilization test of sodium chondroitin sulphate with a view to its use as colonic carrier of drugs.

Several studies have been devoted to cross-linked sodium chondroitin sulphate (SCS), in the context of numerous strategies attempting to target the colon for the absorption or the therapeutic action of a drug. SCS, a glycosaminoglycan presenting a specific degradation in the colon, is in fact soluble in water and its use as drug carrier at such a distance from the digestive tube necessitates its hydrophobisation. One method described in the literature consists in manufacturing a three-dimensional network by cross-linking with bifunctional compounds. However, all the structural characterisations carried out on the products resulting from the catalysed treatments of SCS with diaminoalkanes demonstrate that there are no cross-linking bridges between the polymer chains. Moreover, treated SCS-based tablets containing theophylline as model drug lead in vitro to dissolution profiles which are identical to those obtained with the non-treated SCS. We were therefore unable to find the announced results using the method described.

[Flubendazole in human Echinococcus granulosus hydatidosis. Preoperative care: parasit-pharmacologic study]. / Flubendazole dans l'hydatidose humaine à Echinococcus granulosus. Action pré-opératoire: étude parasito-pharmacologique.

The effect of flubendazole in human hydatic disease due to E. granulosus has been studied in 22 patients with one or several hydatic cysts of different sites. Flubendazole has been given orally before surgery for a 10 days mean period, at 4 g daily in adults and 1 g daily in children. Flubendazole has been titrated by radioimmuno-assay in sera, urines and bile taken 12 to 24 hours after the last ingestion and in the hydatic cyst (membranes and liquid). The scolex vitality was determined by direct optic microscopy and by intra-peritoneal mouse inoculation. Seven non-treated patients, without hydatic disease, were considered as controls. The flubendazole concentrations in sera (3.01 +/- 3.73 ng/ml) and in urines (7.6 +/- 7.5 ng ml) are low. They are also low in membranes (3.21 +/- ng/mg) and in hydatic liquid, but significantly more elevated in the hepatic localisation than in the pulmonary localisation. The bile concentrations are high (167.9 +/- 133.2 ng/ml). There is no correlation between these concentrations and the amounts of flubendazole administered. The scolex vitality was correlated neither with the amounts of flubendazole administered, nor with the concentrations of flubendazole in the hydatic cyst. Further studies are necessary before judging of the efficacy of flubendazole in the human hydatic disease.