The aim of this study was to prepare and evaluate calcium-free sustained release drug delivery systems, based on the in-situ gelation of oral suspensions containing chitosan, sodium alginate and Ranitidine as drug model. The combined effects of polymer concentrations and their interactions on the rheological characteristics of both gels and suspensions and, on the kinetics of drug release were evaluated by using a central composite face-centered design. Rheological analysis showed that suspensions were potentially stable, with a viscosity increased by 1000 times compared to that of water. In addition, the obtained gels were consistent; their storage modulus could reach values close to 50 kPa when alginate concentration was greater than 7.5 g/100 mL and chitosan was fixed to 0.5 g/100 mL. In these conditions gels should have a higher gastric residence time, in comparison to the standard gastric emptying time (∼2 h). Evaluation of the in-vitro release kinetics of Ranitidine showed that the association of the lowest concentration of chitosan (0.5 g/100 mL) with higher alginate concentrations generates sustained release kinetics profiles. The time corresponding to 63% of release was found close to 1.5 h, in which case the process is governed by Fickian diffusion. Finally, calcium-free alginate-chitosan based on the in-situ gelation of suspensions is advantageous as a drug delivery system for sustained-release.

Abstract. Recent decades, it is an awareness of the importance of ecological balance in the environment, balances threatened by industrial pollution. A new spirit presides we seek to minimize pollution of receiving waters. The present work is to study the liquid-gel-extraction of zinc ions in perchlorate medium by an acid extractant: the di (ethyl-2 hexyl) phosphorique acid, or DEHPA. Two types of polymers were used as supports of solvent extraction: a polybutadiene rubber cross-linked respectively with 0.1% dicumyl peroxide and 0.4% dicumyl peroxide, vulcanized at 160°C, one is most cross-linked than the other. The liquid-gel extraction is based on the principles of the liquid-liquid extraction.

The importance of aromatic plants, their essential oil content and the chemical nature of their constituents, give them great prospects for application. Nowadays, essential oils present a major source of a variety of bioactive molecules, they are also used as an alternative to conventional drugs. The evaluation of phytotherapeutic properties, such as antioxidant, antimicrobial and anti-inflammatory are gaining great interest in the research field. The objective of this work is the evaluation of the antibacterial, antifungal and anti-inflammatory effect of the essential oil of wormwood from the region of Blida, Algeria and that of a drinkable emulsion formulated in the presence of this essential oil. Average yield of 0.52% of essential oil extracted by hydrodistillation using a Clevenger from the fresh aerial part of absinthe was obtained. GC/MS analysis demonstrated that wormwood essential oil is dominated by the presence of the compounds βThujone with 45.646% and 7-ethyl, 1,4 dimethyl Azulene with a percentage of 25.95%. The absinthe essential oil extracted showed an activity against all bacteria and fungi tested. The drinkable emulsion exerted remarkable an anti-inflammatory activity which induced an edema reduction rate of 35.70%, close to the one obtained by a Clofenal reference. Toxicity tests of the essential oil of Artemisia absinthium and the drinkable emulsion which were followed for two weeks, showed neither mortality nor abnormality.