Current Drug Delivery - Volume 2, Issue 1, 2005

Four commercial grades of microcrystalline cellulose, Avicel PH 101, Avicel PH 102, Avicel PH 112 and Avicel PH 302 were compared for extrusion spheronization. Model mixes containing Avicel PH 101 with different proportions of fillers like lactose and dicalcium phosphate dihydrate (DCPD) were also compared to observe the influence of these fillers on the pellet properties. The amount of water used for granulation of Avicel Read More

Peroral delivery of hydrophilic drugs is one of the greatest challenges in biopharmaceutical research. Hydrophilic drugs usually present low bioavailability after oral administration. One of the causes of this low bioavailability is their poor intestinal permeation through the paracellular pathway. This pathway is actually restricted by the presence of tight junctions at the apical side of the enterocytes. In the last few years, Read More

There is considerable interest in the skin as a site of drug application both for local and systemic effect. However, the skin, in particular the stratum corneum, poses a formidable barrier to drug penetration thereby limiting topical and transdermal bioavailability. Skin penetration enhancement techniques have been developed to improve bioavailability and increase the range of drugs for which topical and transdermal delivery is Read More

The aim of this study was to increase the understanding on the pharmacokinetic and tissue distribution of paclitaxel as influenced by formulation approach. For this purpose, various formulations investigated in Swiss mice included liposomes, poloxamer 407 gel and chitosan film for subcutaneous route; and water-soluble methacrylate prodrug, liposomes and poloxamer micelles for systemic administration. During thi Read More

The aim of the present study was to study the synergistic hepatoprotective effect of silymarin with phospholipids when it is encaged in microspheres so as to passively target it to liver and to compare these silymarin formulations with silymarin solution. Various silymarin loaded lipid emulsions were formulated which include formulation A prepared with soyabean oil as an internal oily phase, soya lecithin as surfactant Read More

Nano-structured hyperbranched cationic star polymers, called star vectors, were molecularly designed for a novel gene delivery non-viral vector. The linear and 3, 4 or 6 branched water-soluble cationic polymers, which had same molecular weight of ca. 18,000, were synthesized by iniferter (initiator-transfer agent-terminator)-based photo-livingradical polymerization of 3-(N,N-dimethylamino)propyl acrylamide, initiated from Read More

Antinociceptive effects and BBB transport properties of glycosylated enkephalin derivatives are reviewed. Previously, the application of enkephalins as analgesics has been retarded by their poor stability in vivo and by their inability to effectively penetrate the blood brain barrier. This shortcoming has been overcome by glycosylation, paradoxically leading to enhanced BBB transport via transcytosis. Principal design considerations r Read More

Alternative formulations of paclitaxel were developed in order to improve its aqueous solubility, and characterized in vitro. A methacrylic acid based nanoconjugate of paclitaxel was synthesized by a simple esterification reaction with molecular weight of 1657 Da. The in vitro hydrolysis study on the prodrug of paclitaxel in presence of rat plasma has shown that the ester bond was quite stable (less than 1% of paclitaxel was libera Read More

As previously shown, vinblastine, when incorporated into a cationic lipid prior to generation of lipoplexes, increases by ∼30-fold the extent of transfection of pβ-Gal with a cytomegalovirus promoter (pCMV-β- Gal) to vascular smooth muscle cells (VSMC) by 1,2-dioleoyl-sn-glycero-3-ethylphosphocholine (EDOPC)-pCMV- β-Gal complexes. To test if this increase is limited to VSMC and EDOPC, or is general, we examined Read More

This paper deals with the physical and mathematical modelling description of drug release from matrix systems. In the introduction, matrix systems are considered in the wide frame of the controlled release systems and the concept of mathematical model is briefly discussed. Then, matrix structure and topology are matched, analysing the characteristics of the three-dimensional network constituting them. In this context, d Read More