the aim of this study was to develop a derivative of chitosan as pharmaceutical excipient used in sustained-release matrix tablets of poorly soluble drugs. a water-soluble quaternary ammonium carboxymethylchitosan was synthesized by a two-step reaction with carboxymethylchitosan (cmcts), decylalkyl dimethyl ammonium and epichlorohydrin. the elemental analysis showed that the target product with...

a sustained-release tablet formulation should ideally have a proper release profile insensitive to moderate changes in tablet hardness that is usually encountered in manufacturing. in this study, matrix aspirin (acetylsalicylic acid) tablets with ethylcellulose (ec), eudragit rs100 (rs), and eudragit s100 (s) were prepared by direct compression. the release behaviors were then studied in two co...

in the present investigation an attempt has been made to increase therapeutic efficacy, to reduce frequency of administration and to improve patient compliance by developing a sustained release matrix tablets of isosorbide-5-mononitrate. sustained release matrix tablets of isosorbide-5-mononitrate were developed by using different drug: polymer ratios, such in f1 (1:0.75), f2 (1:1), f3 (1:1.5),...

combination formulations of liposomes with collagen have been previously introduced as a means of obtaining more stable and less permeable liposomes. in this study, the effect of aqueous solutions of the collagen products collapur? (col) and collapuron-dak? (cold) from henkle co., on the release rate of sodium chromate (chr) as a water-soluble model drug from stable plurilamellar vesicles (splv...

gel dosage forms are successfully used as drug delivery systems considering their ability to control drug release and to protect medicaments from a hostile environment. the aim of this work was to investigate the properties of carbopol 934p polymeric system in water-misible cosolvents such as glycerin and alcohol. benzocaine is a local anesthetic and the mucosal gel formulation is applied in th...

ketorolac tromethamine (kt) containing microemulsion-based gels (mbgs) have been formulated, based on the previous phase diagram studies, using a pharmaceutically acceptable surfactant (soybean lecithin; epikuron 200) and oil (isopropyl myristate; ipm) and the effect of formulation variables on the release profile of the drug from mbgs through intact guinea pig skin and various artificial membr...

reaction to fire of fire-retarded rigid pur foams and two types of metal faced rigid polyurethane foam core sandwich panel was evaluated by using cone calorimeter test method. the tests were carried out in various radiative heat fluxes from 15 to 75 kw/m2. the radiation rate effect on reaction to fire parameters, including time to ignition (tti), peak of heat release rate (prhr), total heat rel...

the human mdr1 gene encodes for a p-glycoprotein (pgp), which acts as an efflux pump that transports a large variety of substrates from the inside of cells to the outside until protection against xenobiotics. the g2677t/a polymorphism in exon 21 is associated with pgp expression and function in humans. the present study was aimed to determine the frequencies of this polymorphism in a healthy po...