In Vitro and In Vivo evaluation of hydroxypropylmethyl cellulose phthalate capsules

The aim of this study was to develop a novel HPMCP capsule. The HPMCP capsule containing99mTc-DTPA and lactose was evaluated in in vitro and in vivo studies. First of all, the HPMCP capsules were prepared and characterized with lenght and diameter size, brittleness facility, moisture content and microbiological test. In vitro resistance and solubility studies of prepared capsules were tested at pH 1.2 and pH 7.4 buffers. The radiolabeled HPMCP capsules were administrated to fasted volunteers. The disintegration times and positions of capsules were recorded by using gamma scintigraphy. In vitro studies showed that HPMCP capsules were gastro resistant for 2 h at pH 1.2 and dissolved at pH 7.4 in 20-25 minutes. The radiolabeled capsules did not disintegrate in stomach whereas disintegrated in intestines. In conclusion, it was found that, the prepared HPMCP capsules can be an alternative to the hard gelatine capsules and used for intestinal targeting.Keywords: Capsule, hydroxypropylmethylcellulose phthalate (HPMCP), gamma scintigraphy, radiolabelling, technetium-99m

Two new suggestions for pharmaceutical dosage forms: Ethylcellulose and cellulose acetate phthalate capsules

The purpose of this study was to achieve the preparation of controlled-release and enteric-coated dosage forms more easily and simply. For this purpose, ethylcellulose and cellulose acetate phthalate capsules were prepared in the form of Snap-Fit type hard gelatin capsules for controlled-release and enteric-coated dosage forms respectively. A concentrated drug solution was filled into the ethylcellulose capsules drilled in different diameters by using laser, and the in vitro release of the drug was investigated. In addition, the effect of a viscosity increasing agent on the release of the drug was examined. Furthermore, the in vivo release of the drug marked with 99mTc from ethylcellulose capsules drilled by using laser was studied, and a good in vitro/in vivo correlation was found. The resistance and solubility of cellulose acetate phthalate capsules were controlled with in vitro and in vivo tests. According to these results, it was observed that cellulose acetate phthalate capsules were resistant in the stomach and were dissolved in the intestinal medium 2 h after being taken

The stability of oxolamine phosphate and oxolamine citrate in simulated gastric and intestinal media

[No abstract available

Studies on the release of oxolamine citrate from matrix tablets prepared with Eudragit®

The release of oxolamine citrate (OXC) from matrix tablets prepared with direct compression and wet-granulation method was evaluated. Eudragit® RS PM as polymer was used. The release of drug from matrix tablets prepared at different drug-polymer ratios (1:0.5, 1:0.75, 1:1, 1:1.5, 1.2) was examined using USP rotating paddle dissolution method. Drug-polymer ratio was found to be effective on the release of oxolamine citrate from matrix tablets. The matrix tablets prepared with direct compression technique released the drug faster than the matrix tablets prepared with wet-granulation method. Since the granules of matrix tablets at the highest drug-polymer ratio (1:2), were not clamped to each other during the production of the tablets, they release the drug rapidly by disintegrating in the dissolution medium. It was also observed that the release rate of oxolamine citrate could be decreased by heating the matrix tablets prepared both by direct compression and wet-granulation method in an oven at 150°C for five minutes

An approach to the intelligent drug delivery systems: Thermo-responsive membrane for pulsatile drug delivery [Aki{dotless}lli{dotless} ilaç taşi{dotless}ma sistemlerine yeni yaklaşi{dotless}mlar: I{dotless}si{dotless}ya duyarli{dotless} membranlar]

In this study, the potential use of thermotropic liquid crystals as a responsive release system was investigated. Cholesteryl oleyl carbonate liquid crystal (COC) has been embedded in nylon membranes by using vacuum filtration methods. In vitro drug release studies were performed by using a fluid/fluid diffusion cell. Sodium salicylate as a model drug penetration study was performed in nylon membrane with or without COC that is prepared at 25 and 37°C. Also the penetration studies were performed by repeatedly exchanging the temperature cycle (10, 25, 37°C) of the water bath at predetermined intervals. It was observed that COC and temperature have effects on the penetration of sodium salicylate. At 37 °C, the penetration rate of sodium salicylate was found higher than 25 °C and 10 °C, respectively. Also, the penetration amount of sodium salicylate has changed as pulsatile drug delivery in the presence of COC. As a result, according to the patients' requirements, it seems that the penetration rate and profile can be adjusted by developing pulsatile drug delivery as a new system

Studies on zero-order release from hardened gelatin capsules

[No abstract available

Novel microparticle drug delivery systems based on chitosan and Eudragit®RSPM to enhance diltiazem hydrochloride release property

PubMed ID: 21563988The aim of this study was to enhance the release properties of diltiazem hydrochloride (diltiazem HCl) by using microparticle system. For this reason, microparticle drug delivery systems based on chitosan and Eudragit®RSPM were developed. The microparticles were prepared by using double-emulsion solvent extraction method and the mean sizes of microparticles were less than 120 µm. The in vitro drug release from microparticles was studied in simulated gastric (pH 1.2) and intestinal media (pH 7.4) than the results were evaluated by kinetically. In vitro diltiazem HCl release from microparticles showed good zero order kinetic. For the microparticles with chitosan, the release of diltiazem HCl at pH 1.2 could be effectively sustained, while the release of diltiazem HCl increased at pH 7.4 when compared to Eudragit®RSPM microparticles. The highest release percent obtained was 1:1 ratio of drug: polymer at pH 1.2 and 7.4. All results clearly suggest that the release properties of diltiazem HCl were improved by using microparticle systems especially which contain chitosan. © 2012 Informa Healthcare USA, Inc