Flow rate and a 10 ll injection volume. Each sample Imatinib Gleevec was analyzed as n 3 sd at room temperature. All solvents were filtered through a 0.45 lm polytetrafluoroethylene membrane and degassed prior to use. All standard curves were linear over the concentration range of 0.1 150 lg/ml. 2.9. In vitro drug release In vitro drug release of itraconazole was assessed in simulated gastric fluid 0.5 wt.% sodium lauryl sulfate at pH 1.2. Experiments were performed in 10 ml test tubes using a rotary mixer at 65 rpm containing 0.8 0.1 mg of drug. At specific time points, samples were collected and filtered through a 0.45 lm PTFE membrane prior to HPLC analysis. All release samples were measured in triplicate. 2.10. Scanning electron microscopy The morphology was qualitatively evaluated using SEM. Images were taken with a Philips SEM XL30 FEG instrument in high vacuum mode. All samples were gold coated at room temperature prior to imaging. Each sample was analyzed as n 1. 2.11. Tapped density Tapped density was measured using a J. Engelsman jolting volumeter. The 750 lm sieved samples were analyzed after immediate removal from a 40 C vacuum oven at a reduced pressure of 100 mbar. Thirty five milliliters of the untreated COK 12 or 11 14 ml of the granulated material were then poured into a 50 ml graduated cylinder. The volume of the granulated material measured was less due to sample availability. Samples were subjected to successive sets of 500, 750, and 1250 taps at 240 taps/min until a volume difference of 2% was achieved between sets. Reported values for bulk and tapped density are the means for n 3 sd. 2.12. Viscosity An SV 10 sensor unit connected to an SV 10 Vibro Viscometer was used to measure the viscosity of the binder solution. A water bath was used to heat the 50 ml sample from room temperature to 25, 50, or 75 C and measured every 10 s.
Results were processed with the RSVisco version 1.10 software. Reported values are means for n 15 sd. 2.13. Stability Samples were placed in storage conditions to investigate whether drug would displace from the mesopores during storage. ITZ loaded COK 12 treated with either pure milli Q H2O or ethanol were stored in desiccators at 0% RH using phosphorous pentoxide in either a 25 C or a 60 C oven. A saturated solution of potassium iodide was used to prepare the 25 C/69% RH storage conditions. 2.14. PVP quantification A Hewlett Packard 8452A Diode array spectrophotometer UV/Vis was used to quantitatively determine PVP by photometry from a complex of PVP and Iodine. The standard curve was linear over the concentration range of 0 225 lg/ml. Each sample was analyzed n 3 sd at 470 nm wavelength. PVP is a synthetic polymer that consists of a linear chain of 1 vinyl 2 pyrrolidone groups which can vary in degree of polymerization. A binder’s ability to construct strong granules is Celecoxib dependent on the binder itself and its distribution in the granulate. PVP K25 was selected for its adequate viscosity, which allows it to spread more efficiently across the silica surface, thus improving homogeneity and granule strength. Another function is to form a hydrophilic film over the COK 12 surface, which improves wettability and therefore, release rate. The binder increases the particle size by joining two or more particles toge.