Kanamycin sulphate and rifampicin were purchased from Hangzhou Dayangchem Co., Ltd., Zhejiang, China. Acetonitrile and ethanol (High performance liquid chromatography, HPLC, grade) were purchased from Merck, Germany. Sodium dihydrogen phosphate, phenylisocyanate, triethylamine, orthophosphoric acid (analytical reagent grade) and silicone oil (viscosity 10 cSt) were purchased from Sigma–Aldrich, St. Louis, USA. Size 3 hard gelatin capsules were kindly donated by Capsugel Co., Ltd., Tokyo, Japan. Fresh Milli-Q water was collected and filtered through 0.45 μm membrane filter before use. Preparation of powders by spray-drying
Powder particles were produced using a Buchi B-290 Mini Spray-Dryer (Buchi Labortechnik AG, Flawil, Switzerland) with a high performance cyclone in a closed-mode. Feed solutions of kanamycin (as sulphate) or/and rifampicin were prepared in a co-solvent system of ethanol and water (70:30, v/v). Rifampicin was first dissolved in ethanol; kanamycin was dissolved in water. The two solutions were then mixed (at rifampicin and kanamycin ratio of 40 and 60% w/w) and sonicated for 5 …show more content…
Powder samples were dispersed in saturated ethanol and bath sonicated for 15 s before transferring in to fraction cell. The refractive indices of kanamycin (1.67) (for kanamycin-only and kanamycin-rifampicin combination powder) and rifampicin (1.61) were used to automatically measure the particle volumetric diameters of the prepared powders by the built-in LA-950 Horiba software. The particle volumetric diameters were expressed as D10, D50 and D90, indicating the diameter under which 10%, 50% and 90% of the sample resided. Following equation was used to calculate the broadness (span) of size distribution. All measurements were done in triplicate for each
Powder particles were produced using a Buchi B-290 Mini Spray-Dryer (Buchi Labortechnik AG, Flawil, Switzerland) with a high performance cyclone in a closed-mode. Feed solutions of kanamycin (as sulphate) or/and rifampicin were prepared in a co-solvent system of ethanol and water (70:30, v/v). Rifampicin was first dissolved in ethanol; kanamycin was dissolved in water. The two solutions were then mixed (at rifampicin and kanamycin ratio of 40 and 60% w/w) and sonicated for 5 …show more content…
Powder samples were dispersed in saturated ethanol and bath sonicated for 15 s before transferring in to fraction cell. The refractive indices of kanamycin (1.67) (for kanamycin-only and kanamycin-rifampicin combination powder) and rifampicin (1.61) were used to automatically measure the particle volumetric diameters of the prepared powders by the built-in LA-950 Horiba software. The particle volumetric diameters were expressed as D10, D50 and D90, indicating the diameter under which 10%, 50% and 90% of the sample resided. Following equation was used to calculate the broadness (span) of size distribution. All measurements were done in triplicate for each