Čes. slov. farm. 2015, 64(1):14-18 | DOI: 10.36290/csf.2015.003

The effect of the size of a conical hopper aperture on the parameters of the flow equation of sorbitol and its size fractions

Zdenka Šklubalová^*, Hana Hurychová

Charles University in Prague, Faculty of Pharmacy, Department of Pharmaceutical Technology, Hradec Králové, Czech Republic

Determination of the rate of gravitational flow through a hopper aperture is one of the most widely used methods for the evaluation of flowability properties of pharmaceutical materials. This work studies the influence of the diameter of a conical hopper aperture in the range of 0.6-1.5 cm on the mass flow rate Q (g/s) of the pharmaceutical excipient, sorbitol, for direct compression (Merisorb 200, MS 200) and its size fractions in the range of 0.080-0.400 mm in order to recommend the appropriate aperture size for testing. Non-linear dependence of the flow rate on the aperture diameter is modeled by the Jones-Pilpel power equation. Using the actual parameters of the power equation, the precision of the mass flow rate prediction was the basic criterion in optimization of the orifice diameter. It was detected experimentally that for the evaluation of the flow rate of MS 200 and its size fractions in the range used a 1.0 cm aperture is recommended, which allows the most precise prediction of the flow rate.

Keywords: particulate material; excipient; flow equation; conical hopper; size fraction

Grants and funding:

The authors wish to express their thanks to the grant No. 322315/2015 of Grant Agency of Charles University in Prague and the specific research project SVV 260 183 of Charles University in Prague for the financial support, and to Dr. Müller Pharma Ltd. for lending the Automated Powder and Granulate Testing System, PTG S3 (PHARMATEST, Germany).

Received: February 23, 2015; Accepted: March 16, 2015; Published: January 1, 2015  Show citation