Čes. slov. farm. 2009, 58(1):9-13

Evaluation of pellet friability

E. Gryczová, K. Dvořáčková, M. Rabišková^*

University of Veterinary and Pharmaceutical Brno, Faculty of Pharmacy, Department of Pharmaceutics Sciences, Czech Republic

Pellet friability and hardness are important particle characteristics as they predict pellet behavior during technological processes such as film coating, filling into hard gelatin capsules or compressing into tablets. At present no methods for testing of these pellet properties are present in pharmacopoeias and various methods adapted from tablet evaluation are used. A number of methods and different equipment are used to determine pellet friability. These methods in addition differ also in the testing conditions. Therefore pellets of different hardness and composition were chosen on purpose for this experiment to show the influence of method variables on the friability of brittle and hard pellets prepared by different techniques. Pellet friability was tested in the same equipment under different conditions, but always with the equal amount of sample and equal total number of revolutions. All the samples exhibited also similar residue moisture content. As different friability values were obtained for the same sample under different testing conditions it is necessary to pay attention to the method used and its parameters. This experiment indicates that pellet friability is influenced not only by pellet composition but also by the technique of their manufacture.

Keywords: pellets; hardness; friability; methods of evaluation; testing conditions

Grants and funding:

This experimental work has been supported by IGA VFU Project No 136/2008/FaF and the pharmaceutical company Zentiva a.s. Praha, Czech Republic.

Received: November 4, 2008; Accepted: December 1, 2008; Published: January 1, 2009  Show citation