Distribution of crushing strength of tablets.
The distribution of a given set of data is important since most parametric statistical tests are based on the assumption that the studied data are normal distributed. In analysis of fracture mechanics the Weibull distribution is widely used and the derived Weibull modulus is interpreted as a material constant. However, the estimation of this parameter is laborious and subject to estimation problems. It is shown that the Weibull modulus is inherently connected to the coefficient of variation and that the information obtained from the modulus is unclear. The distribution of crushing strength data from nine model tablet formulations and four commercial tablets are shown to follow the normal distribution. The importance of proper cleaning of the crushing strength apparatus is demonstrated.
Sonnergaard
Jørn M
JM
Department of Pharmaceutics, The Royal Danish School of Pharmacy, Copenhagen, Denmark. jms@dfh.dk
D019245:Compressive Strength; D004339:Drug Compounding; D004355:Drug Stability; D008962:Models, Theoretical; D016011:Normal Distribution; D013607:Tablets
D013607:Tablets