J Barra1, F Falson-Rieg, E Doelker. 1. School of Pharmacy, University of Geneva, Quai Ernest-Ansermet, Switzerland. jerome.barra@pharm.unige.ch
Abstract
PURPOSE: Elucidate the compactibility of binary mixes from their organization as compared to the traditional approach involving the different behavior of the materials under compression (plastic or brittle). METHODS: Several materials were selected from their surface energies. Binary mixes 50/50 v/v were prepared from different sieved or freeze-milled fractions. The tensile strengths of the tablets obtained at two compression forces were compared with those of series of compacted binary mixes containing different proportions of the raw materials (concept of equivalent media). RESULTS: In the case of interacting mixes, when the differences in particle size between the fractions blended increased, the material with the lowest particle size coated the largest particles more efficiently. Consequently, the tensile strengths of the tablets obtained became closer to the tensile strengths obtained from the pure coating material. For the non-interacting systems, the experimental tensile strengths were very close to the values calculated from the tensile strengths of the pure materials. CONCLUSIONS: This study clearly demonstrates the influence of the organization of binary mixes on their compactibility. The adhering material makes a percolating network governing the tensile strength of the tablet. From an industrial point of view, it is possible to improve the compactibility of binary mixes without changing their composition by selecting the appropriate organization.
PURPOSE: Elucidate the compactibility of binary mixes from their organization as compared to the traditional approach involving the different behavior of the materials under compression (plastic or brittle). METHODS: Several materials were selected from their surface energies. Binary mixes 50/50 v/v were prepared from different sieved or freeze-milled fractions. The tensile strengths of the tablets obtained at two compression forces were compared with those of series of compacted binary mixes containing different proportions of the raw materials (concept of equivalent media). RESULTS: In the case of interacting mixes, when the differences in particle size between the fractions blended increased, the material with the lowest particle size coated the largest particles more efficiently. Consequently, the tensile strengths of the tablets obtained became closer to the tensile strengths obtained from the pure coating material. For the non-interacting systems, the experimental tensile strengths were very close to the values calculated from the tensile strengths of the pure materials. CONCLUSIONS: This study clearly demonstrates the influence of the organization of binary mixes on their compactibility. The adhering material makes a percolating network governing the tensile strength of the tablet. From an industrial point of view, it is possible to improve the compactibility of binary mixes without changing their composition by selecting the appropriate organization.