title: A novel method for estimating solid fraction of roller-compacted ribbons.
abstract: A simple method has been developed to estimate solid fraction or relative density of compacts using the weight of ribbons produced during roller compaction. The method provides an alternative to the commonly used dimensional measurement, especially for formulations not amenable to forming quality ribbons. Surface texture of the compaction rolls has been taken into consideration in our mathematical treatment along with correction for ribbon relaxation. Ribbon relaxation occurring upon ribbon exiting the compaction zone is estimated using roll geometry, roll gap, and ribbon thickness. Detailed experimental runs have been carried out to confirm the validity of the proposed theory. The predicted solid fraction was found comparable to that from actual dimensional measurement by caliper. In the case of the microcrystalline cellulose/dicalcium phosphate one:one formulation, the predicted solid fraction had an error sum of squares (SSE) of 2.64E-03 when compared to the dimensional method. When relaxation was included, the SSE decreased by four folds. Similarly, for the microcrystalline cellulose/lactose monohydrate 2:1 formulation, the SSE decreased twelfth folds when relaxation was taken into consideration. These results further confirm the utility of the proposed throughput method for estimating the solid fraction of ribbons.
authors.affiliation: Pfizer Global Research & Development, Pharmaceutical Sciences, Ann Arbor, Michigan 48105, USA. paul.nkansah@pfizer.com
authors.forename: Paul
authors.initials: P
authors.lastname: Nkansah
authors.forename: Sy-Juen
authors.initials: SJ
authors.lastname: Wu
authors.forename: Stephanie
authors.initials: S
authors.lastname: Sobotka
authors.forename: Ken
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Zezhi J
authors.initials: ZJ
authors.lastname: Shao
mesh_terms: D002130:Calcium Phosphates / Q000737:chemistry; D002482:Cellulose / Q000737:chemistry; D005079:Excipients / Q000737:chemistry; D007785:Lactose / Q000737:chemistry; D008962:Models, Theoretical; D011208:Powders; D013499:Surface Properties; D013607:Tablets / Q000737:chemistry*; D013678:Technology, Pharmaceutical
chemical_list: D002130:Calcium Phosphates; D005079:Excipients; D011208:Powders; D013607:Tablets; D002482:Cellulose; D007785:Lactose; C485829:calcium phosphate, dibasic, anhydrous; C109691:microcrystalline cellulose