title: Effect of particle size on compaction of materials with different deformation mechanisms with and without lubricants.
abstract: This work investigates the effect of excipient particle size on compaction properties of brittle, plastic and viscoelastic materials with and without added lubricants. Sieve cuts of microcrystalline cellulose (MCC), starch and dibasic calcium phosphate dihydrate were obtained by sieving, then samples were tested without lubrication or with added lubricant (0.5% Mg stearate mixed for either 5 or 30-min). Compacts were left overnight before testing. It was found that in the absence of lubricant, compact tensile strength (TS) was dependent on particle size only for starch. With Mg stearate, lubricant sensitivity shows a strong dependence on excipient particle size for both starch and MCC, where smaller particles are less affected by lubricant. Dibasic calcium phosphate dihydrate was not sensitive to lubricant even after 30 min mixing. This study highlights that in the absence of lubricant, initial particle size of excipients has no impact on compact strength not only for dibasic calcium phosphate dihydrate (brittle), but also for MCC (plastic). On the other hand, TS is dependent on particle size both with or without added lubricant for starch (viscoelastic).
authors.affiliation: Pharmaceutical Sciences Research and Development, Eli Lilly & Company, Indianapolis, IN 46285, USA. almaya_ahmad@lilly.com
authors.forename: Ahmad
authors.initials: A
authors.lastname: Almaya
authors.forename: Aktham
authors.initials: A
authors.lastname: Aburub
mesh_terms: D002130:Calcium Phosphates / Q000737:chemistry; D002482:Cellulose / Q000737:chemistry; D002626:Chemistry, Pharmaceutical; D004339:Drug Compounding; D004548:Elasticity; D005079:Excipients / Q000737:chemistry*; D054327:Lubricants / Q000737:chemistry*; D010316:Particle Size; D011208:Powders; D013213:Starch / Q000737:chemistry; D013229:Stearic Acids / Q000737:chemistry; D013678:Technology, Pharmaceutical / Q000379:methods; D013718:Tensile Strength; D013997:Time Factors; D014783:Viscosity
chemical_list: D002130:Calcium Phosphates; D005079:Excipients; D054327:Lubricants; D011208:Powders; D013229:Stearic Acids; C494369:calcium phosphate, dihydrate; C031183:stearic acid; D002482:Cellulose; D013213:Starch; C485829:calcium phosphate, dibasic, anhydrous; C109691:microcrystalline cellulose