91���˶���Ƶ

Chair(s):

• Shankali Pradhan, Vertex Pharmaceuticals
• Ben Freireich, Particulate Solid Research, Inc.

Description

This session will focus on particle characterization techniques including techniques for granule, crystal, and tablet characterization. Characterization to study particle/tablet formation and disintegration will also be discussed.

Schedule

Abstracts

Tartrazine and dextran blue as surrogates to characterize biopharmaceutical properties of compacted microcrystalline cellulose tablets in batch and flow using UV-VIS spectroscopy

Peng Peng, Gabriella Reis Barham, and Aaron Moment*, Columbia University

Biopharmaceutical formulation properties are conveniently assessed indirectly by dissolution and disintegration under controlled conditions.  In this work we report using the dyes tartrazine (CAS 1934-21-0) and dextran blue (CAS 87915-38-6, MW 2x106) to assess the dissolution and disintegration rates of microcrystalline cellulose 10 mm tablets made on an MTS Universal Testing Instrument, as a function of compaction pressure, loading of the dye, and test configuration.  In batch, the formulations are distinguished using a lumped Noyes-Whitney equation model.  On the other hand, with a custom designed flow cell we report more detailed measurements including diffusion coefficients and overall mass transfer coefficients under low Reynolds number conditions mimicking saliva flow for an intra oral delivery project.  We also offer a preliminary assessment of image analysis algorithms to assess spatial content uniformity of the formulations based on micrographs and photographs.

Key words: compaction, tensile strength, dissolution, disintegration, dextran blue, tartrazine, FD&C Yellow 5, MTS Universal Testing Instrument, microcrystalline cellulose, image analysis, flow cell, UV-VIS spectroscopy, diffusion coefficient, mass transfer coefficient

Physical characterization of blends containing mesoporous particles with a focus on electrostatic properties

Aurelien Neveu, GranuTools

We show the effect of the addition of a small fraction of mesoporous silica (MPS) grains on the flow of cohesive powders. MPS grains are found to decrease the powder cohesiveness by playing a role on both capillary and electrostatic forces. The effect on the flow is quantified with the rotating drum method (GranuDrum instrument). According to both grain and pore size of MPS, the cohesiveness decrease can be immediate (for small MPS grains having small pore size) or on the longer term (for larger MPS grains having higher pore size). The effect on the powder electrostatic properties is analysed with a powder tribo-electrometer called GranuCharge. The quantity of electrostatic charges created during a flow in contact with stainless steel is decreased by the presence of MPS grains. We show that this decrease is induced by a modification of electric resistivity. The MPS grains are adsorbing the humidity contained in the powder and are forming a network having a low resistivity, improving the diffusion of electrostatic charges.