Decoding Fine API Agglomeration as a Key Indicator of Powder Flowability and Dissolution: Impact of Particle Engineering

Document Type

Article

Publication Date

12-1-2022

Abstract

Purpose: Fine API agglomeration and its mitigation via particle engineering, i.e., dry coating, remains underexplored. The purpose was to investigate agglomeration before and after dry coating of fine cohesive APIs and impact on powder processability, i.e., flowability (FFC), bulk density (BD), and dissolution of BCS Class II drugs. Method: Ibuprofen (three sizes), fenofibrate, and griseofulvin (5–20 µm), before and after dry coating with varying amounts of hydrophobic (R972P) or hydrophilic (A200) nano- silica, were assessed for agglomeration, FFC, BD, surface energy, wettability, and dissolution. The granular Bond number (Bog), a dimensionless parameter, evaluated through material-sparing particle-scale measures and particle-contact models, was used to express relative powder cohesion. Results: Significant powder processability improvements after dry coating were observed: FFC increased by multiple flow regimes, BD increased by 25–100%, agglomerate ratio (AR) reduction by over an order of magnitude, and greatly enhanced API dissolution rate even with hydrophobic (R972P) silica coating. Scrutiny of particle-contact models revealed non-triviality in estimating API surface roughness, which was managed through the assessment of measured bulk properties. A power-law correlation was identified between AR and Bog and subsequently, between AR and FFC & bulk density; AR below 5 ensured improved processability and dissolution. Conclusion: Agglomeration, an overlooked material-sparing measure for powder cohesiveness, was a key indicator of powder processability and dissolution. The significant agglomerate reduction was possible via dry coating with either silica type at adequate surface area coverage. Reduced agglomeration after dry coating also countered the adverse impact of increased surface hydrophobicity on dissolution.

Identifier

85131884122 (Scopus)

Publication Title

Pharmaceutical Research

External Full Text Location

https://doi.org/10.1007/s11095-022-03293-z

e-ISSN

1573904X

ISSN

07248741

PubMed ID

35698012

First Page

3079

Last Page

3098

Issue

12

Volume

39

Grant

1919037

Fund Ref

International Fine Particle Research Institute

This document is currently not available here.

Share

COinS