Related Experiment Video
Updated: Nov 19, 2025

A Package of Established Analytical Tools to Investigate the Solid-State Alteration of Lipid-Based Excipients
Published on: August 9, 2022
Amorphous Drug-Polymer Salt with High Stability under Tropical Conditions and Fast Dissolution: The Case of
Abstract:
We report that the stability of amorphous clofazimine (CFZ) against crystallization is vastly improved by salt formation with a polymer without sacrificing dissolution rate. A simple slurry method was used to produce the amorphous salt of CFZ with poly(acrylic acid) (PAA) at 75 wt % drug loading. The synthesis was performed under a mild condition suitable for thermally unstable drugs and polymers. Salt formation was confirmed by visible spectroscopy and glass temperature elevation. The amorphous salt at 75 wt % drug loading is remarkably stable against crystallization at 40 °C and 75% RH for at least 180 days. In contrast, the amorphous solid dispersion containing the un-ionized CFZ dispersed in poly(vinylpyrrolidone) crystallized in 1 week under the same condition. The high stability of the amorphous drug-polymer salt is a result of the absence of a drug-polymer crystalline structure, reduced driving force for crystallizing the free base, and reduced molecular mobility. Despite the elevated stability, the amorphous drug-polymer salt showed fast dissolution and high solution concentration in two biorelevant media (SGF and FaSSIF). Additionally, the amorphous CFZ-PAA salt has improved tabletability and powder flow relative to crystalline CFZ. The CFZ-PAA example suggests a general method to prepare amorphous drugs with high physical stability under tropical conditions and fast dissolution.
More Related Videos
04:09Development and Characterization of Fusidic Acid-Loaded Alginate-Aloe vera Based Hydrogel FilmWound Healing
Published on: December 13, 2024
08:59A Freeze-Thawing Method to Prepare Chitosan-Polyvinyl alcohol Hydrogels Without Crosslinking Agents and Diflunisal Release Studies
Published on: January 14, 2020
Related Concept Videos
Factors Affecting Dissolution: Polymorphism, Amorphism and Pseudopolymorphism
Some polymorphic crystals possess lower aqueous solubility than their amorphous counterparts, leading to incomplete absorption. For instance, the oral suspension of Chloramphenicol, which...
Bioavailability Enhancement: Drug Stability Enhancement and GI Retention
Factors Influencing Drug Absorption: Physicochemical Parameters
Enhanced drug absorption can be achieved by reducing particle sizes and increasing surface areas, thereby facilitating...
Factors Affecting Dissolution: Drug Permeability, Stability and Stereochemistry
Pharmaceutical Alternatives: Polymorphic Form-Related and Particle Size-Related Therapeutic Nonequivalence
Factors Influencing Drug Absorption: Pharmaceutical Parameters