Polymeric solid dispersion Vs co-amorphous technology: A critical comparison

Historically, amorphous solid dispersion technology with polymeric carriers has been employed to stabilize high-energy amorphous phases of poorly water-soluble drug candidates. However, the technology suffers from certain shortcomings like the hygroscopicity of polymers contributing to the phase separation and low drug loading due to the limited phase solubility of certain drugs in polymers. An iteration of amorphous solid dispersion was introduced in 2009, where the polymeric carriers are replaced with small molecular weight compounds. Since then, the co-amorphous technology has become popular at the expense of the limitations of polymeric solid dispersions, or at least it claimed so. However, there is no critical comparison between these technologies concerning stability, solubility, and processability improvement. The claim of co-amorphous technology countering the issues related to polymeric solid dispersion remains to be validated through meta-analysis of the literature. In this context, the objective of this review is to critically compare polymeric amorphous solid dispersion and co-amorphous technology based on improvement in drug loading, stability, solubility, dissolution, and bioavailability. This is achieved by an extensive and comprehensive literature review on polymeric solid dispersion and co-amorphous technology. To enable vis-à-vis comparison, drugs that are in common from both polymeric solid dispersion and co-amorphous articles were selected. Though the performance indicators are molecule specific, the polymeric dispersions outperform co-amorphous materials based on physical stability and bioavailability. Whilst co-amorphous materials tend to possess high drug loadings. Further, the performance of both polymeric solid dispersion and co-amorphous systems is analogous regarding the rate and extent of supersaturation and processability.