# Amorphous solid dispersions as a strategy to enhance the bioavailability and stability of formulations containing plant active ingredients: An integrative review

## TL;DR

This review explores how amorphous solid dispersions can improve the solubility, stability, and bioavailability of plant-based medicines.

## Contribution

The paper provides an integrative review of ASDs for plant-derived APIs, summarizing production methods and characterization techniques.

## Key findings

- ASDs effectively enhance solubility and stability of plant-derived compounds.
- PVP, PVA, and PEG are the most commonly used polymers in ASD formulations.
- Solvent evaporation is the dominant method for ASD production.

## Abstract

Plant-derived active pharmaceutical ingredients (APIs), including crude extracts, phytocomplexes, and isolated compounds, have been extensively investigated due to their therapeutic potential. However, their pharmaceutical application is often hindered by challenges such as low solubility, limited stability, and poor bioavailability. Amorphous solid dispersions (ASDs) have emerged as a promising strategy to overcome these limitations, enhancing solubility, dissolution, and oral absorption of these compounds, while also protecting active constituents and improving their stability. Accordingly, this review aims to explore the use of ASDs for plant-derived APIs, focusing on production methods, polymers and carriers employed, as well as characterization techniques applied to these formulations.

A literature search was conducted in ScienceDirect, Scopus, Web of Science and PubMed databases for articles published between 2000 and 2025. Using terms related to ASDs and plant-derived compounds, 566 articles were retrieved, of which 84 met the inclusion criteria after screening.

The review highlights successful incorporation of several plant-derived APIs into ASDs, primarily to improve solubility and membrane permeability, with isolated compounds being the most frequently studied. The solvent evaporation method was the most used, although efforts toward more sustainable production methods were also reported. Among polymeric carriers, poly(vinylpyrrolidone) (PVP), poly(vinyl alcohol) (PVA), and poly(ethylene glycol) (PEG) were the most frequently employed. The most common physicochemical characterization techniques included scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and X-ray diffraction (XRD).

Overall, ASDs represent a viable and effective approach to unlock the therapeutic potential of plant-derived APIs, supporting the development of more stable and bioactive herbal formulations.