From Waste to Value: Solubility and Dissolution Enhancement of Bioactive Extracts from Olive Leaves Using Poloxamers

The European Union, producing over 2.5 billion tons of waste annually, has prompted the European Parliament to implement legal measures and encourage the shift towards a circular economy. Millions of tons of biowaste from olive plant leaves are generated annually, resulting in environmental and economic challenges. To address this, the biowaste of olive leaves was valorized, resulting in the extraction of valuable components, triterpenes and polyphenols, which hold potential pharmaceutical, food, or cosmetic applications. Our research involved the formulation of a triterpene extract (TTP70, 70% triterpenes) as a solid dispersion using Poloxamer-188 (P188) and Poloxamer-407 (P407). The solid dispersions were prepared using a kneading method and various extract-to-polymer weight ratios, including 1:1, 1:2, and 1:5. The influence of hydrophilic carriers on the solubility, dissolution profile, and in vitro passive permeability of TTP70 was evaluated. Both carriers and all considered weight ratios significantly improved the solubility of hydrophobic extract and the dissolution of triterpenes. PAMPA experiments demonstrated the efficacy of the formulation in improving the passive permeation of triterpenes. Subsequently, the solid dispersions were physically mixed with a polyphenol-enriched extract (OPA40, 49% of polyphenols) also obtained from olive leaves, and they were used to fill hard gelatin capsules and produce an oral dosage form. The composite formulations improved the dissolution of both classes of constituents.