• Processes 2018, 6(7), 73; https://doi.org/10.3390/pr6070073
• Published: 21 June 2018

by Maximilian Sixt and Jochen Strube ^*

Institute for Separation and Process Technology, Clausthal University of Technology, 38678 Clausthal-Zellerfeld, Germany

Abstract

Traditionally used herbal medicines are deep in the consciousness of patients for the treatment of only minor diseases by self-medication. However, manufacturers of herbal medicinal products suffer from major problems such as increasing market pressure by e.g., the food supplement sector, increasing regulations, and costs of production. Moreover, due to more stringent regulation and approval processes, innovation is hardly observed, and the methods used in process development are outdated. Therefore, this study aims to provide an approach based on modern process engineering concepts and including predictive process modelling and simulation for the extraction of traditional herbal medicines as complex extracts. The commonly used solvent-based percolation is critically assessed and compared to the so-called pressurized hot water extraction (PHWE) as a new possible alternative to replace organic solvents. In the study a systematic process design for the extraction of hawthorn (Crataegus monogyna JACQ.) is shown. While for traditional percolation the solvent is optimized to a mixture of ethanol and water (70/30 v/v), the PHWE is run at a temperature of 90 °C. The extracts of various harvest batches are compared to a commercially available product based on a chromatographic fingerprint. For the first time, natural batch variability was successfully incorporated into the physico-chemical process modelling concept. An economic feasibility study reveals that the PHWE is the best choice not only from a technical point of view but also from economic aspects.

Keywords: pressurized hot water extraction; modelling; simulation; harvest; variety

1. Introduction

Herbal medicine is widely used to cure a myriad of diseases such as gastrointestinal complaints, high blood pressure, sore throat, colds, skin disorders and other sicknesses. They are considered to be natural, compatible and healthy. On account of its long tradition, the use and production of herbal medicine must not be overtaken by modern engineering technologies for production and quality management. Assessing small-molecule pharmaceuticals approved between 1981 and 2002 shows that approximately half are either natural products or natural product derivatives [1,2]. In the future, natural products will continue to play a major role as active substances, model molecules for the discovery and validation of drug targets [1].

Therefore, this paper highlights the systematic process development, simulation and cost assessment for a commonly used herbal drug represented by hawthorn (Crataegus monogyna JACQ.). The conventional solvent extraction is compared with the so-called pressurized hot water extraction (PHWE) [3,4,5,6] which shows significant potential for the eco-friendly and solvent-free extraction of plant matrices [3,4,6]. Hawthorn leaves are a representative system for a medical extract. It is used to treat cardiac insufficiency [7]. The flavonoid hyperoside is chosen as a marker substance. The extracts will be characterized by their content of hyperoside and the drug-extract ratio (DER). The DER is defined as the ratio between the plant material used for extraction and the amount of dry matter remaining in the fluid extract after the extraction process has taken place, according to Equation (1).

Reference:

Hawthorn – LIFE FORCE HEALTH CENTER

https://www.mdpi.com/2227-9717/6/7/73/htm