Optimization of a chromatographic process for the purification of saponins in Panax notoginseng extract using a design space approach

An effective and comprehensive optimization strategy for preparing Ginkgo biloba leaf extract enriched in shikimic acid by macroporous resin column chromatography

INTRODUCTION

Previously reported preparation methods of Ginkgo biloba leaf extract (EGBL) have mainly focused on the enrichment of flavonoid glycosides (FG) and terpene trilactones (TT), which led to the underutilization of G. biloba leaves (GBL).

OBJECTIVES

To make full use of GBL, in this study, a comprehensive optimization strategy for preparing EGBL by macroporous resin column chromatography was proposed and applied to enrich FG, TT, and shikimic acid (SA) from GBL.

METHODOLOGY

Initially, the static adsorption and desorption were executed to select suitable resin. Then, the influences of solution pH were investigated by the static and dynamic adsorption. Subsequently, eight process parameters were systematically investigated via a definitive screening design (DSD). After verification experiments, scale-up enrichment was carried out, investigating the feasibility of the developed strategy for application on an industrial scale.

RESULTS

It was found that XDA1 was the most appropriate adsorbent for the preparation of EGBL at solution pH 2.0. Furthermore, based on the constraints of the desired quality attributes, the optimized ranges of operating parameters were successfully acquired, and the verification experiments demonstrated the accuracy and reliability of using DSD to investigate the chromatography process for the preparation of EGBL. Finally, magnified experiments were successfully performed, obtaining the EGBL containing 26.54% FG, 8.96% TT, and 10.70% SA, which reached the SA level of EGB761, an international standard EGBL.

CONCLUSION

The present study not only provided an efficient and convenient approach for the preparation of EGBL enriched in SA but also accelerated efforts to high-value utilization of GBL.

Preparation of Compound Salvia miltiorrhiza-Blumea balsamifera Nanoemulsion Gel and Its Effect on Hypertrophic Scars in the Rabbit Ear Model

Hypertrophic scars (HS) still remain an urgent challenge in the medical community. Traditional Chinese medicine (TCM) has unique advantages in the treatment of HS. However, due to the natural barrier of the skin, it is difficult for the natural active components of TCM to more effectively penetrate the skin and exert therapeutic effects. Therefore, the development of an efficient drug delivery system to facilitate enhanced transdermal absorption of TCM becomes imperative for its clinical application. In this study, we designed a compound Salvia miltiorrhiza-Blumea balsamifera nanoemulsion gel (CSB-NEG) and investigated its therapeutic effects on rabbit HS models. The prescription of CSB-NEG was optimized by single-factor, pseudoternary phase diagram, and central composite design experiments. The results showed that the average particle size and PDI of the optimized CSB-NE were 46.0 ± 0.2 nm and 0.222 ± 0.004, respectively, and the encapsulation efficiency of total phenolic acid was 93.37 ± 2.56%. CSB-NEG demonstrated excellent stability and skin permeation in vitro and displayed a significantly enhanced ability to inhibit scar formation compared to the CSB physical mixture in vivo. After 3 weeks of CSB-NEG treatment, the scar appeared to be flat, pink, and flexible. Furthermore, this treatment also resulted in a decrease in the levels of the collagen I/III ratio and TGF-β1 and Smad2 proteins while simultaneously promoting the growth and remodeling of microvessels. These findings suggest that CSB-NEG has the potential to effectively address the barrier properties of the skin and provide therapeutic benefits for HS, offering a new perspective for the prevention and treatment of HS.

The development of an herbal material quality control strategy considering the effects of manufacturing processes

Background

Quality by design (QbD) is an advanced drug quality control concept that has been gradually implemented in the optimization of manufacturing processes of Chinese medicines. However, the variation of Chinese medicinal material quality has rarely been considered in published works. Because manufacturing processes may lower the variation introduced through different batches of materials, a material quality control strategy should be developed considering the influences of manufacturing processes.

Methods

In this work, the processes of extraction, concentration, water precipitation, and chromatography for notoginseng total saponin (NTS) production were investigated while considering Panax notoginseng quality variation as a sample. Ten process parameters were studied simultaneously using a definitive screening design. After the process critical quality attributes (CQAs) were determined, critical process parameters (CPPs) and critical material attributes (CMAs) were identified simultaneously. Then, models utilizing the CMAs, CPPs, and process CQAs were developed. The design space was then calculated using a Monte Carlo simulation method with an acceptable probability of 0.90. A material quality control strategy considering the influences of manufacturing processes was proposed.

Results

The ginsenoside Rd purity and total saponin purity in the eluate were identified as process CQAs. The ethanol solution concentration used for extraction, the ethanol solution concentration used for elution, and elution time were identified as CPPs. The extractable dry matter content of Panax notoginseng was one of the CMAs. The extractable contents of notoginsenoside R₁, ginsenoside Rg₁, ginsenoside Rb₁, and ginsenoside Rd were the other CMAs. The inequalities implemented to discriminate the high quality and low quality of Panax notoginseng were developed according to the NTS standard of the Xuesaitong injection. Low quality Panax notoginseng should not be released for NTS production. High quality Panax notoginseng can be treated with feasible manufacturing processing parameters. Verification experiments were carried out successfully for 2 batches of high quality Panax notoginseng.

Conclusions

In this work, a quality control strategy for herbal materials was developed considering the matching of process characteristics and material quality attributes. This strategy is promising for application to other Chinese medicines.

The Multi-Template Molecularly Imprinted Polymer Based on SBA-15 for Selective Separation and Determination of Panax notoginseng Saponins Simultaneously in Biological Samples

The feasible, reliable and selective multi-template molecularly imprinted polymers (MT-MIPs) based on SBA-15 (SBA-15@MT-MIPs) for the selective separation and determination of the trace level of ginsenoside Rb₁ (Rb₁), ginsenoside Rg₁ (Rg₁) and notoginsenoside R₁ (R₁) simultaneously from biological samples were developed. The polymers were constructed by SBA-15 as support, Rb₁, Rg₁, R₁ as multi-template, acrylamide (AM) as functional monomer and ethylene glycol dimethacrylate (EGDMA) as cross-linker. The new synthetic SBA-15@MT-MIPs were satisfactorily applied to solid-phase extraction (SPE) coupled with high performance liquid chromatography (HPLC) for the separation and determination of trace Rb₁, Rg₁ and R₁ in plasma samples. Under the optimized conditions, the limits of detection (LODs) and quantitation (LOQs) of the proposed method for Rb₁, Rg₁ and R₁ were in the range of 0.63⁻0.75 ng·mL-1 and 2.1⁻2.5 ng·mL-1, respectively. The recoveries of R₁, Rb₁ and Rg₁ were obtained between 93.4% and 104.3% with relative standard deviations (RSDs) in the range of 3.3⁻4.2%. All results show that the obtained SBA-15@MT-MIPs could be a promising prospect for the practical application in the selective separation and enrichment of trace Panax notoginseng saponins (PNS) in the biological samples.

A Bioactive Chemical Markers Based Strategy for Quality Assessment of Botanical Drugs: Xuesaitong Injection as a Case Study

Current chemical markers based quality assessment methods largely fail to reflect intrinsic chemical complexity and multiple mechanisms of action of botanical drugs (BD). The development of novel quality markers is greatly needed. Here we propose bioactive chemical markers (BCM), defined as a group of chemo-markers that exhibit similar pharmacological activities comparable to the whole BD, which can therefore be used to effectively assess the quality of BD. As a proof-of-concept, a BCM-based strategy was developed and applied to Xuesaitong Injection (XST) for assessing the efficacy and consistency of different batches. Firstly, systemic characterization of chemical profile of XST revealed a total number of 97 compounds. Secondly, notoginsenoside R₁, ginsenoside Rg₁, Re, Rb₁ and Rd were identified as BCM of XST on treating cardiovascular and cerebrovascular diseases according to Adjusted Efficacy Score following an in vivo validation. Analytical method for quantification of BCM was then developed to ensure the efficacy of XST. Finally, chemical fingerprinting was developed and used to evaluate the batch-to-batch consistency. Our present case study on XST demonstrates that BCM-based strategy offers a rational approach for quality assessment of BD and provides a workflow for chemistry, manufacturing, and controls (CMC) study of BD required by regulatory authority.

Chromatographic elution process design space development for the purification of saponins in Panax notoginseng extract using a probability-based approach

A Monte Carlo method was used to develop the design space of a chromatographic elution process for the purification of saponins in Panax notoginseng extract. During this process, saponin recovery ratios, saponin purity, and elution productivity are determined as process critical quality attributes, and ethanol concentration, elution rate, and elution volume are identified as critical process parameters. Quadratic equations between process critical quality attributes and critical process parameters were established using response surface methodology. Then probability-based design space was computed by calculating the prediction errors using Monte Carlo simulations. The influences of calculation parameters on computation results were investigated. The optimized calculation condition was as follows: calculation step length of 0.02, simulation times of 10 000, and a significance level value of 0.15 for adding or removing terms in a stepwise regression. Recommended normal operation region is located in ethanol concentration of 65.0-70.0%, elution rate of 1.7-2.0 bed volumes (BV)/h and elution volume of 3.0-3.6 BV. Verification experiments were carried out and the experimental values were in a good agreement with the predicted values. The application of present method is promising to develop a probability-based design space for other botanical drug manufacturing process.