Waste resulting from edible plants is considered one of the best sources of valuable phytochemicals. A promising approach for using these appreciated wastes is extracting precious medically important constituents, for example, free quercetin. Two new cost-effective and green extraction methods are introduced in the present study: ultrasound-assisted glycerol extraction (UAGE) and microwave-assisted extraction (MAE). These extraction protocols are optimized using factorial design to define the highest yield of extraction, and HPLC-UV at 370 nm was used as a method of yield analysis. Quercetin remained stable during the whole process in both extraction protocols. A standard addition technique was performed to quantify quercetin in different extracts and eliminate the matrix effect. In UAGE and MAE, extraction yields were 16.55 ± 0.81 and 27.20 ± 1.55 mg/1g from red onion scales on a dry base, respectively. The amount of quercetin extracted using MAE was superior to UAGE in terms of time and yield. A greenness assessment of the offered studies compared to previously published relevant extraction methods was performed using the analytical eco-scale assessment method (ESA) and national environmental methods index (NEMI). MAE showed to be a greener method with a higher ESA score and a greener NEMI pictogram.

Paracetamol is one of the most widely consumed analgesic and antipyretic medications worldwide. It is frequently analyzed in many quality control (QC) laboratories in pharmaceutical companies, either in raw materials or drug products. It was reported that paracetamol self-toxicity often occurs, leading to the frequent analysis of paracetamol in toxicological centers in biological fluids. Green analytical chemistry (GAC) is growing to be a global philosophy; therefore, the high frequency of paracetamol analysis poses potential concerns. Chromatographic analytical methods used for the daily analysis of paracetamol could be a potential risk to the environment or the health of the analysts if not thoroughly considered. The presented study aims to establish greenness assessments of nine HPLC methods used to assay paracetamol in raw materials and drug products and twenty-one HPLC methods. The reason for selecting HPLC methods of analysis to be the core of the study is the known reproducibility, reliability and availability in most QC laboratories. The most commonly used metric systems for greenness evaluation are the Analytical GREEnness (AGREE), the eco-scale assessment (ESA) and the national environmental methods index (NEMI) which have been used in this comparative study. The greenest chromatographic method for the analysis of paracetamol in raw materials and drug products was introduced by Rao et al. (the obtained scores were ESA = 76 and AGREE = 0.62, while the greenest chromatographic method for the analysis of paracetamol in biological fluids was proposed by Modick et al.). The obtained scores were ESA = 85 and AGREE = 0.7. The NEMI tool proved to have limited performance compared to other metric systems, hence it could not be used alone. Accordingly, the collaboration of NEMI results with ESA and AGREE for greenness assessment is highly recommended to reach appropriate conclusions.

The natural physiological response to skin injury is wound healing. However, to restore skin continuity, wound healing is a complicated process that involves the collaboration of a variety of cell types and other mediators. This process ultimately results in tissue regeneration and the restoration of skin barrier function. Hydrogels are appealing dosage forms for biomedical regenerative medicine since they are composed of 3D networks with high water content and flexible rheological features. Hydrogels that can self-heal are particularly interesting for wound treatment because they can autonomously restore their original functionalities and repair structural damage. Recently, the use of self-healing hydrogels as biomedical materials has attracted increased interest. In this review, the self-healing systems used in tissue regeneration, especially wound healing, will be explored. A focus on the fabrication methods, characterization tests, and mechanism of self-healing will be introduced, along with the biomedical applications of self-healing hydrogels loaded with conventional and therapeutic biomaterials. In addition, the differences between hydrogels and self-healing hydrogels will be discussed. Graphical Abstract

Background: Extraction is the leading critical stage in the analysis of nutraceuticals. Ginkgo biloba (GB) has gained interest because of its therapeutic usages. Objectives: The aim was to develop four cost-effective extraction techniques for the extraction of quercetin from GB in a sachet containing a mixture of nutraceuticals. These techniques are solid-phase extraction (SPE), liquid–liquid extraction, inverted dispersive liquid–liquid microextraction, and the QuEChERS (quick, easy, cheap, effective, rugged, and safe) method. Method: Direct spectrophotometry was used to monitor the recovery of the standard quercetin throughout the optimization steps. The HPLC–UV method of analysis was optimized to quantify the yields from the extracts present in the complicated contents of the sachets. The present study was assessed by analytical Eco-Scale assessment (ESA) and the National Environmental Method Index (NEMI) for greenness in comparison with the literature. Results: SPE showed the best cleanup outcomes. ESA and NEMI showed an adequate greenness of the proposed extraction protocol. Conclusions: Quercetin (marker for GB) extraction from market nutraceutical sachets is considered an exemplar for analysis in the QC of nutraceuticals. Regarding the greenness results, the proposed method of extraction is better even with adequate greenness as the extraction was a one-step process, in comparison with multistep processes of previously published protocols. Accordingly, it is recommended for use in routine extraction and analysis of such nutraceuticals. Highlights: Four extraction protocols have been developed. For GB ternary-mixture sachets, proper recovery was obtained using C18 SPE. The assessment of greenness of the proposed protocol guaranteed the superiority of the presented method. Safer sorbents and chemicals are favored for use in routine extraction of nutraceuticals.