BACKGROUND: Modern day scientific endeavour strives towards global sustainability through the smart utilisation of renewable resources as base materials for chemicals. Until now, the most common commercial process to produce levulinic acid (a mass‐produced platform chemical) depends on a two‐stage mineral acid‐catalysed reaction, which generates harmful environmental waste. In this work, an environmentally friendly levulinic acid production route using less harmful organic acids assisted by microwave heating from biomass feedstocks is reported for the first time.RESULTS: Using aluminum sulfate as a green Lewis acid catalyst and seven organic acids, levulinic acid was successfully produced from barley straw under microwave heating, with maleic acid giving the highest catalytic conversion. A Response Surface Methodology (RSM) approach was used to rapidly and effectively examine the effect of five reaction variables on the productivity of the levulinic acid. A wide range of different biomass wastes (barley straw, brewery waste, olive cake, spent tea leaves and potato, tomato, and mandarin peels) were subsequently screened to produce the levulinic acid. The highest yield of 86 wt% based on cellulose content from mandarin peel (a value comparable to a lengthier ‘non‐green’ route) was achieved under the following optimized reaction conditions: 180 °C, 38 min, 2 M maleic acid concentration, 0.1 g Al₂(SO₄)₃ and 1:22 biomass: maleic acid ratio (g mL⁻¹).CONCLUSIONS: The proposed method is a promising new route towards the green, high yield production of levulinic acid from a variety of agricultural and household lignocellulosic biomass wastes, without the need for pre‐treatment. © 2020 The Authors. Journal of Chemical Technology & Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Oropharyngeal candidiasis (OPC) is a mucosal infection caused by Candida spp., and it is common among the immunocompromised. This condition is mainly treated using oral antifungals. Chlorhexidine (CHD) is a fungicidal and is available as a mouth wash and oral gel. It is used as an adjuvant in the treatment of OPC due to the low residence time of the current formulations. In this study, its activity was tested against C. albicans biofilm and biocompatibility with the HEK293 human cell line. Then, it was formulated as mucoadhesive hydrogel buccal tablets to extend its activity. Different ratios of hydroxypropyl methylcellulose (HPMC), poloxamer 407 (P407), and three different types of polyols were used to prepare the tablets, which were then investigated for their physicochemical properties, ex vivo mucoadhesion, drug release profiles, and the kinetics of drug release. The release was performed using Apparatus I and a controlled flow rate (CFR) method. The results show that CHD is biocompatible and effective against Candida biofilm at a concentration of 20 µg/mL. No drug excipient interaction was observed through differential scanning calorimetry (DSC) and Fourier-transform infrared spectroscopy (FTIR). The increase in P407 and polyol ratios showed a decrease in the swelling index and an increase in CHD in vitro release. The release of CHD from the selected formulations was 86–92%. The results suggest that chlorhexidine tablets are a possible candidate for the treatment of oropharyngeal candidiasis.