Mahidol University, Biotech, and their Partners Develop a First-of-its-kind ‘Nasal Spray’ Containing Natural Extracts to Help Fight Against Covid-19, H1N1 and RSV

For the first time, Thai researchers and scientists have invented a nasal spray that contains the extract from the peels of citrus fruits to help protect against infectious diseases, including Covid-19, H1N1 and RSV. This innovative product has been shown to be ‘safe and effective’ in laboratory results and marketed under the brand name “Besuto Qlears” at leading drug stores and online shopping sites.


Mahidol University’s Faculty of Tropical Medicine together with the National Center for Genetic Engineering and Biotechnology (Biotec) have joined with Quantum Biotech Co., Ltd. and Healthlead PCL to officially launch “Besuto Qlears,” the first-of-its-kind nasal spray containing citrus extracts to fight respiratory tract infection.

This citrus extract-based spray has been proven to be ‘effective’ in inhibiting viruses that cause respiratory tract infections, including SARs-COV-2 that causes Covid-19; H1N1, one of several flu virus strains that can cause the seasonal flu; and Respiratory Syncytial Virus (RSV) that causes cold-like symptoms commonly in children.

The spray has also undergone toxicity testing by Mahidol University’s Faculty of Tropical Medicine and has been shown to be ‘safe.’

“Besuto Qlears” was developed through the joint efforts of Mahidol University’s Faculty of Tropical Medicine, Biotec, Quantum Biotech Co., Ltd., and Healthlead Public Company Limited. It was built on the findings of the research study: A Citrus Peel Waste Biorefinery for High-Quality Limonene Production, under the Innovation Technology Assistance Program (ITAP), supported by the National Science and Technology Development Agency of Thailand (NSTDA). It responds to the Thai government’s Bio-Circular-Green (BCG) Economic Model strategy that aims to turn the country into a value-based and innovation-driven economy while promoting investments in the country’s four new S-curve industries, namely food and agriculture; bioenergy, biomaterial, and biochemical; medical and wellness; and tourism and creative economy.

Dr. Veerawat Champreeda, Director of the NSTDA’s Biorefinery and Bioproduct Technology Research Group, noted that the anti-Covid citrus extracts-based nasal spray was developed through the research study: A Citrus Peel Waste Biorefinery for High-Quality Limonene Production.

“The product can help create a value-based economy by turning waste materials in agriculture into revenue streams through biorefining,which is economically and environmentally sustainable, while also helping to minimize waste,” he said.

He explained that the high-quality citrus extract that is used in the development of the anti-Covid nasal spray is obtained from the lime peel, which is a major source of agricultural waste. The lime extract has been widely used as an ingredient in cosmetics and healthcare products.

The study, conducted by the National Nanotechnology Center (NANOTEC), showed that the citrus extracts-based nasal spray is effective in helping prevent cell infection, reducing viral infection, relieving allergy symptoms, and, most importantly, preventing SARS-CoV-2 pseudovirus entry into cells, Dr. Veerawat noted. “We have found that the findings from the studies are very satisfactory,” he said.

Dr. Srung Samanmoo, Quantum Biotech Co., Ltd.’s Chief Innovation Office, said a team of scientists from his company who joined the development of this innovative nasal spray, had improved the concentration of citrus essential oils in order to provide better-quality extracts due to their low water solubility. The team was also responsible for turning the natural compounds from citrus extracts into liquid crystals to create the formulation of the most suitable extract to be used in the development of the nasal spray, he added.

The spray has been proven to be capable of suppressing several viruses, including the coronavirus that causes Covid-19, even when the virus mutates, Dr. Srung noted, saying it can offer about 3-4 hours of protection with just one spray per nostril.

“There are no steroids in the nasal spray we produce. We use only naturally formulated and laboratory-tested ingredients, so it would be safe for use. The spray comes in a small bottle, simple to carry and perfect for everyday use. And you don’t need to keep it in the fridge,” he said.

According to him, the anti-Covid nasal spray that contains citrus extracts has been registered with the Thai Food and Drug Administration (FDA), with the registration number 65-1-3-2-0000818 issued on October 3, 2022, making it one of a kind. It’s sold under the tradename of “Besuto Qlears”.

Assoc Prof Dr. Pornsawan Leaungwutiwong, who heads the Microbiology and Immunology Department at Mahidol University’s Faculty of Tropical Medicine, notes that “Besuto Qlears” has been shown to be safe and effective in suppressing viruses that cause respiratory infections in laboratory tested.

According to her, the nasal spray has undergone testing for toxicity using the MTT cell viability assay approach and CACO-2 human caucasian colon adenocarcinoma and has proven to be safe. The results have shown that the spray can inhibit SARS-CoV-2, the virus that causes Covid-19; influenza A; and human coronavirus by 99.9%.

“We have used several testing methods during product development to ensure that it’s safe and effective. This can help build credibility and trust in the product,” Dr. Pornsawan said.
Dr. Nawamin Pinpathomrat, Deputy Director of Clinical Research and Development Unit, Prince of Songkla University’s Medical Science Research & Innovation Institute, said “Besuto Qlears” has been shown to be significantly effective in inhibiting the Respiratory Syncytial Virus (RSV). “RSV could cause upper and lower respiratory tract infections. It’s one of the most common causes of childhood illness, infecting most children by two years of age. It can infect adults too.”

The World Health Organization estimates 33.8 million new episodes of RSV-related infections annually in children under 5 years of age and causing approximately 160,000 deaths in children every year. In Thailand, he explained, the RSV epidemic usually occurs during the rainy season, which is typically between August and November.

Mr. Thatchaphon Chonwattanasakul, CEO of Healthlead PCL, said “Besuto Qlears” is an innovative nasal spray that was invented through the research findings of Thai researchers and scientists. “The spray is truly a Thai innovation. It’s something to be proud of,” he said.
“Besuto Qlears” is priced at THB 295 in order to be more affordable to most of the Thais and is available at leading drugstores nationwide, including Pharmax, ICare, Vitaminclub, Super Drug, and online shopping sites.