New Delhi: Researchers at Indian Institute of Technology Hyderabad have developed a method to produce controlled-release oral tablets by loading the drug molecules onto a base that dissolves gradually to release the drug over a period of of 10 days- effective in treating fungal infections and leishmaniasis. Amphotericin B (AmB) is the drug of choice for progressive and potentially life-threatening fungal infections of the abdomen and heart valves fungal pneumonia , and leishmaniasis, a neglected tropical disease. It is used to treat Kala Azar or black fever, a dangerous and often fatal form of Leishmaniasis, common among the economically underprivileged sections in states such as Bihar, Jharkhand, West Bengal and Uttar Pradesh.The disadvantages associated with AmB include high cost, toxicity and poor bioavailability (<0.9%). Amb is administered through injection, which results in uncontrolled release of the drug into the blood stream. There have been attempts to make oral medication containing AmB to control the delivery of the drug and bring down costs.The team also found that the nanofibrous oral tablet was stable over a wide range of pH, which means that it would not be destroyed in the gastrointestinal track before drug absorption into the blood stream.The research was led by Prof. Saptarshi Majumdar and Dr. Chandra Shekhar Sharma, Associate Professor, Creative and Advanced Research Based on Nanomaterials (CARBON) Laboratory, Department of Chemical Engineering, IIT Hyderabad.“Nanofibres – fibres that are a hundred thousand times thinner than the human hair – are increasingly being considered as a medium for controlled release of drug molecules because of their large surface area and porosity. There are two choices to be made in producing controlled-release tablets. The polymer that is used as the base nanofibre and the mode of producing the nanofibre itself,” said Dr. Chandra Shekhar Sharma.For the first, Dr. Sharma’s team chose gelatine (or gelatin in American terminology), an U.S. Food and Drug Administration (FDA)-approved natural polymer, a form of collagen naturally found in the bones, cartilage, tendon and connecting tissues of animals. Gelatine is biodegradable, nontoxic and biocompatible and is extensively used in food and medical industries.For the manufacturing method, the team chose a process called ‘electrospinning.’ Electrospinning uses electric force to draw charged threads of the polymer into fibres with diameters in the order of some hundred nanometres. The drug, AmB was loaded to the gelatine before electrospinning, and after electrospinning, the drug-loaded nanofibres were crosslinked with saturated vapors of aqueous gluteraldehyde. The nanofiber mats so obtained were finally compressed into tablets.Prof. Majumdar added, “Through careful control of the crosslinking conditions, we could achieve sustained release of AmB over a period of ten days.”The research has been published in the July 2019 issue of the reputed peer-reviewed journal Nano-Structures and Nano-Objects.