The present invention relates to medical dressing formed by using chitosan for wound care, especially for treatment of haemorrhage, burns, tissue regeneration and the method of preparation the same using controlled lyophilisation in which the water removal of frozen biomaterial is done by passing the chitosan solution in solid frozen phase into a gas phase without the substantial formation of an intermediate liquid phase, which maintains the structural integrity of the biomaterial. Lyophilisation process employs a quick freezing and long drying process that enhances porosity and flexibility of medical dressing and the quick freezing cycle (of less than 5 hours) also responsible for the optimal formation of pores with adequate robustness which also helps to reduce the entire lyophilisation cycle to 25 hours.
