PARTIAL CRYSTALLISATION OF LACTOSE IN SPRAY DRYING WAN NUR’AIN NABILA BINTI WAN NAIN A report submitted in partial fulfilment of the requirements for the award of the degree of Bachelor of Chemical Engineering (Bioprocess)

The purpose of this study was to determine the lactose behaviour during partial crystallisation in spray drying. Spray-dried lactose has been widely used in pharmaceutical industries as excipient for dry powder inhalation drugs. Partial crystals of lactose were produced by spray-dried lactose solutions at different operating condition of inlet temperature, feed flow rate and sample concentration. The operating conditions affected the degree of crystallinity and morphology of amorphous lactose. Particle morphology of untreated crystalline lactose monohydrate was in irregular shape with particle size distribution larger than 50 μm. After spraydried, the particle of lactose changed to spherical shape with particle size of less than 10 μm. Spray-dried lactose showed broader spectrum as compared to lactose monohydrate in FT-IR. The DSC thermographs of higher inlet temperature, 6 ml/min feed flow rate and 5% w/w feed concentration gave higher peak for heat of melting and cooling, thus giving the higher degree of crystallinity. As a conclusion, higher degree of crystallinity of spray dried lactose was obtained with the increase of inlet temperature and feed flow rate, but with the decrease of sample concentration.