4A.3.1 Selection of Excipients
Drug loaded Solid Lipid Nanoparticles(D-SLN)were successfully formulated using two different lipidsand surfactants and physicochemical parameters of the same have been assessed.
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Biocompatibility, …show more content…
The batches were optimized as per concentration of lipid and surfactants used.The drug to lipid ratio was kept constant as 0.1:1.5 The concentration of lipid varied from 0.5% w/v to 1.5%w/v as beyond 1.5% w/v, the size of SLN were found to be increased. The temperature of the system is maintained at 500C to 600C to ensure complete melting of the lipid- solubilizer system and entrapment of drug. The concentration of hydrophilic and hydrophobic surfactants was varied from 0.5% to 1.0% and 0.25% to 0.5% respectively and were finalized as 0.5% hydrophilic and 0.25% of hydrophobic surfactant. As the surface to volume ratio was high in SLN, they require high amount of surfactant for stabilization . This was considered as the final batch (D-SLN) and further optimized for 600 RPM stirring speed and time 1 …show more content…
The disadvantages of SLN are lack of physical stability such as agglomeration and fusion of particles and chemical stability such as oxidation of lipids during long-term storage. Freeze drying is a process of water removal from frozen samples by sublimation under vacuum. Freezing and drying generate stress on nanoparticles which can destabilize them. Cryoprotectants have been used to decrease SLN aggregations due to the stress during the process of freeze-drying. In this study, four different types of protecting excipients have been investigated such as Mannitol, a polyol, lactose a disaccharide, trehalose and galactose monosaccharide. These sugars are known to vitrify at a specific temperature denoted Tg, glass transition temperature . The immobilization of nanoparticles within a glassy matrix of cryoprotectant can prevent their aggregation and protect them against the mechanical stress of ice crystals. (Choi HK, subedi