“…Thirdly, the drug incorporation method and variables such as, incubation time, temperature, stirring, solvent, presence of surfactants, MW of PLGA, L:G ratio of PLGA, PLGA concentration, removal rate of organic solvent, etc., are also factors which may influence drug entrapment efficiency (Kader et al 1998) and this in accordance with the explanation of Zeng and Sun (2009). Figure 5a showed initial burst release profile of 54 % of 5-ALA from PLGA NPs after 24 h followed by a slower release rate that lasts for 12 days; this biphasic pattern is characterized by initial burst release followed by a slow and continuous release rate as shown in the figure.…”