Challenges Associated With Solid Lipid Nanoparticles
Solid lipid nanoparticles have several advantages over other types of nanoparticulate systems as discussed earlier in this section. However, there are some limitations too, the most challenging being the degradation of active components during the production process. This may be attributed to the stress and strain associated with the homogenization process, whereas fragile molecules such as DNA, siRNA, and peptides need gentle handling. The production of heat during processing may cause drug degradation so the selection of a proper production method is vital. Other problems include particle size and shape variation, coexistence of several different colloidal forms, and drug expulsion from lipid matrix .
Stability of Solid Lipid Nanoparticles
Solid lipid nanoparticles in general possess adequate stability for periods more than a year (Westesen et al. ). Muller et al. found that glyceryl palmitostearate—containing solid lipid nanoparticles are stable for more than 3 years . They also found that the particle size increases when the nanoparticles are exposed to light. Solid lipid nanoparticles can be freeze-dried to aid in long-term storage [77,78].