Nanostructured Lipid Carriers (NLCs) for Drug Delivery: Role of Liquid Lipid (Oil)

In recent years, SLNs and NLCs are among the popular drug delivery systems studied for the delivery of lipophilic drugs. Both systems have demonstrated several beneficial properties as an ideal drug-carrier, optimal drug-loading, and good long-term stability. NLCs are getting popular due to their stability advantages and the possibility to load various oil components either as an active or as a matrix. This review screens types of oils used till date in combination with solid lipids to form NLCs. These oils are broadly classified into two categories: Natural oils and Essential oils. NLCs offer range of advantages in drug delivery due to the formation of an imperfect matrix owing to the presence of oil. The type and percentage of oil used, determine optimal drug loading and stability. Literature shows that a variety of oils is/are used in NLCs mainly as the matrix, which is from natural origin, triglycerides class. On the other hand, essential oils not only serve as a matrix but also as an active moiety. In short, oil is the key ingredient in the formation of NLCs, hence it needs to be selected wisely as per the performance criteria expected. The aim of this article is to discuss shortly the role of liquid lipids and highlight the use of variety of oils in NLCs preparation.