New perspectives on lipid and surfactant based drug delivery systems for oral delivery of poorly soluble drugs

Abstract

Objectives The aim of this review is to highlight relevant considerations when implementing a rational strategy for the development of lipid and surfactant based drug delivery system and to discuss shortcomings and challenges to the current classification of these delivery systems. We also aim to offer suggestions for an improved classification system that will accommodate lipid based formulations that are not currently accommodated in the lipid formulation classification system. Key findings When categorising lipid and surfactant based drug delivery systems, the current Lipid Formulations Classifications System is a useful tool. However, it does not apply to all marketed lipid and surfactant systems or those reported in research papers. A more profound understanding of the functionalities of lipids and surfactants and their role in emulsion formation will enable a rational development strategy and will create the basis for a revised classification system encompassing all employed lipid and surfactant drug delivery systems. Summary The ever-increasing number of poorly soluble compounds in drug discovery and development calls for the serious need for effective and affordable drug delivery strategies that will enhance bioavailability and decrease variability. Lipid and surfactant based drug delivery systems offer these advantages; however, the development of these systems requires proper understanding of the physicochemical nature of the compound as well as the lipid excipients and gastrointestinal digestion. One major challenge of lipid excipients and delivery systems is the varying range of compounds they contain. This has contributed to the challenge of proper characterisation and evaluation of these delivery systems, their stability, classification and regulatory issues, which consequently have affected the number of these formulations that eventually reach the market. Suggestions as to proper classification of these delivery systems based on their main lipid component and recommended use are put forward. The prospect of these delivery systems looks promising.

Thorough characterization of a Self-Emulsifying Drug Delivery System with Raman hyperspectral imaging: A case study

“…Another approach is the use of Self-Emulsifying Drug Delivery System (SEDDS). These liquid or semi-solid formulations are encapsulated into hard or soft capsules and generate an emulsion in the gastrointestinal tract facilitating the absorption of the drug (Mullertz et al, 2010). There exist a large variety of excipients that can be used ranging from non-polar lipids to polar lipids.…”

“…The studied formulation is categorized as type IV formulation. This type of formulation allows an increased API charge compared to Type I formulations and produces very fine dispersions in an aqueous medium (Mullertz et al, 2010).…”

Systematic development of optimized SNEDDS of artemether with improved biopharmaceutical and antimalarial potential

“…Besides, the higher solubility of the drug in nonionic surfactants can be explained as a function of their lower HLB value, which favors faster solubilization of the lipophilic drugs and imparts spontaneous emulsification ability (Truong et al, 2015). The presence of cosolvent additionally helped in improving the solubility of drug by their solubilization capacity owing to the presence of longchain fatty alcohols (Mullertz et al, 2010). Figure 1(A-D) illustrates the pseudoternary phase diagrams constructed for delineating the suitable nanoemulsion region for the MCT-SNEDDS, indicating higher area for microemulsion region for Captex 355 and S mix ratio of 1:0 containing Cremophor RH40-Transcutol HP.…”

Development andin vitroevaluation of an oral SEDDS for desmopressin

“…It hydrolyzes triglycerides in positions 1 and 3, resulting in two free fatty acids and one 2-monoacylglyceride (Müllertz et al, 2010). The consumption of 0.1 M NaOH during lipolysis of formulations F4 and F15 is illustrated in Figure 5.…”