Self-emulsifying drug delivery system and the applications in herbal drugs

Abstract

Herbal drugs have been used for thousands of years in the east and have had a recent resurgence in popularity among consumers in the west. However, most of herbal drug are poorly soluble and have hydrophobic properties and poor distribution, leading to reduced bioavailability and hence decreased treatment efficacy, requiring repeated administration or increased dose. In the past few decades, considerable attention has been focused on the development of self-emulsifying drug delivery system (SEDDS) for herbal drugs. SEDDS is isotropic and thermodynamically stable solutions consisting of oil, surfactant, co-surfactant and drug that can spontaneously form oil-in-water micro/nanoemulsion when mixed with water under gentle stirring. The formulation can be a viable alternative to classical formulations to take advantage of their lipophilic nature and to solve their problems of poor solubility, poor bioavailability, low oral absorption and instability. The mechanism of self-emulsification, solubility studies, construction of phase diagram, optimization and characterization of herbal drugs-loaded SEDDS formulation and in situ absorption evaluation of herbal drugs in rat intestine are presented in our article.

Nanoemulsion formulations for anti-cancer agent piplartine—Characterization, toxicological, pharmacokinetics and efficacy studies

“…Self-emulsifying nanoemulsions formulated using Solutol HS and PEG 400 or Transcutol were highly unstable. This may be because of high thermodynamic instability when Solutol HS was mixed with either PEG 400 or Transcutol (Zhang et al, 2015). Self-emulsifying nanoemulsions formulated with a combination of Tween 80 and Transcutol displayed instability, which might be due to a shift in HLB towards hydrophobic side because of low HLB of Transcutol.…”

Formulation and Characterizations of Self-Nanoemulsifying Drug Delivery System of Extract Petiveria Alliacea (Singawalang) Leaves

“…Droplet size is an important factor in SNEDDS formulation because it determines the level and rate of drug release and absorption and increases in bioavailability as well there in vivo stability smaller droplets have a larger surface area, which then increases the level of drug release. The small droplet size may be due to increased surfactant concentration, which forms a closed layer of surfactant at the interface, so as to stabilize dispersed droplets [22]. Therefore, in this study, the nanosize of SNEDDS Singawalang leaves extract might allow it to be more easily delivered into cells or to pass across some barriers.…”

Preparation and evaluation of a self-nanoemulsifying drug delivery system loaded with Akebia saponin D–phospholipid complex

“…The first one was to entrap hydrophilic ASD into SNEDDS which was widely employed for poorly water-soluble drugs. [24][25][26] Previous studies demonstrated that phospholipid complexes could improve the liposolubility and oral absorption of the hydrophilic drug. 10,12,27 Thus, APC was prepared, and the liposolubility significantly increased 11.4-fold after formation of APC, which was verified by the solubility test in n-octanol.…”

“…26 Grade of different weight ratios of surfactant/cosurfactant is shown in Table 1. The results clearly indicated that Polyoxyl 35 castor oil was more effective in making a grade I nanoemulsion, and it was preliminarily chosen as the surfactant in the system.…”

“…[23][24][25][26] As a hydrophilic compound, ASD cannot be directly entrapped into SNEDDS without any change. Previously, a phospholipid-based strategy was established to develop SNEDDS for several hydrophilic drugs (matrine and insulin), in which phospholipid complexes were formulated to significantly enhance the liposolubility of water-soluble drugs and drastically facilitate their incorporation into SNEDDS.…”