Oleogels of Olive Oil and Soybean Oil for Topical Drug Delivery: A Comparative Analysis

Abstract

Objective: The objective of the present investigation was to develop olive and soybean oil-based oleogels with Span 40 and/or Tween 80 (as gelator and/or surfactant) and determine the critical gelator concentration (CGC), characterise and compare the rheological, thermal properties and drug release profile of the gels formed for topical delivery.
 Methods: Olive and soybean oil-based Span 40 and Span 40/Tween 80 oleogel formulations were prepared by solid fiber mechanism and subjected to organoleptic evaluation, FT-IR spectroscopy, thermal analysis, rheological study, kinetic modeling of gelation and drug release.
 Results: The critical gelator (Span 40) concentration was found to be lower for olive oil (12% w/v) and depend on the type of oil. Tween 80 reduced CGC of soybean oleogels only. Soybean oil-based oleogel containing 18% w/v Span 40 was found to form more flexible, less viscous and thermally less stable formulation with better release of paracetamol as evident from lower melt flow index, Tg value, lower β and higher α value compared to olive oil-based oleogel with 12% w/v Span 40 (CGC). Surfactant addition can be assumed to modify the microarchitecture of the oleogels to a great extent to produce more flexible and thermally stable gels with even better drug release profile. Span-Tween based soybean oleogel formed a gel-matrix whereas matrix in olive oil-based oleogels containing Span only became slightly flexible to release the drug in zero-order fashion on the addition of surfactant cogelator.
 Conclusion: Nature of oil exerts profound influence on the rheological, thermal and release profile of oleogels containing Span 40 as gelator and/or Tween 80 as surfactant cogelator.

Application of Analytical Methods for the Comprehensive Analysis of Oleogels—A Review

“…A thermo cycling or freeze-thaw cycling method involves incubation of the freshly prepared oleogels at 65 • C for 15 min until they are a liquid, followed by gelation when the time was noted and another incubation at 4 • C for 15 min after which it is stored at 25 • C for 48 h. The cycle is repeated for 6 cycles. Soybean and olive oil-based oleogels structured with SPAN 40 or SPAN 40 and TWEEN 80 mixture were found to be stable up to 6 thermo-cycles [64], but an increase in the gelation time was observed after each cycle, for the olive oil oleogels structured with bot SPAN 40 or the mixture.…”

“…Sorbitan esters (SPAN 40, 60, and SPAN 65) are low molecular weight gelators which have demonstrated structuring capacity; different concentrations (ranging between 15-20%) are needed in order to gel some edible oils for drug delivery purposes [55,64,102]. For instance, 17% Span 60 added to mustard oil will transform the system into an oleogel [55].…”

“…For instance, 17% Span 60 added to mustard oil will transform the system into an oleogel [55]. Surfactants such as Tween 20 and Tween 80 are frequently used as co-gelators since better entrapment, solubility, and drug permeation was observed [64]. A fluid-filled structure technique was used to elaborate oleogels with a 2:1 ratio (w/w) of Tween 80 and Span 80 but with up to 80% water addition [103].…”

Graphene Oxide Increases Corneal Permeation of Ciprofloxacin Hydrochloride from Oleogels: A Study with Cocoa Butter-Based Oleogels

“…It has been reported that the properties of oleogels vary significantly, which is dependent upon the molecular architecture of the oleogelator network [ 2 ]. Over the years, oleogels have been utilized in diverse fields ranging from food (e.g., preparation of cookies, cakes, chocolates, meat products, and ice-cream) and cosmetics to pharmaceutical industries (e.g., topical, ocular, and oral drug delivery systems) [ 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 ]. However, an incredible increment in the popularity and use of oleogel-based systems as novel drug delivery devices have been witnessed ever since.…”

“…The lipophilic nature of the oleogels assists the penetration of the drug molecules across the biological tissues [ 14 ]. Currently, oleogels have become an advanced approach for periodontal [ 14 ], nasal [ 15 ], topical [ 10 ], parenteral [ 16 ], and ocular [ 17 ] drug delivery applications. Unlike other fields, there has been a huge lack of research regarding the usage of oleogels for the controlled release of ocular therapeutics.…”