Development of ionic and non-ionic natural gum-based bigels: Prospects for drug delivery application

Balancing competing objectives in bigel formulations using many-objective optimization algorithms and different decision-making methods

Many-objective optimization, which deals with balancing multiple competing objectives to find compromised solutions, is essential for solving complex problems. This study explores evolutionary algorithms for optimizing the microstructural, rheological, stability, and drug release properties of bigel systems formulated using structured almond oil, mixed organogelators, and carbopol. The oleogel was identified as the dispersed phase, with droplet sizes ranging from 1.43 µm to 7.37 µm, indicating improved characteristics compared to other bigels. Each formulation exhibited non-Newtonian shear-thinning and thixotropic behaviors, which were positively influenced by the proportions of the excipients. After undergoing multiple stress cycles, highly concentrated bigels exhibited phase separation. Unexpectedly, bigels with lower viscosity exhibited reduced rates of drug release. FT-IR and HPLC analyses confirmed the compatibility and stability of drug-excipient interactions, with impurities remaining below 4%. This study emphasizes the complex interactions within mixed lipid-based bigels, requiring many-objective optimization techniques to address conflicting objectives. The objectives of optimization involve simultaneously minimizing microstructural properties while maximizing structural recovery and drug release properties. This led to conflicting objectives, where achieving higher structural recovery did not align with the desired drug release rate. Additionally, more stable formulations did not meet the optimal microstructural objectives. To resolve these conflicts, an RSM-MaOEAs approach was applied, employing various decision-making methods. Among EAs, RSM-RVEA notably achieved exceptional convergence. Furthermore, three MaOEAs-integrated decision-making methods-WSM, WPM, NED-and the RSM-desirability, offered potential solutions. Overall, this research proposes a robust framework for compromising the bigels' performance and stability, with broader applications in drug delivery and related fields.

Edible polysaccharide-based oleogels and novel emulsion gels as fat analogues: A review

Polysaccharide-based oleogels and emulsion gels have become novel strategies to replace solid fats due to safe and plentiful raw material, healthier fatty acid composition, controllable viscoelasticity, and more varied nutrition/flavor embedding. Recently, various oleogelation techniques and novel emulsion gels have been reported further to enrich the potential of polysaccharides in oil structuring, in which a crucial step is to promote the formation of polysaccharide networks determining gel properties through different media. Meanwhile, polysaccharide-based oleogels and emulsion gels have good oil holding, nutrient/flavor embedding, and 3D food printability, and their applications as fat substitutes have been explored in foods. This paper comprehensively reviews the types, preparation methods, and mechanisms of various polysaccharide-based oleogels and emulsion gels; meanwhile, the food applications and new trends of polysaccharide-based gels are discussed. Moreover, some viewpoints about potential developments and application challenges of polysaccharide-based gels are mentioned. In the future, polysaccharide-based gels may be flexible materials for customized nutritional foods and molecular gastronomy. However, it is still a challenge to select the appropriate oleogels or emulsion gels to meet the requirements of the products. Once this issue is addressed, oleogels and emulsion gels are anticipated to be used widely.

A biocompatible lipid-based bigel for topical applications

The development of biocompatible delivery systems is a necessity for medical and topical applications. Herein, the development of a new bigel for topical application is described. It is composed of 40% colloidal lipid hydrogel and 60% olive oil and beeswax oleogel. Its characterization and the potential of the bigel as a drug carrier through the skin was evaluated in vitro using fluorescence microscopy and two phases of the bigel were labeled with two fluorescent probes: sodium fluorescein (hydrophilic phase) and Nile red (lipophilic phase). The structure of the bigel showed two phases with fluorescence microscopy in which the hydrogel phase was incorporated into a continuous oleogel matrix. Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) presented a combination of vibrations characteristic of the different molecules forming the bigel, and Differential Scanning Calorimetry (DSC) showed different transitions attributed to beeswax lipids. Small-angle and wide-angle X-ray scattering (SAXS and WAXS) indicated a predominant lamellar structure with orthorhombic lateral packing that could be related to the arrangement of beeswax crystals. Bigel enables deeper penetration of hydrophilic and lipophilic probes into deeper layers, making it a promising candidate for effective topical carriers in medical and dermatological applications.

Spray-Drying Microencapsulation of Andean Blueberry (Vaccinium meridionale Sw.) Anthocyanins Using Prickly Pear (Opuntia ficus indica L.) Peel Mucilage or Gum Arabic: A Comparative Study

The recovery of byproducts from the food industry is a promising approach to obtain hydrophilic biopolymers with potential health benefits. In this work, the mucilage obtained from the peel of the Opuntia ficus-indica (OFI) fruit was compared with gum arabic (GA) as wall materials for the microencapsulation of Colombian blueberry anthocyanins, using the spray-drying process. For both types of microencapsulates, the following were determined: anthocyanin content (UV-vis and HPLC/MS-MS), total dietary content (enzymatic-gravimetric method), antioxidant activity (ORAC), color (CIELab parameters), morphology (SEM and particle size), and thermal behavior (DSC/TGA). Six different anthocyanins were identified by HPLC/MS-MS in the non-lyophilized Andean blueberry sample (LABP) and in the OFI-mucilage and GA microcapsules. OFI mucilage, compared to GA, favors the formation of larger spherical particles, a smoother surface without cracks, and greater thermal stability. The higher anthocyanin retention capacity in OFI microcapsules leads to higher antioxidant capacity and red coloration for this biomaterial. Consequently, the microencapsulation of anthocyanins with mucilage from the peel of the OFI fruit is proposed as a promising alternative for the protection and incorporation of this natural dye with high antioxidant capacity and dietary fiber content in new functional food/cosmetic formulations, while giving added value to the natural byproducts of OFI.

Bigels as drug delivery systems: From their components to their applications

Bigels are systems that usually result from mixing a hydrogel and an organogel: the aqueous phase is commonly formed by a hydrophilic biopolymer, whereas the organic phase comprises a gelled vegetable oil because of the presence of an organogelator. The proportion of the corresponding gelling agent in each phase, the organogel/hydrogel ratio, and the mixing temperature and speed all need to be taken into consideration for bigel manufacturing. Bigels, which are particularly useful drug delivery systems, have already been formulated for transdermal, buccal, and vaginal routes. Mechanical assessments and microscopy are the most reported characterization techniques. As we review here, their composition and unique structure confer promising drug delivery attributes, such as mucoadhesion, the ability to control drug release, and the possibility of including both hydrophilic and lipophilic drugs in the same system.

Development and characterization of novel bigels based on monoglyceride-beeswax oleogel and high acyl gellan gum hydrogel for lycopene delivery

The aim of present study was to develop novel bigels as a semi-solid vehicle for lycopene delivery. Bigels were prepared by using the mixture of glycerol monostearate (GMS)-beeswax based oleogel and high acyl gellan gum hydrogel in different proportions. The confocal microscopic observations showed that the obtained bigels were oleogel-in-hydrogel, and droplets became larger with increased contents of oleogel. Higher fractions of oleogel increased the mechanical strength (storage modulus, firmness) of bigels. According to the rheological results, all bigels exhibited solid-like characteristics since the storage modulus were larger than loss modulus. DSC results showed that the melting temperature of bigel was higher than that of oleogel. During in vitro simulated gastrointestinal digestion, the total release percentages varied from 60% to 80%, and a higher content of oleogel within bigels could slower down the release of lycopene, suggesting that a higher proportion of oleogel was beneficial for delivery of fat-soluble nutraceuticals.

Review of polysaccharide particle-based functional drug delivery

This review investigates the significant role polysaccharide particles play in functional drug delivery. The importance of these systems is due to the wide variety of polysaccharides and their natural source meaning that they can provide biocompatible and biodegradable systems with a range of both biological and chemical functionality valuable for drug delivery. This functionality includes protection and presentation of working therapeutics through avoidance of the reticuloendothelial system, stabilization of biomacromolecules and increasing the bioavailability of incorporated small molecule drugs. Transport of the therapeutic is also key to the utility of polysaccharide particles, moving drugs from the site of administration through mucosal binding and transport and using chemistry, size and receptor mediated drug targeting to specific tissues. This review also scrutinizes the methods of synthesizing and constructing functional polysaccharide particle drug delivery systems that maintain and extend the functionality of the natural polysaccharides.