Sucrose esters as natural surfactants in drug delivery systems--a mini-review

Functional Nanostructured Lipid Carrier-Enriched Hydrogels Tailored to Repair Damaged Epidermal Barrier

In this study, a functional nanostructured lipid carriers (NLCs)-based hydrogel was developed to repair the damaged epidermal skin barrier. NLCs were prepared via a high-energy approach, using argan oil and beeswax as liquid and solid lipids, respectively, and were loaded with ceramides and cholesterol at a physiologically relevant ratio, acting as structural and functional compounds. Employing a series of surfactants and optimizing the preparation conditions, NLCs of 215.5 ± 0.9 nm in size and a negative zeta potential of -42.7 ± 0.9 were obtained, showing acceptable physical and microbial stability. Solid state characterization by differential scanning calorimetry and X-ray powder diffraction revealed the formation of imperfect crystal NLC-type. The optimized NLC dispersion was loaded into the gel based on sodium hyaluronate and xanthan gum. The gels obtained presented a shear thinning and thixotropic behavior, which is suitable for dermal application. Incorporating NLCs enhanced the rheological, viscoelastic, and textural properties of the gel formed while retaining the suitable spreadability required for comfortable application and patient compliance. The NLC-loaded gel presented a noticeable occlusion effect in vitro. It provided 2.8-fold higher skin hydration levels on the ex vivo porcine ear model than the NLC-free gel, showing a potential to repair the damaged epidermal barrier and nourish the skin actively.

Predicting the Temperature Dependence of Surfactant CMCs Using Graph Neural Networks

The critical micelle concentration (CMC) of surfactant molecules is an essential property for surfactant applications in the industry. Recently, classical quantitative structure-property relationship (QSPR) and graph neural networks (GNNs), a deep learning technique, have been successfully applied to predict the CMC of surfactants at room temperature. However, these models have not yet considered the temperature dependence of the CMC, which is highly relevant to practical applications. We herein develop a GNN model for the temperature-dependent CMC prediction of surfactants. We collected about 1400 data points from public sources for all surfactant classes, i.e., ionic, nonionic, and zwitterionic, at multiple temperatures. We test the predictive quality of the model for the following scenarios: (i) when CMC data for surfactants are present in the training of the model in at least one different temperature and (ii) CMC data for surfactants are not present in the training, i.e., generalizing to unseen surfactants. In both test scenarios, our model exhibits a high predictive performance of R2 ≥ 0.95 on test data. We also find that the model performance varies with the surfactant class. Finally, we evaluate the model for sugar-based surfactants with complex molecular structures, as these represent a more sustainable alternative to synthetic surfactants and are therefore of great interest for future applications in the personal and home care industries.

Unveiling the formation capacity of multicomponent oleogels: Performance of lecithin interacting with monostearate derivatives

Oleogels have been explored as fat substitutes due to their healthier composition compared to trans and saturated fats, also presenting interesting technological perspectives. The aim of this study was to investigate the compositional perspective of multicomponent oleogels. Structuring ability of lecithin (LEC) (20 or 90 wt% of phosphatidylcholine - PC) combined with glycerol monostearate (GMS), sorbitan monostearate (SMS) or sucrose monostearate (SAC) in sunflower oil was evaluated from oleogels properties. The thermal and rheological properties, microstructure and stability of the oleogels were affected by the difference in the chemical composition of LEC and the ratio between LEC and different surfactants. Interestingly, low-phosphatidylcholine LEC (L20) performed better, although systems formed with reduced amounts of LEC tended to be softer (LEC-GMS) and present high oil holding capacity (LEC-SMS). The mixtures of LEC and monostearate-based surfactants showed different behaviors, depending on the surfactant polar head. In LEC-GMS systems, LEC hindered the self-assembly of GMS in sunflower oil, compromising mechanical properties and increasing oil release. When combined with SMS, LEC acted as a crystal habit modifier of SMS, forming a more homogeneous microstructure and producing stronger oleogels with greater oil binding capacity. However, above the threshold concentration, LEC prevented SMS self-assembly, resulting in a weaker gel. A positive interaction was found in LEC-SAC formulations in specific ratios, since SAC cannot act as a single oleogelator. Results show the impact of solubility balance played by LEC and fatty-acid derivatives surfactant when combined and used as oleogelators. This knowledge can contribute to a rational perspective in the preparation and modulation of the properties of edible oleogels.

Temperature response of sucrose palmitate solutions: Role of ratio between monoesters and diesters

HYPOTHESIS

Aqueous solutions of long-chain water-soluble sucrose ester surfactants exhibit non-trivial response to temperature variations, revealing a peak in viscosity around 40-50 °C. While previous investigations have explored the structures within sucrose stearate systems at various constant temperatures, a comprehensive understanding of the entire temperature dependence and the underlying molecular factors, contributing to this phenomenon is currently missing.

EXPERIMENTS

Temperature dependent properties and supramolecular structures formed in aqueous solutions of commercial sucrose palmitate were examined using SAXS/WAXS, DSC, optical microscopy, rheological measurements, NMR, and cryo-TEM.

FINDINGS

The underlying mechanism governing this unusual behavior is revealed and is shown to relate to the mono- to di-esters ratio in the solutions. Solutions primarily containing sucrose monoesters (monoesters molecules ≳ 98% of all surfactant molecules) exhibit behavior typical of nonionic surfactants, with minimal changes with temperature. In contrast, the coexistence of mono- and di-esters results in the formation of discrete monodisperse diester particles and a network of partially fused diester particles at low temperature. As the temperature approaches the diesters' melting point, wormlike mixed micelles form, causing a viscosity peak. The height of this peak increases significantly with the diester concentration. Further temperature increase leads to fluidization of surfactant tails and formation of branched micelles, while excess diester molecules phase separate into distinct droplets.

Protective effect of sucrose esters from cape gooseberry (Physalis peruviana L.) in TNBS-induced colitis

Phytotherapy is an attractive strategy to treat inflammatory bowel disease (IBD) that could be especially useful in developing countries. We previously demonstrated the intestinal anti-inflammatory effect of the total ethereal extract from the Physalis peruviana (Cape gooseberry) calyces in TNBS-induced colitis. This work investigates the therapeutic potential of Peruviose A and B, two sucrose esters that constitute the major metabolites of its calyces. The effect of the Peruvioses A and B mixture on TNBS-induced colitis was studied after 3 (preventive) and 15-days (therapy set-up) of colitis induction in rats. Colonic inflammation was assessed by measuring macroscopic/histologic damage, MPO activity, and biochemical changes. Additionally, LPS-stimulated RAW 264.7 macrophages were treated with test compounds to determine the effect on cytokine imbalance in these cells. Peruvioses mixture ameliorated TNBS-induced colitis in acute (preventive) or established (therapeutic) settings. Although 3-day treatment with compounds did not produce a potent effect, it was sufficient to significantly reduce the extent/severity of tissue damage and the microscopic disturbances. Beneficial effects in the therapy set-up were substantially higher and involved the inhibition of pro-inflammatory enzymes (iNOS, COX-2), cytokines (TNF-α, IL-1β, and IL-6), as well as epithelial regeneration with restoration of goblet cells numbers and expression of MUC-2 and TFF-3. Consistently, LPS-induced RAW 264.7 cells produced less NO, PGE2, TNF-α, IL-6, and MCP-1. These effects might be related to the inhibition of the NF-κB signaling pathway. Our results suggest that sucrose esters from P. peruviana calyces, non-edible waste from fruit production, might be useful as an alternative IBD treatment.

Sucrose Stearates Stabilized Oil-in-Water Emulsions: Gastrointestinal Fate, Cell Cytotoxicity and Proinflammatory Effects after Simulated Gastrointestinal Digestion

Different structural composition ratios of sucrose stearates with hydrophilic-hydrophobic balance (HLB) values ranging from 1 to 16 on lipolysis in emulsion were investigated using a simulated gastrointestinal tract (GIT). Results showed a direct correlation between the HLB values of sucrose stearates and the lipolysis rate of emulsions, and a lower HLB value led to diminished lipolysis in the GIT simulation model. Mechanism study indicated that poor emulsifying capacity of sucrose stearates and lipolysis of sucrose stearates with lower HLB value inhibited the digestive behavior of oil. In addition, monoester was mainly hydrolyzed in the gastric phase, whereas sucrose polyesters caused lipolysis in the intestinal phase using an in vitro digestive model and HPLC analysis, further suppressing lipid digestion. Furthermore, a decrease in cell cytotoxicity and proinflammatory effects on Caco-2 and Raw264.7 were observed post-digestion, respectively. This work offers important insights into the effects of the degree of esterification of sucrose stearate on lipid digestion behavior in oil-in-water emulsions.

Preparation and characterization of lysozyme loaded liposomal dry powder inhalation using non-ionic surfactants

Delivering protein drugs through dry powder inhalation (DPI) remains a significant challenge. Liposomes offer a promising solution, providing protection for proteins from external environment and controlled release capabilities. Furthermore, the use of non-ionic surfactants plays a crucial role in protecting the activity of proteins because of how the surfactants positioning themselves at the liquid-gas interface during the spray-drying process. In this study, lysozyme-loaded liposomal DPI formulations were prepared using various non-ionic surfactants, including polysorbate 80, poloxamer 188, poloxamer 407, and sucrose stearate. Lysozyme solution and 1,2-distearoyl-sn-glycero-3-phosphatidylcholine liposomes were subjected through high-pressure homogenization to form lysozyme-loaded liposomes. Formulations of homogenized lysozyme liposomes were spray-dried and further characterized. The particle size of reconstituted liposomal lysozyme DPI was from 129.5 to 816.9 nm. The formulations showed encapsulation efficiency up to 32.5% with zeta potential value of around - 30 mV, and spherical structures were observed. The aerosol dispersion performance of the dry powder inhalers was evaluated with emitted doses reaching up to 103% and fine particle fractions up to 28.4%. Significantly higher lysozyme activity was confirmed in formulation with drug to PS 80 ratio of 1: 0.5 w/w (92.1%) compared to that of formulation containing no surfactant (59.8%). The formulation stood out as the only formulation that maintained protein activity while demonstrating good aerosol performance.

Sugar-Based Monoester Surfactants: Synthetic Methodologies, Properties, and Biological Activities

Glycolipids are biocompatible and biodegradable amphiphilic compounds characterized by a great scientific interest for their potential applications in various technological areas, including pharmaceuticals, cosmetics, agriculture, and food production. This report summarizes the available synthetic methodologies, physicochemical properties, and biological activity of sugar fatty acid ester surfactants, with a particular focus on 6-O-glucose, 6-O-mannose, 6-O-sucrose, and 6'-O-lactose ones. In detail, the synthetic approaches to this class of compounds, such as enzymatic lipase-catalyzed and traditional chemical (e.g., acyl chloride, Steglich, Mitsunobu) esterifications, are reported. Moreover, aspects related to the surface activity of these amphiphiles, such as their ability to decrease surface tension, critical micelle concentration, and emulsifying and foaming ability, are described. Biological applications with a focus on the permeability-enhancing effect across the skin or mucosa, antimicrobial and antifungal activities, as well as antibiofilm properties, are also presented. The information reported here on sugar-based ester surfactants is helpful to broaden the interest and the possible innovative applications of this class of amphiphiles in different technological fields in the future.

Sucrose Esters and Beeswax Synergize to Improve the Stability and Viscoelasticity of Water-in-Oil Emulsions

W/O emulsions are commonly used to prepare stable low-fat products, but their poor stability limits widespread applications. In this study, sucrose ester (SE) and beeswax were utilized to prepare an oil dispersion system in rapeseed oil, which was used as the external oil phase to further synergistically construct the W/O emulsion systems. The results show that spherical and fine crystals are formed under the synergistic effect of SE and BW (1.5 SE:0.5 BW). In this state, a dense interfacial crystal layer was easily formed, preventing droplet aggregation, leading to droplet size reduction (1-2 μm) and tight packing, improving viscoelasticity and resistance to deformation, and increasing the recovery rate (52.26%). The long-term stability of W/O emulsions containing up to 60 wt% water was found to be more than 30 days. The increase in the aqueous phase led to droplet aggregation, which increased the viscosity (from 400 Pa·s to 2500 Pa·s), improved the structural strength of the emulsion, and increased the width of the linear viscoelastic region (from 1% strain to 5% strain). These findings provide some technical support for the further development of stable low-fat products.

Sucrose monolaurate production from lauric acid through a two-stage process

This work represented the first step toward pioneering the use of a two-stage process for sucrose monolaurate (sucrose ester) production from lauric acid with high productivity and selectivity. In the first stage, lauric acid was firstly converted into methyl laurate via esterification, followed by the transesterification of methyl laurate into sucrose ester in the second stage. In this research, the first stage of process was primarily focused and thoroughly evaluated. Methyl laurate was continuously produced via lauric acid and methanol in a mini fixed-bed reactor. Amberlyst 15 was used as a catalyst. The operating variables were thoroughly investigated and optimized. The optimal condition to achieve 98 wt% yield (99% purity) was as follows: temperature of 110 °C, residence time of 5 min, and feed concentration of 94 g/L. High catalytic stability was observed over the time-on-stream of 30 h. This process provided good productivity compared to the other processes. The methyl laurate obtained from the first stage could be used as a raw material for the second stage to produce sucrose ester, which was demonstrated experimentally. The high selectivity of 95% of sucrose monolaurate was obtained. The continuous production of sucrose ester from lauric acid could be achieved.

Exploring the Versatility of Microemulsions in Cutaneous Drug Delivery: Opportunities and Challenges

Microemulsions are novel drug delivery systems that have garnered significant attention in the pharmaceutical research field. These systems possess several desirable characteristics, such as transparency and thermodynamic stability, which make them suitable for delivering both hydrophilic and hydrophobic drugs. In this comprehensive review, we aim to explore different aspects related to the formulation, characterization, and applications of microemulsions, with a particular emphasis on their potential for cutaneous drug delivery. Microemulsions have shown great promise in overcoming bioavailability concerns and enabling sustained drug delivery. Thus, it is crucial to have a thorough understanding of their formulation and characterization in order to optimize their effectiveness and safety. This review will delve into the different types of microemulsions, their composition, and the factors that affect their stability. Furthermore, the potential of microemulsions as drug delivery systems for skin applications will be discussed. Overall, this review will provide valuable insights into the advantages of microemulsions as drug delivery systems and their potential for improving cutaneous drug delivery.

The useful biological properties of sucrose esters: Opportunities for the development of new functional foods

Sucrose esters have been deployed as surfactants in many food products since the 1950s. In addition to their useful physical characteristics, sucrose esters also have interesting biological properties that enhance their utility. This review critically examines the broad suite of biological activities that has been attributed to both synthetically-derived and naturally-occurring sucrose esters. These include insecticidal, molluscicidal, plant growth-regulating, anti-microbial, anti-tumor, anti-oxidant, anti-depressive, neuro-protective, anti-inflammatory and anti-plasmodial effects. In addition to providing a summary of the structure-activity profiles of sucrose esters, the various known mechanisms-of action of these compounds are also discussed. Furthermore, since sucrose esters are well-known surfactants, the potential to advantageously apply their industrially desirable physical characteristics in combination with their biological properties is considered. Recent advances in synthetic chemistry that have facilitated the deployment of biologically active sucrose esters as food additives are also described.

Green Surfactants (Biosurfactants): A Petroleum-Free Substitute for Sustainability-Comparison, Applications, Market, and Future Prospects

Surfactants are a group of amphiphilic molecules (i.e., having both hydrophobic and hydrophilic domains) that are a vital part of nearly every contemporary industrial process such as in agriculture, medicine, personal care, food, and petroleum. In general surfactants can be derived from (i) petroleum-based sources or (ii) microbial/plant origins. Petroleum-based surfactants are obvious results from petroleum products, which lead to petroleum pollution and thus pose severe problems to the environment leading to various ecological damages. Thus, newer techniques have been suggested for deriving surfactant molecules and maintaining environmental sustainability. Biosurfactants are surfactants of microbial or plant origins and offer much added advantages such as high biodegradability, lesser toxicity, ease of raw material availability, and easy applicability. Thus, they are also termed "green surfactants". In this regard, this review focused on the advantages of biosurfactants over the synthetic surfactants produced from petroleum-based products along with their potential applications in different industries. We also provided their market aspects and future directions that can be considered with selections of biosurfactants. This would open up new avenues for surfactant research by overcoming the existing bottlenecks in this field.

Rhamnopyranoside-Based Fatty Acid Esters as Antimicrobials: Synthesis, Spectral Characterization, PASS, Antimicrobial, and Molecular Docking Studies

The most widely used and accessible monosaccharides have a number of stereogenic centers that have been hydroxylated and are challenging to chemically separate. As a result, the task of regioselective derivatization of such structures is particularly difficult. Considering this fact and to get novel rhamnopyranoside-based esters, DMAP-catalyzed di-O-stearoylation of methyl α-l-rhamnopyranoside (3) produced a mixture of 2,3-di-O- (4) and 3,4-di-O-stearates (5) (ratio 2:3) indicating the reactivity of the hydroxylated stereogenic centers of rhamnopyranoside as 3-OH > 4-OH > 2-OH. To get novel biologically active rhamnose esters, di-O-stearates 4 and 5 were converted into six 4-O- and 2-O-esters 6-11, which were fully characterized by FT-IR, ¹H, and ¹³C NMR spectral techniques. In vitro antimicrobial assays revealed that fully esterified rhamnopyranosides 6-11 with maximum lipophilic character showed better antifungal susceptibility than antibacterial activity. These experimental findings are similar to the results found from PASS analysis data. Furthermore, the pentanoyl derivative of 2,3-di-O-stearate (compound 6) showed better antifungal functionality against F. equiseti and A. flavus, which were found to be better than standard antibiotics. To validate the better antifungal results, molecular docking of the rhamnose esters 4-11 was performed with lanosterol 14α-demethylase (PDB ID: 3LD6), including the standard antifungal antibiotics ketoconazole and fluconazole. In this instance, the binding affinities of 10 (-7.6 kcal/mol), 9 (-7.5 kcal/mol), and 7 (-6.9 kcal/mol) were better and comparable to fluconazole (-7.3 kcal/mol), indicating the likelihood of their use as non-azole type antifungal drugs in the future.

A review on the synthesis of bio-based surfactants using green chemistry principles

OBJECTIVES

With increasing awareness of the potential adverse impact of conventional surfactants on the environment and human health, there is mounting interest in the development of bio-based surfactants (which are deemed to be safer, more affordable, are in abundance, are biodegradable, biocompatible and possess scalability, mildness and performance in formulation) in personal care products.

METHOD

A comprehensive literature review around alkyl polyglucosides (APGs) and sucrose esters (SEs) as bio-based surfactants, through the lens of the 12 green chemistry principles was conducted. An overview of the use of bio-based surfactants in personal care products was also provided.

RESULTS

Bio-based surfactants are derived primarily from natural sources (i.e. both the head and tail molecular group). One of the more common types of bio-based surfactants are those with carbohydrate head groups, where alkyl polyglucosides (APGs) and sucrose esters (SEs) lead this sub-category. As global regulations and user mandate for sustainability and safety increase, evidence to further support these bio-based surfactants as alternatives to their petrochemical counterparts is advantageous. Use of the green chemistry framework is a suitable way to do this. While many of the discussed principles are enforced industrially, others have only yet been applied at a laboratory scale or are not apparent in literature.

CONCLUSION

Many of the principles of green chemistry are currently used in the synthesis of APGs and SEs. These and other bio-based surfactants should, therefore, be considered suitable and sustainable alternatives to conventional surfactants. To further encourage the use of these novel surfactants, industry must make an effort to implement and improve the use of the remaining principles at a commercial level.

Alternative Excipients for Protein Stabilization in Protein Therapeutics: Overcoming the Limitations of Polysorbates

Given their safety and efficiency in protecting protein integrity, polysorbates (PSs) have been the most widely used excipients for the stabilization of protein therapeutics for years. In recent decades, however, there have been numerous reports about visible or sub-visible particles in PS-containing biotherapeutic products, which is a major quality concern for parenteral drugs. Alternative excipients that are safe for parenteral administration, efficient in protecting different protein drugs against various stress conditions, effective in protein stabilization in high-concentrated liquid formulations, stable under the storage conditions for the duration of the product's shelf-life, and compatible with other formulation components and the primary packaging are highly sought after. The aim of this paper is to review potential alternative excipients from different families, including surfactants, carbohydrate- and amino acid-based excipients, synthetic amphiphilic polymers, and ionic liquids that enable protein stabilization. For each category, important characteristics such as the ability to stabilize proteins against thermal and mechanical stresses, current knowledge related to the safety profile for parenteral administration, potential interactions with other formulation components, and primary packaging are debated. Based on the provided information and the detailed discussion thereof, this paper may pave the way for the identification or development of efficient excipients for biotherapeutic protein stabilization.

Highly efficient microencapsulation of phytonutrients by fractioned cellulose using biopolymer complexation technology

A poorly water soluble polar and non-polar bioactive complexes encapsulated in a nanocellulose-based polymeric network are the focus of this research. Ascorbic acid, resveratrol, holy basil extract, pomegranate extract, and niacin are all microencapsulated bioactive complexes that make up Zetalife^®, a nutritional ingredient. It uses an interpenetrating polymeric network (IPN) with more dispersed nanocellulose and phospholipids to increase Zetalife^® s bioavailability. Field Emission Scanning Electron Microscopic (FESEM) images were used in studying the morphology of encapsulated bioactive molecules. The average microbead size was determined to be 244.2 nm. After each month of storage, the sample's microbial content was measured to assess stability. In vitro release followed a first-order kinetic model with high R².

In Vitro and Human Pilot Studies of Different Topical Formulations Containing Rosa Species for the Treatment of Psoriasis

The aim of this study was to evaluate the phytochemical profile and antioxidant properties of the extracts from three Rosa species (R. canina, R. damascena, R. cairo), to develop and investigate topical formulations with lyophilized forms of extracts for the treatment of psoriasis. Phytochemical screening and in vitro total antioxidant capacity (DPPH, FRAP, CUPRAC, SOD) of studied samples were examined and compared. Lyophilized extracts of roses were dissolved in Transcutol HP and different formulations of creams were prepared. Franz diffusion method was used to evaluate the drug release and biocompatibility was tested on HaCaT cells. Rosa damascene had the best results regarding all the analyses that were conducted. After the evaluation of topical products, the formulation with Rosa damascena extract in a self-emulsifying drug delivery system was tested on a human clinical study that involved 20 patients. At the end of the clinical study an improvement in the quality of life of the patients was observed and erythema, induration and scaling were reduced. The present study indicates that our examined extracts exhibited great phenolic content, antioxidant capacity and safety profile of topical formulation and therefore can be used as a reliable source of natural antioxidants and may be used as a complementary treatment to improve the quality life of patients with psoriasis or may be tested on another diseases.

Microemulsion: a novel alternative technique for edible oil extraction_a mechanistic viewpoint

Microemulsions, as isotropic, transparent, nano size (<100 nm), and thermodynamically stable dispersions, are potentially capable of being used in food formulations, functional foods, pharmaceuticals, and in many other fields for various purposes, particularly for nano-encapsulation, extraction of bioactive compounds and oils, and as nano-reactors. However, their functionalities, and more importantly their oil extraction capability, strongly depend on, and are determined by, their formulation, molecular structures and the type, ratio and functionality of surfactants and co-surfactants. This review extensively describes microemulsions (definition, fabrication, thermodynamic aspects, and applications), and their various mechanisms of oil extraction (roll-up, snap-off, and solubilization including those by Winsor Types I, II, III, and IV systems). Applications of various food grade (natural or synthetic) and extended surfactants for edible oil extraction are then covered based on these concepts.

Metabolomics Study of Different Germplasm Resources for Three Polygonatum Species Using UPLC-Q-TOF-MS/MS

Rhizomes of the Polygonatum species are well-known in traditional Chinese medicine. The 2020 edition of Chinese Pharmacopoeia includes three different species that possess different pharmacological effects. Due to the lack of standardized discriminant compounds there has often been inadvertently incorrect prescriptions given for these medicines, resulting in serious consequences. Therefore, it is critical to accurately distinguish these herbal Polygonatum species. For this study, UPLC-Q-TOF-MS/MS based metabolomics was employed for the first time to discriminate between three Polygonatum species. Partial least squares discriminant analysis (PLS-DA) models were utilized to select the potential candidate discriminant compounds, after which MS/MS fragmentation patterns were used to identify them. Meanwhile, metabolic correlations were identified using the R language package corrplot, and the distribution of various metabolites was analyzed by box plot and the Z-score graph. As a result, we found that adenosine, sucrose, and pyroglutamic acid were suitable for the identification of different Polygonatum species. In conclusion, this study articulates how various herbal Polygonatum species might be more accurately and efficiently distinguished.

New, Biocompatible, Chitosan-Gelled Microemulsions Based on Essential Oils and Sucrose Esters as Nanocarriers for Topical Delivery of Fluconazole

Biocompatible gel microemulsions containing natural origin excipients are promising nanocarrier systems for the safe and effective topical application of hydrophobic drugs, including antifungals. Recently, to improve fluconazole skin permeation, tolerability and therapeutic efficacy, we developed topical biocompatible microemulsions based on cinnamon, oregano or clove essential oil (CIN, ORG or CLV) as the oil phase and sucrose laurate (D1216) or sucrose palmitate (D1616) as surfactants, excipients also possessing intrinsic antifungal activity. To follow up this research, this study aimed to improve the adhesiveness of respective fluconazole microemulsions using chitosan (a biopolymer with intrinsic antifungal activity) as gellator and to evaluate the formulation variables' effect (composition and concentration of essential oil, sucrose ester structure) on the gel microemulsions' (MEGELs) properties. All MEGELs were evaluated for drug content, pH, rheological behavior, viscosity, spreadability, in vitro drug release and skin permeation and antifungal activity. The results showed that formulation variables determined distinctive changes in the MEGELs' properties, which were nevertheless in accordance with official requirements for semisolid preparations. The highest flux and release rate values and large diameters of the fungal growth inhibition zone were produced by formulations MEGEL-FZ-D1616-CIN 10%, MEGEL-FZ-D1216-CIN 10% and MEGEL-FZ-D1616-ORG 10%. In conclusion, these MEGELs were demonstrated to be effective platforms for fluconazole topical delivery.

Development of Fully Redispersible Dried Nanocrystals by Using Sucrose Laurate as Stabilizer for Increasing Surface Area and Dissolution Rate of Poorly Water-Soluble Drugs

There is much interest in converting poorly water-soluble drugs into nanocrystals as they provide extremely high surface area that increases dissolution rate and oral bioavailability. However, nanocrystals are prepared as aqueous suspensions, and once the suspensions are dried for development of solid dosage forms, the nanocrystals agglomerate as large particles to reduce the excess surface energy. For successful development of drug products, it is essential that any agglomeration is reversible, and the dried nanocrystals regain original particle sizes after redispersion in aqueous media. We have established that sucrose laurate serves as a superb stabilizer to ensure complete redispersion of dried nanocrystals in aqueous media with mild agitation. Nanocrystals (150-300 nm) of three neutral drugs (fenofibrate, danazol and probucol) were produced with sucrose laurate by media milling, and suspensions were dried by tray drying under vacuum, spray drying, and lyophilization. Dried solids and their tablets redispersed into original particle sizes spontaneously. Preliminary studies showed that sucrose laurate can also redisperse acidic and basic drugs, indicating its versatile application. Fatty acid ester of another disaccharide, lactose laurate, also performed like sucrose laurate. Thus, we have developed a method of retaining high dissolution rate and, by implication, high bioavailability of nanocrystals from solid formulations.

Interactions between poloxamer, PEOx-PPOy-PEOx, and non-ionic surfactant, sucrose monolaurate: A study on potential allergenic effect using model phospholipid membrane

Sugar-based surfactants are involved in skin related allergy cases in the past decade. Skin irritation starts with the interaction of the surfactant with the skin lipids leading to lipid emulsification and eventual barrier damage. Polymers or co-surfactants can be used to mitigate the allergenic effect but the mechanism of formulation mildness on skin remains unclear. We have used the quartz crystal microbalance (QCM) together with dissipative particle dynamics (DPD) simulation, small angle x-ray scattering (SAXS) as well as cell viability tests to decipher the interactions between poloxamers and sucrose monolaurate (SML), and how these interactions could prevent the disruption of a model supported phospholipid bilayer (SLB). Poloxamer addition to the SML solution can delay or totally prevent the disruption of the SLB depending on poloxamer type and concentration. Poloxamer P407 (Pluronic® F127) delays the onset of disruption while poloxamer P188 (Pluronic® F68) does not preserve the bilayer integrity even at high concentration of up to 15% w/w. Preservation of the SLB is likely due to the differences in the aggregates formation between SML-F127 and SML-F68 mixtures with corresponding retarded motion of SML micelles through the SML-F127 polymer matrix that improved cell viability.

Co-delivery of paclitaxel and anti-VEGF siRNA by tripeptide lipid nanoparticle to enhance the anti-tumor activity for lung cancer therapy

The combination of chemotherapeutic drug paclitaxel (PTX) and VEGF siRNA could inhibit cancer development with synergistic efficacy. However, efficient and safe delivery systems with high encapsulation efficiency of PTX and a long-time release of drugs are urgently needed. In this study, novel nanoparticles (PTX/siRNA/FALS) were constructed by using tripeptide lipid (L), sucrose laurate (S), and folate-PEG₂₀₀₀-DSPE (FA) to co-deliver PTX and siRNA. The cancer cell targeting nanoparticle carrier (PTX/siRNA/FALS) showed anticipated PTX encapsulation efficiency, siRNA retardation ability, improved cell uptake and sustained and controlled drug release. It led to significant anti-tumor activity in vitro and in vivo by efficient inhibition of VEGF expression and induction of cancer cell apoptosis. Importantly, the biocompatibility of the carriers and low dosage of PTX required for effective therapy greatly reduced the toxicity to mice. The targeting nanoparticles show potential as an effective co-delivery platform for RNAi and chemotherapy drugs, aiming to improve the efficacy of cancer therapy.

A novel strategy to fabricate stable oil foams with sucrose ester surfactant

HYPOTHESIS

Can a mixture of sucrose ester surfactant in vegetable oil be aerated to yield stable oleofoams? Is foaming achievable from one-phase molecular solutions and/or two-phase crystal dispersions? Does cooling a foam after formation induce surfactant crystallisation and enhance foam stability?

EXPERIMENTS

Concentrating on extra virgin olive oil, we first study the effect of aeration temperature and surfactant concentration on foamability and foam stability of mixtures cooled from a one-phase oil solution. Based on this, we introduce a strategy to increase foam stability by rapidly cooling foam prepared at high temperature which induces surfactant crystallisation in situ. Differential scanning calorimetry, X-ray diffraction, infra-red spectroscopy, surface tension and rheology are used to elucidate the mechanisms.

FINDINGS

Unlike previous reports, both foamability and foam stability decrease upon decreasing the aeration temperature into the two-phase region containing surfactant crystals. At high temperature in the one-phase region, substantial foaming is achieved (over-run 170%) within minutes of whipping but foams ultimately collapse within a week. We show that surfactant molecules are surface-active at high temperature and that hydrogen bonds form between surfactant and oil molecules. Cooling these foams substantially increases foam stability due to both interfacial and bulk surfactant crystallisation. The generic nature of our findings is demonstrated for a range of vegetable oil foams with a maximum over-run of 330% and the absence of drainage, coalescence and disproportionation being achievable.

A novel maltoheptaose-based sugar ester having excellent emulsifying properties and optimization of its lipase-catalyzed synthesis

A novel maltoheptaose-palmitate ester (G7-PA) was synthesized and investigated for emulsion properties. First of all, the optimal conditions for lipase-catalyzed G7-PA synthesis, which were 0.2 of the G7/PA molar ratio, 33.5 U of immobilized CALB per 1 g of PA in 10% DMSO, were determined by response surface methodology. G7-PA was compared with the commercial sucrose-PA (S-PA) in terms of emulsion-forming ability and stability at extreme conditions. At the 0.1% surfactant concentration, G7-PA emulsion exhibited a droplet distribution similar to the 0.2% surfactant condition, while S-PA emulsion was quickly destabilized. G7-PA showed better emulsifying properties than the S-PA at the acidic condition (pH 3). Flocculation and phase separation was observed at the S-PA emulsion, but the G7-PA emulsion was stable for 7-day. In thermostability tests, G7-PA and S-PA both were stable up to the boiling temperature. Conclusively, G7-PA exhibits excellent properties as a biosurfactant in O/W emulsion compared with S-PA.

Non-ionic surfactants as innovative skin penetration enhancers: insight in the mechanism of interaction with simple 2D stratum corneum model system

Transdermal drug delivery is a passive diffusion process of an active compound through the skin which is affected by drug solubility in the multilamellar lipidic matrix of the stratum corneum (SC). Widely used non-ionic surfactants (NIS) can be added into transdermal formulations to enhance the penetration of drugs by influencing the packing of the stratum corneum lipidic matrix. Objective of our study was to analyse the interaction between selected NIS and a simple SC lipidic matrix model system using a variety of surface-sensitive techniques based on the application of Langmuir monolayers. In this work, the well-known surfactant Polysorbate 80 was compared with a modern surfactant Sucrose monolaurate. Infrared reflection-absorption spectroscopy (IRRAS) and epifluorescence microscopy provide information about the effects of those surfactants on the SC model system. Monolayer isotherms of the SC model mixture indicate a very stiff and well-packed layer, however, packing defects are evidenced in epifluorescence studies. The injection of the two NIS underneath the SC monolayers proved their potential to penetrate into the SC model at the air-water interface having a maximum insertion pressure (MIP) above the assumed lateral pressure of biological membranes. The NIS adsorbed preferentially into packing defects seen in epifluorescence microscopy studies with Sucrose monolaurate being more active than Polysorbate 80 in disordering the SC monolayer.

Microwave-Assisted One-Pot Lipid Extraction and Glycolipid Production from Oleaginous Yeast Saitozyma podzolica in Sugar Alcohol-Based Media

Glycolipids are non-ionic surfactants occurring in numerous products of daily life. Due to their surface-activity, emulsifying properties, and foaming abilities, they can be applied in food, cosmetics, and pharmaceuticals. Enzymatic synthesis of glycolipids based on carbohydrates and free fatty acids or esters is often catalyzed using certain acyltransferases in reaction media of low water activity, e.g., organic solvents or notably Deep Eutectic Systems (DESs). Existing reports describing integrated processes for glycolipid production from renewables use many reaction steps, therefore this study aims at simplifying the procedure. By using microwave dielectric heating, DESs preparation was first accelerated considerably. A comparative study revealed a preparation time on average 16-fold faster than the conventional heating method in an incubator. Furthermore, lipids from robust oleaginous yeast biomass were successfully extracted up to 70% without using the pre-treatment method for cell disruption, limiting logically the energy input necessary for such process. Acidified DESs consisting of either xylitol or sorbitol and choline chloride mediated the one-pot process, allowing subsequent conversion of the lipids into mono-acylated palmitate, oleate, linoleate, and stearate sugar alcohol esters. Thus, we show strong evidence that addition of immobilized Candida antarctica Lipase B (Novozym 435^®), in acidified DES mixture, enables a simplified and fast glycolipid synthesis using directly oleaginous yeast biomass.

Topical Biocompatible Fluconazole-Loaded Microemulsions Based on Essential Oils and Sucrose Esters: Formulation Design Based on Pseudo-Ternary Phase Diagrams and Physicochemical Characterization

To initiate our research into the development of biocompatiîle gelled-microemulsions based on essential oils (EOs) and sucrose esters (SEs) for the topical delivery of fluconazole, this formulation study investigated the usefulness of two relatively harmless natural non-ionic surfactants from the group of SEs (sucrose laurate and stearate) to form, in the presence of antifungal EOs, stable, isotropic microemulsions effective on fluconazole solubilization. Fluconazole’s solubility in EO significantly depended on their chemical composition, showing higher values for cinnamon, oregano and clove essential oils, further selected as oil phase components for microemulsion formulations. The phase behavior of several EO–isopropyl miristate/SE–isopropanol/water systems was assessed through pseudo-ternary phase diagrams constructed by microplate dilution technique. The hydrocarbon chain length of the SE and EO type strongly influenced the size of the microemulsion region in the pseudo-ternary phase diagrams. Ten microemulsion formulations containing 2% fluconazole, 6% or 10% oil mixture of EO–isopropyl myristate in 1:1 ratio, 45% SE-isopropanol mixture and water, were selected and evaluated for physicochemical properties (droplet size, polydispersity, viscosity, refractive index, zeta potential and pH). All formulations were physicochemically acceptable, but viscosity enhancement and further in vitro and in vivo tests are required for the development of biocompatible, clinically safe and effective fluconazole topical preparations.

CPE-DB: An Open Database of Chemical Penetration Enhancers

The cutaneous delivery route currently accounts for almost 10% of all administered drugs and it is becoming more common. Chemical penetration enhancers (CPEs) increase the transport of drugs across skin layers by different mechanisms that depend on the chemical nature of the penetration enhancers. In our work, we created a chemical penetration enhancer database (CPE-DB) that is, to the best of our knowledge, the first CPE database. We collected information about known enhancers and their derivatives in a single database, and classified and characterized their molecular diversity in terms of scaffold content, key chemical moieties, molecular descriptors, etc. CPE-DB can be used for virtual screening and similarity search to identify new potent and safe enhancers, building quantitative structure-activity relationship (QSAR) and quantitative structure-property relationship (QSPR) models, and other machine-learning (ML) applications for the prediction of biological activity.

The Effect of the HLB Value of Sucrose Ester on Physiochemical Properties of Bigel Systems

The current research explored the effect of different sucrose esters (SEs), with different hydrophilic–lipophilic balance (HLB) values, on bigel structure and properties. Bigels consisting of a water phase with glycerol and gelatin and an oil phase with glycerol mono-stearate, lecithin, and SEs with different HLB values were prepared. Rheological and thermal analyses revealed similar gelation-melting transitions governed by glycerol-monostearate crystallization (at ≈55 °C) for all bigel samples. The bigel matrix of the H1 and H2 samples (bigels consisting of SEs with HLBs of 1 and 2, respectively) demonstrated physical gel rheological characteristics of higher elastic and solid-like behavior compared with the H6 sample (bigel consisting SE with HLB 6). A similar trend was observed in the mechanical analysis with respect to hardness, firmness, and spreadability values, which were in the order of H1 > H2 > H6. This behavior was attributed to droplet size observed in the microscopy analysis, revealing significantly smaller droplets in the H1 and H2 samples compared with the H6 sample. These differences in droplet size were attributed to the diffusion kinetics of the low-molecular-weight surfactants. More specifically, the ability of mono-esterified SEs to diffuse faster than fully esterified SEs due to lower molar mass leads to a higher SE content at the oil-in-water (O/W) interface as opposed to the bulk oil phase. The results demonstrate the importance of the interface content in O/W bigel systems, providing an effective way to alter and control the bigel bulk properties.

Formulation of Creams Containing Spirulina Platensis Powder with Different Nonionic Surfactants for the Treatment of Acne Vulgaris

Natural products used in the treatment of acne vulgaris may be promising alternative therapies with fewer side effects and without antibiotic resistance. The objective of this study was to formulate creams containing Spirulina (Arthrospira) platensis to be used in acne therapy. Spirulina platensis belongs to the group of micro algae and contains valuable active ingredients. The aim was to select the appropriate nonionic surfactants for the formulations in order to enhance the diffusion of the active substance and to certify the antioxidant and antibacterial activity of Spirulina platensis-containing creams. Lyophilized Spirulina platensis powder (SPP) was dissolved in Transcutol HP (TC) and different types of nonionic surfactants (Polysorbate 60 (P60), Cremophor A6:A25 (CR) (1:1), Tefose 63 (TFS), or sucrose ester SP 70 (SP70)) were incorporated in creams as emulsifying agents. The drug release was evaluated by the Franz diffusion method and biocompatibility was tested on HaCaT cells. In vitro antioxidant assays were also performed, and superoxide dismutase (SOD) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays were executed. Antimicrobial activities of the selected compositions were checked against Staphylococcus aureus (S. aureus) and Cutibacteriumacnes (C. acnes) (formerly Propionibacterium acnes) with the broth microdilution method. Formulations containing SP 70 surfactant with TC showed the most favorable dissolution profiles and were found to be nontoxic. This composition also showed significant increase in free radical scavenger activity compared to the blank sample and the highest SOD enzyme activity was also detected after treatment with the cream samples. In antibacterial studies, significant differences were observed between the treated and control groups after an incubation time of 6 h.

Co-grinding with surfactants as a new approach to enhance in vitro dissolution of praziquantel

This paper evaluates the process of co-grinding with a surfactant as a new approach to enhance physicochemical and biopharmaceutical properties of praziquantel (PZQ), a poorly soluble drug that is essential for the treatment of schistosomiasis, a neglected tropical disease. Surfactants used in this study were poloxamer F-127 and sucrose stearate (C-1816), selected based on their well-documented biocompatibility and solubilizing activity. A series of products were prepared by mechanochemical activation using vibrational ball-mill at different drug to surfactant ratio and milling times. The obtained products were characterised in terms of drug recovery, solubility and in vitro dissolution rates. The obtained results were correlated to solid-state properties of the products analysed by differential scanning calorimetry, powder X-ray diffraction and particle size analysis. Results of UPLC-MS analysis and ¹H-NMR spectroscopy showed that the used surfactants and applied grinding procedures caused no chemical degradation of the PZQ. The physicochemical properties, solubility and the in vitro dissolution enhancement of the co-ground products were related to the drug to surfactant ratio and the grinding protocol applied. The highest enhancement of the in vitro dissolution rate was achieved at the drug to surfactant ratio of 10:3 and 10:2 for F-127 and C-1816, respectively with the milling time of 30 min. The MTT assay on Caco-2 cell line demonstrated the biocompatibility of both co-ground products. Furthermore, the surfactants used did not change intrinsically high intestinal permeability of PZQ (Papp ∼ 4.00 × 10^-5 cm s^-1). The presented results confirmed that the co-grinding with surfactant is a promising new approach in enhancing in vitro dissolution of poorly soluble drugs like PZQ.

Development of New Formula Microcapsules from Nutmeg Essential Oil Using Sucrose Esters and Magnesium Aluminometasilicate

Essential oils are volatile liquids which evaporate and lose their pharmacological effect when exposed to the environment. The aim of this study is to protect nutmeg essential oil from environmental factors by encapsulation (shell material, sodium alginate) and determine the influence of crosslinker concentration (2%, 5% calcium chloride), different emulsifiers (polysorbate 80, sucrose esters), and magnesium aluminometasilicate on microcapsule physical parameters, encapsulation efficiency (EE), swelling index (SI), and other parameters. Nutmeg essential oil (NEO)-loaded calcium alginate microcapsules were prepared by extrusion. The swelling test was performed with and without enzymes in simulated gastric, intestinal, and gastrointestinal media. This study shows that the crosslinker concentration has a significant influence on EE, with 2% calcium chloride solution being more effective than 5%, and capsules being softer with 2% crosslinker solution. Using sucrose esters, EE is higher when polysorbate 80 is used. The swelling index is nearly three times higher in an intestinal medium without enzymes than in the medium with pancreatin. Microcapsule physical parameters depend on the excipients: the hardest capsules were obtained with the biggest amount of sodium alginate; the largest with magnesium aluminometasilicate. Sucrose esters and magnesium aluminometasilicate are new materials used in extrusion.

Development and characterisation of ibuprofen-loaded nanoemulsion with enhanced oral bioavailability

Lipophilic compounds constitute a majority of therapeutics in the pipeline of drug discovery. Despite possessing enhanced efficacy and permeability, some of these drugs suffer poor solubility necessitating the need of a suitable drug delivery system. Nanoemulsion is a drug delivery system that provides enhanced solubility for poorly soluble drugs in an attempt to improve the oral bioavailability. The purpose of this study is to develop a nanoemulsion system using ibuprofen as a model drug in order to investigate the potential of this colloidal system to enhance the absorption of poorly water-soluble drugs. Ibuprofen loaded-nanoemulsion with different drug concentrations (1.5, 3 and 6% w/w) were formulated from olive oil, sucrose ester L-1695 and glycerol using D-phase emulsification technique. A pseudoternary phase diagram was utilised to identify the optimal excipient composition to formulate the nanoemulsion system. In vitro diffusion chamber studies using rodent intestinal linings highlighted improved absorption profile when ibuprofen was delivered as nanoemulsion in comparison to microemulsions and drug-in-oil systems. This was further corroborated by in vivo studies using rat model that highlighted a two-fold increase in ibuprofen absorption when the drug was administered as a nanoemulsion relative to drug-in-oil system. On the other hand, when ibuprofen was administered as microemulsions, only a 1.5-fold increase in absorption was observed relative to drug-in-oil system. Thus, this study highlights the potential of using nanoemulsion as a drug delivery system to enhance the oral bioavailability of hydrophobic drugs.

Development of Dried Emulsion/Mannitol Composite Microparticles through a Unique Spray Nozzle for Efficient Delivery of Hydrophilic Anti-tuberculosis Drug against Alveolar Macrophages

As alveolar macrophages are attractive targets for the treatment of tuberculosis, effective methods for delivery to alveolar macrophages are under development. We investigated a pulmonary formulation for the efficient delivery of high water-soluble drugs at high concentration targeting alveolar macrophages. In this study, a surfactant-coated high water-soluble drug complex (SDC, a hydrophobic dried emulsion), which can preferably target alveolar macrophages and be expected to deliver drug at a high concentration, was prepared in the first process. OCT313, a high water-soluble sugar derivative with anti-tuberculosis activity was used. Then, a unique two-solution, mixing-type nozzle was used to prepare the SDC nanoparticles in mannitol (MAN) microparticles (SDC/MAN microparticles) because it was difficult to disperse the SDC nanoparticles in aqueous solution. The single micron size of OCT313-SDC/MAN microparticles contained OCT313-SDC nanoparticles (mean particle size of OCT313-SDC nanoparticles, 277.9 nm; drug contents, 1.31 ± 0.041 wt%). We found that the treatment of SDC/MAN microparticles exhibited significantly higher drug accumulation in macrophage cells (Raw264.7 cells, 7.5-fold, at 4 h after treatment) in vitro and in alveolar macrophages in rats (9.1-fold, at 4 h after treatment) in vivo than that of drug alone. These results suggest that the SDC/MAN microparticle formulation prepared by spray drying through a two-solution mixing-type nozzle provides efficient delivery of a water-soluble drug targeting alveolar macrophages and may be useful for tuberculosis treatment.

The Role of Functional Excipients in Solid Oral Dosage Forms to Overcome Poor Drug Dissolution and Bioavailability

Many active pharmaceutical ingredients (APIs) exhibit poor solubility and low dissolution rates in aqueous environments such as the luminal fluids of the gastrointestinal tract. The oral bioavailability of these compounds is usually very low as a result of their poor solubility properties. In order to improve the bioavailability of these poorly soluble drugs, formulation strategies have been applied as a means to improve their aqueous solubility and dissolution rates. With respect to formulation approaches, excipients can be incorporated in the formulation to assist in the dissolution process of the drug, or specialized dosage forms can be formulated that improve dissolution rate through various mechanisms. This paper provides an overview of selected excipients (e.g., alkalinizing agents, surfactants and sugars) that can be used in formulations to increase the dissolution rate as well as specialized dosage forms such as self-emulsifying delivery systems and formulation techniques such as inclusion complexes and solid dispersions. These formulation approaches are discussed with available examples with specific reference to positive outcomes in terms of drug solubility and bioavailability enhancement.

Regulating water binding capacity and improving porous carbohydrate matrix's humectant and moisture proof functions by mixture of sucrose ester and Polygonatum sibiricum polysaccharide

The moisture stability of tobacco shred, a typical porous carbohydrate material, is very important during its processing, storage and smoking, moreover, it is sensitive to environmental conditions. Therefore, effect of sucrose esters (SEs) and sucrose ester/Polygonatum sibiricum polysaccharide mixture (SPMs) on the moisture retention and moisture resistance of tobacco shred was assessed. When SEs were added to tobacco shred, moisture resistance was significantly enhanced, whereas moisture holding capacity was attenuated. Contrarily, the addition of SPMs made moisture retention index (MRI) and moisture proof index (MPI) increase from 1.8910 to 2.1612 and from 1.9489 to 2.0665, respectively, revealing that SPMs improved the moisture retention and moisture proof ability of tobacco shred simultaneously. The monolayer moisture content (M₀) was decreased by SEs and increased by SPMs. Low-field nuclear magnetic resonance (LF-NMR) analysis showed that during adsorption, SPMs reduced the interaction between tobacco shred and water via hydrophobic property of SEs; during desorption, SPMs promoted the interaction between tobacco shred and water through hydrophilic binding of polysaccharide, leading to the migration of immobilized water to bound state. The modeling of the isotherms and LF-NMR analysis clarified the mechanism why SPMs could improve moisture stability of tobacco.