Self-emulsifying drug delivery systems: a novel approach to deliver drugs

Incompatibility of antimalarial drugs: challenges in formulating combination products for malaria

Lipophilic drugs require more advance formulation, especially if the intention is to make solutions or semisolid formulations. This also accounts for most antimalarial drugs. Although some of these antimalarial drugs are soluble in lipid vehicles, few of them, such as lumefantrine (LF), are also poorly soluble in oily vehicles. Trying to dissolve and formulate LF as a liquid formulation together with other antimalarial drugs is, therefore, a major task. When mixed in solution together with artemether (AR), precipitation occurs, sometimes with LF precipitating out on its own, and sometimes with AR precipitating out alongside LF. In this study, it was hypothesized that the use of fatty acids could lead to enhanced solubility in lipid formulation. Addition of the fatty acid solved the dissolution challenges, making LF soluble for over a year at room temperature (21-23 °C); but further research is needed to test the mechanism of action of the fatty acid. In addition, design of experiments (MODDE® 13) revealed that the amount of fatty acid in the formulation was the only significant factor for LF precipitation.

Harnessing therapeutic deep eutectic solvents in self-emulsifying systems to improve CBD delivery

In this study, Cannabidiol crystals (CBD) were used as a BCS class II model drug to generate a novel therapeutic deep eutectic solvent (THEDES) with easy preparation using caprylic acid (CA). The hydrogen bonding interaction was confirmed by different techniques such as FT-IR and NMR, resulting in a hydrophobic system suitable for liquid formulations. The CBD-based THEDES, combined with a specific mixture of surfactants and co-surfactants, successfully formed a self-emulsifying drug delivery system (SEDDS) that generated uniform nano-sized droplets once dispersed in water. Hence, the THEDES showed compatibility with the self-emulsifying approach, offering an alternative method to load drugs at their therapeutic dosage. Physical stability concerns regarding the unconventional oily phase were addressed through stress tests using multiple and dynamic light scattering, demonstrating the robustness of the system. In addition, the formulated SEDDS proved effective in protecting CBD from the harsh acidic gastric environment for up to 2 h at pH 1.2. Furthermore, in vitro studies have confirmed the safety of the formulation and the ability of CBD to permeate Caco-2 cells when formulated. This investigation highlights the potential incorporation of THEDES in lipid-based formulations like SEDDS, expanding the avenues for innovative oral drug delivery approaches.

Self-emulsifying drug delivery systems (SEDDS) containing Cymbopogon citratus essential oil: Enhancing the stability and acaricide efficacy against Rhipicephalus (Boophilus) microplus

The objectives of this study were to develop a self-emulsifying drug delivery system (SEDDS) to enhance the stability and efficacy of Cymbopogon citratus essential oil or lemongrass oil (LEO) against cattle tick larvae and engorged females. The system with the highest oil loading in SEDDS was composed of LEO (23.33%w/w), Tween 80: SGKH 4000 in a 2:1 ratio as surfactant (66.67%w/w), and propylene glycol as co-surfactant (10%w/w). The selected SEDDS-LEO has a particle size of 18.78 nm with a narrow size distribution (polydispersity index of 0.27). Notably, the stability of SEDDS was superior to that of the original oil, both during long-term storage and under accelerated conditions. SEDDS-LEO at oil concentrations ranging from 1.458% to 5.833% w/v showed a significantly higher percentage of egg-laying reduction against adult ticks compared with the original oil at the same concentrations (p < 0.05). Furthermore, SEDDS-LEO demonstrated greater larvicidal efficacy than the original oil, with lower LC50 and LC90 values of 0.91 mg/mL and 1.20 mg/mL, respectively, whereas the original oil's LC50 and LC90 values were 1.17 mg/mL and 1.74 mg/mL, respectively. Our findings indicate that SEDDS-LEO is a promising candidate for use as an acaricide in the control of tick populations in dairy cattle.

Throat spray formulated with virucidal pharmaceutical excipients as an effective early prophylactic or treatment strategy against pharyngitis post-exposure to SARS-CoV-2

Our study aimed to develop a virucidal throat spray using bioactive compounds and excipients, focusing on the preparation of Curcumin (CUR) in a self-nano emulsifying drug delivery system (SNEDDS). Two molecular docking studies against SARS-CoV-2 targets guided the selection of proper oil, surfactant, co-surfactant, and natural bioactive that would maximize the antiviral activity of the throat spray. Two self-nanoemulsifying formulas that were diluted with different vehicles to prepare eight CUR-loaded SNESNS (self-nanoemulsifying self-nanosuspension) formulas. In vitro characterization studies and in vitro anti-SARS-CoV-2 effect revealed that the optimal formula, consisted of 20 % Anise oil, 70 % Tween 80, 10 % PEG 400, and 0.1 %w/w CUR, diluted with DEAE-Dx. Preclinical toxicity tests on male rats confirmed the safety of a mild throat spray dose (5 µg/mL CUR). In a rat model of acute pharyngitis induced by ammonia, post-treatment with the optimal formula of CUR loaded SNESNS for one week significantly reduced elevated proinflammatory markers (TNF-α, IL6, MCP1, and IL8). In conclusion, our CUR-loaded SNESNS formula, at 5 µg/mL concentration, shows promising effect as a prophylactic throat spray against SARS-CoV-2 and as a treatment for pharyngitis.

Enhancing the oral bioavailability of fisetin: polysaccharide-based self nano-emulsifying spheroids for colon-targeted delivery

Fisetin (FS) is a flavonoid that possesses antioxidant and anti-inflammatory properties against ulcerative colitis. FS shows poor dissolution rate and permeability. An attempt has been made to develop colon-targeted solid self-nanoemulsifying drug delivery systems (S-SNEDDS) of FS. Initially, liquid (L) SNEDDS were prepared by loading FS into isotropic mixture of L-SNEDDS was prepared using Labrafil M 1944 CS, Transcutol P, and Tween 80. These L-SNEDDS were further converted into solid (S) SNEDDS by mixing the isotropic mixture with 1:1:1 ratio of guar gum (GG), xanthan gum (XG) and pectin (PC) [GG:XG:PC (1:1:1)]. Aerosil-200 (A-200) was added to enhance their flow characteristics. Further, they were converted into spheroids by extrusion-spheronization technique. The solid-state characterization of S-SNEDDS was done by SEM, DSC, and PXRD, which revealed that the crystalline form of FS was converted into the amorphous form. In the dissolution study, S-SNEDDS spheroids [GG:XG:PC (1:1:1)] exhibited less than 20% drug release within the first 5 h, followed by rapid release of the drug between the 5th and 10th h, indicating its release at colonic site. The site-specific delivery of FS to colon via FS-S-SNEDDS spheroids was confirmed by conducting pharmacokinetic studies on rats. Wherein, results showed delay in absorption of FS loaded in spheroids up to 5 h and achievement of Cmax at 7h, whereas L-SNEDDS showed rapid absorption of FS. Furthermore, FS-L-SNEDDS and FS-S-SNEDDS spheroids [GG:XG:PC (1:1:1)] increased oral bioavailability of FS by 6.86-fold and 4.44-fold, respectively, as compared to unprocessed FS.

Self Emulsifying Delivery System of Cissus quadrangularis: Evidence of Enhanced Efficacy and Promising Pharmacokinetic Profile in the Management of Osteoporosis

Treatment therapies used to manage osteoporosis are associated with severe side effects. So worldwide herbs are widely studied to develop alternative safe & effective treatments. Cissus quadrangularis (CQ) has a significant role in bone health and fracture healing. It is documented that its extracts increase osteoblastic differentiation & mineralization. Currently, Cissus quadrangularis is available in the form of tablets in the market for oral delivery. But these conventional forms are associated with poor bioavailability. There is a need for a novel drug delivery system with improving oral bioavailability. Therefore, a Cissus quadrangularis-loaded self-emulsifying drug delivery system (CQ-SEDDS) was developed which disperses rapidly in the gastrointestinal fluids, yielding nano-emulsions containing a solubilized drug. This solubilized form of the drug can be easily absorbed through lymphatic pathways and bypass the hepatic first-pass effect. The emulsification efficiency, zeta potential, globule size, in-vitro dissolution, ex-vivo, in-vivo and bone marker studies were performed to assess the absorption and permeation potential of CQ incorporated in SEDDS. CQ-SEDDS with excipients Tween 80, Cremophor RH40, Transcutol HP & α-Tocopherol acetate had shown about 76% enhancement in the bioavailability of active constituents of CQ. This study provided the pre-clinical data of CQ-SEDDS using osteoporotic rat model studies.

The key factors of solid nanodispersion for promoting the bioactivity of abamectin

Solid nanodispersion (SND) is an important variety of nanopesticides which have been extensively studied in recent years. However, the key influencing factors for bioactivity enhancement of nanopesticides remain unclear, which not only limits the exploration of relevant mechanisms, but also hinders the precise design and development of nanopesticides. In this study, we explored the potential of SND in enhancing the bioactivity of nanopesticides, specifically focusing on abamectin SND prepared using a self-emulsifying-carrier solidifying technique combined with parameter optimization. Our formulation, consisting of 8% abamectin, 1% antioxidant BHT (2,6-di-tert-butyl-4-methylphenol), 12% complex surfactants, and 79% sodium benzoate, significantly increased the pseudo-solubility of abamectin by at least 3300 times and reduced its particle size to a mere 15 nm, much smaller than traditional emulsion in water (EW) and water-dispersible granule (WDG) forms. This reduction in particle size and increase in surface activity resulted in improved foliar adhesion and retention, enabling a more efficient application without the need for organic solvents. The inclusion of antioxidants also enhanced photostability compared to EW, and overall stability tests confirmed SND's resilience under various storage conditions. Bioactivity tests demonstrated a marked increase in toxicity against diamondback moths (Plutella xylostella L.) with abamectin SND, which exhibited 3.7 and 7.6 times greater efficacy compared to EW and WDG, respectively. These findings underscore the critical role of small particle size, high surface activity, and strong antioxidant properties in improving the performance and bioactivity of abamectin SND, highlighting its significance in the design and development of high-efficiency, eco-friendly nanopesticides and contributing valuably to sustainable agricultural practices.

Development of a self-microemulsifying drug delivery system to deliver delamanid via a pressurized metered dose inhaler for treatment of multi-drug resistant pulmonary tuberculosis

Tuberculosis (TB) is a serious health issue that contributes to millions of deaths throughout the world and increases the threat of serious pulmonary infections in patients with respiratory illness. Delamanid is a novel drug approved in 2014 to deal with multi-drug resistant TB (MDR-TB). Despite its high efficiency in TB treatment, delamanid poses delivery challenges due to poor water solubility leading to inadequate absorption upon oral administration. This study involves the development of novel formulation-based pressurized metered dose inhalers (pMDIs) containing self-microemulsifying mixtures of delamanid for efficient delivery to the lungs. To identify the appropriate self-microemulsifying formulations, ternary diagrams were plotted using different combinations of surfactant to co-surfactant ratios (1:1, 2:1, and 3:1). The combinations used Cremophor RH40, Poly Ethylene Glycol 400 (PEG 400), and peppermint oil, and those that showed the maximum microemulsion region and rapid and stable emulsification were selected for further characterization. The diluted self-microemulsifying mixtures underwent evaluation of dose uniformity, droplet size, zeta potential, and transmission electron microscopy. The selected formulations exhibited uniform delivery of the dose throughout the canister life, along with droplet sizes and zeta potentials that ranged from 24.74 to 88.99 nm and - 19.27 to - 10.00 mV, respectively. The aerosol performance of each self-microemulsifying drug delivery system (SMEDDS)-pMDI was assessed using the Next Generation Impactor, which indicated their capability to deliver the drug to the deeper areas of the lungs. In vitro cytotoxicity testing on A549 and NCI-H358 cells revealed no significant signs of toxicity up to a concentration of 1.56 µg/mL. The antimycobacterial activity of the formulations was evaluated against Mycobacterium bovis using flow cytometry analysis, which showed complete inhibition by day 5 with a minimum bactericidal concentration of 0.313 µg/mL. Moreover, the cellular uptake studies showed efficient delivery of the formulations inside macrophage cells, which indicated the potential for intracellular antimycobacterial activity. These findings demonstrated the potential of the Delamanid-SMEDDS-pMDI for efficient pulmonary delivery of delamanid to improve its effectiveness in the treatment of multi-drug resistant pulmonary TB.

Development and Optimization of Proniosomal Formulation of Irbesartan Using a Box-Behnken Design to Enhance Oral Bioavailability: Physicochemical Characterization and In Vivo Assessment

This research work aimed to develop and evaluate proniosomes for the oral delivery of the lipophilic drug Irbesartan (IRB) to improve its solubility and bioavailability. Proniosomes of Irbesartan were formulated using a lipid, surfactant, and carrier by a slurry method. Based on the prepared preliminary trial batches and their evaluation, the formulation was optimized by employing a Box-Behnken design (BBD) in which concentrations of span 60 (X1), cholesterol (X2), and mannitol (X3) were used as three independent variables and the vesicular size (VS) (Y1), % entrapment efficiency (% EE) (Y2), and % cumulative drug release (% CDR) (Y3) were used as dependent variables. The optimized batch B1 was obtained from the BBD experiment after validation of checkpoint analysis, and their characterization was done for VS, % EE, % CDR, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and X-ray diffraction (XRD) analysis. The optimized batch showed a VS of 199 ± 5.4 nm, a % EE of 99.25 ± 2.24%, and a % CDR of 97.36 ± 1.13% at 24 h. Scanning electron microscopy (SEM) study showed a smooth surface of batch B1. DSC and XRD studies indicated the amorphous nature of the proniosomal formulation. The proniosomal formulation showed increased solubility (2.65 ± 0.2 mg/mL) in phosphate buffer, pH 6.8, as compared to water (0.059 ± 0.02 mg/mL). The pharmacokinetic study in rats confirmed the increased bioavailability of the drug in optimized proniosomal formulation compared with its pure drug suspension. Cmax, Tmax, and AUC0-t of the drug also increased by 2-fold compared to those of drug suspension. Thus, in conclusion, the proniosomal formulation proved to be an efficient carrier for improved oral delivery of Irbesartan by improving the solubility and bioavailability of the drug.

Combination of the Topical Photodynamic Therapy of Chloroaluminum Phthalocyanine Liposomes with Fexinidazole Oral Self-Emulsifying System as a New Strategy for Cutaneous Leishmaniasis Treatment

Cutaneous leishmaniasis (CL) is a neglected tropical disease. The treatment is restricted to drugs, such as meglumine antimoniate and amphotericin B, that exhibit toxic effects, high cost, long-term treatment, and limited efficacy. The development of new alternative therapies, including the identification of effective drugs for the topical and oral treatment of CL, is of great interest. In this sense, a combination of topical photodynamic therapy (PDT) with chloroaluminum phthalocyanine liposomes (Lip-ClAlPc) and the oral administration of a self-emulsifying drug delivery system containing fexinidazole (SEDDS-FEX) emerges as a new strategy. The aim of the present study was to prepare, characterize, and evaluate the efficacy of combined therapy with Lip-ClAlPc and SEDDS-FEX in the experimental treatment of Leishmania (Leishmania) major. Lip-ClAlPc and SEDDS-FEX were prepared, and the antileishmanial efficacy study was conducted with the following groups: 1. Lip-ClAlPc (0.05 mL); 2. SEDDS-FEX (50 mg/kg/day); 3. Lip-ClAlPc (0.05 mL)+SEDDS-FEX (50 mg/kg/day) combination; 4. FEX suspension (50 mg/kg/day); and 5. control (untreated). BALB/c mice received 10 sessions of topical Lip-ClAlPc on alternate days and 20 consecutive days of SEDDS-FEX or FEX oral suspension. Therapeutical efficacy was evaluated via the parasite burden (limiting-dilution assay), lesion size (mm), healing of the lesion, and histological analyses. Lip-ClAlPc and SEDDS-FEX presented physicochemical characteristics that are compatible with the administration routes used in the treatments. Lip-ClAlPc+SEDDS-FEX led to a significant reduction in the parasitic burden in the lesion and spleen when compared to the control group (p < 0.05) and the complete healing of the lesion in 43% of animals. The Lip-ClAlPc+SEDDS-FEX combination may be promising for the treatment of CL caused by L. major.

Regulation of immunomodulatory networks by Nrf2-activation in immune cells: Redox control and therapeutic potential in inflammatory diseases

Inflammatory diseases present a serious health challenge due to their widespread prevalence and the severe impact on patients' lives. In the quest to alleviate the burden of these diseases, nuclear factor erythroid 2-related factor 2 (Nrf2) has emerged as a pivotal player. As a transcription factor intimately involved in cellular defense against metabolic and oxidative stress, Nrf2's role in modulating the inflammatory responses of immune cells has garnered significant attention. Recent findings suggest that Nrf2's ability to alter the redox status of cells underlies its regulatory effects on immune responses. Our review delves into preclinical and clinical evidence that underscores the complex influence of Nrf2 activators on immune cell phenotypes, particularly in the inflammatory milieu. By offering a detailed analysis of Nrf2's role in different immune cell populations, we cast light on the potential of Nrf2 activators in shaping the immune response towards a more regulated state, mitigating the adverse effects of inflammation through modeling redox status of immune cells. Furthermore, we explore the innovative use of nanoencapsulation techniques that enhance the delivery and efficacy of Nrf2 activators, potentially advancing the treatment strategies for inflammatory ailments. We hope this review will stimulate the development and expansion of Nrf2-targeted treatments that could substantially improve outcomes for patients suffering from a broad range of inflammatory diseases.

Effects of excipients on the interactions of self-emulsifying drug delivery systems with human blood plasma and plasma membranes

Due to its versatility in formulation and manufacturing, self-emulsifying drug delivery systems (SEDDS) can be used to design parenteral formulations. Therefore, it is necessary to understand the effects of excipients on the behavior of SEDDS formulations upon parenteral administration, particularly their interactions with blood plasma and cell membranes. In this study, we prepared three neutrally charged SEDDS formulations composed of medium-chain triglycerides as the oil phase, polyoxyl-35 castor oil (EL35) and polyethylene glycol (15)-hydroxystearate (HS15) as the nonionic surfactants, medium-chain mono- and diglycerides as the co-surfactant, and propylene glycol as the co-solvent. The cationic surfactant, didodecyldimethylammonium bromide (DDA), and the anionic surfactant, sodium deoxycholate (DEO), were added to the neutral SEDDS preconcentrates to obtain cationic and anionic SEDDS, respectively. SEDDS were incubated with human blood plasma and recovered by size exclusion chromatography. Data showed that SEDDS emulsion droplets can bind plasma protein to different extents depending on their surface charge and surfactant used. At pH 7.4, the least protein binding was observed with anionic SEDDS. Positive charges increased protein binding. SEDDS stabilized by HS15 can adsorb more plasma protein and induce more plasma membrane disruption activity than SEDDS stabilized by EL35. These effects were more pronounced with the HS15 + DDA combination. The addition of DDA and DEO to SEDDS increased plasma membrane disruption (PMD) activities, and DDA (1% w/w) was more active than DEO (2% w/w). PMD activities of SEDDS were concentration-dependent and vanished at appropriate dilution ratios.

Self-Emulsifying Drug Delivery System for Enhanced Oral Delivery of Tenofovir: Formulation, Physicochemical Characterization, and Bioavailability Assessment

Tenofovir (TNF) is a common component of many antiretroviral therapy regimens, but it is associated with poor membrane permeability and low oral bioavailability. To improve its oral bioavailability and membrane permeability, a self-emulsifying drug delivery system (SEDDS) was developed and characterized, and its relative bioavailability was compared to the marketed tablets (Tenof). Based on solubility and ternary phase diagram analysis, eucalyptus oil was selected as an oil phase, Kolliphor EL, and Kollisolv MCT 70 were chosen as surfactant and cosurfactant, respectively, while glycerol was used as cosolvent in surfactant mixture. Optimized SEDDS formulation F6 showed an oil droplet size of 98.82 nm and zeta potential of -13.03 mV, indicating the high stability of oil droplets. Differential scanning calorimetry, X-ray diffraction, and scanning electron microscopy characterization studies were also carried out to assess the amorphous and morphological states of the drug in the prepared SEDDS formulation. The in vitro dissolution profile of SEDDS shows the rapid release of the drug. SEDDS F6 demonstrates a higher drug permeability than the plain TNF and TNF-marketed tablets (Tenof). A pharmacokinetic study in rats revealed that SEDDS F6 showed significantly higher Cmax and AUC0-t than the marketed tablets and pure drug suspension. In addition, the relative bioavailability of SEDDS formulation dramatically improved by 21.53-fold compared to marketed tablets and 66.27-fold compared to pure drugs. These findings show that SEDDS composed of eucalyptus oil, glycerol, Kolliphor EL, and Kollisolv MCT 70 could be a useful tool for enhancing physiochemical properties and oral TNF absorption. Therefore, SEDDS has shown promise in improving the oral bioavailability of poorly water-soluble drugs.

Nanoemulsions: summary of a decade of research and recent advances

Nanoemulsions consist of a combination of several components such as oil, water, emulsifiers, surfactants and cosurfactants. Various techniques for producing nanoemulsions include high-energy and low-energy approaches such as high-pressure homogenization, microfluidization, jet disperser and phase inversion methods. The properties of a formulation can be influenced by elements such as the composition, concentration, size and charge of droplets, which in turn can affect the technique of manufacture. Characterization is conducted by the assessment of several factors such as physical properties, pH analysis, viscosity measurement and refractive index determination. This article offers a thorough examination of the latest developments in nanoemulsion technology, with a focus on their wide-ranging applications and promising future possibilities. It also discusses the administration of nanoemulsions through several methods.

Self-emulsifying drug delivery systems (SEDDS) disrupt the gut microbiota and trigger an intestinal inflammatory response in rats

Self-emulsifying drug delivery systems (i.e. SEDDS, SMEDDS and SNEDDS) are widely employed as solubility and bioavailability enhancing formulation strategies for poorly water-soluble drugs. Despite the capacity for SEDDS to effectively facilitate oral drug absorption, tolerability concerns exist due to the capacity for high concentrations of surfactants (typically present within SEDDS) to induce gastrointestinal toxicity and mucosal irritation. With new knowledge surrounding the role of the gut microbiota in modulating intestinal inflammation and mucosal injury, there is a clear need to determine the impact of SEDDS on the gut microbiota. The current study is the first of its kind to demonstrate the detrimental impact of SEDDS on the gut microbiota of Sprague-Dawley rats, following daily oral administration (100 mg/kg) for 21 days. SEDDS comprising a lipid phase (i.e. Type I, II and III formulations according to the Lipid Formulation Classification Scheme) induced significant changes to the composition and diversity of the gut microbiota, evidenced through a reduction in operational taxonomic units (OTUs) and alpha diversity (Shannon's index), along with statistically significant shifts in beta diversity (according to PERMANOVA of multi-dimensional Bray-Curtis plots). Key signatures of gut microbiota dysbiosis correlated with the increased expression of pro-inflammatory cytokines within the jejunum, while mucosal injury was characterised by significant reductions in plasma citrulline levels, a validated biomarker of enterocyte mass and mucosal barrier integrity. These findings have potential clinical ramifications for chronically administered drugs that are formulated with SEDDS and stresses the need for further studies that investigate dose-dependent effects of SEDDS on the gastrointestinal microenvironment in a clinical setting.

Emulsion Technology in Nuclear Medicine: Targeted Radionuclide Therapies, Radiosensitizers, and Imaging Agents

Radiopharmaceuticals serve as a major part of nuclear medicine contributing to both diagnosis and treatment of several diseases, especially cancers. Currently, most radiopharmaceuticals are based on small molecules with targeting ability. However, some concerns over their stability or non-specific interactions leading to off-target localization are among the major challenges that need to be overcome. Emulsion technology has great potential for the fabrication of carrier systems for radiopharmaceuticals. It can be used to create particles with different compositions, structures, sizes, and surface characteristics from a wide range of generally recognized as safe (GRAS) materials, which allows their functionality to be tuned for specific applications. In particular, it is possible to carry out surface modifications to introduce targeting and stealth properties, as well as to control the particle dimensions to manipulate diffusion and penetration properties. Moreover, emulsion preparation methods are usually simple, economic, robust, and scalable, which makes them suitable for medical applications. In this review, we highlight the potential of emulsion technology in nuclear medicine for developing targeted radionuclide therapies, for use as radiosensitizers, and for application in radiotracer delivery in gamma imaging techniques.

In Vitro and In Vivo Efficacy of Topical Dosage Forms Containing Self-Nanoemulsifying Drug Delivery System Loaded with Curcumin

The external use of curcumin is rare, although it can be a valuable active ingredient in the treatment of certain inflammatory diseases. The aim of our experimental work was to formulate topical dosage forms containing curcumin for the treatment of atopic dermatitis. Curcumin has extremely poor solubility and bioavailability, so we have tried to increase it with the usage of self-emulsifying drug delivery systems. Creams and gels were formulated using penetration-enhancing surfactants and gelling agents. The release of the drug from the vehicle and its penetration through the membrane were determined using a Franz diffusion cell. An MTT cytotoxicity and in vitro antioxidant assays were performed on HaCaT cell line. The in vivo anti-inflammatory effect of the preparations was tested by measuring rat paw edema. In addition, we examined the degree of inflammation induced by UV radiation after pretreatment with the cream and the gel on rats. For the gels containing SNEDDS, the highest penetration was measured after half an hour, while for the cream, it took one hour to reach the maximum concentration. The gel containing Pemulen TR-1 showed the highest drug release. It was determined that the curcumin-containing preparations can be safely applied on the skin and have antioxidant effects. The animal experiments have proven the effectiveness of curcumin-containing topical preparations.

Lipid-Based Delivery Systems for Flavonoids and Flavonolignans: Liposomes, Nanoemulsions, and Solid Lipid Nanoparticles

Herbal chemicals with a long history in medicine have attracted a lot of attention. Flavonolignans and flavonoids are considered as two classes of the above-mentioned compounds with different functional groups which exhibit several therapeutic capabilities such as antimicrobial, anti-inflammatory, antioxidant, antidiabetic, and anticancer activities. Based on the studies, high hydrophobic properties of the aforementioned compounds limit their bioavailability inside the human body and restrict their wide application. Nanoscale formulations such as solid lipid nanoparticles, liposomes, and other types of lipid-based delivery systems have been introduced to overcome the above-mentioned challenges. This approach allows the aforementioned hydrophobic therapeutic compounds to be encapsulated between hydrophobic structures, resulting in improving their bioavailability. The above-mentioned enhanced delivery system improves delivery to the targeted sites and reduces the daily required dosage. Lowering the required daily dose improves the performance of the drug by diminishing its side effects on non-targeted tissues. The present study aims to highlight the recent improvements in implementing lipid-based nanocarriers to deliver flavonolignans and flavonoids.

The Science of Selecting Excipients for Dermal Self-Emulsifying Drug Delivery Systems

Self-emulsification is considered a formulation technique that has proven capacity to improve oral drug delivery of poorly soluble drugs by advancing both solubility and bioavailability. The capacity of these formulations to produce emulsions after moderate agitation and dilution by means of water phase addition provides a simplified method to improve delivery of lipophilic drugs, where prolonged drug dissolution in the aqueous environment of the gastro-intestinal (GI) tract is known as the rate-limiting step rendering decreased drug absorption. Additionally, spontaneous emulsification has been reported as an innovative topical drug delivery system that enables successful crossing of mucus membranes as well as skin. The ease of formulation generated by the spontaneous emulsification technique itself is intriguing due to the simplified production procedure and unlimited upscaling possibilities. However, spontaneous emulsification depends solely on selecting excipients that complement each other in order to create a vehicle aimed at optimizing drug delivery. If excipients are not compatible or unable to spontaneously transpire into emulsions once exposed to mild agitation, no self-emulsification will be achieved. Therefore, the generalized view of excipients as inert bystanders facilitating delivery of an active compound cannot be accepted when selecting excipients needed to produce self-emulsifying drug delivery systems (SEDDSs). Hence, this review describes the excipients needed to generate dermal SEDDSs as well as self-double-emulsifying drug delivery systems (SDEDDSs); how to consider combinations that complement the incorporated drug(s); and an overview of using natural excipients as thickening agents and skin penetration enhancers.

The protective effects of baicalin for respiratory diseases: an update and future perspectives

Background: Respiratory diseases are common and frequent diseases. Due to the high pathogenicity and side effects of respiratory diseases, the discovery of new strategies for drug treatment is a hot area of research. Scutellaria baicalensis Georgi (SBG) has been used as a medicinal herb in China for over 2000 years. Baicalin (BA) is a flavonoid active ingredient extracted from SBG that BA has been found to exert various pharmacological effects against respiratory diseases. However, there is no comprehensive review of the mechanism of the effects of BA in treating respiratory diseases. This review aims to summarize the current pharmacokinetics of BA, baicalin-loaded nano-delivery system, and its molecular mechanisms and therapeutical effects for treating respiratory diseases.

Method: This review reviewed databases such as PubMed, NCBI, and Web of Science from their inception to 13 December 2022, in which literature was related to “baicalin”, “Scutellaria baicalensis Georgi”, “COVID-19”, “acute lung injury”, “pulmonary arterial hypertension”, “asthma”, “chronic obstructive pulmonary disease”, “pulmonary fibrosis”, “lung cancer”, “pharmacokinetics”, “liposomes”, “nano-emulsions”, “micelles”, “phospholipid complexes”, “solid dispersions”, “inclusion complexes”, and other terms.

Result: The pharmacokinetics of BA involves mainly gastrointestinal hydrolysis, the enteroglycoside cycle, multiple metabolic pathways, and excretion in bile and urine. Due to the poor bioavailability and solubility of BA, liposomes, nano-emulsions, micelles, phospholipid complexes, solid dispersions, and inclusion complexes of BA have been developed to improve its bioavailability, lung targeting, and solubility. BA exerts potent effects mainly by mediating upstream oxidative stress, inflammation, apoptosis, and immune response pathways. It regulates are the NF-κB, PI3K/AKT, TGF-β/Smad, Nrf2/HO-1, and ERK/GSK3β pathways.

Conclusion: This review presents comprehensive information on BA about pharmacokinetics, baicalin-loaded nano-delivery system, and its therapeutic effects and potential pharmacological mechanisms in respiratory diseases. The available studies suggest that BA has excellent possible treatment of respiratory diseases and is worthy of further investigation and development.

Application of Design of Experiments in the Development of Self-Microemulsifying Drug Delivery Systems

Oral delivery has become the route of choice among all other types of drug administrations. However, typical chronic disease drugs are often poorly water-soluble, have low dissolution rates, and undergo first-pass metabolism, ultimately leading to low bioavailability and lack of efficacy. The lipid-based formulation offers tremendous benefits of using versatile excipients and has great compatibility with all types of dosage forms. Self-microemulsifying drug delivery system (SMEDDS) promotes drug self-emulsification in a combination of oil, surfactant, and co-surfactant, thereby facilitating better drug solubility and absorption. The feasible preparation of SMEDDS creates a promising strategy to improve the drawbacks of lipophilic drugs administered orally. Selecting a decent mixing among these components is, therefore, of importance for successful SMEDDS. Quality by Design (QbD) brings a systematic approach to drug development, and it offers promise to significantly improve the manufacturing quality performance of SMEDDS. Furthermore, it could be benefited efficiently by conducting pre-formulation studies integrated with the statistical design of experiment (DoE). In this review, we highlight the recent findings for the development of microemulsions and SMEDDS by using DoE methods to optimize the formulations for drugs in different excipients with controllable ratios. A brief overview of DoE concepts is discussed, along with its technical benefits in improving SMEDDS formulations.

Use of the quantum dot-labeled solid lipid nanoparticles for delivery of streptomycin and hydroxychloroquine: A new therapeutic approach for treatment of intracellular Brucella abortus infection

Brucellosis is considered one of the most important infectious diseases affecting any tissue and organ in the human body. Due to the intracellular pathogenesis of Brucella species, the use of conventional antibiotics for managing chronic brucellosis has several limitations. Therefore, the study focused on the use of solid lipid nanoparticles (SLN) to deliver streptomycin (STR) for intracellular infection, with or without the combination of hydroxychloroquine (HCQ) to evaluate if there might be a boost in the antibiotic effect when using the STR or STR-NPs alone. We used the double emulsion technique to synthesize Nano drug carriers; afterward, the physicochemical characteristics of synthesized Nano drug carriers were determined. The in vitro antibacterial activity of free drugs and Nano drug carriers were evaluated using well diffusion, broth microdilution assays (BMD), and murine macrophage-like cells cell line J774A.1. Additionally, acute and chronic phases of brucellosis were inducted into Wistar rats, and healing capacity of Nano drug carriers on liver and spleen tissues was compared with free drugs. The zeta potential of nanoparticles, means of size, Polydispersity Index (PDI), drugs loading, and encapsulation efficiency were 15.2 mV, 312.5 ± 26 nm, 0.433 ± 0.09, 16.6% and 89.5%, respectively. Well diffusion and BMD methods did not show a significantly differ between free drugs and nano drug carriers. However, the Nano drug carriers remarkably decreased the number of bacteria in the cell line compared to the free drugs. STR/HCQ-SLN enhanced the healing processes of the liver and spleen after brucellosis induction. STR/HCQ-SLN showed better inhibitory effects against the chronic phase of B. abortus infection in comparison to the STR-SLN, but this difference was not statistically significant. Using nanoplatforms to enhance conventional anti-brucellosis agents is promising, green and safe. Due to the continuous release of drugs, drugs increase their accumulation at the site of infection, causing a more significant effect on the chronic and acute phases of brucellosis.

Hydrophobic ion pairing-based self-emulsifying drug delivery systems: a new strategy for improving the therapeutic efficacy of water-soluble drugs

INTRODUCTION

Self-emulsifying drug delivery systems (SEDDS) are formulations consisting of oil phase, emulsifiers, and co-emulsifiers, which can be spontaneously emulsified in the body to form O/W microemulsion. Traditionally, SEDDS are used commercially for the improvement of oral absorption and in vivo performances for poorly water-soluble drugs. However, SEDDS formulations were rarely reported for the delivery of water-soluble drugs. Recent studies have found that SEDDS have the potential for water-soluble macromolecular drugs by the application of the hydrophobic ion pairing (HIP) technology.

AREAS COVERED

This review summarized the characteristics of HIP complexes in SEDDS and introduced their advantages and discussed the future prospects of HIP-based SEDDS in drug delivery.

EXPERT OPINION

Hydrophobic ion pairing (HIP) is a technology that combines lipophilic structures on polar counterions to increase the lipophilicity through electrostatic interaction. Recent studies showed that HIP-based SEDDS offer an effective way to increase the mucosal permeability and improve the chemical stability for antibiotics, proteases, DNA-based drugs, and other water-soluble macromolecular drugs. It is believed that HIP-based SEDDS offer a potential and attractive method capable of delivering hydrophilic macromolecules with ionizable groups for oral administration.

Development of Squalene-Based Oil-in-Water Emulsion Adjuvants Using a Self-Emulsifying Drug Delivery System for Enhanced Antigen-Specific Antibody Titers

INTRODUCTION

A recombinant protein cannot induce sufficient immune response by itself. Various substances, including cytokine and mineral, have been used as adjuvants to enhance the immunogenicity and efficacy of vaccines; however, most of them induce excessive immune responses or exhibit cytotoxicity. In this study, a self-emulsifying drug delivery system (SEDDS), an isotropic mixture of oil, surfactant, and solvent, was designed for oil-in-water emulsions as a non-toxic adjuvant to increase immune response to antigens.

METHODS

Squalene-based oil-in-water emulsions were prepared by SEDDS to assess its value as an adjuvant. Fifteen emulsions (F1-F15) were prepared by stirring two types of surfactants (Span® 85 and Kolliphor® RH40), and squalene and carboxymethyl cellulose (CMC) were added at different ratios. The physical properties and viscosity of the 15 emulsions were evaluated by measuring droplet size, zeta potential, and polydispersity index. The toxic effect of emulsions was assessed by acute toxicity test in mice. Mice were immunized twice with 1:1 mixtures of antigen and adjuvant (15 emulsions, phosphate-buffered saline, and commercial alum-based adjuvant). Antigen-specific antibody titers from immunized mice serum were measured by an indirect enzyme-linked immunosorbent assay.

RESULTS

All emulsions exhibited droplet sizes ranging from 322 to 812 nm and maintained zeta potential values between -30 mV to -10 mV for 4 weeks, indicating good physical stability as a vaccine adjuvant. Additionally, all emulsions were non-toxic, and they induced humoral immunity at a similar level compared to commercial alum-based adjuvant in the first immunization. However, 12% squalene-based oil-in-water emulsion containing 0.5% of ultra-high viscosity CMC (F15) showed significantly higher immune response than a commercial adjuvant in the second immunization.

CONCLUSION

Squalene-based oil-in-water emulsions could be conveniently prepared using SEDDS technique and are non-toxic and stable at room temperature storage. Moreover, squalene-based oil-in-water emulsions show enhanced immune induction with antigen; hence, they can possibly be used as effective adjuvants.

Nanocarrier system: An emerging strategy for bioactive peptide delivery

Compared with small-molecule synthetic drugs, bioactive peptides have desirable advantages in efficiency, selectivity, safety, tolerance, and side effects, which are accepted by attracting extensive attention from researchers in food, medicine, and other fields. However, unacceptable barriers, including mucus barrier, digestive enzyme barrier, and epithelial barrier, cause the weakening or the loss of bioavailability and biostability of bioactive peptides. The nanocarrier system for bioactive peptide delivery needs to be further probed. We provide a comprehensive update on the application of versatile delivery systems for embedding bioactive peptides, including liposomes, polymer nanoparticles, polysaccharides, hydrogels, and self-emulsifying delivery systems, and further clarify their structural characterization, advantages, and disadvantages as delivery systems. It aims to provide a reference for the maximum utilization of bioactive peptides. It is expected to be an effective strategy for improving the bioavailability and biostability of bioactive peptides.

Strategic developments in the drug delivery of natural product dihydromyricetin: applications, prospects, and challenges

Dihydromyricetin (DHM) is an important natural flavonoid that has attracted much attention because of its various functions such as protecting the cardiovascular system and liver, treating cancer and neurodegenerative diseases, and anti-inflammation effect, etc. Despite its great development potential in pharmacy, DHM has some problems in pharmaceutical applications such as low solubility, permeability, and stability. To settle these issues, extensive research has been carried out on its physicochemical properties and dosage forms to produce all kinds of DHM preparations in the past ten years. In addition, the combined use of DHM with other drugs is a promising strategy to expand the application of DHM. However, although invention patents for DHM preparations have been issued in several countries, the current transformation of DHM research results into market products is insufficient. To date, there is still a lack of deep research into the pharmacokinetics, pharmacodynamics, toxicology, and action mechanism of DHM preparations. Besides, preparations for combined therapy of DHM with other drugs are scarcely reported, which necessitates the development of dosage forms for this application. Apart from medicine, the development of DHM in the food industry is also of great potential. Due to its multiple effects and excellent safety, DHM preparations can be developed for functional drinks and foods. Through this review, we hope to draw more attention to the development potential of DHM and the above challenges and provide valuable references for the research and development of other natural products with a similar structure-activity relationship to this drug.

Formulation development, optimization and characterization of Pemigatinib-loaded supersaturable self-nanoemulsifying drug delivery systems

Background

Pemigatinib is a small molecule tyrosine kinase inhibitor of fibroblast growth factor receptor inhibitors. The oral bioavailability of Pemigatinib is constricted due to its limited solubility at physiological pH. It is essential to develop a novel formulation of Pemigatinib to improve the intrinsic solubility and to reduce the pharmacokinetic variability. Self-nanoemulsifying drug delivery system is an effective, smart and more adequate formulation approach for poorly soluble drugs. Different from conventional self-nanoemulsifying drug delivery system, a supersaturable self-nanoemulsifying drug delivery system of Pemigatinib was prepared by using a supersaturation promoter.

Results

Among all the oils, Captex® 300 have shown maximum solubility of Pemigatinib. Considering the solubilization potential and emulsification ability Kolliphor®RH 40 was selected as surfactant. Transcutol®HP was selected as co-surfactant. The composition of oil, surfactant and co-surfactant was identified using phase diagrams and further adjusted by simplex-lattice design. HPMC K4M as precipitation inhibitor at 5% concentration resulted in effective supersaturating with increased self-emulsification time. The droplet of sSNEDDS ranges from 166.78 ± 3.14 to 178.86 ± 1.24 nm with PDI 0.212 – 0.256, which is significantly smaller than that observed with plain SNEDDS. TEM images revealed the spherical shape of the nanodroplets. The final optimized formulation formed spontaneous nanoemulsion within 15 secs when added to physiological fluids. The percent transmittance of the diluted formulation was found to be 99.12 ± 0.46. The viscosity was found to be 574 ± 26 centipoises indicating the good flow ability. FTIR and DSC studies indicated the amorphization of the drug. The dissolution profile of sSNEDDS indicated the faster release of drug compared to both pure drug suspension and SNEDDS formulation. The drug release rate is directly proportional to the concentration of the drug. The drug release from the insoluble matrix is a square root of time-dependent Fickian diffusion process. The formulation was found to be stable and transparent at all pH values and the percent transmittance was more than 95%. Any kind of separation or precipitation was not observed at different temperatures cycles. No significant difference was observed with all the samples exposed at different storage conditions.

Conclusions

This study demonstrated the feasibility of stabilizing and improving the in-vitro performance of self-nanoemulsifying drug delivery systems of Pemigatinib by incorporating HPMC K4M as precipitation inhibitor.

3D printed oral solid dosage form: Modified release and improved solubility

Oral solid dosage form is currently the most common used form of drug. 3D Printing, also known as additive manufacturing (AM), can quickly print customized and individualized oral solid dosage form on demand. Compared with the traditional tablet manufacturing process, 3D Printing has many advantages. By rationally selecting the formulation composition and cleverly designing the printing structure, 3D printing can improve the solubility of the drug and achieve precise modify of the drug release. 3D printed oral solid dosage form, however, still has problems such as limitations in formulation selection. And the selection process of the formulation lacks scientificity and standardization. Structural design of some 3D printing approaches is relatively scarce. This article reviews the formulation selection and structure design of 3D printed oral solid dosage form, providing more ideas for achieving modified drug release and solubility improvement of 3D printed oral solid dosage form through more scientific and extensive formulation selection and more sophisticated structural design.