Lipid microemulsions for improving drug dissolution and oral absorption: physical and biopharmaceutical aspects

Design and Development of a Self-nanoemulsifying Drug Delivery System for Co-delivery of Curcumin and Naringin for Improved Wound Healing Activity in an Animal Model

The present study endeavored to design and develop a self-nanoemulsifying drug delivery system to improve the solubility and dermatological absorption of curcumin and naringin. Curcumin and naringin-loaded self-nanoemulsifying drug delivery system formulations were developed using aqueous phase titration. Phase diagrams were used to pinpoint the self-nanoemulsifying drug delivery system zones. Tween 80 and Labrasol (surfactants), Transcutol (cosurfactant), and cinnamon oil were chosen from a large pool of surfactants, cosurfactants, and oils based on their solubility and greatest nano-emulsion region. Fourier transform infrared spectroscopy, zeta sizer, and atomic force microscopy were used to characterize the optimized formulations and test for dilution and thermodynamic stability. The optimized curcumin-naringin-self-nanoemulsifying drug delivery system demonstrated the following characteristics: polydispersity index (0.412 ± 0.03), % transmittance (97%), particle size (212.5 ± 05 nm), zeta potential (- 25.7 ± 1.80 mV) and having a smooth and spherical droplet shape, as shown by atomic force microscopy. The ability of their combined formulation to cure wounds was tested in comparison to pure curcumin suspension, empty self-nanoemulsifying drug delivery system, and standard fusidic acid. Upon topical administration, the optimized curcumin-naringin-self-nanoemulsifying drug delivery system demonstrated significant wound healing activity in comparison with a pure curcumin suspension, empty self-nanoemulsifying drug delivery system, and standard fusidic acid. Based upon this result, we assume that skin penetration was increased by using the optimized curcumin-naringin-self-nanoemulsifying drug delivery system with enhanced solubility.

Phospholipid Complex Formulation Technology for Improved Drug Delivery in Oncological Settings: a Comprehensive Review

Addressing poor solubility and permeability issues associated with synthetic drugs and naturally occurring active compounds is crucial for improving bioavailability. This review explores the potential of phospholipid complex formulation technology to overcome these challenges. Phospholipids, as endogenous molecules, offer a viable solution, with drugs complexed with phospholipids demonstrating a similar absorption mechanism. The non-toxic and biodegradable nature of the phospholipid complex positions it as an ideal candidate for drug delivery. This article provides a comprehensive exploration of the mechanisms underlying phospholipid complexes. Special emphasis is placed on the solvent evaporation method, with meticulous scrutiny of formulation aspects such as the phospholipid ratio to the drug and solvent. Characterization techniques are employed to understand structural and functional attributes. Highlighting the adaptability of the phospholipid complex, the review discusses the loading of various nanoformulations and emulsion systems. These strategies aim to enhance drug delivery and efficacy in various malignancies, including breast, liver, lung, cervical, and pancreatic cancers. The broader application of the drug phospholipid complex is showcased, emphasizing its adaptability in diverse oncological settings. The review not only explores the mechanisms and formulation aspects of phospholipid complexes but also provides an overview of key clinical studies and patents. These insights contribute to the intellectual and translational advancements in drug phospholipid complexes.

Development of lipid-based SEDDS using digestion products of long-chain triglyceride for high drug solubility: Formulation and dispersion testing

A self-emulsifying drug delivery system (SEDDS) containing long chain lipid digestion products (LDP) and surfactants was developed to increase solubility of two model weakly basic drugs, cinnarizine and ritonavir, in the formulation. A 1:1.2 w/w mixture of glyceryl monooleate (Capmul GMO-50; Abitec) and oleic acid was used as the digestion product, and a 1:1 w/w mixture of Tween 80 and Cremophor EL was the surfactant used. The ratio between LDP and surfactant was 1:1 w/w. Since the commercially available Capmul GMO-50 is not pure monoglyceride and contained di-and-triglycerides, the digestion product used would provide 1:2 stoichiometric molar ratio of monoglyceride and fatty acid after complete digestion in gastrointestinal fluid. Both cinnarizine and ritonavir had much higher solubility in oleic acid (536 and 72 mg/g, respectively) than that in glyceryl monooleate and glyceryl trioleate. Therefore, by incorporating oleic acid in place of glyceryl trioleate in the formulation, the solubility of cinnarizine and ritonavir could be increased by 5-fold and 3.5-fold, respectively, as compared to a formulation without the fatty acid. The formulation dispersed readily in aqueous media, and adding 3 mM sodium taurocholate, which is generally present in GI fluid, remarkably improved the dispersibility of SEDDS and reduced particle size of dispersions. Thus, the use of digestion products of long-chain triglycerides as components of SEDDS can enhance the drug loading of weakly basic compounds and increase dispersibility in GI fluids.

Preparation, characterization, and toxicity evaluation of microemulsion formulation containing prunetin for potential oral applications

Phytochemicals as therapeutic alternatives can have a fundamental impact on the various stages of inflammation and its resolution. Prunetin is a naturally occurring isoflavone and has been claimed to have numerous therapeutic potentials. The objective of this study is preparation, characterization, and toxicity evaluation of microemulsion formulation containing prunetin (PMF) for potential oral applications. With this research, it was targeted to emphasize the way of improving the therapeutic efficacy of natural biomolecules with a nontoxic and effective formulation. In the study, the pseudo-ternary phase diagram was developed and PMF was characterized by conductivity, droplet size, viscosity and pH. Effects against to cytokines (IL-1β and IL-6) and TNF-α levels of the PMF were determined by ELISA technique. Genotoxicity and acute oral toxicity tests were carried out according to OECD guidelines. The results showed that PMF is a colloid system that reduced proinflammatory cytokine levels in LPS-induced macrophage cells compared to the control group. PMF demonstrated no mutagenic activity against TA98, TA100, TA1535, and TA1537 Salmonella strains. The in vivo oral acute toxicity test results indicated that PMF did not show mortality or significant side effects even at 2000 mg/kg bw. This study represents PMF showed a good safety profile in animal study. It is thought that this formulation may have anti-inflammatory potential with further in vivo testing.

Enhancing Oral Bioavailability of Domperidone Maleate: Formulation, In vitro Permeability Evaluation In-caco-2 Cell Monolayers and In situ Rat Intestinal Permeability Studies

BACKGROUND

The domperidone maleate, a lipophilic agent classified as a Biopharmaceutical Classification System Class II substance with weak water solubility. Self- Emulsifying Drug Delivery System is a novel approach to improve water solubility and, ultimately bioavailability of drugs.

OBJECTIVE

This study aimed to develop and characterize new domperidone-loaded self-emulsifying drug delivery systems as an alternative formulation and to evaluate the permeability of domperidone-loaded self-emulsifying drug delivery systems by using Caco-2 cells and via single-pass intestinal perfusion method.

METHODS

Three self-emulsifying drug delivery systems were prepared and characterized in terms of pH, viscosity, droplet size, zeta potential, polydispersity index, conductivity, etc. Each formulation underwent 10, 100, 200, and 500 times dilution in intestinal buffer pH 6.8 and stomach buffer pH 1.2, respectively. Female Sprague Dawley rats were employed for in situ single-pass intestinal perfusion investigations.

RESULTS

Results of the study revealed that the ideal self-emulsifying drug delivery systems formulation showed narrow droplet size, ideal zeta potential, and no conductivity. Additionally, as compared to the control groups, the optimum formulation had better apparent permeability (12.74 ± 0.02×10-4) from Caco-2 cell monolayer permeability experiments. The study also revealed greater Peff values (2.122 ± 0.892×10-4 cm/s) for the optimal formulation from in situ intestinal perfusion analyses in comparison to control groups (Domperidone; 0.802 ± 0.418×10-4 cm/s).

CONCLUSION

To conclude, prepared formulations can be a promising way of oral administration of Biopharmaceutical Classification System Class II drugs.

Preparation of Self-microemulsion Solids of Kaempferia galanga (L.) Volatile Oil and Its Effect on Rats with Gastric Ulcer

Kaempferia galanga volatile oil (KVO), the main effective component of the medicinal plant Kaempferia galanga L., possesses a variety of pharmacological activities such as anti-inflammatory, antioxidant, and anti-angiogenic activities and has therapeutic potential for gastric ulcer (GU). However, poor solubility as well as instability limits the clinical application of KVO. In this study, K. galanga volatile oil self-microemulsion solids (KVO-SSMEDDS) were prepared to improve its bioavailability and stability, and the therapeutic effects were evaluated in a rat model with GU. The ratio of oil phase, emulsifier, and co-emulsifier in the KVO-SMEDDS prescription were optimized by plotting the pseudo-ternary phase diagram with the star point design-response surface method. Based on the optimal prescription, self-microemulsifying drug delivery system (SMEDDS) was prepared as solid particles (S-SMEDDS). The prepared KVO-SSMEDDS had a rounded and non-adhesive appearance, formed an O/W emulsion after dissolution in water, and had a uniform particle size distribution with good stability and solubility. It was administered to GU model animals, and the results showed that a certain dose of KVO-SSMEDDS solution could increase the content of gastric mucosal protective factors PGE2, TGF-α, and EGF in gastric tissues and serum, and the expression of inflammatory factors IL-8 and TNF-α was downregulated. Meanwhile, the expression of the NF-κB/COX-2 pathway proteins was inhibited. In conclusion, the prepared KVO-SSMEDDS has good dispersion, solubility, and stability and has a therapeutic effect on rats with GU.

Current challenges ahead in preparation, characterization, and pharmaceutical applications of nanoemulsions

Nanoemulsions (NEs) are emulsions with particle size of less than around 100 nm. Reviewing the literature, several reports are available on NEs, including preparation, characterization, and applications of them. This review aims to brief challenges that researchers or formulators may encounter when working with NEs. For instance, when selecting NE components and identifying their concentrations, stability and safety of the preparation should be evaluated. When preparing an NE, issues over scale-up of the preparation as well as possible effects of the preparation process on the active ingredient need to be considered. When characterizing the NEs, the two major concerns are accuracy of the method and accessibility of the characterizing instrument. Also a highly efficient NE for clinical use to deliver the active ingredient to the target tissue with maximum safety profile is commonly sought. Throughout the review we also have tried to suggest approaches to overcome the challenges. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Formulation and Evaluation of a Self-Microemulsifying Drug Delivery System of Raloxifene with Improved Solubility and Oral Bioavailability

Poor aqueous solubility and dissolution limit the oral bioavailability of Biopharmaceutics Classification System (BCS) class II drugs. In this study, we aimed to improve the aqueous solubility and oral bioavailability of raloxifene hydrochloride (RLX), a BCS class II drug, using a self-microemulsifying drug delivery system (SMEDDS). Based on the solubilities of RLX, Capryol 90, Tween 80/Labrasol ALF, and polyethylene glycol 400 (PEG-400) were selected as the oil, surfactant mixture, and cosurfactant, respectively. Pseudo-ternary phase diagrams were constructed to determine the optimal composition (Capryol 90/Tween 80/Labrasol ALF/PEG-400 in 150/478.1/159.4/212.5 volume ratio) for RLX-SMEDDS with a small droplet size (147.1 nm) and stable microemulsification (PDI: 0.227). Differential scanning calorimetry and powder X-ray diffraction of lyophilized RLX-SMEDDS revealed the loss of crystallinity, suggesting a molecularly dissolved or amorphous state of RLX in the SMEDDS formulation. Moreover, RLX-SMEDDS exhibited significantly higher saturation solubility and dissolution rate in water, simulated gastric fluid (pH 1.2), and simulated intestinal fluid (pH 6.8) than RLX powder. Additionally, oral administration of RLX-SMEDDS to female rats resulted in 1.94- and 1.80-fold higher area under the curve and maximum plasma concentration, respectively, than the RLX dispersion. Collectively, our findings suggest SMEDDS is a promising oral formulation to enhance the therapeutic efficacy of RLX.

Pentacyclic Triterpenes from Olive Leaves Formulated in Microemulsion: Characterization and Role in De Novo Lipogenesis in HepG2 Cells

Olea europaea L. leaves contain a wide variety of pentacyclic triterpenes (TTPs). TTPs exhibit many pharmacological activities, including antihyperlipidemic effects. Metabolic alterations, such as dyslipidemia, are an established risk factor for hepatocellular carcinoma (HCC). Therefore, the use of TTPs in the adjunctive treatment of HCC has been proposed as a possible method for the management of HCC. However, TTPs are characterized by poor water solubility, permeability, and bioavailability. In this work, a microemulsion (ME) loading a TTP-enriched extract (EXT) was developed, to overcome these limits and obtain a formulation for oral administration. The extract-loaded microemulsion (ME-EXT) was fully characterized, assessing its chemical and physical parameters and release characteristics, and the stability was evaluated for two months of storage at 4 °C and 25 °C. PAMPA (parallel artificial membrane permeability assay) was used to evaluate the influence of the formulation on the intestinal passive permeability of the TTPs across an artificial membrane. Furthermore, human hepatocarcinoma (HepG2) cells were used as a cellular model to evaluate the effect of EXT and ME-EXT on de novo lipogenesis induced by elevated glucose levels. The effect was evaluated by detecting fatty acid synthase expression levels and intracellular lipid accumulation. ME-EXT resulted as homogeneous dispersed-phase droplets, with significantly increased EXT aqueous solubility. Physical and chemical analyses showed the high stability of the formulation over 2 months. The formulation realized a prolonged release of TTPs, and permeation studies demonstrated that the formulation improved their passive permeability. Furthermore, the EXT reduced the lipid accumulation in HepG2 cells by inhibiting de novo lipogenesis, and the ME-EXT formulation enhanced the inhibitory activity of EXT on intracellular lipid accumulation.

D-α-tocopherol polyethylene glycol 1000 succinate-based microemulsion delivery system: Stability enhancement of physicochemical properties of luteolin

In the present study, D-α-Tocopherol polyethylene glycol 1000 succinate-based self-microemulsifying drug delivery systems (TPGS-SMEDDS) were introduced to enhance the solubility and stability of luteolin. The ternary phase diagrams were constructed to obtain the maximum area of microemulsion and suitable formulations of TPGS-SMEDDS. The particle size distribution and polydispersity index of selected TPGS-SMEDDS were analyzed to be less than 100 nm and 0.4, respectively. The thermodynamic stability results suggested that the TPGS-SMEDDS was stable during the heat-cool and freeze-thaw cycle. Moreover, the TPGS-SMEDDS exhibited excellent encapsulation capacity (51.21 ± 4.39 to 85.71 ± 2.40%) and loading efficiency (61.46 ± 5.27 to 102.86 ± 2.88 mg/g) to luteolin. In addition, the TPGS-SMEDDS showed an admirable vitro release ability with a ratio of more than 88.40 ± 1.14% for luteolin in 24 h. Therefore, TPGS-based SMEDDS might provide an effective role for the oral administration of luteolin and holds promise as a potential delivery for poorly soluble bioactive compounds.

Effect of hydrophilic/lipophilic balance on the porogenic properties of non-ionic surfactants for monolith preparation and chromatographic separation

The effect of hydrophilic/lipophilic balance (HLB) of polyoxyethylene ethers of different chain lengths on the microporogenic properties of the Brij surfactants has been studied. The objective of this work is to help better understand the role of each porogen and to set criteria for selecting the proper non-ionic surfactant, based on the HLB value. Seven recipes of different porogen compositions were first prepared and the highest efficiency was achieved using decane/decanol/dodecanol mixture with Brij® 30. Then, four other Brij surfactants covering the entire HLB scale were tested, and the prepared monoliths were characterized by SEM, BET, FT-IR and chromatography. The results showed that increasing the HLB from 9.72 to 18.84 was accompanied by an increase in monolith density and surface areas. The optimum HLB range was found to be 10 to 15. Surfactants of lower HLB formed either nonporous or less efficient columns, while those of higher HLB formed non-permeable columns. Adjusting the HLB was possible by mixing surfactants of different HLB. The prepared monoliths could be used in the isocratic mode with a mobile phase consisting of a mixture of ACN and water (20:80, v/v) at a flow rate of 1.5 μL min^-1 to separate five sulfa drugs. The separation results showed that the elution order of the compounds correlated with their lipophilicity, with sulfamerazine (logp = 0.52) being the first to elute, and sulfaquinoxoline (logp=1.70) being the most retained. The asymmetry factors of the separated compounds ranged between 1.18 and 1.25, and the resolution was found to be in the range 2.92-7.80. The prepared monoliths could be also successfully separate a mixture of four different nonsteroidal anti-inflammatory drugs and a mixture of four benzoic acid derivatives. This work assists in optimizing the surfactant-based porogenic mixture to meet the desired porosity, surface area, morphology and chromatographic separation requirements.

Self-nanoemulsifying formulation for oral delivery of sildenafil: effect on physicochemical attributes and in vivo pharmacokinetics

Sildenafil (SLD) is employed for the management of erectile dysfunction and pulmonary arterial hypertension. It exhibits meagre water solubility and is available in the form of citrate salt hydrate to improve the solubility. However, it still exhibits moderate solubility, high first-pass metabolism, resulting in very less oral bioavailability. The present study demonstrates the preparation of self-nanoemulsifying drug delivery system for augmenting the oral bioavailability of SLD. Oleic acid and Capmul MCM C8 blend (oil phase), Cremophor^® RH40 (surfactant), and Labrafil^® M1944 CS (cosurfactant) were selected as main constituents for making liquid preconcentrate based on the solubility and emulsification study. The preconcentrate upon dilution and emulsification showed droplet size 52.03 ± 13.03 nm, PDI 0.143 ± 0.028, and % transmittance was 99.77 ± 1.86% with SLD load of 40 mg/g of formulation. The prepared formulation was further assessed for stability, in vitro release, Caco-2 cell uptake, and in vivo pharmacokinetic performance. SLD-SNEDDS formulation was found to be robust in terms of stability against several folds dilution in the gastrointestinal tract (GIT), freeze-thaw cycles, and had a storage stability of 3 months at 4 °C and 25 °C. SLD-SNEDDS showed ~4.7-fold and ~5-fold increase in time- and concentration-dependent cellular uptake as against SLD cultured with Caco-2 cells. In vivo pharmacokinetic study revealed ~5.8- and ~2.5-fold increase in AUC_0-∞ values in case of SLD-SNEDDS as against SLD suspension and SLD citrate solution, respectively.

Recent Advances in Improving the Bioavailability of Hydrophobic/Lipophilic Drugs and Their Delivery via Self-Emulsifying Formulations

Formulations based on emulsions for enhancing hydrophobic and lipophilic drug delivery and its bioavailability have attracted a lot of interest. As potential therapeutic agents, they are integrated with inert oils, emulsions, surfactant solubility, liposomes, etc.; drug delivering systems that use emulsion formations have emerged as a unique and commercially achievable accession to override the issue of less oral bioavailability in connection with hydrophobic and lipophilic drugs. As an ideal isotropic oil mixture of surfactants and co-solvents, it self-emulsifies and forms fine oil in water emulsions when acquainted with aqueous material. As droplets rapidly pass through the stomach, fine oil promotes the vast spread of the drug all over the GI (gastrointestinal tract) and conquers the slow disintegration commonly seen in solid drug forms. The current status of advancement in technologies for drug carrying has promulgated the expansion of innovative drug carriers for the controlled release of self-emulsifying pellets, tablets, capsules, microspheres, etc., which got a boost for drug delivery usage with self-emulsification. The present review article includes various kinds of formulations based on the size of particles and excipients utilized in emulsion formation for drug delivery mechanisms and the increase in the bioavailability of lipophilic/hydrophobic drugs in the present time.

Development of SEDDS formulation containing caffeine for dermal delivery

OBJECTIVE

The objective of this work was to develop a self-emulsifying drug delivery system (SEDDS) containing caffeine for the treatment of cellulite.

METHODS

SEDDS were prepared using the solution method. 0.5% (w/v) caffeine was added to the previously selected excipients. The system was characterized by droplet size, zeta potential, emulsification time and long-term stability. In vitro release and skin permeation were investigated using Franz-type diffusion cells. The cytotoxicity was evaluated on normal human keratinocytes.

RESULTS

Caffeine SEDDS were thermodynamically stable, with a zeta potential less than - 22 mV and droplet size around 30 nm, and were long-term stable. The permeation study showed that the formulation promoted caffeine accumulation in the skin layers, suggesting an increase in local circulation. Cytotoxicity studies on HaCaT cells were not conclusive as the surfactant used indicated false-positive results due to its high molar mass.

CONCLUSION

It was possible to obtain a stable SEDDS that could cause an increase in blood flow in the applied area, resulting in cellulite reduction.

Curcumin-loaded microemulsion: formulation, characterization, and in vitro skin penetration

OBJECTIVE

Formulation of curcumin in a microemulsion with a high loading capacity and that favors its penetration into the skin.

SIGNIFICANCE

Take advantage of the properties of microemulsions to promote the penetration of curcumin into the skin, with the aim of enhancing its therapeutic effects.

METHODS

Curcumin was formulated in microemulsions based on oleic acid (oil phase), Tween® 80 (surfactant), and Transcutol^® HP (cosurfactant). The microemulsion formation area was mapped by constructing pseudo-ternary diagrams for surfactant:co-surfactant ratios 1:1, 1:2, and 2:1. Microemulsions were characterized through measurements of specific weight, refractive index, conductivity, viscosity, droplet size, and in vitro skin permeation studies.

RESULTS

Nine microemulsions were prepared and characterized, showing clear, stable formulations with globule size dependent on the proportion of the components. The microemulsion with the highest loading capacity (60 mg/mL), based on Tween^® 80, Transcutol^® HP, oleic acid, and water (40:40:10:10) was able to penetrate the viable epidermis, finding a total amount of curcumin in the receptor medium at 24 h of 10.17 ± 9.7 µg/cm². The distribution of curcumin in the skin, visualized by confocal laser scanning microscopy, showed that the maximum amount was located between 20 and 30 µm.

CONCLUSION

The inclusion of curcumin in a microemulsion allows its passage into and through the skin. The localization of curcumin, especially in the viable epidermis, would be important for those cases where local conditions are sought to be treated.

Success of nano-vaccines against COVID-19: a transformation in nanomedicine

INTRODUCTION

The vaccines being used against COVID-19 are composed of either non-viral or viral nanoparticles (NPs). Nanotechnology-based vaccine technology was studied for its potentially transformative advancement of medicine.

AREAS COVERED

NPs protect the encapsulated mRNA in vaccines, thereby enhancing the stability of the ribonucleic acids and facilitating their intact delivery to their specific targets. Compared to liposomes, lipid nanoparticles (LNPs) are unique and, through their rigid morphology and better cellular penetrability, render enhanced cargo stability. To explore nanotechnology-mediated vaccine delivery and its potential in future pandemics, we assessed articles from various databases, such as PubMed, Embase, and Scopus, including editorial/research notes, expert opinions, and collections of data from several clinical research trials. In the current review, we focus on the nanoparticulate approach of the different SARS-CoV-2 vaccines and explore their success against the pandemic.

EXPERT OPINION

The mRNA-based vaccines, with their tremendous efficacy of ~95% (under phase III-IV clinical trials) and distinct nanocarriers (LNPs), represent a new medical front alongside DNA and siRNA-based vaccines.

Microemulsions Enhance the In Vitro Antioxidant Activity of Oleanolic Acid in RAW 264.7 Cells

Oleanolic acid (OA) is the main triterpenic acid of olive leaves known for numerous pharmacological properties, including antioxidant activity. However, it is poorly soluble in water and consequently with low bioavailability, which limits its pharmacological application. Microemulsions (MEs) are dispersed systems consisting of two immiscible phases that promote rapid solubilization and absorption in the gastrointestinal tract. To improve both solubility and intestinal permeability of this molecule, OA has been formulated in two different microemulsions (ME-1 and ME-2). A solubility screening was carried out to select the ME components, and pseudoternary phase diagrams were constructed to evaluate the region of existence and select the appropriate amount of the constituents. ME-1 was prepared using Capmul PG-8/NF as the oily phase, and Transcutol and Tween 20 (7:3) as surfactants, while ME-2 contained Nigella oil and Isopropil myristate as the oily phase, and Transcutol HP and Cremophor EL (2:1) as surfactants. The OA solubility was increased by 1000-fold and 3000-fold in ME-1-OA and ME-2-OA, respectively. The MEs’ droplet size and the PdI were evaluated, and the stability was assessed for 8 weeks by monitoring chemical and physical parameters. The parallel artificial membrane permeability assay (PAMPA) also demonstrated an enhanced intestinal permeability of both OA formulations compared with free OA. The potential ability of both MEs to enhance the bioactivity of OA against LPS-induced oxidative stress in RAW 264.7 murine macrophages was also investigated. Overall, this study suggests that both MEs promote a bio-enhancement of the protective action of OA against the LPS-induced pro-oxidant stress in macrophages. Overall, this study suggests that MEs could be an interesting formulation to improve OA oral bioavailability with potential clinical applications.

Chemical and Pharmacological Properties of Decoquinate: A Review of Its Pharmaceutical Potential and Future Perspectives

Decoquinate (DQ) is an antimicrobial agent commonly used as a feed additive for birds for human consumption. Its use as an additive is well established, but DQ has the potential for therapy as an antimicrobial drug for veterinary treatment and its optimized derivatives and/or formulations, mainly nanoformulations, have antimicrobial activity against pathogens that infect humans. However, DQ has a high partition coefficient and low solubility in aqueous fluids, and these biopharmaceutical properties have limited its use in humans. In this review, we highlight the antimicrobial activity and pharmacokinetic properties of DQ and highlight the solutions currently under investigation to overcome these drawbacks. A literature search was conducted focusing on the use of decoquinate against various infectious diseases in humans and animals. The search was conducted in several databases, including scientific and patent databases. Pharmaceutical nanotechnology and medicinal chemistry are the tools of choice to achieve human applications, and most of these applications have been able to improve the biopharmaceutical properties and pharmacokinetic profile of DQ. Based on the results presented here, DQ prototypes could be tested in clinical trials for human application in the coming years.

Reduced the Food Effect and Enhanced the Oral Bioavailability of Ivacaftor by Self-Nanoemulsifying Drug Delivery System (SNEDDS) Using a New Oil Phase

Purpose

The purpose of this work was to develop an ivacaftor self-nanoemulsion drug delivery system (IVA-SNEDDS) using the newly developed double headed miscellaneous lipid (DHML) as oil phase to reduce the food effect and inter-individual absorption variability of IVA.

Methods

The lipids with the greatest solubility to IVA were selected as the oil phase of IVA-SNEDDS by saturation solubility method. Then, among different surfactants and co-surfactants, those with good emulsifying ability for the selected oil phase were selected, and the proportion of surfactant and co-surfactant was further selected by pseudo-ternary phase diagram. The prepared IVA-SNEDDS were screened and evaluated in vitro and in beagle dogs.

Results

The optimized IVA-SNEDDS formulation consisting of DHML, Tween 80, and Transcutol HP with the weight ratio of 2:2:1 was physically stable and it was easy to disperse in water, pH 1.2 hydrochloric acid and pH 6.8 phosphate buffer solution, and generated a fine homogeneous nanoemulsion, with mean globule size less than 75 nm regardless of dilution ratio. In vitro drug release studies showed that the drug in IVA-SNEDDS could be completely released in a short time, while the drug release in IVA-suspension was less than 1% at 60 min. In vivo, using IVA-suspension (Fed) as a reference, the relative oral bioavailability of IVA-suspension (Fasted), IVA-SNEDDS (Fasted), and IVA-SNEDDS (Fed) were 23.35%, 153.63%, and 149.89%, respectively. This showed that IVA-SNEDDS could eliminate the positive food effect, improve the oral bioavailability, and reduce the IVA absorption difference between individuals.

Conclusion

As the oil phase of SNEDDS, DHML can significantly improve the drug solubility and drug loading of IVA-SNEDDS. Moreover, DHML was easily emulsified and can effectively form a nanoemulsion in vivo and in vitro. The prepared IVA-SNEDDS can reduce the inter-individual absorption variability of IVA, eliminate its food effect and improve its oral bioavailability.

Temporal evolution of viscoelasticity of soft colloid laden air-water interface: a multiple mode microrheology study

Mechanical properties of particle laden interfaces is crucial for various applications. For water droplets containing soft microgel particles, passive microrheology studies have revealed that the dynamically varying surface area of the evaporating drop results in a viscous to viscoelastic transition along the plane of the interface. However, the behaviour of the medium orthogonal to the interface has been elusive to study using passive microrheology techniques. In this work, we employ optical tweezers and birefringent probe particles to extract the direction-resolved viscoelastic properties of the particle-laden interface. By using special types of birefringent tracer particles, we detect not only the in-plane translational mode but also the out-of-plane translational (perpendicular to the interface) and rotational modes. We first compare different passive methods of probing the viscoelasticity of the microgel laden interface of sessile drop and then study the modes perpendicular to the interface and the out-of-plane rotational mode using optical tweezers based passive microrheology. The viscoelasticity of the interface using two different methods, i.e., multiple-particle tracking passive microrheology using video microscopy and by trapping birefringent tracer particles in optical tweezers, relying on different models are studied and found to exhibit comparable trends. Interestingly, the mode orthogonal to the interface and the rotational mode also show the viscous to viscoelastic transition as the droplet evaporates, but with lesser viscoelasticity during the same evaporation time than the in-plane mode.

Addition of Trans-Resveratrol-Loaded Highly Concentrated Double Emulsion to Yoghurts: Effect on Physicochemical Properties

Trans-resveratrol (RSV) needs to be encapsulated to maintain its beneficial properties on the human body. This is due to its extreme photosensitivity, short biological half-life, and easy oxidation. In this study, the use of double emulsions for RSV encapsulation and their further application on functional yoghurts was studied. Different types of yoghurts were prepared: with and without RSV and with two types of volumetric emulsion formulations (20/80 and 30/70). In order to study the influence of the addition of double emulsions to the physical properties of the prepared yoghurts, they were characterised fresh and after a month under storage at 4 °C, in terms of droplet size, morphology, stability, rheology, texturometry, colorimetry, and antioxidant capacity. Results obtained showed that the presence of emulsion in the yoghurts produced a generalised decrease in the predominant droplet size (from 48 µm to 15-25 µm) and an increase in the stability. Additionally, a predominantly elastic character was observed. The firmness values obtained were very similar for all the yoghurts analysed and did not suffer important modifications with time. A slight colour variation was observed with storage time in the control sample, whereas a more notable variation in the case of emulsion yoghurts was observed. An appreciable increase of the antioxidant capacity of the final functional yoghurt (100 g) was observed when it contained 5-8 mg of RSV. Encapsulated RSV added to yoghurts presented a larger protection against RSV oxidation compared with free RSV, presenting a larger antioxidant inhibition after one month of storage. Moreover, the antioxidant capacity of yoghurts with encapsulated RSV was not affected under storage, since slight reductions (3%) were registered after one month of storage at 4 °C.

Flavonoids as Molecules With Anti-Zika virus Activity

Zika virus (ZIKV) is an arthropod-born virus that is mainly transmitted to humans by mosquitoes of the genus Aedes spp. Since its first isolation in 1947, only a few human cases had been described until large outbreaks occurred on Yap Island (2007), French Polynesia (2013), and Brazil (2015). Most ZIKV-infected individuals are asymptomatic or present with a self-limiting disease and nonspecific symptoms such as fever, myalgia, and headache. However, in French Polynesia and Brazil, ZIKV outbreaks led to the diagnosis of congenital malformations and microcephaly in newborns and Guillain-Barré syndrome (GBS) in adults. These new clinical presentations raised concern from public health authorities and highlighted the need for anti-Zika treatments and vaccines to control the neurological damage caused by the virus. Despite many efforts in the search for an effective treatment, neither vaccines nor antiviral drugs have become available to control ZIKV infection and/or replication. Flavonoids, a class of natural compounds that are well-known for possessing several biological properties, have shown activity against different viruses. Additionally, the use of flavonoids in some countries as food supplements indicates that these molecules are nontoxic to humans. Thus, here, we summarize knowledge on the use of flavonoids as a source of anti-ZIKV molecules and discuss the gaps and challenges in this area before these compounds can be considered for further preclinical and clinical trials.

Nanotechnology Assisted Chemotherapy for Targeted Cancer Treatment: Recent Advances and Clinical Perspectives

Nanotechnology has recently provided exciting platforms in the field of anticancer research with promising potentials for improving drug delivery efficacy and treatment outcomes. Nanoparticles (NPs) possess different advantages over the micro and bulk therapeutic agents, including their capability to carry high payloads of drugs, with prolonged half-life, reduced toxicity of the drugs, and increased targeting efficiency. The wide variety of nanovectors, coupled with different conjugation and encapsulation methods available for different theranostic agents provide promising opportunities to fine-tune the pharmacological properties of these agents for more effective cancer treatment methods. This review discusses applications of NPs-assisted chemotherapy in preclinical and clinical settings and recent advances in design and synthesis of different nanocarriers for chemotherapeutic agents. Moreover, physicochemical properties of different nanocarriers, their impacts on different tumor targeting strategies and effective parameters for efficient targeted drug delivery are discussed. Finally, the current approved NPs-assisted chemotherapeutic agents for clinical applications and under different phases of clinical trials are discussed.

Role of nanotechnology behind the success of mRNA vaccines for COVID-19

The emergency use authorization (EUA) by the US-FDA for two mRNA-based vaccines BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna) has brought hope of addressing the COVID-19 pandemic which has killed more than two million people globally. Nanotechnology has played a significant role in the success of these vaccines. Nanoparticles (NPs) aid in improving stability by protecting the encapsulated mRNA from ribonucleases and facilitate delivery of intact mRNA to the target site. The overwhelming success of these two mRNA based vaccines with ~95% efficacy in phase III clinical trials can be attributed to their unique nanocarrier, the "lipid nanoparticles" (LNPs). LNPs are unique compared with bilayered liposomes and provide improved stability of the cargo, possess rigid morphology, and aid in better cellular penetration. This EUA is a major milestone and showcases the immense potential of nanotechnology for vaccine delivery and for fighting against future pandemics. Currently, these two vaccines are aiding in the alleviation of the COVID-19 health crisis and demonstrate the potential utility of nanomedicine for tackling health problems at the global level.

Saponin surfactants used in drug delivery systems: A new application for natural medicine components

Saponins are a group of compounds widely distributed in the plant kingdom. Due to their amphiphilic characteristic structure, saponins have high surface activity and self-assembly property and can be used as natural biosurfactants. Therefore, saponin has become a potential drug delivery system (DDS) carrier and has attracted the attention of many researchers. Increasing studies have found that when drugs combining with saponins, their solubility or bioavailability are improved. This phenomenon may be due to a synergistic mechanism and provides a potentially novel concept for DDS: saponins may be also used for carrier materials. This review emphasized the molecular characteristics and mechanism of saponins as carriers and the research on the morphology of saponin carriers. Besides, the article also introduced the role and application of saponins in DDS. Although there are still some limitations with the application of saponins such as cost, applicability, and hemolysis, the development of technology and in-depth molecular mechanism research will provide saponins with greater application prospects as DDS carriers.

Self-nanoemulsifying Drug Delivery System: A Versatile Carrier for Lipophilic Drugs

BACKGROUND

Lipid-based systems such as self-nanoemulsifying drug delivery systems (SNEDDS) have resurged the eminence of nanoemulsions and offer many useful drug delivery opportunities. In the modern drug discovery era, there is a constant increase in the number of poorly soluble new chemical entities that suffer from poor and erratic bioavailability problems. The oral route possesses some major disadvantages, such as lack of constant drug levels in plasma, firstpass metabolism, which results in poor bioavailability. To address these problems, various lipidbased therapeutic systems are available from which self-enanoemulsifying systems have the potential to increase the bioavailability of poorly soluble drugs.

METHODS

SNEDDS is the isotropic mixture of oils, surfactant, and co-surfactant having droplet size in the range of 100-200 nm, which spontaneously emulsifies when it contacts with aqueous media in gastrointestinal (G.I) fluid. Various preparative methods are available for SNEDDS, such as high-pressure homogenizer, microfluidization, sonication, phase inversion, and shear state methods. These methods show favorable benefits in drug delivery. Self-nanoemulsifying drug delivery system possesses some disadvantages like precipitation of drug in G.I fluid or possible drug leaving in the capsule dosage form due to incompatibility issues, which can be overcome by more advanced techniques like supersaturated SNEDDS containing a precipitation inhibitor or Solid SNEDDS. These areformulated either through spray drying or using a solid carrier.

CONCLUSION

The lipid-based nanocarrier (SNEDDS) plays a significant role in drug delivery to overcome the poor solubility and oral bioavailability. This review highlights the elaborative aspects of the diverse advantages of SNEDDS based formulations.

Lipid-Based Nanocarriers for Ophthalmic Administration: Towards Experimental Design Implementation

Nanotherapeutics based on biocompatible lipid matrices allow for enhanced solubility of poorly soluble compounds in the treatment of ophthalmic diseases, overcoming the anatomical and physiological barriers present in the eye, which, despite the ease of access, remains strongly protected. Micro-/nanoemulsions, solid lipid nanoparticles (SLN) or nanostructured lipid carriers (NLC) combine liquid and/or solid lipids with surfactants, improving drug stability and ocular bioavailability. Current research and development approaches based on try-and-error methodologies are unable to easily fine-tune nanoparticle populations in order to overcome the numerous constraints of ocular administration routes, which is believed to hamper easy approval from regulatory agencies for these systems. The predictable quality and specifications of the product can be achieved through quality-by-design (QbD) implementation in both research and industrial environments, in contrast to the current quality-by-testing (QbT) framework. Mathematical modelling of the expected final nanoparticle characteristics by variation of operator-controllable variables of the process can be achieved through adequate statistical design-of-experiments (DoE) application. This multivariate approach allows for optimisation of drug delivery platforms, reducing research costs and time, while maximising the understanding of the production process. This review aims to highlight the latest efforts in implementing the design of experiments to produce optimised lipid-based nanocarriers intended for ophthalmic administration. A useful background and an overview of the different possible approaches are presented, serving as a starting point to introduce the design of experiments in current nanoparticle research.

Efficient Treatment of Experimental Cerebral Malaria by an Artemisone-SMEDDS System: Impact of Application Route and Dosing Frequency

Artemisone (ART) has been successfully tested in vitro and in animal models against several diseases. However, its poor aqueous solubility and limited chemical stability are serious challenges. We developed a self-microemulsifying drug delivery system (SMEDDS) that overcomes these limitations. Here, we demonstrate the efficacy of this formulation against experimental cerebral malaria in mice and the impact of its administration using different routes (gavage, intranasal delivery, and parenteral injections) and frequency on the efficacy of the treatment. The minimal effective daily oral dose was 20 mg/kg. We found that splitting a dose of 20 mg/kg ART given every 24 h, by administering two doses of 10 mg/kg each every 12 h, was highly effective and gave far superior results compared to 20 mg/kg once daily. We obtained the best results with nasal treatment; oral treatment was ranked second, and the least effective route of administration was intraperitoneal injection. A complete cure of experimental cerebral malaria could be achieved through choosing the optimal route of application, dose, and dosing interval. Altogether, the developed formulation combines easy manufacturing with high stability and could be a successful and very versatile carrier for the delivery of ART in the treatment of human severe malaria.

Challenges of Dissolution Methods Development for Soft Gelatin Capsules

Recently, the development of soft gelatin capsules (SGCs) dosage forms has attracted a great deal of interest in the oral delivery of poorly water-soluble drugs. This is attributed to the increased number of poorly soluble drugs in the pipeline, and hence the challenges of finding innovative ways of developing bioavailable and stable dosage forms. Encapsulation of these drugs into SGCs is one of the approaches that is utilized to deliver the active ingredients to the systemic circulation to overcome certain formulation hurdles. Once formulated, encapsulated drugs in the form of SGCs require suitable in vitro dissolution test methods to ensure drug product quality and performance. This review focuses on challenges facing dissolution test method development for SGCs. A brief discussion of the physicochemical and formulation factors that affect the dissolution properties of SGCs will be highlighted. Likewise, the influence of cross-linking of gelatin on the dissolution properties of SGCs will also be discussed.

Development of Self-Nanoemulsifying Drug Delivery Systems Containing 4-Allylpyrocatechol for Treatment of Oral Infections Caused by Candida albicans

Clinical use of 4-Allylpyrocatechol (APC), a potential antifungal agent from Piper betle, is limited because of its low water solubility. The current study explores the development of the self-nanoemulsifying drug delivery system (SNEDDS) containing APC (APC-SNEDDS) to enhance APC solubility. Results demonstrated that excipient type and concentration played an important role in the solubility of APC in the obtained SNEEDS. SNEDDS, comprising 20% Miglyol 812N, 30% Maisine 35-1, 40% Kolliphor RH40, and 10% absolute ethanol, provided the highest loading capacity and significantly increased water solubility of APC. Oil-in-water nanoemulsions (NE) with droplet sizes of less than 40 nm and a narrow size distribution were obtained after dispersing this APC-SNEDDS in water. The droplets had a negative zeta potential between -10 and -20 mV. The release kinetics of APC from APC-SNEDDS followed the Higuchi model. The NE containing 1.6 mg APC/mL had effective activity against Candida albicans with dose-dependent killing kinetics and was nontoxic to normal cells. The antifungal potential was similar to that of 1 mg nystatin/mL. These findings suggest that APC-SNEDDS are a useful system to enhance the apparent water solubility of APC and are a promising system for clinical treatment of oral infection caused by C. albicans.

Oral Bioavailability Improvement of Tailored Rosuvastatin Loaded Niosomal Nanocarriers to Manage Ischemic Heart Disease: Optimization, Ex Vivo and In Vivo Studies

Rosuvastatin is an efficient antihyperlipidemic agent; however, being a BCS class II molecule, it shows poor oral bioavailability of < 20%. The present study focused on the improvement of oral bioavailability of rosuvastatin using tailored niosomes. The niosomes were prepared by film hydration method and sonication using cholesterol and Span 40. The Box-Behnken design (BBD) was applied to optimize the size (98 nm) and the entrapment efficacy (77%) of the niosomes by selecting cholesterol at 122 mg, Span 40 at 0.52%, and hydration time at 29.88 min. The transmission electron microscopy image showed spherical shape niosomes with smooth surface without aggregation. The ex vivo intestinal permeability studies showed significant improvement in the rosuvastatin permeation (95.5% after 2 h) using niosomes in comparison to the rosuvastatin suspension (40.1% after 2 h). The in vivo pharmacokinetic parameters in the rat model confirmed the improvement in the oral bioavailability with optimized rosuvastatin loaded niosomes (relative bioavailability = 2.01) in comparison to the rosuvastatin suspension, due to high surface area of niosomes and its lymphatic uptake via transcellular route. In conclusion, the optimized rosuvastatin loaded niosomes offers a promising approach to improve the oral bioavailability of rosuvastatin.

Improved Safety and Anti-Glioblastoma Efficacy of CAT3-Encapsulated SMEDDS through Metabolism Modification

13a-(S)-3-pivaloyloxyl-6,7-dimethoxyphenanthro(9,10-b)-indolizidine (CAT3) is a novel oral anti-glioma pro-drug with a potent anti-tumor effect against temozolomide-resistant glioma. 13a(S)-3-hydroxyl-6,7-dimethoxyphenanthro(9,10-b)-indolizidine (PF403) is the active in vivo lipase degradation metabolite of CAT3. Both CAT3 and PF403 can penetrate the blood-brain barrier to cause an anti-glioma effect. However, PF403, which is produced in the gastrointestinal tract and plasma, causes significant gastrointestinal side effects, limiting the clinical application of CAT3. The objective of this paper was to propose a metabolism modification for CAT3 using a self-microemulsifying drug delivery system (SMEDDS), in order to reduce the generation of PF403 in the gastrointestinal tract and plasma, as well as increase the bioavailability of CAT3 in vivo and the amount of anti-tumor substances in the brain. Thus, a CAT3-loaded self-microemulsifying drug delivery system (CAT3-SMEDDS) was prepared, and its physicochemical characterization was systematically carried out. Next, the pharmacokinetic parameters of CAT3 and its metabolite in the rats' plasma and brain were measured. Furthermore, the in vivo anti-glioma effects and safety of CAT3-SMEDDS were evaluated. Finally, Caco-2 cell uptake, MDCK monolayer cellular transfer, and the intestinal lymphatic transport mechanisms of SMEDDS were investigated in vitro and in vivo. Results show that CAT3-SMEDDS was able to form nanoemulsion droplets in artificial gastrointestinal fluid within 1 min, displaying an ideal particle size (15-30 nm), positive charge (5-9 mV), and controlled release behavior. CAT3-SMEDDS increased the membrane permeability of CAT3 by 3.9-fold and promoted intestinal lymphatic transport. Hence, the bioavailability of CAT3 was increased 79% and the level of its metabolite, PF403, was decreased to 49%. Moreover, the concentrations of CAT3 and PF403 were increased 2-6-fold and 1.3-7.2-fold, respectively, in the brain. Therefore, the anti-glioma effect in the orthotopic models was improved with CAT3-SMEDDS compared with CAT3 in 21 days. Additionally, CAT3-SMEDDS reduced the gastrointestinal side effects of CAT3, such as severe diarrhea, necrosis, and edema, and observed less inflammatory cell infiltration in the gastrointestinal tract, compared with the bare CAT3. Our work reveals that, through the metabolism modification effect, SMEDDS can improve the bioavailability of CAT3 and reduce the generation of PF403 in the gastrointestinal tract and plasma. Therefore, it has the potential to increase the anti-glioma effect and reduce the gastrointestinal side effects of CAT3 simultaneously.

Oral self-nanoemulsifying formulation of GLP-1 agonist peptide exendin-4: development, characterization and permeability assesment on Caco-2 cell monolayer

The objective of this study was to prepare a stable self-nanoemulsifying formulation of exendin-4, which is an antidiabetic peptide. As exendin-4 is commercially available only in subcutaneous form, several attempts have been made to discover an effective oral formulation. Self-nanoemulsifying drug delivery systems are known to be suitable carriers for the oral administration of peptide drugs. Various ratios of oil, surfactant, and co-surfactant mixtures were used to determine the area in the pseudoternary phase diagram for clear nanoemulsion. The Design of Experiment approach was used for the optimization of the formulation. Blank self-nanoemulsifying formulations containing ethyl oleate as oil phase, Cremophor EL^®, and Labrasol^® as surfactant, absolute ethanol, and propylene glycol as co-solvent in various proportions were approximately 18-50 nm, 0.08-0.204 and - 3 to - 23 mV in droplet size, polydispersity index, and zeta potential, respectively. When all formulations were compared by statistical analysis, five of them with smaller droplet sizes were selected for further studies. The physical stability test was performed for 1 month at 5 °C ± 3 °C and 25 °C ± 2 °C/60% RH ± 5% RH storage conditions. As a result of the characterization and physical stability test results, ethyl oleate: Cremophor EL^®:absolute ethanol (30:52.5:17.5) formulation and four formulations containing ethyl oleate: Cremophor EL^®:Labrasol^®:propylene glycol:absolute ethanol at varying concentrations were considered for peptide encapsulation efficiency. Formulation having the highest encapsulation efficiency of exendin-4 containing ethyl oleate: Cremophor EL^®:Labrasol^®:propylene glycole:absolute ethanol (15:42.5:21.25:15.94:5.31) was selected for in vitro Caco-2 intestinal permeability study. The permeabiliy coefficient was increased by 1.5-folds by exendin-4-loaded self-nanoemulsifying formulation as compared to the exendin-4 solution. It can be concluded that intestinal permeability has been improved by self-nanoemulsifying formulation.

Recent Advances in Oral Nano-Antibiotics for Bacterial Infection Therapy

Bacterial infections are the main infectious diseases and cause of death worldwide. Antibiotics are used to treat various infections ranging from minor to life-threatening ones. The dominant route to administer antibiotics is through oral delivery and subsequent gastrointestinal tract (GIT) absorption. However, the delivery efficiency is limited by many factors such as low drug solubility and/or permeability, gastrointestinal instability, and low antibacterial activity. Nanotechnology has emerged as a novel and efficient tool for targeting drug delivery, and a number of promising nanotherapeutic strategies have been widely explored to overcome these obstacles. In this review, we explore published studies to provide a comprehensive understanding of the recent progress in the area of orally deliverable nano-antibiotic formulations. The first part of this article discusses the functions and underlying mechanisms by which nanomedicines increase the oral absorption of antibiotics. The second part focuses on the classification of oral nano-antibiotics and summarizes the advantages, disadvantages and applications of nanoformulations including lipid, polymer, nanosuspension, carbon nanotubes and mesoporous silica nanoparticles in oral delivery of antibiotics. Lastly, the challenges and future perspective of oral nano-antibiotics for infection disease therapy are discussed. Overall, nanomedicines designed for oral drug delivery system have demonstrated the potential for the improvement and optimization of currently available antibiotic therapies.

Therapeutic Nanoemulsion: Concept to Delivery

Nanoemulsions (NEs) or nanometric-scaled emulsions are transparent or translucent, optically isotropic and kinetically stable heterogeneous system of two different immiscible liquids namely, water and oil stabilized with an amphiphilic surfactant having droplet size ranges up to 100 nm. They offer a variety of potential interests for certain applications: improved deep-rooted stability; excellent optical clarity; and, enhanced bioavailability due to its nanoscale of particles. Though there is still comparatively narrow insight apropos design, development, and optimization of NEs, which mainly stems from the fact that conventional characteristics of emulsion development and stabilization only partly apply to NEs. The contemporary article focuses on the nanoemulsion dosage form journey from concept to key application in drug delivery. In addition, industrial scalability of the nanoemulsion, as well as its presence in commercial and clinical practice, are also addressed.

Abdulbaqi I, Seok Ming T, Siok Yee C, A. Wahab H, Asif SM, Darwis Y. Liquid and Solid Self-Emulsifying Drug Delivery Systems (SEDDs) as Carriers for the Oral Delivery of Azithromycin: Optimization, In Vitro Characterization and Stability Assessment

Azithromycin (AZM) is a macrolide antibiotic used for the treatment of various bacterial infections. The drug is known to have low oral bioavailability (37%) which may be attributed to its relatively high molecular weight, low solubility, dissolution rate, and incomplete intestinal absorption. To overcome these drawbacks, liquid (L) and solid (S) self-emulsifying drug delivery systems (SEDDs) of AZM were developed and optimized. Eight different pseudo-ternary diagrams were constructed based on the drug solubility and the emulsification studies in various SEDDs excipients at different surfactant to co-surfactant (Smix) ratios. Droplet size (DS) < 150 nm, dispersity (Đ) ≤ 0.7, and transmittance (T)% > 85 in three diluents of distilled water (DW), 0.1 mM HCl, and simulated intestinal fluids (SIF) were considered as the selection criteria. The final formulations of L-SEDDs (L-F1(H)), and S-SEDDs (S-F1(H)) were able to meet the selection requirements. Both formulations were proven to be cytocompatible and able to open up the cellular epithelial tight junctions (TJ). The drug dissolution studies showed that after 5 min > 90% and 52.22% of the AZM was released from liquid and solid SEDDs formulations in DW, respectively, compared to 11.27% of the pure AZM, suggesting the developed SEDDs may enhance the oral delivery of the drug. The formulations were stable at refrigerator storage conditions.

Lipid-nanopotentiated combinatorial delivery of tamoxifen and sulforaphane: ex vivo, in vivo and toxicity studies

Aim: This study aims to load tamoxifen (TAM) and sulforaphane (SFN) into nanostructured lipid carriers (NLCs) to enhance their oral delivery. Materials & methods: TAM-SFN-NLCs were prepared using Precirol® ATO5 and Transcutol® HP, characterized and evaluated in vitro and ex vivo to assess the drug release profile and intestinal permeability, respectively. In vivo pharmacokinetic and acute toxicity assessment was performed in Wistar rats. Results: Optimized TAM-SFN-NLCs exhibited a particle size of 121.9 ± 6.42 nm and zeta potential of -21.2 ± 2.91 mV. The NLCs enhanced intestinal permeability of TAM and SFN and augmented oral bioavailability of TAM and SFN 5.2-fold and 4.8-fold, respectively. SFN significantly reduced TAM-associated toxicity in vivo. Conclusion: This coencapsulation of a chemotherapeutic agent with a herbal bioactive in NLCs could pave a novel treatment approach against cancer.