Self-Nano-Emulsifying Drug-Delivery Systems: From the Development to the Current Applications and Challenges in Oral Drug Delivery

Quality by design aided self-nano emulsifying drug delivery systems development for the oral delivery of Benidipine: Improvement of biopharmaceutical performance

The primary objective of the research effort is to establish efficient solid self-nanoemulsifying drug delivery systems (S-SNEDDS) for benidipine (BD) through the systematic application of a quality-by-design (QbD)-based paradigm. Utilizing Labrafil M 2125 CS, Kolliphor EL, and Transcutol P, the BD-S-SNEDDS were created. The central composite design was adopted to optimize numerous components. Zeta potential, drug concentration, resistance to dilution, pH, refractive index, viscosity, thermodynamic stability, and cloud point were further investigated in the most efficient formulation, BD14, which had a globule size of 156.20 ± 2.40 nm, PDI of 0.25, zeta potential of -17.36 ± 0.18 mV, self-emulsification time of 65.21 ± 1.95 s, % transmittance of 99.80 ± 0.70%, and drug release of 92.65 ± 1.70% at 15 min. S-SNEDDS were formulated using the adsorption process and investigated via Fourier transform infrared spectroscopy, Differential scanning calorimeter, Scanning electron microscopy, and powder X-ray diffraction. Optimized S-SNEDDS batch BD14 dramatically decreased blood pressure in rats in contrast to the pure drug and the commercial product, according to a pharmacodynamics investigation. Accelerated stability tests validated the product's stability. Therefore, the development of oral S-SNEDDS of BD may be advantageous for raising BD's water solubility and expanding their releasing capabilities, thereby boosting oral absorption.

Antiretroviral action of Rosemary oil-based atazanavir formulation and the role of self-nanoemulsifying drug delivery system in the management of HIV-1 infection

Atazanavir or ATV is an FDA-approved, HIV-1 protease inhibitor that belongs to the azapeptide group. Over time, it has been observed that ATV can cause multiple adverse side effects in the form of liver diseases including elevations in serum aminotransferase, indirect hyper-bilirubinemia, and idiosyncratic acute liver injury aggravating the underlying chronic viral hepatitis. Hence, there is an incessant need to explore the safe and efficacious method of delivering ATV in a controlled manner that may reduce the proportion of its idiosyncratic reactions in patients who are on antiretroviral therapy for years. In this study, we assessed ATV formulation along with Rosemary oil to enhance the anti-HIV-1 activity and its controlled delivery through self-nanoemulsifying drug delivery system or SNEDDS to enhance its oral bioavailability. While the designing, development, and characterization of ATV-SNEDDS were addressed through various evaluation parameters and pharmacokinetic-based studies, in vitro cell-based experiments assured the safety and efficacy of the designed ATV formulation. The study discovered the potential of ATV-SNEDDS to inhibit HIV-1 infection at a lower concentration as compared to its pure counterpart. Simultaneously, we could also demonstrate the ATV and Rosemary oil providing leads for designing and developing such formulations for the management of HIV-1 infections with the alleviation in the risk of adverse reactions.

Self-Nanoemulsifying Drug Delivery System (SNEDDS) Using Lipophilic Extract of Viscum album subsp. austriacum (Wiesb.) Vollm

Background and Purpose

Natural products are potential sources of anticancer components. Among various species, the lipophilic extract of the Viscum album subsp. austriacum (Wiesb.) Vollm. (VALE) has shown promising therapeutic potential. The present work aimed to qualify the plant source and characterize the extract's chemical profile. In addition, a self-nanoemulsifying drug delivery system (SNEDDS) containing VALE (SNEDDS-VALE) was developed.

Methods

V. album subsp. austriacum histochemistry was performed, and the chemical profile of VALE was analyzed by GC-MS. After the SNEEDS-VALE development, its morphology was visualized by transmission electron microscopy (TEM), while its stability was evaluated by the average droplet size, polydispersity index (PdI) and pH. Lastly, SNEDDS-VALE chemical stability was evaluated by LC-DAD-MS.

Results

The histochemical analysis showed the presence of lipophilic compounds in the leaves and stems. The major compound in the VALE was oleanolic acid, followed by lupeol acetate and ursolic acid. SNEDDS was composed of medium chain triglyceride and Kolliphor® RH 40 (PEG-40 hydrogenated castor oil). A homogeneous, isotropic and stable nanoemulsion was obtained, with an average size of 36.87 ± 1.04 nm and PdI of 0.14 ± 0.02, for 14 weeks.

Conclusion

This is the first histochemistry analysis of V. album subsp. austriacum growing on Pinus sylvestris L. which provided detailed information regarding its lipophilic compounds. A homogeneous, isotropic and stable SNEDDS-VALE was obtained to improve the low water solubility of VALE. Further, in vitro and in vivo experiments should be performed, in order to evaluate the antitumoral potential of SNEDDS-VALE.

Modified Release 3D-Printed Capsules Containing a Ketoprofen Self-Nanoemulsifying System for Personalized Medical Application

This study explores the realm of personalized medicine by investigating the utilization of 3D-printed dosage forms, specifically focusing on patient-specific enteric capsules designed for the modified release of ketoprofen, serving as a model drug. The research investigates two distinct scenarios: the modification of drug release from 3D-printed capsules crafted from hydroxypropyl methylcellulose phthalate:polyethylene glycol (HPMCP:PEG) and poly(vinyl alcohol) (PVA), tailored for pH sensitivity and delayed release modes, respectively. Additionally, a novel ketoprofen-loaded self-nanoemulsifying drug delivery system (SNEDDS) based on pomegranate seed oil (PSO) was developed, characterized, and employed as a fill material for the capsules. Through the preparation and characterization of the HPMCP:PEG based filament via the hot-melt extrusion method, the study thoroughly investigated its thermal and mechanical properties. Notably, the in vitro drug release analysis unveiled the intricate interplay between ketoprofen release, polymer type, and capsule thickness. Furthermore, the incorporation of ketoprofen into the SNEDDS exhibited an enhancement in its in vitro cylooxygenase-2 (COX-2) inhibitory activity. These findings collectively underscore the potential of 3D printing in shaping tailored drug delivery systems, thereby contributing significantly to the advancement of personalized medicine.

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.

Solubility enhancement of fexofenadine using self-nano emulsifying drug delivery system for improved biomimetic attributes

BACKGROUND

Fexofenadine is a poorly water-soluble drug, which limit its bioavailability and ultimately therapeutic efficacy. Liquid self-nano emulsifying drug delivery system (L-SNEDDs) is an approach that can enhance the solubility of fexofenadine by increasing its surface area and reducing the particle size, which increases the rate and extent of drug dissolution.

METHOD

In this investigation, L-SNEDDs of fexofenadine was made up using surfactants and co-surfactant. The SNEDDS formulation was optimized using a pseudo-ternary phase diagram and characterized.

RESULTS

The optimized L-SNEDDS incorporated fexofenadine were thermodynamically stable and showed mean droplet size and zeta potential of 155nm and -18mV, respectively unaffected by the media pH. In addition, the viscosity, and refractive index were observed 18.4 and 1.49 cps, respectively for optimized L-SNEDDS fortified fexofenadine. The results of Fourier transform infrared spectroscopy revealed an insignificant interaction between the fexofenadine and excipients. A drug loading efficiency of 94.20% resulted with a complete in vitro drug release in 2h, compared with the pure drug, which demonstrate significant improvement in the efficacy. Moreover, these results signify that on further in vivo assessment L-SNEDDS fortified fexofenadine can indicate improvement in pharmacokinetic and clinical outcome.

CONCLUSION

Thus, the investigation revealed that, the L-SNEDDs incorporated fexofenadine was most effective with a mixture of surfactant and co-surfactant with improved solubility intend to relieve pain associated with inflammation with single-dose oral administration.

Polysaccharides as a Hydrophilic Building Block of Amphiphilic Block Copolymers for the Conception of Nanocarriers

Polysaccharides are gaining increasing attention for their relevance in the production of sustainable materials. In the domain of biomaterials, polysaccharides play an important role as hydrophilic components in the design of amphiphilic block copolymers for the development of drug delivery systems, in particular nanocarriers due to their outstanding biocompatibility, biodegradability, and structural versatility. The presence of a reducing end in polysaccharide chains allows for the synthesis of polysaccharide-based block copolymers. Compared with polysaccharide-based graft copolymers, the structure of block copolymers can be more precisely controlled. In this review, the synthesis methods of polysaccharide-based amphiphilic block copolymers are discussed in detail, taking into consideration the structural characteristics of polysaccharides. Various synthetic approaches, including reductive amination, oxime ligation, and other chain-end modification reactions, are explored. This review also focuses on the advantages of polysaccharides as hydrophilic blocks in polymeric nanocarriers. The structure and unique properties of different polysaccharides such as cellulose, hyaluronic acid, chitosan, alginate, and dextran are described along with examples of their applications as hydrophilic segments in the synthesis of amphiphilic copolymers to construct nanocarriers for sustained drug delivery.

Self-Nanoemulsion Intrigues the Gold Phytopharmaceutical Chrysin: In Vitro Assessment and Intrinsic Analgesic Effect

Chrysin is a natural flavonoid with a wide range of bioactivities. Only a few investigations have assessed the analgesic activity of chrysin. The lipophilicity of chrysin reduces its aqueous solubility and bioavailability. Hence, self-nanoemulsifying drug delivery systems (SNEDDS) were designed to overcome this problem. Kollisolv GTA, Tween 80, and Transcutol HP were selected as oil, surfactant, and cosurfactant, respectively. SNEDDS A, B, and C were prepared, loaded with chrysin (0.1%w/w), and extensively evaluated. The optimized formula (B) encompasses 25% Kollisolv GTA, 18.75% Tween 80, and 56.25% Transcutol HP was further assessed. TEM, in vitro release, and biocompatibility towards the normal oral epithelial cell line (OEC) were estimated. Brain targeting and acetic acid-induced writhing in a mouse model were studied. After testing several adsorbents, powdered SNEDDS B was formulated and evaluated. The surfactant/cosurfactant (S/CoS) ratio of 1:3 w/w was appropriate for the preparation of SNEDDS. Formula B exhibited instant self-emulsification, spherical nanoscaled droplets of 155.4 ± 32.02 nm, and a zeta potential of - 12.5 ± 3.40 mV. The in vitro release proved the superiority of formula B over chrysin suspension (56.16 ± 10.23 and 9.26 ± 1.67%, respectively). The biocompatibility of formula B towards OEC was duplicated (5.69 ± 0.03 µg/mL). The nociceptive pain was mitigated by formula B more efficiently than chrysin suspension as the writhing numbers reduced from 8.33 ± 0.96 to 0 after 60 min of oral administration. Aerosil R972 was selected as an adsorbent, and its chemical compatibility was confirmed. In conclusion, our findings prove the therapeutic efficacy of chrysin self-nanoemulsion as a potential targeting platform to combat pain.

Enhanced Stability and Improved Oral Absorption of Enzalutamide with Self-Nanoemulsifying Drug Delivery System

The purpose of this study is to develop and evaluate a self-nanoemulsifying drug delivery system (SNEDDS) to improve the oral absorption of poorly water-soluble enzalutamide (ENZ). Considering the rapid recrystallization of the drug, based on solubility and crystallization tests in various oils, surfactants and co-surfactants, Labrafac PG 10%, Solutol HS15 80%, and Transcutol P 10%, which showed the most stable particle size and polydispersity index (PDI) without drug precipitation, were selected as the optimal SNEDDS formulation. The optimized SNEDDS formulation showed excellent dissolution profiles for all the drugs released at 10 min of dissolution due to the increased surface area with a small particle size of approximately 16 nm. Additionally, it was confirmed to be stable without significant differences in physical and chemical properties for 6 months under accelerated conditions (40 ± 2 °C, 75 ± 5% RH) and stressed conditions (60 ± 2 °C). Associated with the high dissolutions of ENZ, pharmacokinetic parameters were also greatly improved. Specifically, the AUC was 1.9 times higher and the Cmax was 1.8 times higher than those of commercial products (Xtandi® soft capsule), resulting in improved oral absorption. Taken together with the results mentioned above, the SNEDDS could be an effective tool as a formulation for ENZ and other similar drugs.

Curcumin-loaded nanostructured systems for treatment of leishmaniasis: a review

Leishmaniasis is a neglected tropical disease that has affected more than 350 million people worldwide and can manifest itself in three different forms: cutaneous, mucocutaneous, or visceral. Furthermore, the current treatment options have drawbacks which compromise efficacy and patient compliance. To face this global health concern, new alternatives for the treatment of leishmaniasis have been explored. Curcumin, a polyphenol obtained from the rhizome of turmeric, exhibits leishmanicidal activity against different species of Leishmania spp. Although its mechanism of action has not yet been fully elucidated, its leishmanicidal potential may be associated with its antioxidant and anti-inflammatory properties. However, it has limitations that compromise its clinical use. Conversely, nanotechnology has been used as a tool for solving biopharmaceutical challenges associated with drugs, such as curcumin. From a drug delivery standpoint, nanocarriers (1-1000 nm) can improve stability, increase solubility, promote intracellular delivery, and increase biological activity. Thus, this review offers a deep look into curcumin-loaded nanocarriers intended for the treatment of leishmaniasis.

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.

Future Nanotechnology-Based Strategies for Improved Management of Helicobacter pylori Infection

Helicobacter pylori (H. pylori) is a recalcitrant pathogen, which can cause gastric disorders. During the past decades, polypharmacy-based regimens, such as triple and quadruple therapies have been widely used against H. pylori. However, polyantibiotic therapies can disturb the host gastric/gut microbiota and lead to antibiotic resistance. Thus, simpler but more effective approaches should be developed. Here, some recent advances in nanostructured drug delivery systems to treat H. pylori infection are summarized. Also, for the first time, a drug release paradigm is proposed to prevent H. pylori antibiotic resistance along with an IVIVC model in order to connect the drug release profile with a reduction in bacterial colony counts. Then, local delivery systems including mucoadhesive, mucopenetrating, and cytoadhesive nanobiomaterials are discussed in the battle against H. pylori infection. Afterward, engineered delivery platforms including polymer-coated nanoemulsions and polymer-coated nanoliposomes are poposed. These bioinspired platforms can contain an antimicrobial agent enclosed within smart multifunctional nanoformulations. These bioplatforms can prevent the development of antibiotic resistance, as well as specifically killing H. pylori with no or only slight negative effects on the host gastrointestinal microbiota. Finally, the essential checkpoints that should be passed to confirm the potential effectiveness of anti-H. pylori nanosystems are discussed.

Statistically Optimized Polymeric Buccal Films of Eletriptan Hydrobromide and Itopride Hydrochloride: An In Vivo Pharmacokinetic Study

A migraine is a condition of severe headaches, causing a disturbance in the daily life of the patient. The current studies were designed to develop immediate-release polymeric buccal films of Eletriptan Hydrobromide (EHBR) and Itopride Hydrochloride (ITHC) to improve their bioavailability and, hence, improve compliance with the patients of migraines and its associated symptoms. The prepared films were evaluated for various in vitro parameters, including surface morphology, mechanical strength, disintegration test (DT), total dissolving time (TDT), drug release and drug permeation, etc., and in vivo pharmacokinetic parameters, such as area under curve (AUC), mean residence time (MRT), half-life (t1/2), time to reach maximum concentration (Tmax), and time to reach maximum concentration (Cmax). The outcomes have indicated the successful preparation of the films, as SEM has confirmed the smooth surface and uniform distribution of drugs throughout the polymer matrix. The films were found to be mechanically stable as indicated by folding endurance studies. Furthermore, the optimized formulations showed a DT of 13 ± 1 s and TDT of 42.6 ± 0.75 s, indicating prompt disintegration as well as the dissolution of the films. Albino rabbits were used for in vivo pharmacokinetics, and the outcomes were evident of improved pharmacokinetics. The drug was found to rapidly permeate across the buccal mucosa, leading to increased bioavailability of the drug: Cmax of 130 and 119 ng/mL of ITHC and EHBR, respectively, as compared to 96 (ITHC) and 90 ng/mL (EHBR) of oral solution. The conclusion can be drawn that possible reasons for the enhanced bioavailability could be the increased surface area in the form of buccal films, its rapid disintegration, and faster dissolution, which led toward the rapid absorption of the drug into the blood stream.

Development and Evaluation of a Self-Nanoemulsifying Drug Delivery System for Sinapic Acid with Improved Antiviral Efficacy against SARS-CoV-2

This study aimed to develop a self-nanoemulsifying drug delivery system (SNE) for sinapic acid (SA) to improve its solubility and antiviral activity. Optimal components for the SA-SNE formulation were selected, including Labrafil as the oil, Cremophor EL as the surfactant, and Transcutol as the co-surfactant. The formulation was optimized using surface response design, and the optimized SA-SNE formulation exhibited a small globule size of 83.6 nm, high solubility up to 127.1 ± 3.3, and a 100% transmittance. In vitro release studies demonstrated rapid and high SA release from the formulation. Pharmacokinetic analysis showed improved bioavailability by 2.43 times, and the optimized SA-SNE formulation exhibited potent antiviral activity against SARS-CoV-2. The developed SA-SNE formulation can enhance SA's therapeutic efficacy by improving its solubility, bioavailability, and antiviral activity. Further in silico, modeling, and Gaussian accelerated molecular dynamics (GaMD)-based studies revealed that SA could interact with and inhibit the viral main protease (Mpro). This research contributes to developing effective drug delivery systems for poorly soluble drugs like SA, opening new possibilities for their application via nebulization in SARS-CoV-2 therapy.

Self-nanoemulsifying drug delivery system (SNEDDS) of docetaxel and carvacrol synergizes the anticancer activity and enables safer toxicity profile: optimization, and in-vitro, ex-vivo and in-vivo pharmacokinetic evaluation

Docetaxel (DTX) is a first-line chemotherapeutic molecule with a broad-spectrum anticancer activity. On the other hand, carvacrol (CV) has anti-inflammatory, antioxidant, cytotoxic, and hepatoprotective properties that could reduce undue toxicity caused by DTX chemotherapy. Thus, in order to overcome the challenges posed by DTX's poor aqueous solubility, low permeability, hepatic first pass, and systemic toxicities, we have developed a novel solid self-nanoemulsifying drug delivery system (S-SNEDDS) co-loaded with DTX and CV. In the present investigation, liquid-SNEDDS (L-SNEDDS) were fabricated using Nigella sativa oil, Cremophor RH 40, and Ethanol which was converted into solid by lyophilization using Aerosil 200. The reconstituted CV-DTX-S-SNEDDS showed an average globule size of < 200 nm with promising flow properties (angle of repose θ: 33.22 ± 0.06). Additionally, 2.3-fold higher dissolution of DTX was observed from CV-DTX-S-SNEDDS after 6 h as compared to free DTX. Similar trend was followed in dialysis release experiments with 1.5-fold higher release within 24 h. Ex vivo permeation studies demonstrated significantly increased permeation of 1077.02 ± 12.72 μg/cm2 of CV-DTX-S-SNEDDS after 12 h. In vitro cell cytotoxicity studies revealed 5.2-fold reduction in IC50 as compared to free DTX in MDA-MB-231 cells. Formulation was able to induce higher apoptosis in cells treated with CV-DTX-S-SNEDDS as compared to free DTX and CV. It was evident from toxicity studies that CV-DTX-S-SNEDDS was well tolerated at higher dose where CV was able to manage the toxic effects of free DTX. In vivo pharmacokinetic study showed 3.4-fold increased Cmax and improved oral bioavailability as compared to free DTX. Thus, CV-DTX-S-SNEDDS could be an encouraging option for facilitating DTX oral therapy.

Emerging Applications of Nanotechnology in Healthcare and Medicine

Knowing the beneficial aspects of nanomedicine, scientists are trying to harness the applications of nanotechnology in diagnosis, treatment, and prevention of diseases. There are also potential uses in designing medical tools and processes for the new generation of medical scientists. The main objective for conducting this research review is to gather the widespread aspects of nanomedicine under one heading and to highlight standard research practices in the medical field. Comprehensive research has been conducted to incorporate the latest data related to nanotechnology in medicine and therapeutics derived from acknowledged scientific platforms. Nanotechnology is used to conduct sensitive medical procedures. Nanotechnology is showing successful and beneficial uses in the fields of diagnostics, disease treatment, regenerative medicine, gene therapy, dentistry, oncology, aesthetics industry, drug delivery, and therapeutics. A thorough association of and cooperation between physicians, clinicians, researchers, and technologies will bring forward a future where there is a more calculated, outlined, and technically programed field of nanomedicine. Advances are being made to overcome challenges associated with the application of nanotechnology in the medical field due to the pathophysiological basis of diseases. This review highlights the multipronged aspects of nanomedicine and how nanotechnology is proving beneficial for the health industry. There is a need to minimize the health, environmental, and ethical concerns linked to nanotechnology.

Co-Dispersion Delivery Systems with Solubilizing Carriers Improving the Solubility and Permeability of Cannabinoids (Cannabidiol, Cannabidiolic Acid, and Cannabichromene) from Cannabis sativa (Henola Variety) Inflorescences

Cannabinoids: cannabidiol (CBD), cannabidiolic acid (CBDA), and cannabichromene (CBC) are lipophilic compounds with limited water solubility, resulting in challenges related to their bioavailability and therapeutic efficacy upon oral administration. To overcome these limitations, we developed co-dispersion cannabinoid delivery systems with the biopolymer polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol (Soluplus) and magnesium aluminometasilicate (Neusilin US2) to improve solubility and permeability. Recognizing the potential therapeutic benefits arising from the entourage effect, we decided to work with an extract instead of isolated cannabinoids. Cannabis sativa inflorescences (Henola variety) with a confirming neuroprotective activity were subjected to dynamic supercritical CO2 (scCO2) extraction and next they were combined with carriers (1:1 mass ratio) to prepare the co-dispersion cannabinoid delivery systems (HiE). In vitro dissolution studies were conducted to evaluate the solubility of CBD, CBDA, and CBC in various media (pH 1.2, 6.8, fasted, and fed state simulated intestinal fluid). The HiE-Soluplus delivery systems consistently demonstrated the highest dissolution rate of cannabinoids. Additionally, HiE-Soluplus exhibited the highest permeability coefficients for cannabinoids in gastrointestinal tract conditions than it was during the permeability studies using model PAMPA GIT. All three cannabinoids exhibited promising blood-brain barrier (BBB) permeability (Papp higher than 4.0 × 10-6 cm/s), suggesting their potential to effectively cross into the central nervous system. The improved solubility and permeability of cannabinoids from the HiE-Soluplus delivery system hold promise for enhancement in their bioavailability.

Pharmacological studies of the genus rice (Oryza L.): a literature review

Rice (Oryza L.) is an essential food for more than 50 percent of the world's population and is the world's second-largest grain crop. Pigmented rice comes in various colors, such as black, red, brown, and green. Anthocyanins, like cyanidin-3-O-glucoside and peonidin-3-O-glucoside, are the primary color pigments in colored rice, whereas proanthocyanidins and flavan-3-ol oligosaccharides, with catechins as the central synthesis unit, are found in brown rice. This review article's aim is to give information and a summary of rice activities, research methods, also mechanisms of action (Oryza L.). Intake of pigmented rice was already associated with a number of health benefits, including antioxidant activity, anticancer, antitumor, antidiabetic activity, and a reduced risk of cardiovascular disease. Rice contains several bioactive compounds, such as γ-oryzanol, phenolic acid, anthocyanins, proanthocyanidins, flavonoids, carotenoids, and phytosterols, which have been widely studied and shown to have several pharmacological activities. The use of current herbal compounds is rapidly increasing, including the practice of pharmacological disease prevention and treatment. Herbal remedies have entered the international market as a result of research into plant biopharmaceuticals and nutraceuticals. Through a variety of pharmacological activities, it is clear that Oryza L. is a popular herb. As a result, additional research on Oryza L. can be conducted to investigate more recent and comprehensive pharmacological effectiveness, to provide information and an overview of Rice (Oryza L.) activities, research methods, and mechanisms of action. Several natural substances are characterized by low water solubility, low stability, and sensitivity to light and oxygen, and the potential for poor absorption of the active substances requires modification of the formulation. To improve the effectiveness of pharmacologically active substances originating from natural ingredients, drug delivery systems that use lipid-based formulations can be considered innovations.

Comparing PVP and Polymeric Micellar Formulations of a PEGylated Photosensitizing Phthalocyanine by NMR and Optical Techniques

Phthalocyanines are ideal candidates as photosensitizers for photodynamic therapy (PDT) of cancer due to their favorable chemical and photophysical properties. However, their tendency to form aggregates in water reduces PDT efficacy and poses challenges in obtaining efficient forms of phthalocyanines for therapeutic applications. In the current work, polyvinylpyrrolidone (PVP) and micellar formulations were compared for encapsulating and monomerizing a water-soluble zinc phthalocyanine bearing four non-peripheral triethylene glycol chains (Pc1). 1H NMR spectroscopy combined with UV-vis absorption and fluorescence spectroscopy revealed that Pc1 exists as a mixture of regioisomers in monomeric form in dimethyl sulfoxide but forms dimers in an aqueous buffer. PVP, polyethylene glycol castor oil (Kolliphor RH40), and three different triblock copolymers with varying proportions of polyethylene and polypropylene glycol units (termed P188, P84, and F127) were tested as micellar carriers for Pc1. 1H NMR chemical shift analysis, diffusion-ordered spectroscopy, and 2D nuclear Overhauser enhancement spectroscopy was applied to monitor the encapsulation and localization of Pc1 at the polymer interface. Kolliphor RH40 and F127 micelles exhibited the highest affinity for encapsulating Pc1 in the micellar core and resulted in intense Pc1 fluorescence emission as well as efficient singlet oxygen formation along with PVP. Among the triblock copolymers, efficiency in binding and dimer dissolution decreased in the order F127 > P84 > P188. PVP was a strong binder for Pc1. However, Pc1 molecules are rather surface-attached and exist as monomer and dimer mixtures. The results demonstrate that NMR combined with optical spectroscopy offer powerful tools to assess parameters like drug binding, localization sites, and dynamic properties that play key roles in achieving high host-guest compatibility. With the corresponding adjustments, polymeric micelles can offer simple and easily accessible drug delivery systems optimizing phthalocyanines' properties as efficient photosensitizers.

Nanotechnology-based ocular drug delivery systems: recent advances and future prospects

Ocular drug delivery has constantly challenged ophthalmologists and drug delivery scientists due to various anatomical and physiological barriers. Static and dynamic ocular barriers prevent the entry of exogenous substances and impede therapeutic agents' active absorption. This review elaborates on the anatomy of the eye and the associated constraints. Followed by an illustration of some common ocular diseases, including glaucoma and their current clinical therapies, emphasizing the significance of drug therapy in treating ocular diseases. Subsequently, advances in ocular drug delivery modalities, especially nanotechnology-based ocular drug delivery systems, are recommended, and some typical research is highlighted. Based on the related research, systematic and comprehensive characterizations of the nanocarriers are summarized, hoping to assist with future research. Besides, we summarize the nanotechnology-based ophthalmic drugs currently on the market or still in clinical trials and the recent patents of nanocarriers. Finally, inspired by current trends and therapeutic concepts, we provide an insight into the challenges faced by novel ocular drug delivery systems and further put forward directions for future research. We hope this review can provide inspiration and motivation for better design and development of novel ophthalmic formulations.

Nose-to-brain delivery of perampanel formulated in a self-microemulsifying drug delivery system improves anticonvulsant and anxiolytic activity in mice

Perampanel (PER) is a potent third-generation antiepileptic drug only available for oral administration. Additionally, PER has shown potential in managing epilepsy comorbidities such as anxiety. Previously, we demonstrated that the intranasal (IN) administration of PER, loaded in a self-microemulsifying drug delivery system (SMEDDS), improved brain-targeting and exposure in mice. Herein, we investigated PER brain biodistribution, its anticonvulsant and anxiolytic effects, and its potential olfactory and neuromotor toxicity after IN administration to mice (1 mg/kg). PER showed a rostral-caudal brain biodistribution pattern when administered intranasally. At short times post-nasal dosing, high PER concentrations were found in olfactory bulbs (olfactory bulbs/plasma ratios of 1.266 ± 0.183 and 0.181 ± 0.027 after IN and intravenous administrations, respectively), suggesting that a fraction of the drug directly reaches brain through the olfactory pathway. In maximal electroshock seizure test, IN PER protected 60% of mice against seizure development, a substantially higher value than the 20% protected after receiving oral PER. . PER also demonstrated anxiolytic effects in open field and elevated plus maze tests. Buried food-seeking test showed no signs of olfactory toxicity. Neuromotor impairment was found in rotarod and open field tests at the times of PER maximum concentrations after IN and oral administrations. Nevertheless, neuromotor performance was improved after repeated administrations. Compared with IN vehicle, PER IN administration decreased brain levels of L-glutamate (0.91 ± 0.13 mg/mL vs 0.64 ± 0.12 mg/mL) and nitric oxide (100 ± 15.62% vs 56.62 ± 4.95%), without interfering in GABA levels. Altogether, these results suggest that the IN PER delivery through the developed SMEDDS can be a safe and promising alternative to oral treatment, which support the design of clinical studies to evaluate the IN PER delivery to treat epilepsy and neurological-related conditions as anxiety.

Concurrent oral delivery of non-oncology drugs through solid self-emulsifying system for repurposing in hepatocellular carcinoma

OBJECTIVE

Present study aimed to identify a safe and effective non-oncology drug cocktail as an alternative to toxic chemotherapeutics for hepatocellular carcinoma treatment. The assessment of cytotoxicity of cocktail (as co-adjuvant) in combination with chemotherapeutic docetaxel (DTX) is also aimed. Further, we aimed to develop an oral solid self-emulsifying drug delivery system (S-SEDDS) for the simultaneous delivery of identified drugs.

SIGNIFICANCE

The identified non-oncology drug cocktail could overcome the shortage of anticancer therapeutics and help to reduce cancer-related mortality. Moreover, the developed S-SEDDS could be an ideal system for concurrent oral delivery of non-oncology drug combinations.

METHODS

The non-oncology drugs (alone and in combinations) were screened in vitro for anticancer effect (against HepG2 cells) using (3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide; MTT) dye assay, and cell cycle arresting and apoptotic behaviors using the fluorescence-activated cell sorting (FACS) technique. The S-SEDDS is composed of drugs such as Ketoconazole (KCZ), Disulfiram (DSR), Tadalafil (TLF), and excipients like span-80, tween-80, soybean oil, Leciva S-95, Poloxamer F108 (PF-108), and Neusilin® US2 (adsorbent carrier) was developed and characterized.

RESULTS

The cocktail composed of KCZ, DSR, and TLF has showed substantial cytotoxicity (at the lowest concentration of 3.3 picomoles), HepG2 cell arrest at G0/G1 and S phases, and substantial cell death via apoptosis. The Docetaxel (DTX) inclusion into this cocktail has further resulted in increased cytotoxicity, cell arrest at the G2/M phase, and cell necrosis. The optimized blank liquid SEDDS that remains transparent without phase separation for more than 6 months is used for the preparation of drug-loaded liquid SEDDS (DL-SEDDS). The optimized DL-SEDDS with low viscosity, good dispersibility, considerable drug retention upon dilution, and smaller particle size is further converted into drug-loaded solid SEDDS (DS-SEDDS). The final DS-SEDDS demonstrated acceptable flowability and compression characteristics, significant drug retention (more than 93%), particle size in nano range (less than 500 nm) and nearly spherical morphology following dilutions. The DS-SEDDS showed substantially increased cytotoxicity and Caco-2 cell permeability than plain drugs. Furthermore, DS-SEDDS containing only non-oncology drugs caused lower in vivo toxicity (only 6% body weight loss) than DS-SEDDS containing non-oncology drugs with DTX (about 10% weight loss).

CONCLUSION

The current study revealed a non-oncology drug combination effective against hepatocellular carcinoma. Further, it is concluded that the developed S-SEDDS containing non-oncology drug combination alone and in combination with DTX could be a promising alternative to toxic chemotherapeutics for the effective oral treatment of hepatic cancer.

Self-Nanoemulsifying Drug Delivery System-Containing the Poorly Absorbed Drug - Valsartan in Post-Bariatric Surgery

Purpose

Morbid obesity and its related metabolic syndrome are an important health issue. Recently, sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB) have accounted for the most popular bariatric surgeries. Valsartan (VST) is a common hypertension drug, and nano-carriers can increase its solubility and bioavailability. This study aims to explore the nano-VST formula in bariatric surgery subjects.

Methods

High-fat fed animals were used as obese models. Operations were performed according to a standardized protocol. The drug was administrated by gavage, and blood samples were taken by serial tail vein sampling. Caco-2 cells were used for examining cell viability and drug uptake. A self-nano-emusifying drug delivery system (SNEDDS) formula was composed of sefsol-218, RH-40 and propylene glycol by a specified ratio, while high-performance liquid chromatography (HPLC) was used for determining drug concentrations.

Results

Post-operatively, subjects that underwent RYGB lost more body weight compared to the SG group. The SNEDDS did not exhibit cytotoxicity after adequate dilution, and the cytotoxicity was not related to VST dose. A better cellular uptake of SNEDDS was observed in vitro. The SNEDDS formula achieved a diameter of 84 nm in distilled water and 140 nm in simulated gastric fluid. In obese animals, the maximum serum concentration (C_max) of VST was increased 1.68-folds by SNEDDS. In RYGB with SUS, the C_max was reduced to less than 50% of the obese group. SNEDDS increased the C_max to 3.5 folds higher than SUS and resulted in 3.28-folds higher AUC_0-24 in the RYGB group. Fluorescence imaging also confirmed a stronger signal of SNEDDS in the gastrointestinal mucosa. SNEDDS accumulated a higher drug concentration than suspension alone in the liver of the obese group.

Conclusion

SNEDDS could reverse the VST malabsorption in RYGB. Further studies are mandatory to clarify post-SG change of drug absorption.

3D Printing Technology as a Promising Tool to Design Nanomedicine-Based Solid Dosage Forms: Contemporary Research and Future Scope

3D printing technology in medicine is gaining great attention from researchers since the FDA approved the first 3D-printed tablet (Spritam®) on the market. This technique permits the fabrication of various types of dosage forms with different geometries and designs. Its feasibility in the design of different types of pharmaceutical dosage forms is very promising for making quick prototypes because it is flexible and does not require expensive equipment or molds. However, the development of multi-functional drug delivery systems, specifically as solid dosage forms loaded with nanopharmaceuticals, has received attention in recent years, although it is challenging for formulators to convert them into a successful solid dosage form. The combination of nanotechnology with the 3D printing technique in the field of medicine has provided a platform to overcome the challenges associated with the fabrication of nanomedicine-based solid dosage forms. Therefore, the major focus of the present manuscript is to review the recent research developments that involved the formulation design of nanomedicine-based solid dosage forms utilizing 3D printing technology. Utilization of 3D printing techniques in the field of nanopharmaceuticals achieved the successful transformation of liquid polymeric nanocapsules and liquid self-nanoemulsifying drug delivery systems (SNEDDS) to solid dosage forms such as tablets and suppositories easily with customized doses as per the needs of the individual patient (personalized medicine). Furthermore, the present review also highlights the utility of extrusion-based 3D printing techniques (Pressure-Assisted Microsyringe-PAM; Fused Deposition Modeling-FDM) to produce tablets and suppositories containing polymeric nanocapsule systems and SNEDDS for oral and rectal administration. The manuscript critically analyzes contemporary research related to the impact of various process parameters on the performance of 3D-printed solid dosage forms.

Current Advances in Lipid Nanosystems Intended for Topical and Transdermal Drug Delivery Applications

Skin delivery is an exciting and challenging field. It is a promising approach for effective drug delivery due to its ease of administration, ease of handling, high flexibility, controlled release, prolonged therapeutic effect, adaptability, and many other advantages. The main associated challenge, however, is low skin permeability. The skin is a healthy barrier that serves as the body's primary defence mechanism against foreign particles. New advances in skin delivery (both topical and transdermal) depend on overcoming the challenges associated with drug molecule permeation and skin irritation. These limitations can be overcome by employing new approaches such as lipid nanosystems. Due to their advantages (such as easy scaling, low cost, and remarkable stability) these systems have attracted interest from the scientific community. However, for a successful formulation, several factors including particle size, surface charge, components, etc. have to be understood and controlled. This review provided a brief overview of the structure of the skin as well as the different pathways of nanoparticle penetration. In addition, the main factors influencing the penetration of nanoparticles have been highlighted. Applications of lipid nanosystems for dermal and transdermal delivery, as well as regulatory aspects, were critically discussed.

The Development and Optimization of Lipid-Based Self-Nanoemulsifying Drug Delivery Systems for the Intravenous Delivery of Propofol

PURPOSE

Propofol is a relatively short-acting potent anesthetic lipophilic drug used during short surgical procedures. Despite the success of propofol intravenous emulsions, drawbacks to such formulations include inherent emulsion instability, the lack of a safe vehicle to prevent sepsis, and concern regarding hyperlipidemia-related side effects. The aim of the current investigation was to develop a novel, lipid-based self-nanoemulsifying drug delivery system (SNEDDS) for propofol with improved stability and anesthetic activity for human use.

METHODS

A series of SNEDDS formulations were developed using naturally obtained medium-chain/long-chain mono-, di-, and triglycerides, glyceryl monocaprylate, and water-soluble cosolvents with hydrogenated castor oil constructing ternary phase diagrams for propofol. The developed SNEDDS formulations were characterized using visual observation, particle size analysis, zeta potential, transmission electron microscopy, equilibrium solubility, in vitro dynamic dispersion and stability, and in vivo sleeping disorder studies in rats. The in vivo bioavailability of the SNEDDSs in rats was also studied to compare the representative formulations with the marketed product Diprivan^®.

RESULTS

Medium-chain triglycerides (M810) with mono-diglycerides (CMCM) as an oil blend and hydrogenated castor oil (KHS15) as a surfactant were selected as key ingredients in ternary phase diagram studies. The nanoemulsifying regions were identified from the studies and a number of SNEDDSs were formulated. Results from the characterization studies demonstrated the formation of efficient nanosized particles (28-45 nm globule size, 0.10-0.20 PDI) in the optimized SNEDDS with a drug loading of 50 mg/g, which is almost 500-fold higher than free propofol. TEM analysis showed the formation of spherical and homogeneous nanoparticles of less than 50 nm. The dissolution rate of the representative SNEDDS was faster than raw propofol and able to maintain 99% propofol in aqueous solution for around 24 h. The optimized liquid SNEDDS formulation was found to be thermodynamically stable. The intravenous administration of the SNEDDS in male Wistar rats induced a sleeping time of 73-88 min. The mean plasma concentrations after the IV administration of propofol nano-formulations PF2-SNEDDS and PF8-SNEDDS were 1348.07 ± 27.31 and 1138.66 ± 44.97 µg/mL, as compared to 891.44 ± 26.05 µg/mL (p = 0.05) observed after the IV administration of raw propofol.

CONCLUSION

Propofol-loaded SNEDDS formulations could be a potential pharmaceutical product with improved stability, bioavailability, and anesthetic activity.

The delivery of nanoparticles improves the pharmacokinetic properties of celecoxib to open a therapeutic window for oral administration of insoluble drugs

A sensitive and reliable LC-MS/MS method is established and validated to determine the concentration of celecoxib, in the serum of cynomolgus monkey, using celecoxib-D7 as an internal standard. The pharmacokinetic process was investigated after giving Celebrex, celecoxib nanoparticles (CXB-NPs) and hyaluronic acid celecoxib nanoparticles (HA-CXB-NPs) by intragastric (i.g.) administration. Chromatographic separation was performed with a C₁₈ column (2.1 × 100 mm, 2.6 μm) at 40°C with a mobile phase of 2‰ HCOOH in water and acetonitrile. The mass spectral acquisition was then performed in the multiple reaction monitoring mode, with negative ESI ion at m/z 380.0 → 316.0 and m/z 387.1 → 323.1 for celecoxib and celecoxib-D7, respectively. Good linearity was observed over the concentration range from 3 to 2,000 ng/ml (R²  = 0.9954). The intra- and inter-day precision and accuracy, matrix effect and extraction recovery, as well as stability, all met the determination requirements of biological samples. The pharmacokinetic parameters of Celebrex, CXB-NPs and HA-CXB-NPs were determined as: area under the curve, 1,855.98 ± 346.59, 1,908.00 ± 1,130.24 and 2,164.48 ± 657.47 h·ng/ml; peak concentration, 261.08 ± 113.26, 261.12 ± 94.67 and 263.34 ± 151.78 μg/L; time to peak concentration, 2.00 ± 1.22, 4.00 ± 0.00 and 3.60 ± 0.89 h; half-life, 4.39 ± 1.26, 2.33 ± 0.94 and 4.92 ± 3.13 h; relative bioavailability, 102.80 ± 49.62 and 116.63 ± 25.55%. The validated method was successfully applied to the pharmacokinetic study of celecoxib in cynomolgus monkey, after i.g. administration. The preparation of the nanoparticles of celecoxib and the modification of hyaluronic acid on the surface of nanoparticles could improve the bioavailability and prolong the circulation of celecoxib in vivo, which could lay the foundation for further development of celecoxib nanoparticles.

Brain Targeting by Intranasal Drug Delivery: Effect of Different Formulations of the Biflavone "Cupressuflavone" from Juniperus sabina L. on the Motor Activity of Rats

The polar fractions of the Juniperus species are rich in bioflavonoid contents. Phytochemical study of the polar fraction of Juniperus sabina aerial parts resulted in the isolation of cupressuflavone (CPF) as the major component in addition to another two bioflavonoids, amentoflavone and robustaflavone. Biflavonoids have various biological activities, such as antioxidant, anti-inflammatory, antibacterial, antiviral, hypoglycemic, neuroprotective, and antipsychotic effects. Previous studies have shown that the metabolism and elimination of biflavonoids in rats are fast, and their oral bioavailability is very low. One of the methods to improve the bioavailability of drugs is to alter the route of administration. Recently, nose-to-brain drug delivery has emerged as a reliable method to bypass the blood-brain barrier and treat neurological disorders. To find the most effective CPF formulation for reaching the brain, three different CPF formulations (A, B and C) were prepared as self-emulsifying drug delivery systems (SEDDS). The formulations were administered via the intranasal (IN) route and their effect on the spontaneous motor activity in addition to motor coordination and balance of rats was observed using the activity cage and rotarod, respectively. Moreover, pharmacokinetic investigation was used to determine the blood concentrations of the best formulation after 12 h. of the IN dose. The results showed that formulations B and C, but not A, decreased the locomotor activity and balance of rats. Formula C at IN dose of 5 mg/kg expressed the strongest effect on the tested animals.

Exploring the Potential of Cannabinoid Nanodelivery Systems for CNS Disorders

Cannabinoids have a major therapeutic value in a variety of disorders. The concepts of cannabinoids are difficult to develop, but they can be used and are advantageous for a number of diseases that are not sufficiently managed by existing treatments. Nanoconjugation and encapsulation techniques have been shown to be effective in improving the delivery and the therapeutic effectiveness of drugs that are poorly soluble in water. Because the bioavailability of cannabinoids is low, the challenge is to explore different administration methods to improve their effectiveness. Because cannabinoids cross the blood-brain-barrier (BBB), they modify the negative effects of inflammatory processes on the BBB and may be a key factor in the improvement of BBB function after ischemic disease or other conditions. This review discusses various types of cannabinoid administration, as well as nanotechnologies used to improve the bioavailability of these compounds in CNS diseases.

Self-nanoemulsifying drug delivery systems (SNEDDS) of anti-cancer drugs: a multifaceted nanoplatform for the enhancement of oral bioavailability

OBJECTIVE

A significant problem faced by the health care industry today is that though there are numerous drugs available to tackle diseases like cancer, their intrinsic properties make it difficult to be delivered to patients in a feasible manner. One of the key players that have helped researchers overcome poor solubility and permeability of drugs is Nanotechnology, this article further iterates on the same.

SIGNIFICANCE

Nanotechnology is used as an umbrella term in pharmaceutics and describes under it multiple technologies. Upcoming nanotechnology is a Self Nanoemulsifying System which is considered to be a futuristic delivery system both due to its scientific simplicity and relative ease of patient delivery.

METHODS

Self-Nano Emulsifying Drug Delivery Systems (SNEDDS) are homogenous lipidic concoctions containing the drug solubilized in the oil phase and surfactants. The choice of components depends on the physicochemical properties of the drugs, the solubilization capability of oils and the physiological fate of the drug. The article contains further details of various methodologies that have been adopted by scientists to formulate and optimize such systems in order to make anticancer drugs orally deliverable.

RESULTS

The results that have been generated by scientists across the globe have been summarized in the article and all of the data supports the claim that SNEDDS significantly enhance the solubility and bioavailability of hydrophobic anticancer drugs.

CONCLUSIONS

This article mainly provides the application of SNEDDS in cancer therapy and concludes to provide a step for the oral administration of several BCS class II and IV anticancer drugs.

Satranidazole-loaded chitosan/locust bean gum/xanthan gum polysaccharide composite multiunit pellets for colon targeting: in vitro–in vivo investigation

Background

The colon has a significant site to deliver numerous active materials for colonic diseases. Highly biodegradable polymers hold significant promise among the several techniques available to deliver the drug to the colon. This research aimed to prepare chitosan, locust bean gum and xanthan gum polysaccharide composite satranidazole multiunit pellets for colonic release and assesses the bioavailability with pharmacokinetic parameters after administration of satranidazole raw drug compared to multiunit pellets. Satranidazole multiple unit pellets were prepared based on chitosan, locust bean gum and xanthan gum, which were inexpensive and harmless. The bioavailability study was done by crossover design in which satranidazole raw drug and test formulation was administered to six healthy white albino rats.

Results

The pharmacokinetic analyses were estimated using the deconvolution of the plasma profile. Compared to the satranidazole drug used as a reference, for the pellets, the maximum plasma concentration was lower (35.02 ± 3.91 ng/ml vs. 51.07 ± 1.21 ng/ml for the satranidazole drug), and the time to attain maximum concentration was 2.50 ± 0.55 h for both drugs and test formulation. Colonic drug content was significantly higher than that of free administered drug.

Conclusion

The results indicate the acquired pharmacokinetic studies and colonic analysis established the reliability of the pharmaceutical technique and the ability to release satranidazole at the colonic site.

Graphical Abstract

Insights into Lipid-Based Delivery Nanosystems of Protein-Tyrosine Kinase Inhibitors for Cancer Therapy

According to the WHO, cancer caused almost 10 million deaths worldwide in 2020, i.e., almost one in six deaths. Among the most common are breast, lung, colon and rectal and prostate cancers. Although the diagnosis is more perfect and spectrum of available drugs is large, there is a clear trend of an increase in cancer that ends fatally. A major advance in treatment was the introduction of gentler antineoplastics for targeted therapy-tyrosine kinase inhibitors (TKIs). Although they have undoubtedly revolutionized oncology and hematology, they have significant side effects and limited efficacy. In addition to the design of new TKIs with improved pharmacokinetic and safety profiles, and being more resistant to the development of drug resistance, high expectations are placed on the reformulation of TKIs into various drug delivery lipid-based nanosystems. This review provides an insight into the history of chemotherapy, a brief overview of the development of TKIs for the treatment of cancer and their mechanism of action and summarizes the results of the applications of self-nanoemulsifying drug delivery systems, nanoemulsions, liposomes, solid lipid nanoparticles, lipid-polymer hybrid nanoparticles and nanostructured lipid carriers used as drug delivery systems of TKIs obtained in vitro and in vivo.

Optimized self-microemulsifying drug delivery system improves the oral bioavailability and brain delivery of coenzyme Q10

Our study aimed to develop a self-microemulsifying drug delivery system for the poorly aqueous-soluble drug Coenzyme Q₁₀, to improve the dissolution and the oral bioavailability. Excipients were selected based on their Coenzyme Q₁₀ solubility, and their concentrations were set for the optimization of the microemulsion by using a D-optimal mixture design to achieve a minimum droplet size and a maximum solubility of Coenzyme Q₁₀ within 15 min. The optimized formulation was composed of an oil (omega-3; 38.55%), a co-surfactant (Lauroglycol® 90; 31.42%), and a surfactant (Gelucire^® 44/14; 30%) and exhibited a mean droplet size of 237.6 ± 5.8 nm and a drug solubilization (at 15 min) of 16 ± 2.48%. The drug dissolution of the optimized formulation conducted over 8 h in phosphate buffer medium (pH 6.8) was significantly higher when compared to that of the Coenzyme Q₁₀ suspension. A pharmacokinetic study in rats revealed a 4.5-fold and a 4.1-fold increase in the area under curve and the peak plasma concentration values generated by the optimized formulation respectively, as compared to the Coenzyme Q₁₀ suspension. A Coenzyme Q₁₀ brain distribution study revealed a higher Coenzyme Q₁₀ distribution in the brains of rats treated with the optimized formulation than the Coenzyme Q₁₀ suspension. Coenzyme Q₁₀-loaded self microemulsifying drug delivery system was successfully formulated and optimized by a response surface methodology based on a D-optimal mixture design and could be used as a delivery vehicle for the enhancement of the oral bioavailability and brain distribution of poorly soluble drugs such as Coenzyme Q₁₀.

Boosting Tadalafil Bioavailability via Sono-Assisted Nano-Emulsion-Based Oral Jellies: Box-Behnken Optimization and Assessment

Tadalafil (TAD) is a poorly soluble, phosphodiesterase inhibitor used to treat erectile dysfunction. The primary goal of this project was to prepare nano-emulsions using ultrasonic technology to address TAD bioavailability concerns. The Box−Behnken design was employed to find prominent correlations between factors impacting the sono-emulsification process. The emulsifier concentration, amplitude level, and ultrasonication time were the independent factors, whereas the average droplet size (ADS) and polydispersity index (PDI) were designated as the response variables. TAD-loaded nano-emulsions (93−289 nm) were generated and the emulsifier concentration showed a crucial role in directing emulsion droplet size. The model desirability function was utilized to optimize a nano-emulsion with a small ADS (99.67 ± 7.55 nm) and PDI (0.45 ± 0.04) by adjusting the emulsifiers concentration, amplitude level, and ultrasonication time at 9.85%, 33%, 49 s, respectively. The optimized nano-emulsions did not demonstrate any precipitation or phase separation after stability stress tests. TAD jellies were formulated based on the optimized nano-emulsion and subjected to in vitro evaluation for physical characteristics; TAD content, pH, spreadability, viscosity, syneresis, and taste-masking ability. An optimized nano-emulsion-based jelly (NEJ) formulation showed more than 96% drug dissolution in 30 min relative to 14% for the unprocessed TAD. In vivo assessment of NEJ in experimental rats demonstrated a significant enhancement (p < 0.05) of TAD bioavailability with an AUC0−24h of 2045 ± 70.2 vs. 259.9 ± 17.7 ng·h·mL−1 for the unprocessed TAD. Storage stability results revealed that NEJ remained stable with unremarkable changes in properties for 3 months. Overall, NEJ can be regarded as a successful therapeutic option for TAD administration with immediate-release properties and improved bioavailability.

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.

Multivariate Data Analysis and Central Composite Design-Oriented Optimization of Solid Carriers for Formulation of Curcumin-Loaded Solid SNEDDS: Dissolution and Bioavailability Assessment

The study was initiated with two major purposes: investigating the role of isomalt (GIQ9) as a pharmaceutical carrier for solid self-nanoemulsifying drug delivery systems (S-SNEDDSs) and improving the oral bioavailability of lipophilic curcumin (CUN). GIQ9 has never been explored for solidification of liquid lipid-based nanoparticles such as a liquid isotropic mixture of a SNEDDS containing oil, surfactant and co-surfactant. The suitability of GIQ9 as a carrier was assessed by calculating the loading factor, flow and micromeritic properties. The S-SNEDDSs were prepared by surface adsorption technique. The formulation variables were optimized using central composite design (CCD). The optimized S-SNEDDS was evaluated for differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), microscopy, dissolution and pharmacokinetic studies. The S-SNEDDS showed a particle size, zeta potential and PDI of 97 nm, -26.8 mV and 0.354, respectively. The results of DSC, XRD, FTIR and microscopic studies revealed that the isotropic mixture was adsorbed onto the solid carrier. The L-SNEDDS and S-SNEDDS showed no significant difference in drug release, indicating no change upon solidification. The optimized S-SNEDDS showed 5.1-fold and 61.7-fold enhancement in dissolution rate and oral bioavailability as compared to the naïve curcumin. The overall outcomes of the study indicated the suitability of GIQ9 as a solid carrier for SNEDDSs.

Tadalafil-Loaded Self-Nanoemulsifying Chewable Tablets for Improved Bioavailability: Design, In Vitro, and In Vivo Testing

This research aimed to develop innovative self-nanoemulsifying chewable tablets (SNECT) to increase oral bioavailability of tadalafil (TDL), a nearly insoluble phosphodiesterase-5 inhibitor. Cinnamon essential oil, PEG 40 hydrogenated castor oil (Cremophor® RH 40), and polyethylene glycol 400 served as the oil, surfactant, and cosurfactant in the nanoemulsifying system, respectively. Primary liquid self-nanoemulsifying delivery systems (L-SNEDDS) were designed using phase diagrams and tested for dispersibility, droplet size, self-emulsifying capability, and thermodynamic stability. Adsorption on a carrier mix of silicon dioxide and microcrystalline cellulose was exploited to solidify the optimum L-SNEDDS formulation as self-nanoemulsifying granules (SNEG). Lack of crystalline TDL within the granules was verified by DSC and XRPD. SNEG were able to create a nanoemulsion instantaneously (165 nm), a little larger than the original nanoemulsion (159 nm). SNECT were fabricated by compressing SNEG with appropriate excipients. The obtained SNECT retained their quick dispersibility dissolving 84% of TDL within 30 min compared to only 18% dissolution from tablets of unprocessed TDL. A pharmacokinetic study in Sprague−Dawley rats showed a significant increase in Cmax (2.3-fold) and AUC0−24 h (5.33-fold) of SNECT relative to the unprocessed TDL-tablet (p < 0.05). The stability of TDL-SNECT was checked against dilutions with simulated GI fluids. In addition, accelerated stability tests were performed for three months at 40 ± 2 °C and 75% relative humidity. Results revealed the absence of obvious changes in size, PDI, or other tablet parameters before and after testing. In conclusion, current findings illustrated effectiveness of SNECT to enhance TDL dissolution and bioavailability in addition to facilitating dose administration.

Preparation and Characterization of Pazopanib Hydrochloride-Loaded Four-Component Self-Nanoemulsifying Drug Delivery Systems Preconcentrate for Enhanced Solubility and Dissolution

The aim of this study was to develop a four-component self-nanoemulsifying drug delivery system (FCS) to enhance the solubility and dissolution of pazopanib hydrochloride (PZH). In the solubility test, PZH showed a highly pH-dependent solubility (pH 1.2 > water >> pH 4.0 and pH 6.8) and was solubilized at 70 °C in the order Kollisolv PG (5.38%, w/w) > Kolliphor RH40 (0.49%) > Capmul MCM C10 (0.21%) and Capmul MCM C8 (0.19%), selected as the solubilizer, the surfactant, and the oils, respectively. In the characterization of the three-component SNEDDS (TCS) containing Kolliphor RH40/Capmul MCM C10, the particle size of dispersion was very small (<50 nm) and the PZH loading was 0.5% at the weight ratio of 9/1. In the characterization of FCS containing additional Kollisolv PG to TCS, PZH loading was increased to 5.30% without any PZH precipitation, which was 10-fold higher compared to the TCS. The optimized FCS prepared with the selected formulation (Kolliphor RH40/Capmul MCM C10/Kollisolv PG) showed a consistently complete and high dissolution rate (>95% at 120 min) at four different pHs with 1% polysorbate 80, whereas the raw PZH and Kollisolv PG solution showed a pH-dependent poor dissolution rate (about 40% at 120 min), specifically at pH 6.8 with 1% polysorbate 80. In conclusion, PZH-loaded FCS in this work demonstrated enhanced solubility and a consistent dissolution rate regardless of medium pH.

A QbD Approach to Design and to Optimize the Self-Emulsifying Resveratrol-Phospholipid Complex to Enhance Drug Bioavailability through Lymphatic Transport

Objectives: Despite having profound therapeutic value, the clinical application of resveratrol is restrained due to its <1% bioavailability, arising from the extensive fast-pass effect along with enterohepatic recirculation. This study aimed to develop a self-emulsifying formulation capable of increasing the bioavailability of resveratrol via lymphatic transport. Methods: The resveratrol−phospholipid complex (RPC) was formed by the solvent evaporation method and characterized by FTIR, DSC, and XRD analyses. The RPC-loaded self-emulsifying drug delivery system (SEDDS) was designed, developed, and optimized using the QbD approach with an emphasis on resveratrol transport through the intestinal lymphatic pathway. The in vivo pharmacokinetic study was investigated in male Wister Albino rats. Results: The FTIR, DSC, and XRD analyses confirmed the RPC formation. The obtained design space provided robustness of prediction within the 95% prediction interval to meet the CQA specifications. An optimal formulation (desirability value of 7.24) provided Grade-A self-emulsion and exhibited a 48-fold bioavailability enhancement compared to the pure resveratrol. The cycloheximide-induced chylomicron flow blocking approach demonstrated that 91.14% of the systemically available resveratrol was transported through the intestinal lymphatic route. Conclusions: This study suggests that an optimal self-emulsifying formulation can significantly increase the bioavailability of resveratrol through lymphatic transport to achieve the desired pharmacological effects.

Nanocarriers for delivery of siRNA as gene silencing mediator

The term nanocarrier refers to sub-micrometric particles of less than 100 nm, designed to transport, distribute, and release nanotechnology-based drug delivery systems. siRNA therapy is a novel strategy that has great utility for a variety of treatments, however naked siRNA delivery has not been an effective strategy, resulting in the necessary use of nanocarriers for delivery. This review aims to highlight the versatility of carriers based on smart drug delivery systems. The nanocarriers based on nanoparticles as siRNA DDS have provided a set of very attractive advantages related to improved physicochemical properties, such as high surface-to-volume ratio, versatility to package siRNA, provide a dual function to both protect extracellular barriers that lead to elimination and overcome intracellular barriers limiting cytosolic delivery, and possible chemical modifications on the nanoparticle surface to improve stability and targeting. Lipid and polymeric nanocarriers have proven to be stable, biocompatible, and effective in vitro, further exploration of the development of new nanocarriers is needed to obtain safe and biocompatible tools for effective therapy.

Self-Emulsifying Drug Delivery Systems: An Alternative Approach to Improve Brain Bioavailability of Poorly Water-Soluble Drugs through Intranasal Administration

Efforts in discovering new and effective neurotherapeutics are made daily, although most fail to reach clinical trials. The main reason is their poor bioavailability, related to poor aqueous solubility, limited permeability through biological membranes, and the hepatic first-pass metabolism. Nevertheless, crossing the blood–brain barrier is the major drawback associated with brain drug delivery. To overcome it, intranasal administration has become more attractive, in some cases even surpassing the oral route. The unique anatomical features of the nasal cavity allow partial direct drug delivery to the brain, circumventing the blood–brain barrier. Systemic absorption through the nasal cavity also avoids the hepatic first-pass metabolism, increasing the systemic bioavailability of highly metabolized entities. Nevertheless, most neurotherapeutics present physicochemical characteristics that require them to be formulated in lipidic nanosystems as self-emulsifying drug delivery systems (SEDDS). These are isotropic mixtures of oils, surfactants, and co-surfactants that, after aqueous dilution, generate micro or nanoemulsions loading high concentrations of lipophilic drugs. SEDDS should overcome drug precipitation in absorption sites, increase their permeation through absorptive membranes, and enhance the stability of labile drugs against enzymatic activity. Thus, combining the advantages of SEDDS and those of the intranasal route for brain delivery, an increase in drugs’ brain targeting and bioavailability could be expected. This review deeply characterizes SEDDS as a lipidic nanosystem, gathering important information regarding the mechanisms associated with the intranasal delivery of drugs loaded in SEDDS. In the end, in vivo results after SEDDS intranasal or oral administration are discussed, globally revealing their efficacy in comparison with common solutions or suspensions.

Formulation and Evaluation of SNEDDS Loaded with Original Lipophenol for the Oral Route to Prevent Dry AMD and Stragardt’s Disease

Dry age-related macular degeneration (Dry AMD) and Stargardt’s disease (STGD1) are common eye diseases, characterized by oxidative and carbonyl stress (COS)-inducing photoreceptor degeneration and vision loss. Previous studies have demonstrated the protective effect of photoreceptors after the intravenous administration of a new lipophenol drug, phloroglucinol-isopropyl-DHA (IP-DHA). In this study, we developed an oral formulation of IP-DHA (BCS Class IV) relying on a self-nanoemulsifying drug delivery system (SNEDDS). SNEDDS, composed of Phosal® 53 MCT, Labrasol®, and Transcutol HP® at a ratio of 25/60/15 (w/w/w), led to a homogeneous nanoemulsion (NE) with a mean size of 53.5 ± 4.5 nm. The loading of IP-DHA in SNEDDS (SNEDDS-IP-DHA) was successful, with a percentage of IP-DHA of 99.7% in nanoemulsions. The in vivo study of the therapeutic potency of SNEDDS-IP-DHA after oral administration on mice demonstrated photoreceptor protection after the induction of retinal degeneration with acute light stress (73–80%) or chronic light stress (52–69%). Thus, SNEDDS formulation proved to increase the solubility of IP-DHA, improving its stability in intestinal media and allowing its passage through the intestinal barrier after oral force-fed administration, while maintaining its biological activity. Therefore, SNEDDS-IP-DHA is a promising future preventive treatment for dry AMD and STGD1.

Formulation and Evaluation of Self-Nanoemulsifying Drug Delivery System Derived Tablet Containing Sertraline

Being a biopharmaceutics classification system class II drug, the absorption of sertraline from the gut is mainly limited by its poor aqueous solubility. The objective of this investigation was to improve the solubility of sertraline utilizing self-nanoemulsifying drug delivery systems (SNEDDS) and developing it into a tablet dosage form. Ternary phase diagrams were created to identify nanoemulsion regions by fixing oil (glycerol triacetate) and water while varying the surfactant (Tween 80) and co-surfactant (PEG 200) ratio (S_mix). A three-factor, two-level (2³) full factorial design (batches F1–F8) was utilized to check the effect of independent variables on dependent variables. Selected SNEDDS (batch F4) was solidified into powder by solid carrier adsorption method and compressed into tablets. The SNEDDS-loaded tablets were characterized for various pharmaceutical properties, drug release and evaluated in vivo in Wistar rats. A larger isotropic region was noticed with a S_mix ratio of 2:1 and the nanoemulsion exhibited good stability. Screening studies’ data established that all three independent factors influence the dependent variables. The prepared tablets displayed optimal pharmaceutical properties within acceptable limits. In vitro sertraline release demonstrated from solid SNEDDS was statistically significant (p < 0.0001) as compared to pure sertraline. Differential Scanning Calorimetry and X-Ray Diffraction data established the amorphous state of the drug in SNEDDS formulation, while FTIR spectra indicate the compatibility of excipients and drug. Pharmacokinetic evaluation of the SNEDDS tablet demonstrated significant increment (p < 0.0001) in AUC_0-α (~5-folds), C_max (~4-folds), and relative bioavailability (386%) as compared to sertraline suspension. The current study concludes that the solid SNEDDS formulation could be a practicable and effective strategy for oral therapy of sertraline.

Famotidine-loaded solid self-nanoemulsifying drug delivery system demonstrates exceptional efficiency in amelioration of peptic ulcer

Famotidine (FMD) is a highly potent H₂-receptor antagonist used in peptic ulcer treatment. However, the drug possesses poor aqueous solubility and permeability. FMD-loaded solid self-nanoemulsifying drug delivery system (FMD-S-SNEDDS) comprised of Labrafil® M 1944 CS, Tween® 20 and PEG 400, adsorbed on Aerosil® 200, has been developed. FMD-S-SNEDDS has demonstrated acceptable micromeritic properties, and upon reconstitution in water, spherical nanosized particles were released, as demonstrated by dynamic light scattering studies and transmission electron microscopy imaging. High encapsulation efficiency of FMD in the developed SNEDDS has been attained, and the saturated solubility of the drug has increased by 20-fold when it was incorporated in the SNEDDS. Several in vitro characterizations have been carried out, including, Fourier transform-infrared spectroscopy, differential scanning calorimetry, scanning electron microscopy, and drug dissolution studies. In vivo, upon administration of the free drug suspension, marketed product (FAMOTIN®) and FMD-S-SNEDDS (40 mg/kg) in peptic ulcer rat models, FMD-S-SNEDDS and the marketed FMD demonstrated 12.5- and 4.7-fold reduction in ulcers number, and 28.7- and 7.2-fold reduction in ulcer severity, respectively, compared to the control untreated animals. FMD-S-SNEDDS showed a significant (p < 0.05) increase in the levels of depleted glutathione and endothelial nitric oxide synthase, and significantly (p < 0.05) reduced the elevated level of malondialdehyde, as compared to the free and marketed FMD. Only FMD-S-SNEDDS could restore the elevated proton pump activity and cyclic adenosine monophosphate RNA expression to their normal levels. Hence, FMD-S-SNEDDS provides a great potential as a nanotherapeutic system for treatment of peptic ulcer.

Targeting Neuroimmune Interactions in Diabetic Neuropathy with Nanomedicine

Significance: Diabetes is a major source of neuropathy and neuropathic pain that is set to continue growing in prevalence. Diabetic peripheral neuropathy (DPN) and pain associated with diabetes are not adequately managed by current treatment regimens. Perhaps the greatest difficulty in treating DPN is the complex pathophysiology, which involves aspects of metabolic disruption and neurotrophic deficits, along with neuroimmune interactions. There is, therefore, an urgent need to pursue novel therapeutic options targeting the key cellular and molecular players. Recent Advances: To that end, cellular targeting becomes an increasingly compelling drug delivery option as our knowledge of neuroimmune interactions continues to mount. These nanomedicine-based approaches afford a potentially unparalleled specificity and longevity of drug targeting, using novel or established compounds, all while minimizing off-target effects. Critical Issues: The DPN therapeutics directly targeted at the nervous system make up the bulk of currently available treatment options. However, there are significant opportunities based on the targeting of non-neuronal cells and neuroimmune interactions in DPN. Future Directions: Nanomedicine-based agents represent an exciting opportunity for the treatment of DPN with the goals of improving the efficacy and safety profile of analgesia, as well as restoring peripheral neuroregenerative capacity. Antioxid. Redox Signal. 36, 122-143.