Enhanced pharmacokinetic behavior and hepatoprotective function of ginger extract-loaded supersaturable self-emulsifying drug delivery systems

Lipid-based systems with precipitation inhibitors as formulation approach to improve the drug bioavailability and/or lower its dose: a review

Lipid-based systems, such as self-microemulsifying systems (SMEDDS) are attracting strong attention as a formulation approach to improve the bioavailability of poorly water-soluble drugs. By applying the "spring and parachute" strategy in designing supersaturable SMEDDS, it is possible to maintain the drug in the supersaturated state long enough to allow absorption of the complete dose, thus improving the drug's bio-availability. As such an approach allows the incorporation of larger amounts of the drug in equal or even lower volumes of SMEDDS, it also enables the production of smaller final dosage forms as well as decreased gastrointestinal irritation, being of particular importance when formulating dosage forms for children or the elderly. In this review, the technological approaches used to prolong the drug supersaturation are discussed regarding the type and concentration of polymers used in liquid and solid SMEDDS formulation. The addition of hypromellose derivatives, vinyl polymers, polyethylene glycol, polyoxyethylene, or polymetacrylate copolymers proved to be effective in inhibiting drug precipitation. Regarding the available literature, hypromellose has been the most commonly used polymeric precipitation inhibitor, added in a concentration of 5 % (m/m). However, the inhibiting ability is mainly governed not only by the physicochemical properties of the polymer but also by the API, therefore the choice of optimal precipitation inhibitor is recommended to be evaluated on an individual basis.

Gingerols and shogaols: A multi-faceted review of their extraction, formulation, and analysis in drugs and biofluids to maximize their nutraceutical and pharmaceutical applications

Gingerols represent the main bioactive compounds in ginger drugs mostly Zinigiber officinale (F. Zingebraceae) and account for the biological activities and the strong/pungent flavor in ginger. Ginger (Z. officinale) rhizome is one of the most valued herbal drugs for ailments' treatment in many ayurvedic medicine asides from its culinary applications as a spice. Gingerols and their dehydrated products shogaols are phenolic phytochemicals found in members of the Zingiberaceae family and account for most of their effects including anti-inflammatory and anticancer activities. This review entails most of the novel trends related to the extraction, optimization, and formulations of gingerols and shogaols to insure best recoveries and efficacies from their natural resources. Further, it presents a comprehensive overview of the different analytical approaches for the determination of gingerols/shogaols' levels in nutraceuticals to ensure highest quality and for their detection in body fluids for proof of efficacy.

Immunomodulatory and anti-inflammatory therapeutic potential of gingerols and their nanoformulations

Ginger (Zingiber officinale Roscoe), a member of the Zingiberaceae family, is one of the most popular spices worldwide, known since ancient times, and used both as a spice and a medicinal plant. The phenolic compounds found in ginger are predominantly gingerols, shogaols, and paradols. Gingerols are the major phenolic compounds found in fresh ginger and contain mainly 6-gingerol as well as 4-, 5-, 8-, 10-, and 12-gingerols. Gingerols possess a wide array of bioactivities, such as antioxidant and anticancer, among others. Regarding the different array of biological activities and published data on the mechanisms underlying its action, the complex interaction between three key events, including inflammation, oxidative stress, and immunity, appears to contribute to a plethora of pharmacological activities of this compound. Among these, the immunomodulatory properties of these compounds, which attract attention due to their effects on the immune system, have been the focus of many studies. Gingerols can alleviate inflammation given their ability to inhibit the activation of protein kinase B (Akt) and nuclear factor kappa B (NF-κB) signaling pathways, causing a decrease in proinflammatory and an increase in anti-inflammatory cytokines. However, given their low bioavailability, it is necessary to develop new and more effective strategies for treatment with gingerols. In order to overcome this problem, recent studies have addressed new drug delivery systems containing gingerols. In this review, the immunomodulatory activities of gingerol and its underlying mechanisms of action combined with the contributions of developed nanodrug delivery systems to this activity will be examined.

Self-Emulsifying Systems for Delivery of Bioactive Compounds from Natural Origin

Nature has been used as therapeutic resources in the treatment of diseases for many years. However, some natural compounds have poor water solubility. Therefore, physicochemical strategies and technologies are necessary for development of systems for carrying these substances. The self-emulsifying drug delivery systems (SEDDS) have been used as carriers of hydrophobic compounds in order to increase the solubility and absorption, improving their bioavailability. SEDDS are constituted with a mixture of oils and surfactants which, when come into contact with an aqueous medium under mild agitation, can form emulsions. In the last years, a wide variety of self-emulsifying formulations containing bioactive compounds from natural origin has been developed. This review provides a comprehensive overview of the main excipients and natural bioactive compounds composing SEDDS. In addition, applications, new technologies and innovation are reviewed as well. Examples of self-emulsifying formulations administered in different sites are also considered for a better understanding of the use of this strategy to modify the delivery of compounds from natural origin.

Supersaturation-Based Drug Delivery Systems: Strategy for Bioavailability Enhancement of Poorly Water-Soluble Drugs

At present, the majority of APIs synthesized today remain challenging tasks for formulation development. Many technologies are being utilized or explored for enhancing solubility, such as chemical modification, novel drug delivery systems (microemulsions, nanoparticles, liposomes, etc.), salt formation, and many more. One promising avenue attaining attention presently is supersaturated drug delivery systems. When exposed to gastrointestinal fluids, drug concentration exceeds equilibrium solubility and a supersaturation state is maintained long enough to be absorbed, enhancing bioavailability. In this review, the latest developments in supersaturated drug delivery systems are addressed in depth.

Eplerenone repurposing in management of chorioretinopathy: Mechanism, nanomedicine-based delivery applications and future trends

Chronic central serous chorioretinopathy (CSCR) is an ocular threatening disease, a common cause of central vision loss, affecting the posterior pole of the eye. Eplerenone (EPL) is a selective mineralocorticoid receptor antagonist that used primarily to treat hypertension. Recently, it has shown many benefits in modifying the physio-pathological processes occurring upon stimulation of renin-angiotensin aldosterone system at the ocular level. In CSCR treatment, several clinical studies and case reports prove the efficacy and safety of EPL. However, some setbacks for such studies as a relatively small number of participants and short follow-up periods. This review article is intended to describe theories about the nature and classification of CSCR and recapitulate EPL therapeutic benefits as selective mineralocorticoid receptor antagonist in the treatment of CSCR. Furthermore, a literature survey on clinical studies discussing the results of use of EPL in treatment of CSCR. In addition, EPL therapeutic formulations that were developed up to date, and the future potential delivery systems will be suggested.

Supersaturable self-microemulsifying delivery systems: an approach to enhance oral bioavailability of benzimidazole anticancer drugs

This study explored the design of supersaturable self-microemulsifying drug delivery systems (S-SMEDDS) to address poor solubility and oral bioavailability of a novel benzimidazole derivative anticancer drug (BI). Firstly, self-microemulsifying drug delivery systems SMEDDS made of Miglyol® 812, Kolliphor® RH40, Transcutol® HP, and ethanol were prepared and loaded with the BI drug. Upon dispersion, the systems formed neutrally charged droplets of around 20 nm. However, drug precipitation was observed following incubation with simulated gastric fluid (pH 1.2). Aiming at reducing this precipitation and enhancing drug payload, supersaturable systems were then prepared by adding 1% hydroxypropyl cellulose as precipitation inhibitor. Supersaturable systems maintained a higher amount of drug in a supersaturated state in gastric medium compared with conventional formulations and were stable in simulated intestinal medium (pH 6.8). In vitro cell studies using Caco-2 cell line showed that these formulations reduced in a transient manner the transepithelial electrical resistance of the monolayers without toxicity. Accordingly, confocal images revealed that the systems accumulated at tight junctions after a 2 h exposure. In vivo pharmacokinetic studies carried out following oral administration of BI-loaded S-SMEDDS, SMEDDS, and free drug to healthy mice showed that supersaturable systems promoted drug absorption compared with the other formulations. Overall, these data highlight the potential of using the supersaturable approach as an alternative to conventional SMEDDS for improving oral systemic absorption of lipophilic drugs.

Orally administered self-emulsifying drug delivery system in disease management: advancement and patents

Introduction: Oral administration of a drug is the most common, ideal and preferred route of administration. The main problem of oral drug formulations is their low bioavailability arises from poor aqueous solubility of drug. Aqueous solubility of lipophilic drugs can be improved by various techniques like salt formation, complexation, addition of co-solvent etc. but self-emulsifying drug-delivery system (SEDDS) is getting more attention for increasing the solubility of such drugs. The SEDDS is an isotropic mixture of drug, lipids, and emulsifiers, usually with one or more hydrophilic co-solvents/co-emulsifiers. This system is having ability to generate oil-in-water (o/w) emulsions or microemulsions upon gentle agitation followed by dilution with aqueous phase. The SEDDSs are relatively newer, lipid-based technological innovations possessing unparalleled potential in improving oral bioavailability of poorly water-soluble drugs.Areas covered: This review provides updated information regarding the types of SEDDS, their preparation techniques, drug delivery and related recent patents along with marketed formulations.Expert opinion: The SEDDS has been explored for improving bioavailability, rising intra-subject heterogeneity, and increasing solubility. SEDDS offers the benefit of a protective effect against the hostile environment in the gut. The unique fabrication techniques provide specific strategy to overcome the low bioavailability and poor solubility problems.

Current Status of Supersaturable Self-Emulsifying Drug Delivery Systems

Self-emulsifying drug delivery systems (SEDDSs) are a vital strategy to enhance the bioavailability (BA) of formulations of poorly water-soluble compounds. However, these formulations have certain limitations, including in vivo drug precipitation, poor in vitro in vivo correlation due to a lack of predictive in vitro tests, issues in handling of liquid formulation, and physico-chemical instability of drug and/or vehicle components. To overcome these limitations, which restrict the potential usage of such systems, the supersaturable SEDDSs (su-SEDDSs) have gained attention based on the fact that the inclusion of precipitation inhibitors (PIs) within SEDDSs helps maintain drug supersaturation after dispersion and digestion in the gastrointestinal tract. This improves the BA of drugs and reduces the variability of exposure. In addition, the formulation of solid su-SEDDSs has helped to overcome disadvantages of liquid or capsule dosage form. This review article discusses, in detail, the current status of su-SEDDSs that overcome the limitations of conventional SEDDSs. It discusses the definition and range of su-SEDDSs, the principle mechanisms underlying precipitation inhibition and enhanced in vivo absorption, drug application cases, biorelevance in vitro digestion models, and the development of liquid su-SEDDSs to solid dosage forms. This review also describes the effects of various physiological factors and the potential interactions between PIs and lipid, lipase or lipid digested products on the in vivo performance of su-SEDDSs. In particular, several considerations relating to the properties of PIs are discussed from various perspectives.

Supersaturable Self-Emulsifying Drug Delivery System of Krill Oil with Improved Oral Absorption and Hypotriglyceridemic Function

This study aimed to develop a supersaturable self-emulsifying drug delivery system (S-SEDDS) of krill oil (KO), a rich source of docosahexaenoic acid and eicosapentaenoic acid (EPA), to improve its hypotriglyceridemic function. S-SEDDS of KO (KO/S-SEDDS) was prepared by the addition of lysolecithin, glycerin, and hydroxypropyl methylcellulose (HPMC). Self-emulsifying drug delivery system of KO (KO/SEDDS) and KO with HPMC (KO/HPMC) were also prepared for comparison purposes. The physicochemical and pharmacokinetic properties of KO samples were characterized, and the hypotriglyceridemic function of KO/S-SEDDS was evaluated. Micronized droplets in KO/SEDDS and KO/S-SEDDS with a mean diameter of ca. 270 nm could be observed in comparison to KO and KO/HPMC. Both KO/HPMC and KO/S-SEDDS tended to enhance the dissolution behavior of KO, and the S-SEDDS formulation improved the dissolution behavior of KO as a result of micronized droplets and the addition of HPMC. KO/S-SEDDS (60 mg of EPA/kg) improved the oral absorption of KO based on the pharmacokinetic profiling of EPA, and repeated oral administration of KO/S-SEDDS (250 mg of KO kg^-1 day^-1) for 7 days had a potent hypotriglyceridemic effect on rats with corn-oil-induced hypertriglyceridemia compared to orally administered KO. On the basis of these findings, the S-SEDDS approach might be an efficacious dosage option to enhance the nutraceutical properties of KO.