Quercetin-containing self-assemble proliposome preparation and evaluation

Aspects of quercetin stability and its liposomal enhancement in yellow onion skin extracts

Quercetin is a flavonoid that occurs in many types of fruit and vegetables and is stable for no longer than 4.5 h in the investigated pH range (6.0-8.0), even at 4 °C in the dark. At higher temperatures, the degradation/oxidation process is much faster. Simple but effective proliposomal encapsulation was used to protect the quercetin from environmental conditions such as pH. With this approach, 65 to 90% of pure quercetin and quercetin-rich onion extract was kept after >60 days under conditions that favoured its oxidation (pH 7.4). In addition, the encapsulated quercetin decreases the lipid peroxidation induced by pulsed UV light by >50%. At a mass ratio of 1:100 quercetin to lipids (w/w), the liposomes remained intact in solutions for six months. Quercetin in lipid bilayers simultaneously protects the unsaturated lipids from peroxidation.

Simple preparation and greatly improved oral bioavailability: The supersaturated drug delivery system of quercetin based on PVP K30

Quercetin, as a representative flavonoid, is widely present in daily diet and has been developed as a dietary supplement due to its beneficial physiological activities. However, the application of quercetin is limited due to its poor water solubility and extensive metabolism. So far, the nano-drug delivery systems designed to improve its bioavailability generally have the shortcomings of low drug loading content and difficulty in industrial production. In order to tackle these problems, quercetin supersaturated drug delivery system (QSDDS) was successfully prepared using solvent method, for which PVP K30 was employed as a crystallization and precipitation inhibitor to maintain the supersaturated state of quercetin in aqueous system. The obtained QSDDS, with a relative high drug loading content of 13%, could quickly disperse in water and form colloidal system with the mean particle size of about 200 nm, meanwhile induce the generation of supersaturated quercetin solution more than 12 h. In vivo pharmacokinetic study proved that QSDDS achieved a high absolute bioavailability of 36.05%, 10 times as that of physical quercetin suspension, which was dose-dependent with higher bioavailability at higher dose. Considering the simple preparation method, QSDDS provided a feasible strategy and a simple way to improve oral absorption of insoluble flavonoids.

A drift on liposomes to proliposomes: recent advances and promising approaches

Liposomes are nano-structured vesicles, made up of phospholipids that provide active ingredients at the site of action at a predetermined rate and add the advantage of the sustained-release formulation. Liposomes have stability issues that tend to agglomerate and fuse upon storage, which reflects their drawback. Hence to overcome the aggregation, fusion, hydrolysis, and/or oxidation problems associated with liposomes a new technology named Proliposomes has been introduced. Proliposomes are defined as carbohydrate carriers coated with phospholipids, which upon addition of water generate liposomes. The objective of the review is to cover the concept of proliposomes for pulmonary or alveolar delivery of drugs and compare it with that of liposomes; highlight the methods used for preparations along with the characterization parameters. This is the first systematic review that covers the categorization of liposomes, characteristic methods, and recent examples of drugs from 2015 to 2021, supplied in form of proliposomes to the macrophages as well as others and offers an advantage over the free drug by offering a prolonged drug release and sufficient bioavailability in addition to overcome the stability issues related to liposomes. Since this is a very new technology and many scientists are continuously working in this field to make the drug available for clinical trials and ultimately in the market for the targeted delivery of drugs with better storage life.HIGHLIGHTSProliposomes as an alternative to overwhelm the stability and storage-related issues of liposomes.Anhydrous carbohydrate carriers are utilized for proliposomal preparation.Inhaled delivery of drugs as solid lipid nanoparticles offers a significant impact on pulmonary tract infections, particularly in cystic fibrosis.Size of liposomes attained after proliposome hydrolysis is critical for drug delivery via respiration.

Emerging nanoformulation strategies for phytocompounds and applications from drug delivery to phototherapy to imaging

Over thousands of years, natural bioactive compounds derived from plants (bioactive phytocompounds, BPCs) have been used worldwide to address human health issues. Today, they are a significant resource for drug discovery in the development of modern medicines. Although many BPCs have promising biological activities, most of them cannot be effectively utilized in drugs for therapeutic applications because of their inherent limitations of low solubility, structural instability, short half-life, poor bioavailability, and non-specific distribution to organs. Researchers have utilized emerging nanoformulation (NF) technologies to overcome these limitations as they have demonstrated great potential to improve the solubility, stability, and pharmacokinetic and pharmacodynamic characteristics of BPCs. This review exemplifies NF strategies for resolving the issues associated with BPCs and summarizes recent advances in their preclinical and clinical applications for imaging and therapy. This review also highlights how innovative NF technologies play a leading role in next-generation BPC-based drug development for extended therapeutic applications. Finally, this review discusses the opportunities to take BPCs with meaningful clinical impact from bench to bedside and extend the patent life of BPC-based medicines with new formulations or application to new adjacent diseases beyond the primary drug indications.

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Natural bioactive phytocompounds derived from plants have been used worldwide to address human health issues. However, most of them cannot be effectively utilized in drugs for therapeutic applications because of their inherent limitations.

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Nanoformulation approach has recently been underlined as an emerging pharmaceutical strategy to overcome the intrinsic drawbacks of bioactive phytocompounds.

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Various types of nanoformulation and their up-to-date applications for targeted delivery, phototherapy, and imaging are reviewed. Finally, their clinical implications for the repurposing of bioactive phytocompounds are deliberated.

Lipid-Based Nanocarrier System for the Effective Delivery of Nutraceuticals

Nutraceuticals possess several health benefits and functions; however, most nutraceuticals are prone to degradation in the gastrointestinal environment and have poor bioavailability. Application of a novel carrier system is of increasing importance to overcome obstacles and provide efficient applicability. Lipid-based nanocarriers provide a large surface-to-mass ratio, enhanced intestinal absorption by solubilization in the intestinal milieu, intestinal lymphatic transport, and altering enterocyte-based transport. A critical overview of the current limitation, preparation, and application of lipid-based nanocarriers (liposomes and niosomes) and lipid nanoparticles (SLNs and NLCs) is discussed. Physical and gastrointestinal stability and bioavailability of nanoencapsulated nutraceuticals are considered as well.

Carboxymethyl chitosan-decorated proliposomes as carriers for improved stability and sustained release of flaxseed oil

A flaxseed oil carboxymethyl chitosan-decorated proliposome system was fabricated in this research. The physicochemical characteristics, stability, and in vitro release behaviors of flaxseed oil were studied and compared with that of flaxseed oil-loaded liposomes. The results of dynamic light scattering, transmission electron microscopy, and oxidation stability indicated that the storage stability of proliposomes was better. After 28 days of storage, the peroxide value of flaxseed oil-loaded liposomes (20.1 meq/kg) was significantly (P < 0.05) higher than that of flaxseed oil-loaded proliposomes (9.0 meq/kg); the thiobarbituric acid reactive substances in the former (0.53 mmol/kg) was also higher than that in the latter (0.27 mmol/kg). The in vitro release behavior of flaxseed oil indicated the proliposomes were more stable in the simulated gastrointestinal fluids. Therefore, the flaxseed oil-loaded proliposome system could be a promising vehicle for delivery flaxseed oil in food industry. PRACTICAL APPLICATION: A flaxseed oil-loaded proliposome delivery system was fabricated in this research. Their physical and oxidation stability of flaxseed oil were improved, and the in vitro cumulative release of flaxseed oil was delayed compared with flaxseed oil liposomes. This system may provide an effective strategy for the flaxseed oil encapsulation in the food industry.

Quercetin Loaded Nanoparticles in Targeting Cancer: Recent Development

The spread of metastatic cancer cell is the main cause of death worldwide. Cellular and molecular basis of the action of phytochemicals in the modulation of metastatic cancer highlights the importance of fruits and vegetables. Quercetin is a natural bioflavonoid present in fruits, vegetables, seeds, berries, and tea. The cancer-preventive activity of quercetin is well documented due to its anti-inflammatory, anti-proliferative and anti-angiogenic activities. However, poor water solubility and delivery, chemical instability, short half-life, and low-bioavailability of quercetin limit its clinical application in cancer chemoprevention. A better understanding of the molecular mechanism of controlled and regulated drug delivery is essential for the development of novel and effective therapies. To overcome the limitations of accessibility by quercetin, it can be delivered as nanoconjugated quercetin. Nanoconjugated quercetin has attracted much attention due to its controlled drug release, long retention in tumor, enhanced anticancer potential, and promising clinical application. The pharmacological effect of quercetin conjugated nanoparticles typically depends on drug carriers used such as liposomes, silver nanoparticles, silica nanoparticles, PLGA (Poly lactic-co-glycolic acid), PLA (poly(D,L-lactic acid)) nanoparticles, polymeric micelles, chitosan nanoparticles, etc. In this review, we described various delivery systems of nanoconjugated quercetin like liposomes, silver nanoparticles, PLGA (Poly lactic-co-glycolic acid), and polymeric micelles including DOX conjugated micelles, metal conjugated micelles, nucleic acid conjugated micelles, and antibody-conjugated micelles on in vitro and in vivo tumor models; as well as validated their potential as promising onco-therapeutic agents in light of recent updates.