Enhanced water dispersibility of coenzyme Q10 by complexation with albumin hydrolysate

Bioavailability enhancement of coenzyme Q10: An update of novel approaches

Coenzyme Q10 (CoQ10) is an essential, lipid-soluble vitamin involved in electron transport in the oxidoreductive reactions of the mitochondrial respiratory chain. Structurally, the quinone ring is connected to an isoprenoid moiety, which has a high molecular weight. Over the years, coenzyme Q10 has become relevant in the treatment of several diseases, like neurodegenerative disorders, coronary diseases, diabetes, hypercholesterolemia, cancer, and others. According to studies, CoQ10 supplementation might be beneficial in the treatment of CoQ10 deficiencies and disorders associated with oxidative stress. However, the water-insoluble nature of CoQ10 is a major hindrance to successful supplementation. So far, many advancements in CoQ10 bioavailability enhancement have been developed using novel drug carriers such as solid dispersion, liposomes, micelles, nanoparticles, nanoemulsions, self-emulsifying drug systems, or various innovative approaches (CoQ10 complexation with proteins). This article aims to provide an update on methods to improve CoQ10 solubility and bioavailability.

Dominant factors that determine the dissolution state of complexes between poorly water-soluble ingredients and casein hydrolysate

Casein hydrolysate (Pep) is a dispersant for poorly water-soluble drugs and nutraceutical ingredients. However, two types of complexes may be between Pep and poorly water-soluble molecules: those that are (1) dispersed as hydrocolloids in aqueous media with a particle size of 100-500 nm; and (2) not hydrocolloids, as indicated by permeability of the complex through an ultrafiltration (UF) membrane and the fact that the particle size is ambiguous by dynamic light scattering. This study was conducted to clarify the factors that determine the dissolution state of the complexes between poorly water-soluble ingredients and casein hydrolysate. We classified the dissolution state of the complexes between poorly water-soluble ingredients and Pep by the permeability using a UF membrane. Complexes containing larger and more-hydrophobic molecules are hydrocolloids and do not permeate the UF membrane, whereas complexes containing comparatively smaller and less-hydrophobic molecules do permeate the UF membrane. A complex containing indomethacin, which has borderline solubility properties, does not permeate the UF membrane at pH values in which the indomethacin carboxylic acid group is protonated, but it is permeable at pH values in which its carboxylic acid group is deprotonated. Furthermore, we determined the stoichiometry and association constant for the complex between a major peptide in Pep and poorly water-soluble resveratrol (Res) based on fluorescence quenching. We calculated the stoichiometry of Res and PepY to be 2:3 and the association constant to be 2.4 × 10⁷ M^-1.

Enhanced water dispersibility and permeability through a Caco-2 cell monolayer of β-cryptoxanthin extracted from kumquats by complexation with casein

β-Cryptoxanthin (BCX) possesses potential therapeutic and health benefits. However, BCX absorption is low because of its poor aqueous solubility. In this study, a complex between BCX and casein (Cas) was prepared to improve the water dispersibility and bioavailability of BCX. BCX was recovered quantitatively from freeze-dried kumquat powder through solid-liquid extraction and saponification. The complexation significantly improved the apparent solubility of BCX under acidic and neutral conditions. A cell membrane permeation test using a Caco-2 cell monolayer was performed to evaluate the bioavailability of the BCX-Cas complex. This complex and a blank sample were digested in vitro and added to the apical side of the Caco-2 cell membrane. The quantity of BCX that permeated using the BCX-Cas complex after 24 h was 22.7 times greater than that of the blank. Thus, complexation of BCX with Cas improved dramatically the bioavailability of BCX from a kumquat extract.

Green Formulation of Triglyceride/Phospholipid-Based Nanocarriers as a Novel Vehicle for Oral Coenzyme Q10 Delivery

This study was aimed to develop a novel nanocarrier for coenzyme Q10 (CoQ10) by a green process that prevented the use of surfactants and organic solvents. Triglyceride/phospholipid-based nanocarriers were developed through high-pressure homogenization (an industrial feasible process), and a 2^5-1 fractional factorial design was adopted to assess the influences of formulation variables on the considered responses, including vesicle size, entrapment efficiency, loading capacity, and solubility of the vehicles in simulated gastrointestinal fluids. The optimized formulation was further in-depth characterized in terms of morphology, release behavior, biocompatibility (Caco-2 cell cytotoxicity and histological examination), thermal behavior, and Fourier transform infrared analysis. Optimal nanocarriers were found to have mean particle size of 75 nm, narrow particle distribution, and CoQ10 entrapment of 95%. The optimized formulation was stable upon incubation in simulated gastrointestinal fluids without considerable leakage of cargo, which was in agreement with their sustained release behavior. Microscopic observations also confirmed nanosized nature of the vesicles and revealed their spherical shape. Moreover, toxicity evaluations at the cellular and tissue levels revealed their nontoxic nature. In conclusion, triglyceride/phospholipid-based nanocarriers proved to be a green safe vehicle for delivery of CoQ10 with industrial-scale production capability and could provide a new horizon for delivery of hydrophobic nutraceuticals. PRACTICAL APPLICATION: Green nanostructure formulation approaches have recently gained tremendous attraction for their safe profile especially when it comes to supplements, which are generally recommended for daily use. However, their sufficient association with cargoes and industrial-scale production have remained considerable challenges. This study focuses on the development of lipid-based nanocarriers for CoQ10 by an industrial feasible process that prevents the use of any surfactants or organic solvents.

Improved stability, epithelial permeability and cellular antioxidant activity of β-carotene via encapsulation by self-assembled α-lactalbumin micelles

The low aqueous solubility, stability and bioavailability of hydrophobic bioactive compounds, such as β-carotene (β-c), greatly hinder their application in foods. Nanocarriers could overcome this problem by facilitating the delivery of the functional ingredients. We prepared lactalbumin (α-lac) micelles by partial enzymatic hydrolysis in aqueous solution. β-c can be incorporated into the cores of these micelles via hydrophobic interactions. The aqueous solubility and stability under 60 °C heating or UV light irradiation of encapsulated β-c improved significantly compared with free β-c. Moreover, it had an increased cellular uptake (3 times) and transmembrane permeability (13 times) in a Caco-2 cell monolayer model. It suggested that α-lac micelle-encapsulated β-c had an enhanced cellular absorption and transport efficiency. Encapsulated β-c also exhibited an enhanced cellular anti-oxidant activity (CAA) compared with free β-c. This work demonstrates that α-lac micelles showed a great potential for delivery of hydrophobic bioactive compounds in foods.

Preparation and Characterization of Mucoadhesive Nanoparticles for Enhancing Cellular Uptake of Coenzyme Q10

The mucoadhesive nanoparticles (NPs) for oral delivery of coenzyme Q10 (CoQ10) were prepared using natural mucoadhesive polysaccharides, chitosan (CS), and dextran sulfate sodium salt (DS) in order to improve the solubility, cellular uptake, and thermo- and photostability of CoQ10. CoQ10-loaded NPs were prepared in the range of 340-450 nm with an entrapment efficiency of 60-98%. The mucoadhesiveness and cellular uptake of NPs were evaluated by measuring the amount of mucin adsorbed on NPs and CoQ10 absorbed in Caco-2 cells, respectively. CS/DS NPs had higher mucoadhesive strength than CS/sodium triphosphate pentabasic NPs (control group). Moreover, the solubility, cellular uptake, thermo- and photostability of CS/DS NPs were significantly improved compared with non-nanoencapsulated free CoQ10. Particularly, CS/DS NPs prepared with 0.5 mg/mL of CS and DS produced the highest mucoadhesiveness, solubility, cellular uptake, and cellular antioxidant activity. Thus, mucoadhesive CS/DS NPs may be an effective oral delivery platform for improving bioavailability of CoQ10.

PEGylated Solanesol for Oral Delivery of Coenzyme Q10

Coenzyme Q₁₀ (CoQ₁₀) is widely used in preventive or curative treatment of cardiovascular diseases. However, CoQ₁₀ exhibits an extremely low solubility in aqueous medium as well as a poor oral bioavailability. Therefore, solanesyl poly(ethylene glycol) succinate (SPGS) and CoQ₁₀ were formulated as CoQ₁₀-SPGS micelles with a high content of CoQ₁₀ to improve the bioavailability of CoQ₁₀ in rat. Findings indicate that, in the CoQ₁₀-SPGS micelles, SPGS is self-assembled into stable nanosized micelles with a CoQ₁₀ loading capacity of more than 39%. The CoQ₁₀-SPGS micelles exhibit an enhanced photostability upon exposure to simulated sunlight. In vivo experiments demonstrate that, as compared to that of the coarse suspensions of CoQ₁₀, there was three-fold enhancement of oral bioavailability for CoQ₁₀-loaded SPGS micelles depending on varying molecular weight of SPGS. In the encapsulation of CoQ₁₀ by SPGS micelles, the self-assembled nanocarriers with strong muco-adhesive properties lead to increases in the solubility and oral absorption of lipophilic CoQ₁₀ nanoparticles.

Formulation development and in vivo hepatoprotective activity of self nanoemulsifying drug delivery system of antioxidant coenzyme Q10

Coenzyme Q10 (CQ10) is known as an endogenous cellular antioxidant, naturally found in every cell of the human body and plays an important role in maintaining human health. It is widely used as a nutritional supplement and pharmaceutical drug for various disorders like diabetes mellitus, carcinomas, neurodegenerative disorders etc. However, CQ10 is practically insoluble even in the presence of 5 % sodium lauryl sulfate in water and poorly absorbed from the gastrointestinal tract. The present research is aimed to formulate and evaluate self nanoemulsifying drug delivery system (SNEDDS) of CQ10 primarily to improve its aqueous solubility, dissolution velocity as well as hepatoprotective activity and thus enhancing its nutraceutical and pharmaceutical values. Robustness to dilution, thermodynamic stability study, droplet size analysis and drug release were adopted to optimize liquid SNEDDS. Droplet size of the SNEDDS was found to be size less than 200 nm and appeared round in shape without aggregation under transmission electron microscopy examination. Liquid SNEDDS were adsorbed on porous carrier to get solid SNEDDS (S-SNEDDS). S-SNEDDS gave rapid (>90 %) drug release within 30 min while pure drug was not practically dissolved within 1 h. In vivo hepatoprotective activity showed that S-SNEDDS achieved the most liver protection as compared to the pure drug. Further S-SNEDDS was successfully converted to self nanoemulsifying mouth dissolving tablet. The enhanced solubility, dissolution velocity as well as hepatoprotective activity of CQ10, unravels the potential of S-SNEDDS as suitable carrier for enhancing nutraceutical and pharmaceutical values of CQ10.