Studies on the curcumin phospholipid complex solidified with Soluplus®

The effect of naringenin-phospholipid complex on thermal oxidative stability of soybean oil under heating condition

Naringenin (NGE), a typical flavanone abundant in citrus fruits, exhibits remarkable antioxidant activities. However, its low solubility in oil restricts its widespread use in inhibiting lipid oxidation. In this study, we present a novel and effective approach to address this limitation by developing a naringenin-phospholipid complex (NGE-PC COM). Comprehensive analytical techniques including Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), and X-ray diffraction (XRD) were employed to confirm the formation of the NGE-PC COM and elucidate the interaction mechanism between NGE and phospholipids molecules. Notably, the oil-solubility of NGE was significantly enhanced by approximately 2700-fold when formulated as a phospholipid complex in soybean oil. The improved oil-solubility of NGE-PC COM enabled effective inhibition of oil thermal oxidation under high temperature conditions. Generally, this investigation proposed a novel and promising strategy for employing flavanones with strong antioxidant activities to enhance the thermal oxidative stability of edible oil during heating processes.

Phospholipid Complexation for Bioavailability Improvement of Albendazole: Preparation, Characterization and In Vivo Evaluation

The current study aimed to improve the poor solubility of albendazole (ABZ) by means of phospholipid complexation, hence to improve its oral bioavailability. The solvent-evaporation method for ABZ-phospholipid complex (ABZ-PC) preparation was established for the first time. And a systematic optimization of preparation conditions of ABZ-PC was performed. Physicochemical studies of ABZ-PC were performed with FTIR, DSC, and XRD measurements to confirm the formation of the ABZ-PC and reveal the interaction mechanism between ABZ and phospholipid molecules. Solubility determination and morphological characterization were applied to verify the solubility improvement of prepared ABZ-PC. Moreover, the pharmacokinetic performance of ABZ-PC was further evaluated in vivo compared with raw materials of ABZ. Under optimal preparation conditions, the AE of ABZ-PC could be approximately 100%. Physicochemical studies indicated that the P = O group in the phospholipid molecule would interact with the N-H group in the ABZ molecule through hydrogen bonds and ABZ was dispersed in an amorphous state after being prepared into ABZ-PC. The aqueous solubility of ABZ-PC in deionized water (pH7.0) improved by 30-folds than free ABZ, and the AUC_0-t of ABZ-PC was significantly increased by 2.32 times in comparison with raw materials of ABZ through oral administration. The current study developed an effective method for the phospholipid complexation of ABZ. With significantly improved solubility in an aqueous environment, the prepared ABZ-PC exhibited improved oral bioavailability and pharmacokinetic characteristics indicating it could be potentially applied in the oral drug delivery of ABZ.

Comparative Study of Preparation, Evaluation, and Pharmacokinetics in Beagle Dogs of Curcumin β-Cyclodextrin Inclusion Complex, Curcumin Solid Dispersion, and Curcumin Phospholipid Complex

Curcumin is a natural acidic polyphenol extracted from turmeric with a wide range of biological and pharmacological effects. However, the application of curcumin for animal production and human life is limited by a low oral bioavailability. In this study, natural curcumin was prepared for the curcumin β-cyclodextrin inclusion complex (CUR-β-CD), curcumin solid dispersion (CUR-PEG-6000), and curcumin phospholipid complex (CUR-HSPC) using co-precipitation, melting, and solvent methods, respectively. Curcumin complex formations were monitored using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FT-IR) techniques via the shifts in the microscopic structure, molecular structure, and crystalline state. Subsequently, twenty-four female beagle dogs were randomly divided into four groups to receive unmodified curcumin and three other curcumin preparations. The validated UPLC-MS assay was successfully applied to pharmacokinetic and bioavailability studies of curcumin in beagle dog plasma, which were collected after dosing at 0 min (predose), 5 min, 15 min, 30 min, 40 min, 50 min, 1.5 h, 3 h, 4.5 h, 5.5 h, 6 h, 6.5 h, 9 h, and 24 h. The relative bioavailabilities of CUR-β-CD, CUR-PEG-6000, and CUR-HSPC were 231.94%, 272.37%, and 196.42%, respectively. This confirmed that CUR-β-CD, CUR-HSPC, and especially CUR-PEG-6000 could effectively improve the bioavailability of curcumin.

Curcumin: Biological Activities and Modern Pharmaceutical Forms

Curcumin (1,7-bis-(4-hydroxy-3-methoxyphenyl)-hepta-1,6-diene-3,5-dione) is a natural lipophilic polyphenol that exhibits significant pharmacological effects in vitro and in vivo through various mechanisms of action. Numerous studies have identified and characterised the pharmacokinetic, pharmacodynamic, and clinical properties of curcumin. Curcumin has an anti-inflammatory, antioxidative, antinociceptive, antiparasitic, antimalarial effect, and it is used as a wound-healing agent. However, poor curcumin absorption in the small intestine, fast metabolism, and fast systemic elimination cause poor bioavailability of curcumin in human beings. In order to overcome these problems, a number of curcumin formulations have been developed. The aim of this paper is to provide an overview of recent research in biological and pharmaceutical aspects of curcumin, methods of sample preparation for its isolation (Soxhlet extraction, ultrasound extraction, pressurised fluid extraction, microwave extraction, enzyme-assisted aided extraction), analytical methods (FTIR, NIR, FT-Raman, UV-VIS, NMR, XRD, DSC, TLC, HPLC, HPTLC, LC-MS, UPLC/Q-TOF-MS) for identification and quantification of curcumin in different matrices, and different techniques for developing formulations. The optimal sample preparation and use of an appropriate analytical method will significantly improve the evaluation of formulations and the biological activity of curcumin.

Curcuma as an adjuvant in colorectal cancer treatment

Colorectal cancer (CRC) is the second leading cause of cancer death worldwide and mostly affects men. Around 20% of its incidence is by familiar disposition due to hereditary syndromes. The CRC treatment involves surgery and chemotherapy; however, the side effects of treatments and the fast emergence of drug resistance evidence the necessity to find more effective drugs. Curcumin is the main polyphenol pigment present in Curcuma longa, a plant widely used as healthy food with antioxidant properties. Curcumin has synergistic effects with antineoplastics such as 5-fluorouracil and oxaliplatin, as well anti-inflammatory drugs by inhibiting cyclooxygenase-2 and the Nuclear factor kappa B. Furthermore, curcumin shows anticancer properties by inhibition of the Wnt/β-catenin, Hedgehog, Notch, and the phosphatidylinositol-3-kinase (PI3K)/Akt and the mammalian target of rapamycin (mTOR) signaling pathways implicated in the progression of CRC. However, the consumption of pure curcumin is less suitable, as the absorption is poor, and the metabolism and excretion are high. Pharmacological formulations and essential oils of the plant improve the curcumin absorption, resulting in therapeutical dosages. Despite the evidence obtained in vitro and in vivo, clinical studies have not yet confirmed the therapeutic potential of curcumin against CRC. Here we reviewed the last scientific information that supports the consumption of curcumin as an adjuvant for CRC therapy.

Antitumoral Activities of Curcumin and Recent Advances to ImProve Its Oral Bioavailability

Curcumin, a main bioactive component of the Curcuma longa L. rhizome, is a phenolic compound that exerts a wide range of beneficial effects, acting as an antimicrobial, antioxidant, anti-inflammatory and anticancer agent. This review summarizes recent data on curcumin's ability to interfere with the multiple cell signaling pathways involved in cell cycle regulation, apoptosis and the migration of several cancer cell types. However, although curcumin displays anticancer potential, its clinical application is limited by its low absorption, rapid metabolism and poor bioavailability. To overcome these limitations, several curcumin-based derivatives/analogues and different drug delivery approaches have been developed. Here, we also report the anticancer mechanisms and pharmacokinetic characteristics of some derivatives/analogues and the delivery systems used. These strategies, although encouraging, require additional in vivo studies to support curcumin clinical applications.

Combination of Phospholipid Complex and Matrix Dispersion

Phospholipid complexation, despite being a successful, versatile, and burgeoning strategy, stickiness of phospholipids leads to suboptimal dissolution rate of drugs. This work was undertaken to fabricate simvastatin-phospholipid complex (SIM-PLC)-loaded matrix dispersion (SIM-PLC-MD) using Soluplus® as carrier material, to augment dispersibility and dissolution of SIM-PLC without altering complexation between simvastatin (SIM) and phospholipid. SIM-PLC and SIM-PLC-MD were prepared using solvent evaporation and discontinuous solvent evaporation techniques, respectively. The successful complexation was substantiated by FTIR method. Besides, PXRD and SEM studies disclosed the absence of crystallinity of SIM in both SIM-PLC and SIM-PLC-MD. The TEM analysis monitored the self-assembly of SIM-PLC and SIM-PLC-MD into colloidal structures, which could be correlated with redispersion in GIT fluids upon oral administration. The considerable increase in hydrophilicity of SIM-PLC-MD and SIM-PLC as evident from partition coefficient experiment can further be correlated with their remarkably improved solubility profiles in the following pattern: SIM-PLC-MD˃SIM-PLC˃SIM. Correspondingly, improved dispersibility of SIM-PLC-MD in comparison to SIM-PLC can be accountable for accelerated dissolution rate by 2.53-fold and 1.5-fold in pH 1.2 and 6.8 conditions, respectively. The oral pharmacokinetic evaluation in Sprague Dawley (SD) rats revealed 3.19-fold enhancement in oral bioavailability of SIM through SIM-PLC-MD when compared with plain SIM, whereas 1.83-fold increment was observed in the case of SIM-PLC. Finally, the efficacy experimentation in SD rats revealed that SIM-PLC-MD significantly reduced triglycerides and cholesterol levels in comparison to SIM and SIM-PLC. These outcomes suggest that a matrix dispersion strategy improves oral bioavailability and hypolipidemic activity of SIM.

Improvement of the bioavailability of curcumin by a supersaturatable self nanoemulsifying drug delivery system with incorporation of a hydrophilic polymer: in vitro and in vivo characterisation

OBJECTIVES

The current study was focused on preparing curcumin (CUR) supersaturated self-nano-emulsion (PI-CUR-SNEDDS) using hydrophilic polymer and to study the influence of polymer precipitation inhibitor on the physicochemical and biopharmaceutical properties of the PI-CUR-SNEDDS.

METHODS

PI-CUR-SNEDDS were prepared using hydrophilic polymer in order to maintain the supersaturation of CUR in nano-emulsion solution, artificial gastrointestinal fluid (AGF), and the precipitates formed, and characterised by in vitro dispersion tests, in vitro intestinal absorption and in vivo pharmacokinetic and compared with CUR-SNEDDS.

KEY FINDINGS

PI-CUR-SNEDDS prepared with 2% hydroxypropyl methylcellulose 55-60 (HPMC55-60) as precipitation inhibitor (PI) significantly improved the viscosity, physical stability and CUR's equilibrium solubility of nanoemulsion. HPMC55-60 and CUR interact in AGF through intermolecular interactions, form hydrogen bonds, and produce amorphous precipitates. Compared with CUR-SNEDDS, the proportion of CUR in the hydrophilic phase increased by about 3-fold, and apparent permeability coefficient (Papp) in duodenum, jejunum, ileum, and colon increased by 2.30, 3.65, 1.54 and 2.08-fold, respectively, and the area under the plasma concentration-time curve0-12h of PI-CUR-SNEDDS also increased by 3.50-fold.

CONCLUSIONS

Our results suggested that HPMC55-60 maintained the CUR supersaturation state by forming hydrogen bonds with CUR, increasing the solution's viscosity and drug solubilisation, thus improving the absorption and bioavailability of CUR.

Curcumin micelles entrapped in eudragit S-100 matrix: a synergistic strategy for enhanced oral delivery

Background:

Therapeutic activities of curcumin (CUR) via oral administration are hampered by the lack of bioavailability due to its poor water solubility and rapid degradation in GI tract.

Materials & methods:

This preliminary study developed CUR micelle-eudragit S100 (EUD) dry powder (CM-EDP) spray-dried formulations. Poloxamer 407 was used as a micelle-forming agent and EUD as an entrapping matrix for protection over hydrolysis and enzymes in the GI tract.

Results:

The morphology of CM-EDP showed agglomeration with cratering on the surface of particles. Differential thermal analysis and x-ray diffractometry data exhibited evidence that CUR was converted into amorphous solid. An increased concentration of micelle-forming and dispersion matrix polymers resulted in a high fraction of drug being converted into the amorphous state. A significant increase in dissolution by 7–10 times was achieved compared with that of raw CUR.

Conclusion:

The present study disclosed the CM-EDP potency for future development of CUR oral formulation.

Curcumin (CUR) is a natural compound that shows several pharmacological activities, including anti-inflammatory and potential actions against Parkinson’s and Alzheimer’s. However, several drawbacks need to be addressed its application as a therapeutic agent via oral administration. These drawbacks include its poor water solubility and rapid degradation in the GI tract. The present study developed CUR micelle-eudragit S100 (EUD) dry powder formulation involving poloxamer 407 as solubilizing agent and EUD as entrapping matrix for protection in acidic environments and the enzymes in the GI tract. The final product is in the form of dry powder, which showed potency in enhancing CUR absorption following oral administration.

An Update on the Pharmacological Usage of Curcumin: Has it Failed in the Drug Discovery Pipeline?

The pharmacological propensities of curcumin have been reported in a plethora of pre-clinical and clinical studies. However, innate attributes account for extremely low oral bioavailability which impedes its development as a therapeutic agent. Regardless, these drawbacks have not deterred researchers from optimizing its potentials. This review discussed the pharmacokinetic properties of curcumin relative to its outlook as a lead compound in drug discovery. Also, we highlighted therapeutic strategies that have expedited improvements in curcumin oral bioavailability and delivery to target sites over the years. Recent implementations of these strategies were also covered. More research efforts should be directed towards investigating the pharmacokinetic impacts of these novel curcumin formulations in human clinical studies since inter-species disparities could limit the accuracies of animal studies. We envisaged that integrative-clinical research would help determine 'actual' improvements in curcumin pharmacokinetics coupled with suitable administrative routes, optimal dosing, and drug-enzyme or drug-drug interactions. In addition, this could help determine formulations for achieving higher systemic exposure of parent curcumin thereby providing a strong impetus towards the development of curcumin as a drug candidate in disease treatment.

A matrix dispersion based on phospholipid complex system: preparation, lymphatic transport, and pharmacokinetics

Raloxifene hydrochloride (RH) suffers from low oral bioavailability due to its low water-solubility and first-pass metabolism. Therefore, a novel phospholipid complex of RH (RHPC) and a matrix dispersion based on phospholipid complex (RHPC-MD) were successfully prepared and optimized. Several methods were used to validate the formation of RHPC and RHPC-MD, such as differential scanning calorimetry, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, infrared spectroscopy, particle size, and zeta potential, meanwhile, their octanol-water partition coefficient, solubility, and dissolution in vitro were also evaluated. To investigate the absorption mechanism of RHPC in vivo, the RHPC was administered to the chylomicron flow blockage rat model. Interestingly, as we expected, a significant reduction in RHPC absorption (67%) (**p< .01) in presence of cycloheximide (CXI) inhibitor was observed, thus confirming the RHPC could be absorbed by lymphatic transport in vivo. Pharmacokinetic studies revealed that the relative oral bioavailability of RHPC as well as RHPC-MD was 223% and 329%, respectively, when comparing with the commercial RH tablets. These outcomes suggested that the current study provided an attractive formulation to enhance the oral bioavailability of RH and stimulated to further research the absorption mechanism of RHPC in vivo.

Polymer/lipid interplay in altering in vitro supersaturation and plasma concentration of a model poorly soluble drug

Supersaturation drug delivery system (SDDS) based on amorphous solid dispersion (ASD) is a widely used strategy to improve oral absorption of poorly water-soluble drugs by achieving a supersaturated state where drug concentration is significantly higher than drug solubility. However, dissolved drugs tend to recrystallize in gastrointestinal (GI) tract if without effective stabilizing excipients. In this paper, well-recognized polymer (polyvinylpyrrolidone, PVP) and lipid (phosphatidylcholine, PC) excipients are combined as ASD carrier, aiming at investigating the effects on evolution of in vitro supersaturation and in vivo plasma concentration of a model poorly soluble drug indomethacin (IND). Fundamental aspects including polymer/lipid composition ratio, drug loading (DL) degree and administration dose were investigated. The in vitro dissolution profiles of ASDs were assessed by supersaturation degree, duration, maximum achievable drug concentration and dose-normalized efficiency, and correlated with in vivo pharmacokinetic data. Results showed that both in vitro and in vivo concentration-time profiles of IND were significantly varying with abovementioned factors. Solution viscosity, solid-state properties and morphology of ASDs were related to the results. This study revealed fundamental mechanisms of PVP/PC mixture effect on IND supersaturation and oral bioavailability, demonstrating that polymer/lipid mixture could be used as a promising carrier to alter supersaturation profile and oral bioavailability of SDDS products.

Benefits of curcumin in brain disorders

Curcumin is widely consumed in Asia either as turmeric directly or as one of the culinary ingredients in food recipes. The benefits of curcumin in different organ systems have been reported extensively in several neurological diseases and cancer. Curcumin has got its global recognition because of its strong antioxidant, anti-inflammatory, anti-cancer, and antimicrobial activities. Additionally, it is used in diabetes and arthritis as well as in hepatic, renal, and cardiovascular diseases. Recently, there is growing attention on usage of curcumin to prevent or delay the onset of neurodegenerative diseases. This review summarizes available data from several recent studies on curcumin in various neurological diseases such as Alzheimer's disease, Parkinson's disease, Multiple Sclerosis, Huntington's disease, Prions disease, stroke, Down's syndrome, autism, Amyotrophic lateral sclerosis, anxiety, depression, and aging. Recent advancements toward increasing the therapeutic efficacy of curcuma/curcumin formulation and the novel delivery strategies employed to overcome its minimal bioavailability and toxicity studies have also been discussed. This review also summarizes the ongoing clinical trials on curcumin for different neurodegenerative diseases and patent details of curcuma/curcumin in India.

Preparation and preliminary pharmacokinetics study of GNA-loaded zein nanoparticles

OBJECTIVES

Gambogenic acid (GNA), one of the main active ingredients isolated from Garcinia cambogia, has shown diverse antitumour activities. However, short biological half-life and low oral bioavailability severely limit its clinical application. Here, we developed GNA-loaded zein nanoparticles (GNA-ZN-NPs) based on phospholipid complex and zein nanoparticles to prolong the circulation time and enhance oral bioavailability of GNA.

METHODS

The physicochemical properties of GNA-ZN-NP were characterized in details. The in vitro release profile, in vivo pharmacokinetic experiments and tissue distribution of GNA-ZN-NPs were also evaluated.

KEY FINDINGS

The particle size, PDI and encapsulation efficiency of GNA-ZN-NPs were 102.90 nm, 0.027 and 76.35 ± 0.64%, respectively. The results of SEM, FTIR, DSC and XRD demonstrated that GNA-ZN-NPs were prepared successfully. The in vitro dissolution of GNA-ZN-NPs exhibited controlled release compared with raw GNA solution. The pharmacokinetic study showed that the AUC of GNA-ZN-NPs was significantly increased, and the t_1/2 and MRT values of GNA-ZN-NPs were 3.21-fold and 2.19-fold higher than that of GNA solution. Tissue distribution results illustrated that GNA-ZN-NPs showed hepatic-targeting properties.

CONCLUSION

GNA-ZN-NPs significantly enhanced the oral bioavailability and prolonged half-life of GNA, providing a promising oral drug delivery system to improve in vivo pharmacokinetic behaviour of GNA.

Enhanced water solubility, antioxidant activity, and oral absorption of hesperetin by D-α-tocopheryl polyethylene glycol 1000 succinate and phosphatidylcholine

Hesperetin, an abundant bioactive component of citrus fruits, is poorly water-soluble, resulting in low oral bioavailability. We developed new formulations to improve the water solubility, antioxidant activity, and oral absorption of hesperetin. Two nano-based formulations were developed, namely hesperetin-TPGS (D-α-tocopheryl polyethylene glycol 1000 succinate) micelles and hesperetin-phosphatidylcholine (PC) complexes. These two formulations were prepared by a simple technique called solvent dispersion, using US Food and Drug Administration (FDA)-approved excipients for drugs. Differential scanning calorimetry (DSC) and dynamic light scattering (DLS) were used to characterize the formulations' physical properties. Cytotoxicity analysis, cellular antioxidant activity assay, and a pharmacokinetic study were performed to evaluate the biological properties of these two formulations. The final weight ratios of both hesperetin to TPGS and hesperetin to PC were 1:12 based on their water solubility, which increased to 21.5- and 20.7-fold, respectively. The hesperetin-TPGS micelles had a small particle size of 26.19 nm, whereas the hesperetin-PC complexes exhibited a larger particle size of 219.15 nm. In addition, the cellular antioxidant activity assay indicated that both hesperetin-TPGS micelles and hesperetin-PC complexes increased the antioxidant activity of hesperetin to 4.2- and 3.9-fold, respectively. Importantly, the in vivo oral absorption study on rats indicated that the micelles and complexes significantly increased the peak plasma concentration (C_max) from 2.64 μg/mL to 20.67 and 33.09 μg/mL and also increased the area under the concentration-time curve of hesperetin after oral administration to 16.2- and 18.0-fold, respectively. The micelles and complexes increased the solubility and remarkably improved the in vitro antioxidant activity and in vivo oral absorption of hesperetin, indicating these formulations' potential applications in drugs and healthcare products.

Curcumin-loaded self-nanomicellizing solid dispersion system: part I: development, optimization, characterization, and oral bioavailability

Curcumin (CUR) is considered as one of the most bioactive molecules ever discovered from nature due to its proven anti-inflammatory and antioxidant in both preclinical and clinical studies. Despite its proven safety and efficacy, the clinical translation of CUR into a useful therapeutic agent is still limited due to its poor oral bioavailability. To overcome its limitation and enhance oral bioavailability by improving its aqueous solubility, stability, and intestinal permeability, a novel CUR formulation (NCF) was developed using the self-nanomicellizing solid dispersion strategy. From the initial screening of polymers for their potential to improve the solubility and stability, Soluplus (SOL) was selected. The optimized NCF demonstrated over 20,000-fold improvement in aqueous solubility as a result of amorphization, hydrogen bonding interaction, and micellization determined using differential scanning calorimetry, X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, nuclear magnetic resonance, dynamic light scattering, and transmission electron microscopy. Moreover, the greater stabilizing effect in alkaline pH and light was observed. Furthermore, significant enhancement of dissolution and permeability of CUR across everted sacs of rat small intestine were noticed. Pharmacokinetic studies demonstrated that the oral bioavailability of CUR was increased 117 and 17-fold in case of NCF and physical mixture of CUR and SOL compared to CUR suspension. These results suggest NCF identified as a promising new approach for repositioning of CUR for pharmaceutical application by enhancing the oral bioavailability of CUR. The findings herein stimulate further in vivo evaluations and clinical tests of NCF.