Drug-Phospholipid Complex-a Go Through Strategy for Enhanced Oral Bioavailability

Characterization of the daucosterol-lecithin complex and its impact on lipid metabolism in hyperlipidemic mice

This investigation delves into the daucosterol-lecithin complex (DS-LC) and its effects on lipid homeostasis in hyperlipidemic mice. DS-LC was assessed for complexation efficiency, physicochemical properties (UV, XRD, FTIR, SEM, DSC), and its impact on organ health and serum lipid levels. The results revealed that daucosterol formed an effective complex with lecithin at a 2 : 1 ratio, producing a translucent beige DS-LC with distinctive aggregation. UV-vis spectra confirmed that daucosterol's chromophore structure remained intact in DS-LC, indicating no new compound formation. FTIR analysis identified hydrogen bonding and increased molecular association without changing lecithin peaks, highlighting specific intermolecular interactions. SEM and XRD showed that complexation transformed daucosterol into an irregular form within the lecithin matrix, forming a new phase and demonstrating a strong lecithin-daucosterol interaction. Thermal analysis suggested homogeneous daucosterol distribution due to intermolecular interactions. DS-LC treatment effectively alleviated hyperlipidemia, enhancing liver function and reducing lipid accumulation in epididymal fat. It also significantly decreased total cholesterol, triglycerides, LDL-C, and arteriosclerosis index in hyperlipidemic mice, indicating DS-LC's potential as a therapeutic agent for lipid metabolism and related metabolic disorders.

Amorphous Polymer-Phospholipid Solid Dispersions for the Co-Delivery of Curcumin and Piperine Prepared via Hot-Melt Extrusion

Curcumin and piperine are plant compounds known for their health-promoting properties, but their use in the prevention or treatment of various diseases is limited by their poor solubility. To overcome this drawback, the curcumin-piperine amorphous polymer-phospholipid dispersions were prepared by hot melt extrusion technology. X-ray powder diffraction indicated the formation of amorphous systems. Differential scanning calorimetry confirmed amorphization and provided information on the good miscibility of the active compound-polymer-phospholipid dispersions. Owing to Fourier-transform infrared spectroscopy, the intermolecular interactions in systems were investigated. In the biopharmaceutical properties assessment, the improvement in solubility as well as the maintenance of the supersaturation state were confirmed. Moreover, PAMPA models simulating the gastrointestinal tract and blood-brain barrier showed enhanced permeability of active compounds presented in dispersions compared to the crystalline form of individual compounds. The presented paper suggests that polymer-phospholipid dispersions advantageously impact the bioaccessibility of poorly soluble active compounds.

A new crystalline daidzein-piperazine salt with enhanced solubility, permeability, and bioavailability

To overcome the poor solubility, permeability, and bioavailability of the plant isoflavone daidzein (DAI), a novel salt of DAI with anhydrous piperazine (PIP) was obtained based on cocrystallization strategy. The new salt DAI-PIP was characterized by powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier-transform infrared (FT-IR) spectroscopy, and optical microscopy. The results showed that the maximum apparent solubility (Smax) of DAI-PIP increased by 7.27-fold and 1000-fold compared to DAI in pH 6.8 buffer and water, respectively. The peak apparent permeability coefficient (P app ) of DAI-PIP in the Caco-2 cell model was 30.57 ± 1.08 × 10-6 cm/s, which was 34.08% higher than that of DAI. Additionally, compared to DAI, the maximum plasma concentration (Cmax) value of DAI-PIP in beagle dogs was approximately 4.3 times higher, and the area under the concentration-time curve (AUC0-24) was approximately 2.4 times higher. This study provides a new strategy to enhance the dissolution performance and bioavailability of flavonoid drugs, laying a foundation for expanding their clinical applications.

Advancements in nanotechnology for the delivery of phytochemicals

Phytosomes (phytophospholipid complex) are dosage forms that have recently been introduced to increase the stability and therapeutic effect of herbal medicine. Currently, bioactive herbs and the phytochemicals they contain are considered to be the best remedies for chronic diseases. One promising approach to increase the efficacy of plant-based therapies is to improve the stability and bioavailability of their bio-active ingredients. Phytosomes employ phospholipids as their active ingredients, and use their amphiphilic properties to solubilize and protect herbal extracts. The unique properties of phospholipids in drug delivery and their use in herbal medicines to improve bioavailability results in significantly enhanced health benefits. The introduction of phytosome nanotechnology can alter and revolutionize the current state of drug delivery. The goal of this review is to explain the application of phytosomes, their future prospects in drug delivery, and their advantages over conventional formulations. Please cite this article as: Chauhan D, Yadav PK, Sultana N, Agarwal A, Verma S, Chourasia MK, Gayen JR. Advancements in nanotechnology for the delivery of phytochemicals. J Integr Med. 2024; 22(4): 385-398.

Research progress on pharmacological effects and bioavailability of berberine

Berberine (BBR), a benzylisoquinoline alkaloid obtained from natural medicines such as coptidis rhizoma, has a wide range of pharmacological activities such as protecting the nervous system, protecting the cardiovascular system, anti-inflammatory, antidiabetic, antihyperlipidemic, antitumor, antibacterial, and antidiarrheal. However, factors such as poor solubility, low permeability, P-glycoprotein (P-gp) efflux, and hepatic-intestinal metabolism result in BBR having a low bioavailability (< 1%), which restricts its application in clinical settings. Therefore, improving its bioavailability is a prerequisite for its clinical applications. This review summarizes the various pharmacological effects of BBR and analyzes the main reasons for its poor bioavailability. It introduces methods to improve the bioavailability of BBR through the use of absorption enhancers and P-gp inhibitors, structural modification of BBR, and preparation of BBR salts and cocrystals as well as the development of new formulations and focuses on the bioavailability study of the new formulations of BBR. The research of BBR was also prospected in order to provide reference for the further research of BBR.

Phospholipid Complex Formulation Technology for Improved Drug Delivery in Oncological Settings: a Comprehensive Review

Addressing poor solubility and permeability issues associated with synthetic drugs and naturally occurring active compounds is crucial for improving bioavailability. This review explores the potential of phospholipid complex formulation technology to overcome these challenges. Phospholipids, as endogenous molecules, offer a viable solution, with drugs complexed with phospholipids demonstrating a similar absorption mechanism. The non-toxic and biodegradable nature of the phospholipid complex positions it as an ideal candidate for drug delivery. This article provides a comprehensive exploration of the mechanisms underlying phospholipid complexes. Special emphasis is placed on the solvent evaporation method, with meticulous scrutiny of formulation aspects such as the phospholipid ratio to the drug and solvent. Characterization techniques are employed to understand structural and functional attributes. Highlighting the adaptability of the phospholipid complex, the review discusses the loading of various nanoformulations and emulsion systems. These strategies aim to enhance drug delivery and efficacy in various malignancies, including breast, liver, lung, cervical, and pancreatic cancers. The broader application of the drug phospholipid complex is showcased, emphasizing its adaptability in diverse oncological settings. The review not only explores the mechanisms and formulation aspects of phospholipid complexes but also provides an overview of key clinical studies and patents. These insights contribute to the intellectual and translational advancements in drug phospholipid complexes.

Utilization of Lipophilic Salt and Phospholipid Complex in Lipid-Based Formulations to Modulate Drug Loading and Oral Bioavailability of Pazopanib

Pazopanib hydrochloride (PAZ) displays strong intermolecular interaction in its crystal lattice structure, limiting its solubility and dissolution. The development of lipid-based formulations (LbFs) resulted in reduced PAZ loading due to solid-state mediated low liposolubility. This study aims to enhance our understanding of PAZ crystallinity by synthesizing a lipophilic salt and phospholipid complex and investigating its impact on the drug loading in LbFs. The synthesized pazopanib lipophilic salt and phospholipid complex were extensively characterized. The solid form of pazopanib docusate (PAZ-DOC) and pazopanib phospholipid complex (PAZ-PLC) indicates a reduction in characteristic diffraction peaks of crystalline PAZ. The lipid formulations were prepared using synthesized PAZ-DOC and PAZ-PLC, where PAZ-DOC demonstrated six fold higher drug solubility than the commercial salt form and twice that of the PAZ-PLC due to differences in the crystallinity. Further, the impact of salt and complex formation was assessed on the aqueous drug solubilization using lipolysis and multimedia dissolution experiments. Moreover, the LbFs showed notably faster dissolution compared to the crystalline PAZ and marketed tablet. In terms of in vivo pharmacokinetics, the PAZ-DOC LbF exhibited a remarkable 11-fold increase in AUC value compared to the crystalline PAZ and a 2.5-fold increase compared to Votrient®. Similarly, PAZ-PLC LbF showed an approximately nine fold increase in drug exposure compared to the crystalline PAZ, and a 2.2-fold increase compared to Votrient®. These findings suggest that disrupting the crystallinity of drugs and incorporating them into LbF could be advantageous for enhancing drug loading and overcoming limitations related to drug absorption.

Novel PEGylated cholephytosomes for targeting fisetin to breast cancer: in vitro appraisal and in vivo antitumoral studies

Fisetin (FIS) is a multifunctional bioactive flavanol that has been recently exploited as anticancer drug against various cancers including breast cancer. However, its poor aqueous solubility has constrained its clinical application. In the current work, fisetin is complexed for the first time with soy phosphatidylcholine in the presence of cholesterol to form a novel biocompatible phytosomal system entitled "cholephytosomes." To improve fisetin antitumor activity against breast cancer, stearylamine bearing cationic cholephytosomes (mPHY) were prepared and furtherly modified with hyaluronic acid (HPHY) to allow their orientation to cancer cells through their surface exposed phosphatidylserine and CD-44 receptors, respectively. In vitro characterization studies revealed promising physicochemical properties of both modified vesicles (mPHY and HPHY) including excellent FIS complexation efficiency (˷100%), improved octanol/water solubility along with a sustained drug release over 24 h. In vitro cell line studies against MDA-MB-231 cell line showed about 10- and 3.5-fold inhibition in IC50 of modified vesicles compared with free drug and conventional drug-phospholipid complex, respectively. Preclinical studies revealed that both modified cholephytosomes (mPHY and HPHY) had comparable cytotoxicity that is significantly surpassing free drug cytotoxicity. TGF-β1and its non-canonical related signaling pathway; ERK1/2, NF-κB, and MMP-9 were involved in halting tumorigenesis. Thus, tailoring novel phytosomal nanosystems for FIS could open opportunity for its clinical utility against cancer.

Development and Evaluation of a Novel Hyaluronic Acid and Chitosan-modified Phytosome for Co-delivery of Oxymatrine and Glycyrrhizin for Combination Therapy

BACKGROUND

Multidrug resistance (MDR) of cancer cells is a major obstacle to efficient cancer chemotherapy. Combination therapy is expected to enhance the anticancer effect and reverse MDR. Numerous patents involve different kinds of nanoparticles for the co-delivery of multiple chemotherapeutics, but the FDA has approved none.

OBJECTIVE

In this study, oxymatrine (OMT) and glycyrrhizin (GL) were co-loaded into phytosomes as the core of nanocarriers, and the shell was cross-linked with chitosan (CS) and hyaluronic acid (HA) with the capability for the controlled, sequential release and the targeted drug uptake.

METHODS

Phospholipid complexes of OMT and GL (OGPs) were prepared by a solvent evaporation technique and could self-assemble in an aqueous solution to form phytosomes. CS and HA were sequentially coated on the surface of OGPs via electrostatic interactions to obtain CS coated OGPs (CS-OGPs) and HA modified CS-OGPs (HA-CS-OGPs), respectively. The particle size and zeta potential were measured to optimize the formulations. In vitro cytotoxicity and cellular uptake experiments on HepG2 cells were performed to evaluate the anticancer activity.

RESULTS

OGPs were obtained with nano-size around 100 nm, and CS and HA coating on phytosomes could change the particle size and surface potential. The drug loading of OMT and GL showed that the nanocarriers could maintain a fixed ratio of 1:1. The in vitro release experiments indicated the release of OMT and GL was pH-dependent and sequential: the release of OMT from CS-OGPs and HA-CS-OGPs was significantly increased at pH 5.0 compared to the release at pH 7.4, while GL exhibited sustained released from CS-OGPs and HA-CS-OGPs at pH 5.0. Furthermore, in vitro cytotoxicity and cellular uptake experiments on HepG2 cells demonstrated that the co-delivery system based on phytosomes had significant synergistic anti-tumor activities, and the effects were enhanced by CS and HA modification.

CONCLUSION

The delivery of OMT and GL via HA-CS-OGPs might be a promising treatment to reverse MDR in cancer therapy.

The Chimera of TPGS and Nanoscale Lipid Carriers as Lymphatic Drug Delivery Vehicles to Fight Metastatic Cancers

The lymphatic system (LS) plays a crucial role in fluid balance, transportation of macromolecules, and immune response. Moreover, LS is a channel for microbial invasion and cancer metastasis. Particularly, solid tumors, including lung, breast, melanoma, and prostate cancers, are metastasized across highways of LS. Subsequently, the fabrication of chimeric lymphatic drug delivery systems (LDDS) is a promising strategy to fight cancer metastasis and control microbial pandemics. In this regard, LDDS, in terms of PEG-nanoscaled lipid carriers, elicited a revolution during the COVID-19 pandemic as cargoes for mRNA vaccines. The drug delivered by the lymphatic pathway escapes first-pass metabolism and enhances the drug's bioavailability. Ample approaches, including synthesis of prodrugs, trigging of chylomicron biosynthesis, and fabrication of nanocarriers, facilitate lymphatic drug delivery. Specifically, nanoscales lipid cargoes have the propensity to lymphatic trafficking. Interestingly, TPGSengineered nanoscale lipid cargoes enhance lymphatic trafficking, increase tissue permeation, and, specifically, uptake. Moreover, they overcome biological barriers, control biodistribution, and enhance organelles localization. Most anticancer agents are non-specific, have low bioavailability, and induced drug resistance. Therefore, TPGS-engineered nanoscale lipid chimeras improve the therapeutic impact of anticancer agents. This review highlights lymphatic cancer metastasis, nanoscales lipid cargoes as LDDS, and their influence on lymphatic trafficking, besides the methods of LDD studies.

Crocin-Phospholipid Complex: Molecular Docking, Molecular Dynamics Simulation, Preparation, Characterization, and Antioxidant Activity

Background

Crocin is a water-soluble carotenoid compound present in saffron (Crocus sativus L.), known for its wide range of pharmacological activities, including cardioprotective, hepatoprotective, anti-tumorigenic, anti-atherosclerosis, and anti-inflammatory effects.

Objectives

The instability of crocin, its low miscibility with oils, and poor bioavailability pose challenges for its pharmaceutical applications. This study aimed to design and prepare a crocin-phospholipid complex (CPC) and assess its physicochemical properties.

Methods

The study investigated the formation of the complex and its binding affinity through molecular docking. Molecular dynamics (MD) simulations were conducted to find the optimal molar ratio of crocin to phospholipid for the complex's preparation. The CPC was produced using the solvent evaporation method. Techniques such as X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), field-emission scanning electron microscopy (FE-SEM), nuclear magnetic resonance (NMR), and solubility studies were utilized to characterize and confirm the formation of CPC. Additionally, the in vitro antioxidant activity of crocin and CPC was evaluated.

Results

Molecular dynamic simulations explored molar ratios of 1: 1, 1: 1.5, and 1: 2 for crocin to phospholipid. The ratio of 1: 2 was found to be the most stable, exhibiting the highest probability of hydrogen bond formation. Molecular docking, FTIR, and NMR studies indicated hydrogen bond interactions between crocin and phospholipid, confirming CPC's formation. XRD and FE-SEM analyses showed a decrease in crocin's crystallinity within the phospholipid complex. Furthermore, the solubility of crocin in n-octanol was enhanced post-complexation, indicating an increase in crocin's lipophilic nature.

Conclusions

Phospholipid complexation emerges as a promising technique for enhancing the physicochemical characteristics of crocin.

Preparation and in vivo evaluation of an intravenous emulsion loaded with an aprepitant-phospholipid complex

In present, there was no detailed report on the formulation optimization and quality evaluation of aprepitant (APT) injectable lipid emulsion (APT-IE). The aim of the present investigation was to prepare and evaluate its properties of APT-IE loaded with an APT phospholipid complex (APT-PC) in vitro and in vivo. APT-PC was obtained by solvent evaporation with APT and phospholipids, then analyzed by X-ray diffraction, Fourier transform infrared spectroscopy and differential scanning calorimetry. Lipid emulsions are a new formulation that can reduce side effects and improve drug loading.APT-IE prepared by High-pressure homogenization and optimized by response surface methodology (RSM). The proportion of sodium oleate, poloxamer 188 and soybean oil were selected as variables for the optimization. The optimal formulation of ATP-IE had the following characteristics: particle size, 82.83 ± 1.89 nm; polydispersity index, 0.243 ± 0.008; zeta potential, -59.0 ± 2.54 mV; encapsulation efficiency, 98.84%±1.43%; drug loading, 7.08 ± 0.16 mg/mL; and osmotic pressure, 301 ± 2.15 mOsmol/kg. Transmission electron microscopy images indicated that the particle diameter of APT-IE was approximately 100 nm, with a morphology of spheroidal or spherical. APT-IE exhibited sufficient stability after storage at 4 ± 2 °C for more than 6 months. The results of the pharmacokinetic study demonstrated that APT-IE had the advantages of better safety, higher bioavailability, and obvious liver targeting than APT solution (APT-SL). The area under the curve (AUC) of APT-IE was 3-fold enhanced compared with APT-SL. The targeted enhancement multiple of APT-IE to liver tissue was greater than that of APT-SL. These results suggested that APT-IE has broad clinical application and industrial production potential.

Self-assembled fisetin-phospholipid complex: Fisetin-integrated phytosomes for effective delivery to breast cancer

Nowadays, fisetin (FIS) is extensively studied as potent anticancer surrogate with a multitarget actions against various types of cancers including breast cancer. However, its poor aqueous solubility handicapped its clinical utility. The current work endeavored, for the first time, to develop FIS phytosomes (FIS-PHY) for improving its physicochemical properties and subsequently its anticancer activity. Optimization of FIS- phytosomes involved different preparation techniques (Thin film hydration and ethanol injection) and different FIS: phospholipid molar ratios (1:1, 1:2, and 1:3). Complex formation was confirmed by complexation efficiency, infrared spectroscopy (IR), solubility studies and transmission electron microscope. The optimized FIS-PHY of 1:1 M ratio (PHY1) exhibited a nanometric particle size of 233.01 ± 9.46 nm with homogenous distribution (PDI = 0.27), negative zeta potential of - 29.41 mV, 100% complexation efficiency and controlled drug release over 24 h. In-vitro cytotoxicity study showed 2.5-fold decrease in IC50 of PHY1 compared with free FIS. Also, pharmacodynamic studies confirmed the promoted cytotoxicity of PHY1 against breast cancer through modulating TGF-β1/MMP-9 molecular pathways of tumorigenesis. Overall, overcoming FIS drawbacks were successfully achieved through development of innovative biocompatible phytosomal system.

Berberine-phospholipid nanoaggregate-embedded thiolated chitosan hydrogel for aphthous stomatitis treatment

Aim: This study aimed to develop nanoaggregates of berberine-phospholipid complex incorporated into thiolated chitosan (TCS) hydrogel for the treatment of aphthous stomatitis. Methods: The berberine-phospholipid complex was formulated through the solvent evaporation technique and assembled into nanoaggregates. TCS was synthesized through the attachment of thioglycolic acid to chitosan (CS). Nanoaggregates-TCS was prepared by the incorporation of nanoaggregates into TCS and underwent in vitro and in vivo tests. Results: Nanoaggregates-TCS exhibited prolonged release of berberine. The mucoadhesive strength of nanoaggregates-TCS increased 1.75-fold compared with CS hydrogel. In vivo studies revealed the superior therapeutic efficacy of nanoaggregates-TCS compared with that of other groups. Conclusion: Due to prolonged drug release, appropriate residence time and anti-inflammatory effects, nanoaggregates-TCS is an effective system for the treatment of aphthous stomatitis.

Drug complexes: Perspective from Academic Research and Pharmaceutical Market

Despite numerous research efforts, drug delivery through the oral route remains a major challenge to formulation scientists. The oral delivery of drugs poses a significant challenge because more than 40% of new chemical entities are practically insoluble in water. Low aqueous solubility is the main problem encountered during the formulation development of new actives and for generic development. A complexation approach has been widely investigated to address this issue, which subsequently improves the bioavailability of these drugs. This review discusses the various types of complexes such as metal complex (drug-metal ion), organic molecules (drug-caffeine or drug-hydrophilic polymer), inclusion complex (drug-cyclodextrin), and pharmacosomes (drug-phospholipids) that improves the aqueous solubility, dissolution, and permeability of the drug along with the numerous case studies reported in the literature. Besides improving solubility, drug-complexation provides versatile functions like improving stability, reducing the toxicity of drugs, increasing or decreasing the dissolution rate, and enhancing bioavailability and biodistribution. Apart, various methods to predict the stoichiometric ratio of reactants and the stability of the developed complex are discussed.

Mechanisms of theaflavins against gout and strategies for improving the bioavailability

BACKGROUND

Gout is a crystal related arthropathy caused by monosodium urate deposition. At present, the identification of appropriate treatments and new drugs to reduce serum uric acid levels and gout risk is a major research area.

PURPOSE

Theaflavins are naturally occurring compounds characterized by a benzodiazepine skeleton. The significant benefits of theaflavins have been well documented. A large number of studies have been carried out and excellent anti-gout results have been achieved in recent years.

STUDY DESIGN

A comprehensive analysis of the mechanism of the anti-gout effect of theaflavins is presented through a literature review and network pharmacology prediction, and strategies for increasing the bioavailability of theaflavins are summarized.

METHODS

In this review, the active components and pharmacological mechanisms of theaflavins in the treatment of gout were summarized, and the relationship between theaflavins and gout, the relevant components, and the potential mechanisms of anti-gout action were clarified by reviewing the literature on the anti-gout effects of theaflavins and network pharmacology.

RESULTS

Theaflavins exert anti-gout effects by down regulating the gene and protein expression of glucose transporter 9 (GLUT9) and uric acid transporter 1 (URAT1), while upregulating the mRNA expression levels of organic anion transporter 1 (OAT1), organic cation transporter N1 (OCTN1), organic cation transporters 1/2 (Oct1/2), and organic anion transporter 2 (OAT2). Network pharmacology prediction indicate that theaflavins can regulate the AGE-RAGE and cancer signaling pathways through ATP-binding cassette subfamily B member 1 (ABCB1), recombinant mitogen activated protein kinase 14 (MAPK14), telomerase reverse tranase (TERT), signal transducer and activator of transcription 1 (STAT1), matrix metalloproteinase 2 (MMP2), B-cell lymphoma-2 (BCL2), and matrix metalloproteinase 14 (MMP14) targets for anti-gout effects.

CONCLUSION

This review presents the mechanisms of anti-gout action of theaflavins and strategies for improving the bioavailability of theaflavins, as well as providing research strategies for anti-gout treatment measures and the development of novel anti-gout drugs.

Amphotericin B and monoacyl-phosphatidylcholine form a stable amorphous complex

Amphotericin B (AmB) is a "life-saving" medicine for the treatment of invasive fungal infections and visceral leishmaniasis. To date, all marketed AmB formulations require parenteral administration, which causes high rates of acute infusion-related side effects and dose-dependent nephrotoxicity. The development of an oral AmB formulation will entail numerous advantages including increased patient compliance, eliminated infusion-related toxicities and reduced nephrotoxicity. Unfortunately, the gastrointestinal absorption of AmB is negligible due to its extremely low solubility in both aqueous and lipid solvents, and its poor gastrointestinal permeability. Drug-phospholipid complexation is an emerging strategy for oral delivery of poorly soluble drugs. In this study, monoacyl-phosphatidylcholine (MAPC) was complexed with AmB forming an AmB-MAPC complex (APC), to enhance the dissolution rate and aqueous solubility of AmB, in order to enable oral delivery of AmB. X-ray powder diffraction demonstrated that AmB was transformed to its amorphous form following complexation with MAPC, i.e. in the APC. Fourier-transform infrared spectroscopy suggested molecular interactions between AmB and MAPC. Dynamic light scattering indicated formation of colloidal structures after aqueous dispersion of APC; Cryogenic transmission electron microscopy showed that APC formed small round, "rod-like" and "worm-like" micellar structures and Small-angle neutron scattering provided three-dimensional micellar structures formed by APC upon aqueous dispersion, which indicated that AmB was inserted into the micellar mono-layer membrane formed by MAPC. Additionally, APC showed an increased dissolution rate and a higher amount of AmB solubilized in fasted state simulated intestinal fluid, compared to AmB/MAPC physical mixtures and crystalline AmB. In conclusion, an APC exhibiting amorphous properties was developed, the APC showed improved dissolution rate and increased apparent aqueous solubility compared to AmB, indicating that the application of APC could be a promising strategy to enable the oral delivery of AmB.

Preparation, Characterization, and In Vivo Evaluation of Gentiopicroside-Phospholipid Complex (GTP-PC) and Its Self-Nanoemulsion Drug Delivery System (GTP-PC-SNEDDS)

The objective of the present study was to develop a gentiopicroside-phospholipid complex (GTP-PC) and its self-nanoemulsion drug delivery system (GTP-PC-SNEDDS) to increase the oral bioavailability of gentiopicroside (GTP). The factors affecting the formation of GTP-PC were studied with the complexation efficiency and dissociation rate. The properties of the complex were investigated by means of differential scanning calorimetry (DSC), X-ray diffraction (XRD), Fourier transform infrared spectra (FT-IR), dissolution, etc. Then, GTP-PC was loaded into SNEDDS by investigating the effects of weight ratios of GTP-PC to blank SNEDDS, preparation technology, dilution media, and dilution multi, based on the screening results of oils, surfactants, and cosurfactants. In rats, GTP, GTP-PC, and GTP-PC-SNEDDS were orally administered at different times, and GTP concentrations were determined using RP-HPLC. The optimal GTP-PC was prepared with tetrahydrofuran as the reaction solvent, GTP:phospholipid = 1:2, and stirring for 4 h. The optimal prescription for GTP-PC-SNEDDS was as follows: Maisin 35-1:Miglycol = 30%, Labrasol:Cremophor EL = 1:4 = 40%, Transcutol P = 30%; Maisin 35-1:Miglycol = 12, and the ratio of GTP-PC to blank was 1:10-then the mixture was stirred at 37 °C for 1 d and then placed for 2 d to form stable GTP-PC-SNEDDS. After oral administration of GTP, GTP-PC and GTP-PC-SNEDDS, and mean plasma GTP concentration-time curves were all in accordance with the single-compartment model. The C_max, AUC_0-∞, and Fr of the three formulations were significantly higher than that of GTP, demonstrating that GTP was metabolized rapidly, and its higher bioavailability could be achieved by the formation of GTP-PC and GTP-PC-SNEDDS. Among the three formations, the bioavailability of GTP-PC-SNEDDS was highest, with approximately 2.6-fold and 1.3-fold of Fr value, compared with GTP-PC (suspension) and GTP-PC (oil solution), respectively. Compared with GTP, GTP-PC and GTP-PC-SNEDDS enhanced the bioavailability of GTP significantly. In the future, this study could serve as a reference for clinical trials using GTP-PC and GTP-PC-SNEDDS.

Chrysin-phospholipid complex-based solid dispersion for improved anti-aging and neuroprotective effects in mice

The present study aimed to improve the neuroprotective effect of chrysin (CHR) by combining two formulation techniques, phospholipid (PL) complexation and solid dispersion (SD). CHR-phospholipid complex (CHR-PLC) was prepared through solvent evaporation. The molar ratio CHR/PL (1:3), which exhibited the highest complexation efficiency, was selected for the preparation of CHR-PLC loaded SD (CHR-PLC-SD) with 2-hydroxypropyl β cyclodextrin (2-HPβCD) and polyvinylpyrrolidone 8000. CHR-PLC/2-HPβCD (1:2, w/w) displayed the highest aqueous solubility of CHR (5.86 times more than that of plain CHR). CHR-SD was also prepared using 2-HPβCD for comparison. The in vitro dissolution of CHR-PLC-SD4 revealed an enhancement in the dissolution rate over CHR-PLC (1:3), CHR-SD, and plain CHR by six times. The optimum formulations and plain CHR were evaluated for their neuroprotective effect on brain aging induced by D-galactose in mice. The results demonstrated a behavioral activity elevation, an increase of AMPK, LKB1, and PGC1α brain contents as well as a reduction of AGEs, GFAP, NT-3, TNF-α, and NF-κβ brain contents when compared with those of the D-galactose control group. Thus, the developed formulations stimulated neurogenesis and mitochondrial biogenesis as well as suppressed neuroinflammation and neurodegeneration. The order of activity was as follows: CHR-PLC-SD4 > CHR-PLC (1:3) > CHR-SD > plain CHR.

Strategic developments in the drug delivery of natural product dihydromyricetin: applications, prospects, and challenges

Dihydromyricetin (DHM) is an important natural flavonoid that has attracted much attention because of its various functions such as protecting the cardiovascular system and liver, treating cancer and neurodegenerative diseases, and anti-inflammation effect, etc. Despite its great development potential in pharmacy, DHM has some problems in pharmaceutical applications such as low solubility, permeability, and stability. To settle these issues, extensive research has been carried out on its physicochemical properties and dosage forms to produce all kinds of DHM preparations in the past ten years. In addition, the combined use of DHM with other drugs is a promising strategy to expand the application of DHM. However, although invention patents for DHM preparations have been issued in several countries, the current transformation of DHM research results into market products is insufficient. To date, there is still a lack of deep research into the pharmacokinetics, pharmacodynamics, toxicology, and action mechanism of DHM preparations. Besides, preparations for combined therapy of DHM with other drugs are scarcely reported, which necessitates the development of dosage forms for this application. Apart from medicine, the development of DHM in the food industry is also of great potential. Due to its multiple effects and excellent safety, DHM preparations can be developed for functional drinks and foods. Through this review, we hope to draw more attention to the development potential of DHM and the above challenges and provide valuable references for the research and development of other natural products with a similar structure-activity relationship to this drug.

Development and Evaluation of a Novel Diammonium Glycyrrhizinate Phytosome for Nasal Vaccination

The objective of the present research was to formulate diammonium glycyrrhizinate (DG) into phytosomes (DG-P) to induce nasal immune responses and enhance absorption. Plackett- Burman design was used for process optimization, incorporating specific formulation and process variables to obtain the optimal parameters. Fourier transform infrared spectroscopy (FTIR), X-ray power diffraction (P-XRD), and transmission electron microscopy (TEM) were used for characterization. The adjuvant activity of the DG-P was evaluated by using bone marrow dendritic cells. In vitro nasal mucosal permeation and in situ nasal perfusion were also investigated to evaluate nasal absorption. The DG phytosomes were in the size range of 20~30 nm and zeta-potential range of −30~−40 mV. DG-P demonstrated 4.2-fold increased solubility in n-octanol. Coculturing bone marrow dendritic cells with DG-P led to enhanced dendritic cell maturation. Apparent permeability coefficient of the phytosomal formulation was almost four times higher than that of free DG determined by ex vivo permeation studies on excised porcine mucosa. In situ nasal perfusion studies in rats demonstrated that the nasal absorption of DG-P was significantly higher than that of free DG. Conclusively, the results confirmed that DG-P have potential for use as an adjuvant for nasal vaccine.

Preparation of an isorhamnetin phospholipid complex for improving solubility and anti-hyperuricemia activity

To improve the solubility and anti-hyperuricemia activity of the insoluble natural flavonoid isorhamnetin (ISO), an isorhamnetin phospholipid complex (ISO-PC) was prepared. ISO-PC was prepared through solvent evaporation and its prescription process was optimized. The formation of ISO-PC was verified via multiple characterization methods. Parameters such as drug loading, solubility, octanol-water partition coefficient, stability, and in vivo anti-hyperuricemia activity of ISO-PC were investigated. The complexation efficiency of ISO-PC was 95.1% ± 0.56%. The characterization results confirmed that ISO-PC was bound by intermolecular interactions between ISO and phospholipids. Compared to ISO, the solubility of ISO-PC in water and 1-octanol increased by 122 and 16.5 times, respectively. Additionally, the octanol-water partition coefficient decreased to 1.08. Pharmacodynamic studies have reported that ISO-PC has a more significant effect on reducing serum uric acid levels and renal protection. In conclusion, the findings of this study suggested that ISO-PC could be used as a promising formulation to improve the solubility and the anti-hyperuricemia activity of ISO.

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.

Bioavailability Improvement Strategies for Icariin and Its Derivates: A Review

In recent years, there has been considerable interest in icariin (ICA) and its derivates, icariside II (ICS) and icaritin (ICT), due to their wide range of potential applications in preventing cancer, cardiovascular disease, osteoporosis, delaying the effects of Alzheimer’s disease, treating erectile dysfunction, etc. However, their poor water solubility and membrane permeability, resulting in low bioavailability, dampens their potential beneficial effects. In this regard, several strategies have been developed, such as pharmaceutical technologies, structural transformations, and absorption enhancers. All these strategies manage to improve the bioavailability of the above-mentioned flavonoids, thus increasing their concentration in the desired places. This paper focuses on gathering the latest knowledge on strategies to improve bioavailability for enhancing the efficacy of icariin, icariside II, and icaritin. We conclude that there is an opportunity for many further improvements in this field. To the best of our knowledge, no such review articles scoping the bioavailability improvement of icariin and its derivates have been published to date. Therefore, this paper can be a good starting point for all those who want to deepen their understanding of the field.

Pharmacokinetics and tissue distribution of Trans-ferulic acid-4-β-glucoside in rats by UPLC-MS/MS

Trans-ferulic acid-4-β-glucoside (FAG) is a monomer extracted from Radix Aconiti Lateralis Preparata, which is a potential candidate for the prevention and treatment of the cold injury. To determine the concentration FAG in rats, it is essential to develop an ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) method. The chromatographic separation was achieved by ACQUITY UPLC BEH C18 column(2.1×50mm, 1.7μm). A Xevo triple quadrupole tandem mass spectrometer was used to quantitative determination of FAG in the negative ion mode. The standard calibration curve was linear over the concentration range of 0.1-100 μg/mL and 0.0626-31.28 μg/g for rat plasma and liver tissue homogenates samples, separately. The inter-and intra-batch precision (RSD%) of the assay was ≤ 8.29% and accuracy (RE%) ranged from -7.41 to 10.99%. The matrix effect was between 92.99 and 102.39%. The oral absolute bioavailability of FAG was obtained as 1.80%. The results of tissue distribution suggested that FAG spread rarely in liver and brown adipose, which was not propitious to exert its ability to treat cold injury. In general, the above studies were significant to provide necessary information for further study.

Preparation of injectable clopidogrel loaded submicron emulsion for enhancing physicochemical stability and anti-thrombotic efficacy

Due to the superior safety and therapeutic efficacy, clopidogrel (CLP) has been widely used to prevent postoperative thrombosis. However, limitations of delayed absorption and metabolic activation of clopidogrel after oral administration hinder its clinic use for acute thrombosis treatment in percutaneous coronary intervention (PCI). Although clopidogrel aqueous injection systems were designed and developed, chemical instability under physiological condition or vascular irritation remains to be solved. In this study, we aim to prepare an injectable clopidogrel loaded submicron emulsion to overcome the drawbacks of conventional clopidogrel aqueous formulation and improve the antiplatelet aggregation effects. Results showed that this delivery system exerted inspiring features including uniform particle size, higher drug loading capacity and sustained drug release behavior. It can dramatically upgrade the formulation stability and prevent the drug degradation under sterilization or higher pH environments. No remarkable droplet size increase or drug content decrease was observed during storage. Compared to CLP tablet, the peak drug concentration (C_max) and area under the curve (AUC) of CLP emulsion increased by 12.01-fold and 4.69-fold, respectively. Most importantly, it exerted excellent in vivo anti-thrombotic effect on numerous designed animal models. Conclusively, submicron emulsion is a promising delivery system for improving clopidogrel stability and anti-thrombotic efficacy.

Exploring a Novel Fasudil-Phospholipid Complex Formulated as Liposomal Thermosensitive in situ Gel for Glaucoma

Purpose

Methods

Results

Conclusion

Dual Strategy for Improving the Oral Bioavailability of Resveratrol: Enhancing Water Solubility and Inhibiting Glucuronidation

Resveratrol (RES) suffers from poor water solubility and extensive metabolism, which lead to low bioavailability. A phospholipid complex (PC) containing RES and a UDP-glucuronosyltransferase (UGT) inhibitor was prepared to address these two limiting factors, thereby improving RES bioavailability. First, 11 natural active ingredients metabolized by similar enzyme subtypes to RES were screened in a glucuronidation assay in liver microsomes. Then, glycyrrhetinic acid (GA), the strongest inhibitor, was prepared with RES in a PC. RES-PC was prepared as a control. As expected, the water solubility and the cumulative dissolution of RES were significantly enhanced by RES-PC and RES/GA-PC. Compared with the RES group, the AUC_0-10 of RES and resveratrol-3-glucuronide (R-3-G) in the RES/GA-PC group showed increases of 2.49- and 1.70-fold, respectively, with the proportion of RES absorption to total absorption increasing 1.45 times. These results demonstrated that RES/GA-PC could improve the bioavailability of RES by increasing its water solubility and inhibiting its glucuronidation.

An Investigation of the Antigastric Cancer Effect in Tumor Microenvironment of Radix Rhei Et Rhizome: A Network Pharmacology Study

Background

Tumor microenvironment (TME) takes a vital effect on the occurrence and development of cancer. Radix Rhei Et Rhizome (RRER, Da-Huang in pinyin), a classical Chinese herb, has been widely used in gastric cancer (GC) for many years in China. However, inadequate systematic studies have focused on the anti-GC effect of RRER in TME. This study intended to uncover the mechanism of it by network pharmacology.

Methods

We collected compounds and targets of RRER from traditional Chinese medicine system pharmacology database and analysis platform (TCMSP) and SwissTargetPrediction. GC targets were obtained from GeneCards. Protein-protein interaction (PPI) network and RRER-GC-target network were built by STRING and Cytoscape 3.2.1. Furthermore, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed using Database for Annotation, Visualization, and Integrated Discovery (DAVID).

Results

We obtained 92 compounds of RRER. A total of 10 key compounds and 20 key targets were selected by “RRER-GC-target network” topological analysis. GO analysis showed that the biological process mainly involved in response to the tumor necrosis factor, positive regulation of fibroblast proliferation, and DNA damage response, signal transduction by p53 class mediator resulting in cell cycle arrest. Molecular functions included cyclin-dependent protein serine/threonine kinase activity, RNA polymerase II transcription factor activity, ligand-activated sequence-specific DNA binding, and transmembrane receptor protein tyrosine kinase activity. Cellular components mainly were centrosome, cell surface, and membrane. KEGG pathway enrichment results mainly involved in the p53 signaling pathway, estrogen signaling pathway, and regulation of lipolysis in adipocytes.

Conclusion

This study explored the anti-GC mechanism of RRER from the perspective of TME based on network pharmacology, which contributed to the development and application of RRER.

Phyto-Phospholipid Complexation as a Novel Drug Delivery System for Management of Cancer with Better Bioavailability: Current Perspectives and Future Prospects

Cancer is the foremost cause of death, and it supports the need for the identification of novel anticancer drugs to improve the efficacy of current-therapy. While the synthetic anticancer drug is associated with numerous side effects. Hence the plant active or phytoconstituents are in high demand for the treatment of cancer due to minimum side effects. But the polar nature of phytoconstituents hindered the absorption of the drug and lowered the therapeutic efficacy. The plant activity incorporated into Phyto-phospholipid Complexation can enhance bioavailability and improved therapeutic efficacy. In this review article, advantages, limitation and application of Phyto-phospholipid complexes have been illustrated. The article highlights the application of Phyto-phospholipid complexes as a promising drug carrier system to treat cancer.

Raloxifene-loaded SLNs with enhanced biopharmaceutical potential: QbD-steered development, in vitro evaluation, in vivo pharmacokinetics, and IVIVC

Raloxifene hydrochloride, a second-generation selective estrogen receptor modulator, has been approved for the management of breast cancer. However, it is known to exhibit poor (~ 2%) and inconsistent oral bioavailability in humans, primarily ascribable to its low aqueous solubility, extensive first-pass metabolism, P-gp efflux, and presystemic glucuronide conjugation. The present research work entails the systematic development and evaluation of SLNs of RLX for its enhanced biopharmaceutical performance against breast cancer. Factor screening studies were conducted using Taguchi design, followed by optimization studies employing Box-Behnken design. Preparation of SLNs was carried out using glyceryl monostearate and Compritol® 888 ATO (i.e., lipid), Phospholipid S-100 (i.e., co-surfactant), and TPGS-1000 (i.e., surfactant) employing solvent diffusion method. The optimized formulation was evaluated for zeta potential, average particle size, field emission scanning electron microscope, transmission electron microscopy, and in vitro release study. Further, MCF-7 cells (cell cytotoxicity assay, apoptosis assay, and reactive oxygen species assay) and Caco-2 cells (cell uptake studies and P-gp efflux assay) were employed to evaluate the in vitro anticancer potential of the developed optimized formulation. In vivo pharmacokinetic studies were conducted in Sprague-Dawley rats to evaluate the therapeutic profile of the developed formulation. The optimized SLN formulations exhibited a mean particle size of 109.7 nm, PDI 0.289 with a zeta potential of - 13.7 mV. In vitro drug dissolution studies showed Fickian release, with release exponent of 0.137. Cell cytotoxicity assay, apoptosis assay, and cellular uptake indicated 6.40-, 5.40-, and 3.18-fold improvement in the efficacy of RLX-SLNs vis-à-vis pure RLX. Besides, the pharmacokinetic studies indicated quite significantly improved biopharmaceutical performance of RLX-SLNs vis-à-vis pure drug, with 4.06-fold improvement in C_max, 4.40-fold in AUC_(0-72 h), 4.56-fold in AUC_(0-∞), 1.53-fold in K_a, 2.12-fold in t_1/2, and 1.22-fold in T_max. Further, for RLX-SLNs and pure drug, high degree of level A linear correlation was established between fractions of drug dissolved (in vitro) and of drug absorbed (in vivo) at the corresponding time-points. Stability studies indicated the robustness of RLX-SLNs when stored at for 3 months. Results obtained from the different studies construe promising the anticancer potential of the developed RLX-SLNs, thereby ratifying the lipidic nanocarriers as an efficient drug delivery strategy for improving the biopharmaceutical attributes of RLX.

An updated review on therapeutic potential and recent advances in drug delivery of Berberine: Current status and future prospect

Natural products are well known for their high potency with minimum side effects. Plant extracts are the most commonly used natural products because of their ease of availability and relatively low production cost. Berberine (BBR), a phytochemical component of some Chinese medicinal herbs (most commonlyBerberis vulgaris), is an isoquinoline alkaloid with several biological and pharmacological effects including antioxidant, anti-inflammatory, antitumour, antimicrobial, antidepressant,hepatoprotective, hypolipidemic, and hypoglycemic actions. Interestingly, multiple studies have shown that BBR is a potential drug candidate with a multi-spectrum therapeutic application. However, the oral delivery of BBR is challenged owing to its poor bioavailability. Therefore, its oral bioavailability needs to be enhanced before it can be used in many clinical applications. This review provides an overview of the various studies that support the broad range of pharmacological activities of BBR. Also, it includes a section to address the issues and challenges related with the drug and methods to improve the properties of BBR such as solubility, stability and bioavailability that may be explored to help patients reap the maximum benefit from this potentially useful drug.

Improving Breviscapine Oral Bioavailability by Preparing Nanosuspensions, Liposomes and Phospholipid Complexes

Breviscapine (BVP), a flavonoid compound, is widely used in the treatment of cardiovascular and cerebrovascular diseases; however, the low oral bioavailability and short half-life properties limit its application. The aim of this study was to investigate the three preparations for improving its oral bioavailability: nanosuspensions (BVP-NS), liposomes (BVP-LP) and phospholipid complexes (BVP-PLC). In vitro and in vivo results suggested that these three could all significantly improved the cumulative released amount and oral bioavailability compared with physical mixture, in which BVP-PLC was the most optimal preparation with the relative bioavailability and mean retention time of 10.79 ± 0.25 (p < 0.01) and 471.32% (p < 0.01), respectively. Furthermore, the influence of drug-lipid ratios on the in vitro release and pharmacokinetic behavior of BVP-PLC was also studied and the results showed that 1:2 drug-lipid ratio was the most satisfactory one attributed to the moderate-intensity interaction between drug and phospholipid which could balance the drug loading and drug release very well.

Self-Assembled Lecithin/Chitosan Nanoparticles Based on Phospholipid Complex: A Feasible Strategy to Improve Entrapment Efficiency and Transdermal Delivery of Poorly Lipophilic Drug

PURPOSE

Lecithin/chitosan nanoparticles have shown great promise in the transdermal delivery of therapeutic agents. Baicalein, a natural bioactive flavonoid, possesses multiple biological activities against dermatosis. However, its topical application is limited due to its inherently poor hydrophilicity and lipophilicity. In this study, the baicalein-phospholipid complex was prepared to enhance the lipophilicity of baicalein and then lecithin/chitosan nanoparticles loaded with the baicalein-phospholipid complex were developed to improve the transdermal retention and permeability of baicalein.

METHODS

Lecithin/chitosan nanoparticles were prepared by the solvent-injection method and characterized in terms of particle size distribution, zeta potential, and morphology. The in vitro release, the ex vivo and in vivo permeation studies, and safety evaluation of lecithin/chitosan nanoparticles were performed to evaluate the effectiveness in enhancing transdermal retention and permeability of baicalein.

RESULTS

The lecithin/chitosan nanoparticles obtained by the self-assembled interaction of chitosan and lecithin not only efficiently encapsulated the drug with high entrapment efficiency (84.5%) but also provided sustained release of baicalein without initial burst release. Importantly, analysis of the permeation profile ex vivo and in vivo demonstrated that lecithin/chitosan nanoparticles prolonged the retention of baicalein in the skin and efficiently penetrated the barrier of stratum corneum without displaying skin irritation.

CONCLUSION

These results indicate the potential of drug-phospholipid complexes in enhancing the entrapment efficiency and self-assembled lecithin/chitosan nanoparticles based on phospholipid complexes in the design of a rational transdermal delivery platform to improve the efficiency of transdermal therapy by enhancing its percutaneous retention and penetration in the skin.

Interactions of anticancer drugs doxorubicin and idarubicin with lipid monolayers: New insight into the composition, structure and morphology

We quantify directly here for the first time the extents of interactions of two different anthracycline drugs with pure and mixed lipid monolayers with respect to the surface pressure and elucidate differences in the resulting interaction mechanisms. The work concerns interactions of doxorubicin (DOx) and idarubicin (IDA) with monolayers of the zwitterionic DMPC (1,2-dimyristoyl-sn-glycero-3-phosphocholine) and negatively charged DMPS (1,2-dimyristoyl-sn-glycero-3-phospho-L-serine (sodium salt)) as well as a 7:3 mixture of the two lipids. These drugs are used in current cancer treatments, while the lipid systems were chosen as phosphocholines are the major lipid component of healthy cell membranes, and phosphoserines are the major lipid component that is externalized into the outer leaflet of cancerous cell membranes. It is shown that DOx interacts with DMPS monolayers to a greater extent than with DMPC monolayers by lower limits of a factor of 5 at a surface pressure of 10 mN/m and a factor of 12 at 30 mN/m. With increasing surface pressure, the small amount of drug (~0.3 µmol/m²) bound to DMPC monolayers is excluded from the interface, yet its interaction with DMPS monolayers is enhanced until there is even more drug (~3.2 µmol/m²) than lipid (~2.6 µmol/m²) at the interface. Direct evidence is presented for all systems studied that upon surface area compression lipid is reproducibly expelled from the monolayer, which we infer to be in the form of drug-lipid aggregates, yet the nature of adsorption of material back to the monolayer upon expansion is system-dependent. At 30 mN/m, most relevant to human physiology, the interactions of DOx and IDA are starkly different. For DOx, there is a conformational change in the interfacial layer driven by aggregation, resulting in the formation of lateral domains that have extended layers of drug. For the more lipophilic IDA, there is penetration of the drug into the hydrophobic acyl chain region of the monolayer and no indication of lateral segregation. In addition to the Langmuir technique, these advances were made as a result of direct measurements of the interfacial composition, structure and morphology using two different implementations of neutron reflectometry and Brewster angle microscopy. The results provide new insight into key processes that determine the uptake of drugs such as limited drug penetration through cell membranes by passive diffusion as well as activation of drug removal mechanisms related to multidrug resistance.

Development and Evaluation of Docetaxel-Phospholipid Complex Loaded Self-Microemulsifying Drug Delivery System: Optimization and In Vitro/Ex Vivo Studies

Docetaxel (DTX) has clinical efficacy in the treatment of breast cancer, but it is difficult to develop a product for oral administration, due to low solubility and permeability. This study focused on preparing a self-microemulsifying drug delivery system (SME) loaded with DTX-phospholipid complex (DTX@PLC), to improve the dissolution and gastrointestinal (GI) permeability of DTX. A dual technique combining the phospholipid complexation and SME formulation described as improving upon the disadvantages of DTX has been proposed. We hypothesized that the complexation of DTX with phospholipids can improve the lipophilicity of DTX, thereby increasing the affinity of the drug to the cell lipid membrane, and simultaneously improving permeability through the GI barrier. Meanwhile, DTX@PLC-loaded SME (DTX@PLC-SME) increases the dissolution and surface area of DTX by forming a microemulsion in the intestinal fluid, providing sufficient opportunity for the drug to contact the GI membrane. First, we prepared DTX@PLC-SME by combining dual technologies, which are advantages for oral absorption. Next, we optimized DTX@PLC-SME with nanosized droplets (117.1 nm), low precipitation (8.9%), and high solubility (33.0 mg/g), which formed a homogeneous microemulsion in the aqueous phase. Dissolution and cellular uptake studies demonstrated that DTX@PLC-SME showed 5.6-fold higher dissolution and 2.3-fold higher DTX uptake in Caco-2 cells than raw material. In addition, an ex vivo gut sac study confirmed that DTX@PLC-SME improved GI permeability of DTX by 2.6-fold compared to raw material. These results suggested that DTX@PLC-SME can significantly overcome the disadvantages of anticancer agents, such as low solubility and permeability.

Successful oral delivery of fexofenadine hydrochloride by improving permeability via phospholipid complexation

The present work aimed to enhance liposolubility along with intestinal permeability of BCS class III drug fexofenadine (FEX) via phospholipid complexation strategy in order to improve its oral bioavailability. This work demonstrated the minimized P-gp efflux and augmented absorption of FEX when fabricated as phospholipid complex. The fexofenadine-phospholipid complex (FEX-PLC) was prepared using widely used solvent evaporation method. Among three phospholipids, Phospholipon® 90 H was screened out for further studies due to high drug content and physical form. The FTIR spectra demonstrated the disappearance of characteristic peaks of FEX which could be attributed to shielding by phospholipid due to molecular interactions between FEX and phospholipid. The differential scanning calorimetry (DSC) and powder X-ray diffractometry (PXRD) revealed the amorphous state of FEX in the complex. The partition coefficient study indicated the increased in lipophilicity which can further be correlated with 1.85 ± 0.850 fold enhancement in intestinal permeability of FEX-PLC in comparison to FEX in Caco-2 permeability assay. Furthermore, efflux ratio of FEX was decreased significantly from 4.04 (FEX) to 1.34 (FEX-PLC) which indicated inhibition of P-gp efflux of FEX. The in vivo evaluation in Wistar rats presented 3.38 fold increment in oral bioavailability of FEX-PLC as compared to FEX. In summary, the phospholipid complexation demonstrated as a simple and promising approach to tackle oral bioavailability hurdles of BCS class III drugs and convert them to BCS class I drugs.

Inflammation and cardiovascular disease: are marine phospholipids the answer?

This review presents the latest research on the cardioprotective effects of n-3 fatty acids (FA) and n-3 FA bound to polar lipids (PL). Overall, n-3 PL may have enhanced bioavailability and potentially bioactivityversusfree FA and ester forms of n-3 FA.