Phospholipid Complex Research Articles

Fortifying SNEDDS with Hybrid Technologies: Present and Future Prospects

Self-nano-emulsifying drug delivery systems (SNEDDS) have gained attention in recent years as an effective approach for improving the solubility and oral bioavailability of poorly water-soluble drugs. However, there have been reports of drawbacks such as low drug loading, limited stability and variability in absorption. Various technologies have been investigated in conjunction with SNEDDS to alleviate such issues such as polymers being used to improve stability and drug loading; phospholipid complexes used to improve absorption and reduce inter and intrasubject variability; SNEDDS for drug targeting improves the targeting of drugs to specific site reducing the dosage required for action. 3D printing is used to create personalized and precise dosages; supersaturated SNEDDS is used to increase drug concentration; and solid SNEDDS are used to improve storage stability and patient compliance. The amalgamation of SNEDDS with these technologies has demonstrated promising results with regard to the improvement of medication delivery and has control over SNEDDS limitations. The present review elucidates the application of blended technologies with SNEDDS and the future potential for such drug delivery.

Preparation and characterization of solid lipid nanoparticles phospholipid complex loaded with fenticonazole nitrate for topical management of Candida Albicans

Preparation and characterization of solid lipid nanoparticles phospholipid complex loaded with fenticonazole nitrate for topical management of Candida Albicans

Pulmonary delivery of forsythin-phospholipid complexes improves the lung anti-inflammatory efficacy in mice by enhancing dissolution and lung tissue affinity

Forsythin, currently in phase II clinical trials in China for the treatment of the common cold and influenza, faces challenges in achieving adequate lung drug exposure due to its limited dissolution and permeability, thereby restricting its therapeutic efficacy. The objective of this work was to formulate a forsythin-phospholipid complex (FPC) to enhance its dissolution properties and lung affinity with a particular view to improving pulmonary drug exposure and anti-inflammatory response. The results revealed that forsythin reacted with dipalmitoyl-phosphatidylcholine to form a stable, nanosized FPC suspension. This formulation significantly improved the in vitro drug's dissolution, cellular uptake, and lung affinity compared to its uncomplexed form. Intratracheal administration of FPC in a mouse model of acute lung injury induced by lipopolysaccharide (LPS) resulted in a substantial increase in drug exposure to lung tissues (39.6-fold) and immune cells in the epithelial lining fluid (198-fold) compared to intraperitoneal injection. In addition, FPC instillation exhibited superior local anti-inflammatory effects, leading to improved survival rates among mice with LPS-induced acute respiratory distress syndrome, outperforming both instilled forsythin and injected FPC. Overall, this work demonstrated the potential of phospholipid complexes as a viable option for developing inhalation products for drugs with limited solubility and permeability properties.

Novel Delivery Systems of Raloxifene Hydrochloride for Improved Bioavailability and Therapeutic Efficacy: A Review

Raloxifene hydrochloride belongs to the selective estrogen receptor modulator category. Initially, US FDA approved its use for the prevention and treatment of osteoporosis in postmenopausal women. Later, raloxifene hydrochloride was also approved for the prevention of invasive breast carcinoma in post-menopausal women under the high-risk category. Despite its immense and diverse therapeutic potential, the oral bioavailability of raloxifene hydrochloride is only ~ 2%. The factors responsible for the poor bioavailability of raloxifene hydrochloride include its amphiphobic nature, para-glycoprotein pump-mediated efflux in the intestine, and high pre-systemic glucuronidation. In the past two decades, multiple novel delivery systems, viz. lipid-based nanocarriers, polymeric nanoparticles, polymer-lipid hybrid nanoparticles, micelles, and mixed micelles, have been developed to overcome its drawbacks. Moreover, inclusion complex, phospholipid complex, and solid dispersion have also been developed to improve its solubility and dissolution rate. Further, some research groups successfully explored non-peroral routes like nasal and transdermal for augmenting the raloxifene hydrochloride bioavailability and its therapeutic efficacy. Hence, the principal objective of this review paper is to critically analyze all the delivery systems developed for raloxifene hydrochloride with their advantages and limitations. In addition, a detailed discussion of the physicochemical and pharmacokinetic parameters of raloxifene hydrochloride has been included in this paper. An in-depth understanding of these parameters will assist formulation scientists in developing efficient delivery systems in the future. In conclusion, the literature review revealed that the nanoparticulate systems successfully augmented the raloxifene hydrochloride bioavailability and therapeutic efficacy in pre-clinical experiments. However, future clinical trials should be conducted to assess their safety and therapeutic efficacy for rapid preclinical to clinical translation.

Extraction, Isolation, Characterization, and Development of Phospholipids Complex Nanocarrier for Improved Solubility, Antiasthmatic, and Pharmacokinetic Potential of Curcuminoids.

Curcuma longa Linn. (Zingiberaceae) is a medicinal plant with significant biological activities owing to curcuminoids (CURs). Nevertheless, its low oral bioavailability because of low water solubility, inadequate absorption, short half-life, and rapid clearance hampered its clinical applications. The study aimed to extract, isolate, characterize, and formulate the Phospholipon ®90H complex and evaluate for improved solubility, antiasthmatic and pharmacokinetic potential of CURs. Phospholipon®90H-based complex of curcuminoids (CPLC) was synthesized via solvent evaporation technique and reported an improvement of solubility, antiasthmatic, and pharmacokinetic potential of CURs. CPLC was physico-chemically and functionally evaluated by Fourier transforms infrared spectroscopy, differential scanning calorimetry, powder x-ray diffractometry, oral bioavailability, and antiasthmatic activity. Ethyl acetate rhizome extracts (EARE) displayed ~17.42 % w/w extraction yield of CURs. CPLC revealed high entrapment of CURs (~ 92.55 % w/w) within the polar head of phospholipids. Small particle size ~ 194 nm with zeta potential value ~ -20.4 mV suggests the physical stability of CPLC. Physical analysis evidenced the formation of stable and amorphous CPLC by establishing hydrophobic and weak intermolecular forces between CURs and Phospholipon ®90H. Undoubtedly, the amorphous CPLC raised the aqueous solubility of CURs (~2-fold) compared to pure CURs. CPLC formulations (~ 20 mg/kg of CURs, p.o.) significantly lowered the leucocyte and eosinophil count compared to pure CURs. CPLC improved the oral bioavailability of CURs compared to pure CURs. Results highlight that CPLC could be established as a breakthrough respiratory nanocarrier for CURs and other phytocompounds with respiratory potential.

Development and Assessment of Helicteres isora Extract Loaded Phospholipid Complex for Anti-Nociceptive Activity

Its primary objective is to assess the efficacy of a phospholipid complex formulation containing an extract of Helicteres isora in reducing inflammation, to determine its progress and evaluation. An Indian Screw Tree, also known as Helicteres isora, is an extremely healing plant. In addition to improving solubility and stability, the phospholipid complex formulation also increases bioavailability and efficacy. This formulation was created by combining Helicteres isora extract with phospholipids using a technique known as phospholipid complexation. Several parameters were evaluated to evaluate the formulation, including particle size, zeta potential, encapsulation efficiency, and drug release profile. Using both in vitro and in vivo models, the anti-inflammatory properties of a phospholipid complex formulation of Helicteres isora were assessed. The experiments were conducted using a rat model of carrageenan-induced paw edema. In this work, phospholipid complex formulations were shown to have improved physicochemical properties, including smaller particle sizes and higher encapsulation rates. According to the results of the in vivo evaluation, phospholipid complex formulations significantly reduced paw edema compared with plain extracts, indicating improved anti-inflammatory activity. The bioavailability, anti-inflammatory activity, and bioavailability of Helicteres isora extract are enhanced by the phospholipid complex formulation.

Molecular docking, molecular dynamics simulation, preparation, and characterization of naltrexone-phospholipid complex: A novel cargo with improved loading into multivesicular liposomes

Naltrexone hydrochloride (NTX), a water-soluble opioid receptor antagonist, is prescribed widely for opioid and alcohol dependence and pain reduction. However, the significant limitations of NTX are low lipophilicity and extensive first-pass metabolism. This study aimed to design and prepare a novel phospholipid complex of NTX and load it into multivesicular liposomes (MVLs). In silico studies, including molecular docking and molecular dynamics (MD) simulation, were performed to determine the interactions between NTX and phospholipid and evaluate their best molar ratio to prepare the complex, respectively. The NTX phospholipid complex was prepared by solvent evaporation technique and characterized by PXRD, SEM, FTIR, 1HNMR, solubility study, and n-octanol/water partition coefficient analyses. NTX-SPC complex-loaded MVLs (NTX-SPC-MVLs) were prepared by the double-emulsion method and characterized by encapsulation efficiency (EE)%, size, PXRD, FTIR, SEM, and release pattern. MD simulation reported the 1:1.5 M ratio of NTX to phospholipid as the best molar ratio. Complexation led to reduced water solubility and enhanced n-octanol/water partition coefficient. Loading of NTX-SPC complex into MVLs enhanced EE and extended the release duration in comparison to NTX MVLs. Thus, the NTX-SPC complex may be an appropriate system to enhance the physicochemical features of NTX and improve the EE in vesicular drug delivery systems like MVLs.

Cytotoxicity and bioavailability assessment from micellar system based Thiamine-Phospholipid complexes

Poor absorption (3–5 %) of thiamine hydrochloride (TH), is primarily concerned with impaired permeability across intestinal mucosa. To modulate the permeability of TH, a phospholipid (PL) interaction-based hydrophobic complex of thiamine was investigated. Using the solvent evaporation approach, thiamine-phospholipid complexes (TPCs) were prepared between free bases of thiamine and PLs in the weight ratio (1:1, 1:2, and 2:1) and characterized using FTIR, spectrophotometry, XRD, and conductometric methods. Electrical conductivity and partition coefficient studies demonstrated that TPCs were hydrophobic transformations formed via PL interaction with a free thiamine base. TPCs were embedded into the micellar system (Tween20/Ethanol), characterized by electrical conductivities and zeta-sizing studies, and exploited in its micellar delivery system design. TPC 1:1 & 1:2 had much lower conductivity than TH and its physical mixture (TH/PL) in the Tween20/Ethanol environment diluted with an aqueous phase. The average size of micellar systems loaded with TPC (10 % w/w) was within the range of 12–25 nm, and conductivity was in the range of 122-130µS/cm. In vitro release characterization from complexes and their micellar systems in HCl 1.2, phosphate buffer (PB) 6.8, and bidistilled water showed a delayed release pattern. TPC modulated the intestinal permeability of thiamine as revealed from ex vivo studies. TPC (1:1) and its micellar system produced significant differences in drug permeability (p < 0.001) compared to TH and physical mixture. Pharmacokinetic assessment of the micellar system of complexes in Wistar rats showed that the TPC (1:1) loaded micellar system produced a 2.4-fold enhancement of AUC(0−24) over (TH) followed by oral administration. Assessment of cell viability in mouse fibroblast cell line (L929) culture showed that TPC or micellar system did not inhibit cell growth and was safe at various concentration levels. TPc complexes developed using phospholipid complexation yield hydrophobic transformation in TH and their micellar system-based delivery modulates the intestinal permeability and bioavailability enhancement.

Defining the mechanisms behind the hepatoprotective properties of curcumin.

As a critical cause of human dysfunctionality, hepatic failure leads to approximately two million deaths per year and is on the rise. Considering multiple inflammatory, oxidative, and apoptotic mechanisms behind hepatotoxicity, it urges the need for finding novel multi-targeting agents. Curcumin is a phenolic compound with anti-inflammatory, antioxidant, and anti-apoptotic roles. Curcumin possesses auspicious health benefits and protects against several diseases with exceptional safety and tolerability. This review focused on the hepatoprotective mechanisms of curcumin. The need to develop novel delivery systems of curcumin (e.g., nanoparticles, self-micro emulsifying, lipid-based colloids, solid lipid nanoparticles, cyclodextrin inclusion, phospholipid complexes, andnanoemulsions) is also considered.

Pulmonary delivery of icariin-phospholipid complex prolongs lung retention and improves therapeutic efficacy in mice with acute lung injury/ARDS

Icariin has been shown the promising therapeutic potential to treat inflammatory airway diseases, yet its poor lung distribution and retention restrict the clinical applications. To this end, this work aimed to prepare an icariin-phospholipid complex (IPC) formulation for sustained nebulization delivery that enabled excellent inhalability, improved lung exposure and prolonged duration of action. Icariin was found to react with soybean phospholipid to form supramolecular IPC, which was able to self-assemble into nanoparticle suspension. The suspension was stable during steam sterilization and nebulization processes, and its aerosols generated by a commercial nebulizer exhibited excellent aerodynamic properties and delivery efficiency. In vitro studies showed that the formation of complex sustained drug release, enhanced lung affinity and slowed lung clearance. The drug distribution in lung epithelial lining fluid (ELF) also demonstrated in vivo sustained release after intratracheal administration to mice. In addition, compared to free icariin, IPC improved the drug exposure to lung tissues and immune cells in the ELF by 4.61-fold and 39.5-fold, respectively. This resulted in improved and prolonged local anti-inflammatory effects up to 24 h in mice with lipopolysaccharide (LPS)-induced acute lung injury. Moreover, IPC improved survival rate of mice with acute respiratory distress syndrome (ARDS). Overall, the present phospholipid complex represented a promising formulation of icariin for the treatment of acute lung injury/ARDS by nebulization delivery.

Controlled dual release of phenol compounds from phospholipid complexes of short-chain lipophenols

Ethanol evaporation method was applied to synthesize phospholipid complexes from phosphatidylcholine (PC) and short-chain alkyl gallates (A-GAs, a typical representative of lipophenols) including butyl-, propyl- and ethyl gallates. 1H NMR, UV and FTIR showed that A-GAs were interacted with PC through weak physical interaction. Through the analysis of concentrations of A-GAs and gallic acid (GA) by an everted rat gut sac model coupled with HPLC-UV detection, phospholipid complexes were found to gradually release A-GAs. These liberated A-GAs were further hydrolyzed by intestinal lipases to release GA. Both of GA and A-GAs could cross intestinal membrane. Especially, the transmembrane A-GAs could also be hydrolyzed to produce GA. Undoubtedly, the dual release of phenol compounds from phospholipid complexes of short-chain lipophenols will be effective to extend the in vivo residence period of phenol compounds. More importantly, such behavior is easily adjusted by changing the acyl chain lengths of lipophenols in phospholipid complexes.

Inhalable spray-dried porous microparticles containing dehydroandrographolide succinate phospholipid complex capable of improving and prolonging pulmonary anti-inflammatory efficacy in mice.

Due to the unique physiological barriers within the lungs, there are considerable challenges in developing drug delivery systems enabling prolonged drug exposure to respiratory epithelial cells. Here, we report a PulmoSphere-based dry powder technology that incorporates a drug-phospholipid complex to promote intracellular retention of dehydroandrographolide succinate (DAS) in respiratory epithelial cells following pulmonary delivery. The DAS-phospholipid complex has the ability to self-assemble into nanoparticles. After spray-drying to produce PulmoSphere microparticles loaded with the drug-phospholipid complex, the rehydrated microparticles discharge the phospholipid complex without altering its physicochemical properties. The microparticles containing the DAS-phospholipid complex exhibit remarkable aerodynamic properties with a fine particle fraction of ∼ 60% and a mass median aerodynamic diameter of ∼ 2.3μm. These properties facilitate deposition in the alveolar region. In vitro cell culture and lung tissue explants experiments reveal that the drug-phospholipid complex prolongs intracellular residence time and lung tissue retention due to the slow intracellular disassociation of drug from the complex. Once deposited in the lungs, the DAS-phospholipid complex loaded microparticles increase and extend drug exposure to the lung tissues and the immune cells compared to the free DAS counterpart. The improved drug exposure to airway epithelial cells, but not immune cells, is related to a prolonged duration of pulmonary anti-inflammation at decreased doses in a mouse model of acute lung injury induced by lipopolysaccharide. Overall, the phospholipid complex loaded microparticles present a promising approach for improved treatment of respiratory diseases, e.g. pneumonia and acute respiratory distress syndrome.

Gemcitabine-Phospholipid Complex Loaded Lipid Nanoparticles for Improving Drug Loading, Stability, and Efficacy against Pancreatic Cancer.

This study aims to encapsulate gemcitabine (GEM) using a phospholipid complex (PLC) in lipid nanoparticles (NPs) to achieve several desirable outcomes, including high drug loading, uniform particle size, improved therapeutic efficacy, and reduced toxicities. The successful preparation of GEM-loaded lipid NPs (GEM-NPs) was accomplished using the emulsification-solidification method, following optimization through Box-Behnken design. The size of the GEM-NP was 138.5 ± 6.7 nm, with a low polydispersity index of 0.282 ± 0.078, as measured by a zetasizer and confirmed by transmission electron and atomic force microscopy. GEM-NPs demonstrated sustained release behavior, surpassing the performance of the free GEM and phospholipid complex. Moreover, GEM-NPs exhibited enhanced cytotoxicity, apoptosis, and cell uptake in Panc-2 and Mia PaCa cells compared to the free GEM. The in vivo pharmacokinetics revealed approximately 4-fold higher bioavailability of GEM-NPs in comparison with free GEM. Additionally, the pharmacodynamic evaluation conducted in a DMBA-induced pancreatic cancer model, involving histological examination, serum IL-6 level estimation, and expression of cleaved caspase-3, showed the potential of GEM-NPs in the management of pancreatic cancer. Consequently, the lipid NP-based approach developed in our investigation demonstrates high stability and uniformity and holds promise for enhancing the therapeutic outcomes of GEM.

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

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

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.

Bilirubin derivatives in bile, blood, and liver of rats upon correction of experimental fatty hepatosis

The relevance of this study lies in the lack of reliable information on the key aspects of the molecular mechanisms of fatty hepatosis, a common mammalian disease, and its dangerous complications, such as fibrosis, cirrhosis, and hepatocellular carcinoma. These circumstances substantially complicate the prompt diagnosis of this hepatopathology and reduce the effectiveness of treatment. The metabolism of the heme derivative bilirubin is unique and inherent in the liver, which undergoes transformation due to hepatocyte enzyme systems to form neutral compounds, such as glucurono-conjugates and sulphoconjugates, which undergoes changes and requires analysis in fatty hepatosis in animals. The aim of the study was to determine the characteristic changes in the content of unconjugated bilirubin and its sulphoconjugate, glucuronide, monoglucuronide, monoglucoside, and diglucuronide in the blood, bile, and liver of rats under the modelling of fatty hepatosis and the administration of rehabilitation therapy. For this, the thin-layer chromatography method was used. It was found that under tetracycline-induced fatty hepatosis in laboratory rats, the concentration of unconjugated bilirubin in the blood decreased by 39.3%, bilirubin glucuronide by 44.4%, and the total fraction of bilirubin monoglucuronide and monoglycoside by 78.9%. Oral administration of the milk phospholipid complex in the composition of the BAS “FLP-MD” to sick animals ensured the maintenance of these indicators at the control level. The content of bilirubin glucuronide and bilirubin diglucuronide decreased in the liver tissue of the treated rats. When these animals were administered a phospholipid-containing bioadditives, the level of unconjugated bilirubin in the liver tissue increased by 22.2%, but the content of its conjugated forms decreased. The content of all the studied bilirubin fractions decreased in the bile of sick rats during self-rehabilitation. The components of the BAS “FLP-MD” in fatty hepatosis in rats did not affect the reduction of unconjugated bilirubin in bile but eliminated the inhibitory effect of the modelled pathology on the content of all conjugated forms of bilirubin. The findings can be used as biochemical markers to monitor the pigment metabolism in the development of fatty hepatosis in mammals

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

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

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 sixfold 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 ninefold 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.

Reversing the Natural Drug Resistance of Gram-Negative Bacteria to Fusidic Acid via Forming Drug-Phospholipid Complex.

Drug resistance substantially compromises antibiotic therapy and poses a serious threat to public health. Fusidic acid (FA) is commonly used to treat staphylococcal infections, such as pneumonia, osteomyelitis and skin infections. However, Gram-negative bacteria have natural resistance to FA, which is almost restrained in cell membranes due to the strong interactions between FA and phospholipids. Herein, we aim to utilize the strong FA-phospholipid interaction to pre-form a complex of FA with the exogenous phospholipid. The FA, in the form of an FA-phospholipid complex (FA-PC), no longer interacts with the endogenous membrane phospholipids and thus can be delivered into bacteria cells successfully. We found that the water solubility of FA (5 µg/mL) was improved to 133 µg/mL by forming the FA-PC (molar ratio 1:1). Furthermore, upon incubation for 6 h, the FA-PC (20 µg/mL) caused a 99.9% viability loss of E. coli and 99.1% loss of P. aeruginosa, while free FA did not work. The morphology of the elongated bacteria cells after treatment with the FA-PC was demonstrated by SEM. The successful intracellular delivery was shown by confocal laser scanning microscopy in the form of coumarin 6-PC (C6-PC), where C6 served as a fluorescent probe. Interestingly, the antibacterial effect of the FA-PC was significantly compromised by adding extra phospholipid in the medium, indicating that there may be a phospholipid-based transmembrane transport mechanism underlying the intracellular delivery of the FA-PC. This is the first report regarding FA-PC formation and its successful reversing of Gram-negative bacteria resistance to FA, and it provides a platform to reverse transmembrane delivery-related drug resistance. The ready availability of phospholipid and the simple preparation allow it to have great potential for clinical use.

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.