Cremophor Research Articles

Design and Evaluation of Hydrophobic Ion Paired Insulin Loaded Self Micro-Emulsifying Drug Delivery System for Oral Delivery.

Despite several novel and innovative approaches, clinical translation of oral insulin delivery into commercially viable treatment is still challenging due to its poor absorption and rapid degradation in GIT. Thus, an insulin-SDS hydrophobic ion pair loaded self-microemulsifying drug delivery system (SMEDDS) was formulated to exploit the hypoglycemic effects of orally delivered insulin. Insulin was initially hydrophobically ion paired with sodium dodecyl sulphate (SDS) to enhance its lipophilicity. The successful complexation of Insulin-SDS was confirmed by FTIR and surface morphology was evaluated using SEM. Stability of insulin after its release from HIP complex was evaluated using SDS PAGE. Subsequently, Ins-SDS loaded SMEDDS was optimized using two factorial designs. In vitro stability of insulin entrapped in optimized SMEDDS against proteolytic degradation was also assessed. Further, antidiabetic activity of optimized Ins-SDS loaded SMEDDS was evaluated in diabetic rats. Insulin complexed with SDS at 6:1 (SDS/insulin) molar ratio with almost five-fold increased lipophilicity. The SMEDDS was optimized at 10% Labraphil M2125 CS, 70% Cremophore EL, and 20% Transcutol HP with better proteolytic stability and oral antidiabetic activity. An Ins-SDS loaded SMEDDS was successfully optimized. Compared with insulin and Ins-SDS complex, the optimized SMEDDS displayed considerable resistance to GI enzymes. Thus, the SMEDDS showed potential for effective delivery of macromolecular drugs with improved oral bioavailability.

Nab-Paclitaxel in the Treatment of Gastrointestinal Cancers-Improvements in Clinical Efficacy and Safety.

Taxanes (paclitaxel and docetaxel) are one of the most useful classes of anticancer drugs. Taxanes are highly hydrophobic; therefore, these drugs must be dissolved in organic solvents (polysorbate or Cremophor EL), which contribute to their toxicities. To reduce this toxicity and to enhance their efficacy, novel formulations have been developed. Nanoparticle albumin-bound paclitaxel (nab-paclitaxel) is an albumin-stabilized, Cremophor-free, and water-soluble nanoparticle formulation of paclitaxel. Nab-paclitaxel has better solubility and less infusion-associated toxicity compared to solvent-based paclitaxel. Additionally, nab-paclitaxel can be given at higher doses and concentrations compared with solvent-based paclitaxel. Based on its superior clinical efficacy and safety profile, nab-paclitaxel received FDA approval for metastatic breast cancer (2008) and NSCLC (2011). Among gastrointestinal cancers, it is now approved in the USA for treating patients with metastatic adenocarcinoma of the pancreas as first-line therapy in combination with gemcitabine. Furthermore, several clinical trials have suggested the potential efficacy of nab-paclitaxel as a single agent or in combination with other agents for the treatment of metastatic esophageal, gastric, bowel, and biliary tract cancers. Nab-paclitaxel has been demonstrated to have greater overall response rates (ORR) with enhanced progression-free survival (PFS), overall survival (OS) and a superior safety profile with fewer adverse effects in patients with gastrointestinal tract cancers. This review summarizes the advantages associated with nab-paclitaxel-based regimens in terms of improving clinical efficacy and the safety profile in upper gastrointestinal cancer.

Formulation of Piperine-Loaded Nanoemulsion: In Vitro Characterization, Ex Vivo Evaluation, and Cell Viability Assessment.

Piperine is an alkaloid, but its therapeutic efficacy is limited due to poor aqueous solubility. In this study, piperine nanoemulsions were prepared using oleic acid (oil), Cremophore EL (surfactant), and Tween 80 (co-surfactant) using the high-energy ultrasonication approach. The optimal nanoemulsion (N2) was further evaluated using transmission electron microscopy, release, permeation, antibacterial, and cell viability studies based on minimal droplet size and maximum encapsulation efficiency. The prepared nanoemulsions (N1-N6) showed a transmittance of more than 95%, a mean droplet size between 105 ± 4.11 and 250 ± 7.4 nm, a polydispersity index of 0.19 to 0.36, and a ζ potential of -19 to -39 mV. The optimized nanoemulsion (N2) showed significantly improved drug release and permeation compared with pure piperine dispersion. The nanoemulsions were stable in the tested media. The transmission electron microscopy image showed a spherical and dispersed nanoemulsion droplet. The antibacterial and cell line results of piperine nanoemulsions were significantly better than the pure piperine dispersion. The findings suggested that piperine nanoemulsions may be a more advanced nanodrug delivery system than conventional ones.

#4394TACROLIMUS BUT NOT VOCLOSPORIN INHIBITS KIDNEY TUBULAR CALCIUM AND MAGNESIUM REABSORPTION IN RATS AT CLINICALLY THERAPEUTIC DOSES

Abstract Background and Aims Clinically, the calcineurin inhibitor tacrolimus frequently causes hypercalciuria and hypomagnesemia by inhibiting kidney tubular calcium and magnesium reabsorption. Voclosporin, a novel calcineurin inhibitor approved in the USA and Europe for the treatment of adults with active lupus nephritis, has fewer side-effects including less hypomagnesemia. However, the differences between the kidney tubular effects of tacrolimus and voclosporin are unknown. To address this, we compared the effects of tacrolimus, voclosporin, and vehicle in rats. Method Tacrolimus (0.5 mg/kg) and voclosporin (0.5 mg/kg) were administrated by daily intraperitoneal injections in male Wistar rats and were compared against vehicle (Cremophor EL: 95% ethanol:saline (5:5:90, v:v:v)) for 28 days (n = 8–9/group). Dosages were determined based on pharmacokinetic studies in rats and aimed to achieve the area under the concentration-time curve observed in clinical studies. At day 18, blood and 24 h urine were collected to measure trough levels of the drugs and to analyze the fractional excretions of calcium and magnesium. At sacrifice, kidneys were harvested for immunoblotting of tubular proteins. Results Both tacrolimus and voclosporin reached clinically therapeutic doses with trough levels of 2.4 μg/L ± 0.6 μg/L and 25.8 μg/L ± 9.6 μg/L, respectively. Compared to vehicle, tacrolimus caused significantly higher fractional excretions of calcium (+348% ± 127%, P < 0.001) and magnesium (+60% ± 38%, P < 0.01) and also caused hypomagnesemia (plasma magnesium 0.65 mmol/L ± 0.04 mmol/L vs. 0.81 mmol/L ± 0.02 mmol/L, P < 0.001). Compared to vehicle, voclosporin only caused a slight, but non-statistically significant, increase in fractional calcium excretion (+ 44% ± 38%, P = 0.08) and did not cause higher fractional magnesium excretion (+5% ± 30%, P = 0.96) or hypomagnesemia (plasma magnesium 0.8 mmol/L ± 0.04 mmol/L, P = 0.9). Compared to vehicle, tacrolimus caused an 11-fold decrease in the protein abundance of the cytosolic calcium-binding protein calbindin-D28K and a 2-fold decrease in the abundance of the sodium-chloride cotransporter (NCC). In contrast, voclosporin did not decrease the protein abundances of calbindin-D28K and NCC. No differences were observed between vehicle, tacrolimus, and voclosporin in the calcium channel TRPV5 and magnesium channel TRPM6 (Figure 1). Conclusion In contrast to the calcineurin inhibitor tacrolimus, voclosporin does not inhibit the kidney tubular reabsorption of calcium and magnesium and therefore does not cause hypercalciuria or hypomagnesemia. A possible explanation for this difference is that tacrolimus but not voclosporin affects tubular transport in the distal convoluted tubule, which was further supported by the selective inhibition of calbindin-D28K and NCC by tacrolimus. Our data show that tubulotoxicity of tacrolimus is not apparent with voclosporin treatment, at clinically relevant doses.

SCREENING OF PIROXICAM SELF-NANOEMULSIFYING DRUG DELIVERY SYSTEM (SNEDDS) USING FRACTIONAL FACTORIAL DESIGN

Piroxicam belongs to BCS class II and has low solubility. Self-nanoemulsifying drug delivery systems (SNEDDS) are considered a potential approach for increasing the solubility and release of piroxicam. This study aimed to select the components and component ratios of piroxicam SNEDDS using fractional factorial design 26-2 (FFD). The variables used in the DFT development of piroxicam SNEDDS are the type and concentration of oil (triacetin and oleic acid), surfactant (kolliphor EL and Tween 60), and co-surfactants (Transcutol and PEG 400). The FFD results showed 16 runs with different proportions of the piroxicam SNEDDS components, which were then characterized by critical parameters including emulsification time, %transmittance, droplet size, and drug loading. The components and component ratios of the PKM SNEDDS were determined using single-factor plot analysis. The results showed that triacetin (oil), kolliphor EL (surfactant), Transcutol (co-surfactant) had the greatest contribution to the formation of piroxicam SNEDDS with an oil ratio range of 11.11–28.57%, surfactant 44.44–77.78%, co-surfactant 11.11–44.44 %.

Development of positively charged amphiphile containing self-nanoemulsifying drug delivery system for improved therapeutic efficacy of metronidazole against Helicobacterpylori

Metronidazole (MTZ) has been extensively used to treat bacterial infections for over five decades, but MTZ bacterial resistance has been on the rise, making it less effective against Bacteroides species. This study aimed to improve the antibacterial activity of MTZ-loaded self-emulsifying drug delivery systems (SNEDDS) against H. pylori by the incorporation of alkylated morpholine serving as a positively charged amphiphile. The studies of drug solubility and emulsification led to the development of a ternary phase diagram for selecting formulation ingredients. The key ingredients of the formulation were selected as cinnamon oil (lipid), cremophor EL (surfactant), and polyethylene Glycol (PEG) 200 (co-surfactant). The optimized formulations were characterized for various physicochemical properties. The average droplet size and zeta potential of MTZ-SNEDDS were determined to be 146.03 ± 2.1 nm and −15.3 ± 0.50 mV while for alkylated morpholine incorporated MTZ-SNEDDS, these were 183.36 ± 21.42 nm and −16.2 ± 1.30 mV, respectively. The thermodynamically robust alkylated morpholine incorporated SNEDDS was successful in maintaining the chemical integrity of the MTZ. The antibacterial potential of MTZ-SNEDDS was significantly enhanced against H. pylori upon the incorporation of alkylated morpholine. It can be concluded that incorporating amphiphilic positively charged morpholine into SNEDDS can lead to more intake of them by H. pylori, and prolonging the contact duration of the SNEDDS with the outer membrane of H. pylori increased the transmembrane penetration of SNEDDS.

β-Lactoglobulin stabilized lipid nanoparticles enhance oral absorption of insulin by slowing down lipolysis

Lipid-based nanocarriers have staged a remarkable comeback in the oral delivery of proteins and peptides, but delivery efficiency is compromised by lipolysis. β-Lactoglobulin (β-lg) stabilized lipid nanoparticles, including nanoemulsions (NE@β-lg) and nanocapsules (NC@β-lg), were developed to enhance the oral absorption of insulin by slowing down lipolysis due to the protection from β-lg. Cremophor EL stabilized nanoemulsions (NE@Cre-EL) were prepared and set as a control. The lipid nanoparticles produced mild and sustained hypoglycemic effects, amounting to oral bioavailability of 3.0% ± 0.3%, 7.0% ± 1.1%, and 7.7% ± 0.8% for NE@Cre-EL, NE@β-lg, and NC@β-lg, respectively. Aggregation-caused quenching (ACQ) probes enabled the identification of intact nanoparticles, which were used to investigate the in vivo and intracellular fates of the lipid nanoparticles. In vitro digestion/lipolysis and ex vivo imaging confirmed delayed lipolysis from β-lg stabilized lipid nanoparticles. NC@β-lg was more resistant to intestinal lipolysis than NE@β-lg due to the Ca2+-induced crosslinking. Live imaging revealed the transepithelial transport of intact nanoparticles and their accumulation in the liver. Cellular studies confirmed the uptake of intact nanoparticles. Slowing down lipolysis via food proteins represents a good strategy to enhance the oral absorption of lipid nanoparticles and thus co-formulated biomacromolecules.

Inhalable Solubilized Zileuton for Improved Lung Targeting in vitro and in vivo Analysis

Abstract: Background: Pulmonary diseases that affect the normal functioning of the lungs show airway symptoms ranging from change in airflow to bronchiectasis. Zileuton is an inhibitor of 5-lipoxygenase enzyme that catalyzes the synthesis of leukotrienes. Zileuton is used in the management of inflammatory conditions of the upper airways like obstructive pulmonary conditions and acute lung inflammation. Although a promising therapeutic, zileuton is poorly water-soluble and requires frequent administration to overcome bioavailability issues and maintain therapeutic levels that often lead to adverse reactions, especially to the non-targeted organs. Materials and Methods: Therefore, we designed a rapidly nanoemulsifying formulation of zileuton using Acrysol K150 as an oil, Cremophor EL as a surfactant, and Transcutol HP as a cosolvent. Results: This self-emulsifying composition exhibited showed a mean globule size of 133 ± 3.6 nm with a polydispersity index of 0.38. Scanning electron microscopy (SEM) images revealed the spherical shape of emulsion globules. In vitro lung deposition showed >80% delivery to the deep lung tissue. Mass median aerodynamic diameter of 2.05±0.98 μm for the aerosolized formulation. In vivo, pharmacokinetic studies in Wistar rats by inhalation route showed that the zileuton-loaded nanoemulsifying formulation had a significantly higher concentration in the lung compared to other non-target organs. The in vivo efficacy in the lipopolysaccharide-induced acute lung inflammation model in rats significantly impeded the protein accumulation and neutrophil infiltration in the lungs. Conclusion: The zileuton-loaded nanoemulsifying inhalable formulation successfully improved the therapeutic efficacy of zileuton specifically to the lung thereby minimizing the off-target organ side effects. Keywords: Self-emulsifying, Zileuton, Aerosols, Pharmacodynamics, in vivo, Lung targeting.

Phase 2 study of weekly polymeric micelle-formulated paclitaxel plus gemcitabine in patients with recurrent and metastatic adenocarcinoma of the pancreas.

e16257 Background: Cremophor EL(CrEL), used to enhance drug solubility, may add paclitaxel’s toxicities such as hypersensitivity reactions or peripheral neuropathy. The rationale for developing an alternative paclitaxel formulation concerns CrEL-related side effects, and a novel paclitaxel delivery system might augment its therapeutic efficacy. GENEXOL-PM (GPM) is a novel polymeric micelle formulated paclitaxel free of CrEL. This is to report the efficacy and safety of the weekly combined chemotherapy with GPM and gemcitabine in patients with recurrent and metastatic adenocarcinoma of the pancreas conducted in multicenter, Republic of Korea. Methods: This was a multicenter, phase 2 study of weekly GENEXOL-PM plus gemcitabine in subjects with recurrent and metastatic adenocarcinoma of the pancreas. The patients who had met the inclusion/exclusion criteria were enrolled and received GPM (125 mg/m2) and gemcitabine (1000 mg/m2) intravenously on day 1, 8, and 15 in every 4 weeks, unless definite disease progression was confirmed. Tumor evaluation was conducted at the end of every 2 cycles according to Response Evaluation Criteria in Solid Tumors (RECIST). Pre-planned test and adverse reaction evaluation were managed after each cycle of drug administration and before the next cycle. The primary end point of this study was objective response rate, and the secondary end points were toxicity, progression free survival and overall survival. Results: Between January 2016 and February 2022, total 32 patients were enrolled; median age was 65 years; male (n=16) and female (n=16). 26 patients were assessable for efficacy. Overall response rate was 19.2% (5/26 patients) and clinical benefit rate (partial response + stable disease) was 34.6% (9/26 patients). The median progression-free survival and overall survival were 8 months, 22 months, respectively. The median number of cycles administered was 5.0 (range=1-21). Most common grade 3 or higher hematological toxicities were: neutropenia occurred in 9 patients (29.0%), neutrophil count decrease 5 patients (16.1%) and anemia 5 patients (16.1%). The most common grade 3/4 non-hematological toxicities were generalized muscle weakness 3 patients (11.5%), pneumonitis 3 patients (11.5%) and liver abscess 2 patients (4.3%). Conclusions: Treatment of advanced pancreatic cancer with combination of GENEXOL-PM and gemcitabine was generally well tolerated and showed a favorable toxicity profile. In this study, efficacy results of combination regimen were comparable to that observed historically with albumin-bound paclitaxel and gemcitabine combination. This regimen demonstrated chemotherapeutic effects to warrant further development when used as first-line chemotherapy for advanced pancreatic cancer. Future studies directly comparing GENEXOL-PM and albumin-bound paclitaxel are required. Clinical trial information: NCT02739633 .

Exploiting itraconazole-loaded nanomixed micelles in coated capsules as efficient colon-targeted delivery system for improved antifungal and potential anticancer efficacy

Chronic Inflammatory bowel diseases are usually accompanied by opportunistic colonic fungal infections. Itraconazole (ITZ), is a highly lipophilic broad-spectrum antifungal drug that is superiorly effective against several fungal species. Box-Behnken design was adopted to design ITZ-nanomixed micelles (ITZ-NMMs), aiming to enhance ITZ solubility, using various concentrations of Pluronic® L121, Cremophor EL, and with either sodium-deoxycholate or Pluronic® F68 through thin film hydration technique. Optimized formula composed of 90 % Pl–L121, 9.1% Cremophor EL, 3.127 % ITZ concentration and SDC as the hydrophilic surfactant and its particle size, Polydispersity index, zeta potential, entrapment efficiency, and release extent after 3 h were found to be 17.82 ± 0.189 nm, 0.26 ± 0.014, -6.72 ± 0.725 mV, 66 ± 7.4%, and 96.3 ± 7.22%, respectively. In vitro ITZ release study implied the ability of optimal ITZ-NMMs to enhance ITZ solubility in comparison to ITZ suspension. Also, augmented anti-fungal and anti-cancer activities were proven as ITZ-NMMs IC50 was 16.5 times that of pure ITZ. Afterwards, lyophilized optimal ITZ-NMMs formula was loaded into Eudragit S100-coated capsules where in vitro release and in vivo X-ray imaging ensured protection of ITZ release in either the stomach or intestine and targeting it to the colon. Such results suggested promising ITZ-NMMs system, capable of enhancing ITZ solubility in the intended target site, therefore, can be used not only in the treatment of colon fungal infections but also augments colon cancer therapy.

5-Fluorouracil-Loaded PLGA Nanoparticles: Formulation, Physicochemical Characterisation, and In VitroAnti-Cancer Activity.

The major goal of this investigation was to prepare a drug delivery of polymeric nanoparticles (NPs) from 5-fluorouracil (FU) that could be delivered intravenously and improve the therapeutic index of the FU. In order to achieve this, interfacial deposition method was used to prepare FU entrapped poly-(lactic-co-glycolic acid) nanoparticles (FU-PLGA-NPs). The influence of various experimental settings on the effectiveness of FU integration into the NPs was assessed. Our findings show that the technique used to prepare the organic phase and the ratio of the organic phase to the aqueous phase had the greatest impact on the effectiveness of FU integration into NPs. The results show that the preparation process produced spherical, homogenous, negatively charged particles with a nanometric size of 200 nm that are acceptable for intravenous delivery. A quick initial release over 24 h and then slow and steady release of FU from the formed NPs, exhibiting a biphasic pattern. Through the human small cell lung cancer cell line (NCI-H69), the in vitro anti-cancer potential of the FU-PLGA-NPs was evaluated. It was then associated to the in vitro anti-cancer potential of the marketed formulation Fluracil®. Investigations were also conducted into Cremophor-EL (Cre-EL) potential activity on live cells. The viability of NCI-H69 cells was drastically reduced when they were exposed to 50 µg·mL-1 Fluracil®. Our findings show that the integration of FU in NPs significantly increases the drug cytotoxic effect in comparison to Fluracil®, with this potential effect being particularly important for extended incubation durations.

Investigating Key Molecular Descriptors Affecting Particle Size: A Predictive Exemplary Approach for Self-Emulsifying System.

The self-nano/microemulsifying drug delivery system is one of the well-established techniques for enhancing the solubility of poorly water-soluble drug molecules. The ratio of oil:surfactant:cosolvent plays a key role in globule size on dispersion into water, but there is very limited information on how a drug molecule affects the size. The rationale of this project was to illustrate the correlation between the particle size of nanoemulsion droplets and molecular descriptors of a drug. In the study, a self-nanoemulsifying preconcentrate containing drug with medium chain triglycerides (oil), dimethylacetamide (DMA, cosolvent), and Kolliphor EL (surfactant) was prepared for 40 drug molecules with diverse physicochemical properties. The self-nanoemulsifying preconcentrate was dispersed in water, and dynamic light scattering particle size was analyzed. A majority of drugs showed a significant increase in globule size compared to blank formulation, while few drugs showed a stark reduction in globule size. It is interesting to understand the attributes of molecules driving the self-emulsification and the diameter of nanoglobules. A systematic correlation of resultant particle size with 1D, 2D, and 3D molecular descriptors (overall more than 700 descriptors) was carried out for the data set using the PaDEL tool kit. The data compilation, curation, and analysis were performed using the SIMCA14 software. In the process of molecular descriptors screening, thereafter curation, 50 descriptors were selected using the genetic algorithm screening. The PLS-DA statistical method was employed for conversion of data into binomial systems. Final group of 5 descriptors: SpMiSpMin2_Bhe, RNCS, TDB9i, JG17, and ETA_Shape showed the correlation with particle size and classifying the drug molecules facilitating increase or decrease in particle size.

Improvement of Entrapment and Ocular Permeability of Ganciclovir Nanostructured Lipid Carriers Using Various Conditions of Preparations

Ganciclovir (GCV) is a drug included in BCS-Class III, having high solubility and low permeability. It is a synthetic acyclic nucleoside analog of 2′-deoxyguanosine, considered a potent inhibitor of herpes viruses and cytomegalovirus (CMV) infection. Herpes simplex virus (HSV) infections are very common and are also considered a major cause of corneal blindness. This study intended to advance a pioneering nanostructured lipid carriers (NLCs) system for improving the ocular permeability of GCV. Several procedures were used for the preparation. Cold homogenization, solvent injection, and emulsifi cationultrasonication methods. A mixture of palmitic acid (PA) and oleic acid (OA) as a lipid matrix, cremophore EL, and transcutol HP were used as emulsifi ers. To evaluate the optimum method, the particle size (PS), polydispersity index (PDI), zeta potential (ZP), entrapment effi ciency (EE), and drug loading (DL%) were determined for the prepared NLCs. Due to the decreased particle size value, the polydispersity index, and the high value of EE%, emulsifi cation/ultrasonication outcomes were more practical than cold homogenization and solvent injection procedures. The fi ndings demonstrated that the preparation procedure had a substantial impact on the EE%.The emulsifi cation method can prepare the NLCs of GCV successfully.

Formulation and Evaluation of Castor Oil Containing Self-emulsifying Pellets by Using Design of Experiment

Abstract: Background/Objectives: The objective of the study was to examine the feasibility of extrusion/ spheronization techniques for formulation of castor oil loaded self-emulsifying pellets. The study was also aimed at optimization of the self-emulsifying pellet system with design of experiments. Materials and Methods: Various surfactants and co-surfactants were tested for their ability to emulsify castor oil. The proportion of components (castor oil, surfactant and co-surfactant) in self-emulsifying pellets was optimized using a D-optimal mixture design. During optimization, the effect of composition of oil(X1), surfactant(X2) and cosurfactant(X3) blend on responses like dispersion time (Y1), resultant globule size (Y2) and polydispersity index (Y3) was studied. The developed self-emulsifying mixture was further loaded on pellet formulation using extrusion spheronization technique. Results: The application of D-optimal mixture design resulted in 16 batches, out of which the optimized batch consists of castor oil (30.92%), Cremophore EL (58.56%) and PEG 400(10.51%) having dispersion time of 53 sec, globule size of 242 nm and polydispersity index of 0.243 with desirability value of 1. All the formulation components affected the performance of pellets significantly. Free flowing pellets were obtained with 30% of oil loading. Conclusion: The self-emulsifying pellets of castor oil were successfully optimized with mixture design. The developed system containing castor oil can be used for orally for conditions like arthritis or can also serve as a carrier system for any drug or herbal active. Keywords: Solid self-emulsifying drug delivery system, Castor oil, Self-emulsifying pellets, Extrusion spheronization, Dispersion time.

Hydrophobic Ion Pairing of Small Molecules: How to Minimize Premature Drug Release from SEDDS and Reach the Absorption Membrane in Intact Form.

The present work aimed to form hydrophobic ion pairs (HIPs) of a small molecule remaining inside the oily droplets of SEDDS to a high extent. HIPs of ethacridine and various surfactants classified by functional groups of phosphates, sulfates, and sulfonates were formed and precipitation efficiency, log Dn-octanol/water, and solubility in different excipients were investigated. Most lipophilic HIPs were incorporated into SEDDS and evaluated regarding drug release. Docusate HIPs showed the highest increase in lipophilicity with a precipitation efficiency of 100%, a log Dn-octanol/water of 2.66 and a solubility of 132 mg/mL in n-octanol, 123 mg/mL in oleyl alcohol, and 40 mg/mL in medium chain triglycerides. Docusate HIPs were incorporated into three SEDDS of increasing lipophilicity (F1 < F2 < F3) based on medium chain triglycerides, oleyl alcohol, Kolliphor EL, and Tween 80 (F1: 1 + 5 + 2 + 2; F2: 3 + 3 + 2 + 2; F3: 5 + 1 + 4 + 0). Highest achievable payloads ranged from 74.49 mg/mL (F3) to 97.13 mg/mL (F1) and log DSEDDS/RM increased by at least 7.5 units (4.99, F1). Drug release studies via the diffusion membrane method confirmed minor release of docusate HIPs from all SEDDS (<2.7% within 4 h). In conclusion, highly lipophilic HIPs remain inside the oily phase of SEDDS and likely reach the absorption membrane in intact form.

Unveiling the dielectric properties of self-nanoemulsifying drug delivery systems (SNEDDS)

Self-nanoemulsifying Drug Delivery System (SNEDDS) improves the bioavailability of bioactive compounds that exhibit low water solubility. In this regard, our study aims to assess the formulation of SNEDDS in a wide range of oil concentrations (0–8.6 wt%) by dynamic light scattering, FTIR, dielectric measurements, and the characterization of the interface layer and its molecular interactions with water. The proper formulation of SNEDDS accounted for the lipophilic/hydrophilic balance leading to a homogeneous distribution of oil droplets in water with constant sizes of 20–22 nm, which does not depend on oil concentration. Dielectric spectroscopy measurements in the GHz frequency range allowed us to obtain the dependence of relaxation time as a function of oil concentration and its relationship with the viscosity of the nanoemulsion. The classical two-phase model of Hanai, Maxwell-Garnet, Bruggeman, and Lichtenecker fails to describe the dielectric properties of nanoemulsions. Therefore, in this work, a three-phase model is proposed to model the dielectric measurements, which include water as the continuous phase, oil droplets, and interface layer due to using Cremophor EL (HLB = 12–14) and Labrafil M1944CS (HLB = 2–3) as surfactant and co-surfactant. This model fits well with the experimental results and allows us to obtain SNEDDS properties such as the dielectric constant (20.9), volume fraction, and the interface layer thickness (ca. 5 nm). Investigated oil–water nanoemulsions can be a model for developing different drug delivery systems. Additionally, proposed measurements in the GHz frequency range and their interpretation can be generalized for nanoemulsion characterization.

Nanoformulation of the K-Ras(G12D)-inhibitory peptide KS-58 suppresses colorectal and pancreatic cancer-derived tumors

Single amino acid mutations of Ras occur in 30% of human cancers. In particular, K-Ras(G12D) has been detected in the majority of intractable colorectal and pancreatic cancers. Although efforts to target K-Ras(G12D) are currently underway, no effective drugs are available. We previously found that the K-Ras(G12D)-inhibitory bicyclic peptide KS-58 exhibits antitumor activity against syngeneic colon and orthotopic grafted pancreatic tumors; however, pristine KS-58 is difficult to handle because of low water solubility and it requires frequent administration to obtain sufficient antitumor activity. In this study, we used a nanoformulation of KS-58 prepared with the highly biocompatible surfactant Cremophor® EL (CrEL) to improve water solubility and reduce the dosing frequency. Nanoformulations of KS-58 with CrEL dramatically improved its water solubility and increased its stability. Weekly intravenous administration of KS-58 nanoparticles (NPs) suppressed the growth of CT26 and PANC-1 cell-derived tumors in vivo, and fluorescent bioimaging indicated that the NP-encapsulated near-infrared fluorescent probe indocyanine green selectively accumulated in the tumor and was safely excreted through the kidneys following intravenous injection. Histopathological analysis of CT26 tumors and Western blotting of PANC-1 tumors revealed that KS-58 NPs reduced ERK phosphorylation, a downstream signal of K-Ras(G12D). Our results suggest that KS-58 NPs represent a novel therapeutic agent for treating colorectal and pancreatic cancers.

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 Cmax, AUC0-∞, 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.

Characterization of a Novel Amphiphilic Cationic Chlorin Photosensitizer for Photodynamic Applications.

A novel amphiphilic cationic chlorin e6 derivative was investigated as a promising photosensitizer for photodynamic therapy. Two cationic -N(CH3)3+ groups on the periphery of the macrocycle provide additional hydrophilization of the molecule and ensure its electrostatic binding to the mitochondrial membranes and bacterial cell walls. The presence of a hydrophobic phytol residue in the same molecule results in its increased affinity towards the phospholipid membranes while decreasing its stability towards aggregation in aqueous media. In organic media, this chlorin e6 derivative is characterized by a singlet oxygen quantum yield of 55%. Solubilization studies in different polymer- and surfactant-based supramolecular systems revealed the effective stabilization of this compound in a photoactive monomolecular form in micellar nonionic surfactant solutions, including Tween-80 and Cremophor EL. A novel cationic chlorin e6 derivative also demonstrates effective binding towards serum albumin, which enhances its bioavailability and promotes effective accumulation within the target tissues. Laser confocal scanning microscopy demonstrates the rapid intracellular accumulation and distribution of this compound throughout the cells. Together with low dark toxicity and a rather good photostability, this compound demonstrates significant phototoxicity against HeLa cells causing cellular damage most likely through reactive oxygen species generation. These results demonstrate a high potential of this derivative for application in photodynamic therapy.

Development of an Oral Isoliquiritigenin Self-Nano-Emulsifying Drug Delivery System (ILQ-SNEDDS) for Effective Treatment of Eosinophilic Esophagitis Induced by Food Allergy.

Isoliquiritigenin (ILQ) is a natural flavonoid with various pharmacological activities. In this study, we optimized the preparation method of self-nano-emulsion-loaded ILQ to further improve its bioavailability based on our previous study. In addition, its effect on the treatment of eosinophilic esophagitis was also evaluated. Combined surfactants and co-surfactants were screened, and the optimal formulation of ILQ-SNEDDS was determined according to droplet size, droplet dispersity index (DDI), and drug loading. The formulation was composed of ethyl oleate (oil phase), Tween 80 & Cremophor EL (surfactant, 7:3), and PEG 400 & 1,2-propylene glycol (cosurfactant, 1:1), with a mass ratio of 3:6:1. Its physicochemical properties, including drug loading, droplets' size, Zeta potential, appearance, and Fourier transform infrared (FTIR) spectroscopy, were characterized. In vitro release profile, in situ intestinal absorption, and in vivo pharmacokinetics were applied to confirm the improvement of oral ILQ bioavailability by NEDDS. Finally, the efficacy of ILQ-SNEDDS in the treatment of food allergy-induced eosinophilic esophagitis (EOE) was further evaluated. When the ILQ drug loading was 77.9 mg/g, ILQ-SNEDDS could self-assemble into sub-spherical uniform droplets with an average size of about 33.4 ± 2.46 nm (PDI about 0.10 ± 0.05) and a Zeta potential of approximately -10.05 ± 3.23 mV. In situ intestinal absorption showed that optimized SNEDDS significantly increased the apparent permeability coefficient of ILQ by 1.69 times, and the pharmacokinetic parameters also confirmed that SNEDDS sharply increased the max plasma concentration and bioavailability of ILQ by 3.47 and 2.02 times, respectively. ILQ-SNEDDS also significantly improved the apparent signs, allergic index, hypothermia and body weight of EoE model mice. ILQ-SNEDDS treatment significantly reduced the levels of inflammatory cytokines, such as TNF-α, IL-4, and IL-5, and the level of PPE-s-IgE in serum, and significantly inhibited the expression of TGF-β1 in esophageal tissue. SNEDDS significantly improved the solubility and bioavailability of ILQ. Additionally, ILQ-SNEDDS treatment attenuated symptomatology of EoE model mice, which was associated with inhibiting the production of TH2 inflammatory cytokines and PPE-s-IgE and the expression of TGF-β1. The above results shows that ILQ-SNEDDS has great potential as a good candidate for the treatment of eosinophilic esophagitis.