Venous irritation, pharmacokinetics, and tissue distribution of tirilazad in rats following intravenous administration of a novel supersaturated submicron lipid emulsion

Enhanced brain delivery with lower hepatic exposure of lazaroid loaded nanostructured lipid carriers developed using a design of experiment approach

The current study was designed to develop and optimize lazaroid loaded nano-structured lipid carriers (LAZ-NLCs) using design of experiment approach for enhancing lazaroid brain exposure. Response surface plots were used to determine the effects of independent variables (amount of PEGylating agent and liquid lipid) on dependent variables (particle size, zeta potential and encapsulation efficiency), while numerical optimization was used for optimizing LAZ-NLCs composition. The optimal LAZ-NLCs were spherical in shape with measured size of 172.3 ± 3.54 nm, surface charge of -4.54 ± 0.87 mV and encapsulation efficiency of 85.01 ± 2.60%. The optimal LAZ-NLCs were also evaluated for hemolytic potential, storage stability and solid-state properties. The plasma pharmacokinetics along with brain and hepatic distributions of control lazaroid citrate solution and optimal LAZ-NLCs formulation were evaluated in Sprague-Dawley rats after the single bolus intravenous administration. The optimized LAZ-NLCs and the control lazaroid citrate solution had similar plasma pharmacokinetic profiles; however, differential organ bio-distributions were observed. The lazaroid exposure in brain was enhanced by two times with a decreased liver exposure by half for the NLCs group compared to the solution group.

Cinnamaldehyde in a Novel Intravenous Submicrometer Emulsion: Pharmacokinetics, Tissue Distribution, Antitumor Efficacy, and Toxicity

The purpose of our research is to find a new lipid emulsion to deliver a low water-soluble compound, cinnamaldehyde (CA). Its characteristics, pharmacokinetics, antitumor efficacy, and toxicity were evaluated. The mean particle size, zeta potential, and encapsulation efficiency of the submicromemter emulsion of CA (SME-CA) were 130 ± 5.92 nm, -25.7 ± 6.00 mV, and 99.5 ± 0.25%, respectively. The area under the curve from 0 h to termination time (AUC(0-t)) of SME-CA showed a significantly higher value than that of CA (589 ± 59.2 vs 375 ± 83.5 ng h/L, P < 0.01). Tissue distribution study showed various changes; among them, a 27% higher concentration was found in brain tissue when using SME-CA at 15 min after administration. For the efficacy evaluation, SME-CA exhibited 8- and 11-fold antitumor activity in the depression of HeLa and A549 cell lines with the IC50 decreasing to 0.003 and 0.001 mmol/L, respectively. The LD50 values of CA and SME-CA in mice were 74.8 and 125 mg/kg, suggesting increased safety from the new formulation. The new formulation exhibited lower toxicity, higher antitumor activity, and a more satisfactory pharmacokinetic property, which displayed great potential for future pharmacological application.

Influence of particle size on the in vitro and in vivo anti-inflammatory and anti-allergic activities of a curcumin lipid nanoemulsion

The polyphenolic compound, curcumin, is a natural yellow pigment component of turmeric. It exerts various biological effects, such as anti-inflammatory effects, and we have previously demonstrated that curcumin is a specific inhibitor of DNA polymerase λ. Curcumin is characterized by poor bioavailability as it is water-insoluble, is poorly absorbed and is systemically eliminated. In order to increase the bioavailability of curcumin, in this study, we produced a curcumin-loaded lipid nanoemulsion of various particle sizes (50, 100 and 200 nm). The curcumin lipid nanoemulsion was prepared by a modified thin-film hydration method followed by sonication. To identify the optimal particle size which exhibits the strongest physiological activity, we investigated the inhibitory effects of the obtained nanoemulsions against inflammatory and allergic activities. In in vitro cell culture experiments, the 100-nm curcumin lipid nanoemulsion showed the most prominent inhibitory effect on the production of tumor necrosis factor-α (TNF-α) induced by lipopolysaccharide (LPS) in RAW264.7 murine macrophages, and on the release of β-hexosaminidase induced by the calcium ionophore, A23187, in rat basophilic leukemia RBL-2H3 cells. In an in vivo experiment, in which mice were administered the curcumin-loaded lipid nanoemulsion of various particle sizes, the 100-nm curcumin lipid nanoemulsion showed the most prominent anti-inflammatory and anti-allergic effects, inhibiting 12-O-tetradecanoylphorbol-13-acetate-induced inflammatory ear edema and immunoglobulin E (IgE)-induced passive cutaneous anaphylactic (PCA) reaction. The effects of particle size on serum curcumin absorption were also assessed in mice, and the 100-nm lipid nanoemulsion showed the greatest absorption. The results from our study suggest that the physiological activities of curcumin lipid nanoemulsions differ depending on particle size. Our data indicate that the curcumin lipid nanoemulsion with a particle size of 100 nm has potential for use in enhancing the bioavailability and medical value of curcumin.

Comparison of the endothelial toxicity induced by short-term amiodarone and diazepam exposure in a human umbilical vein endothelial cell line (EVC304)

CONTEXT

Venous irritation is the most common side effect of intravenous therapy. Although many in vitro models have been developed to evaluate intravenous drug irritation, these models are not widely accepted.

OBJECTIVES

The aim of this paper is to determine whether delayed or immediate cytotoxicity better reflects the in vivo venous irritation ranking.

MATERIALS AND METHODS

We compared the endothelial toxicity induced by high-concentrations of amiodarone and diazepam after short-term exposure (20 min) in a human umbilical vein endothelial cell line (EVC304) by using five in vitro models: lactate dehydrogenase (LDH), glucose-6-phosphate dehydrogenase (G6PD), glutathione (GSH), adenosine triphosphate (ATP), and MTT assays.

RESULTS

In the 24-h MTT assay, the IC50 of diazepam and amiodarone was 1.08 and 1.96 mM, respectively. In the 48-h MTT assay, the IC50 of diazepam and amiodarone was 1.114 and 1.128 mM, respectively. In the intracellular LDH and G6PD assays, the EC50 of diazepam was found to be 3.307 and 1.53 mM, while the values of amiodarone were 0.853 and 0.325 mM, respectively. In the intracellular ATP and GSH assays, the EC50 of diazepam was 0.905 and 1.283 mM, while the values of amiodarone were 0.040 and 0.326 mM, respectively.

CONCLUSION

Both the results of intracellular macromolecule activities and micromolecule concentrations were similar to that observed in in vivo venous irritation studies. However, the delayed cytotoxicity rank from the MTT assay is inconsistent with the in vivo venous irritation rank, suggesting that initial toxicity, but not the delayed toxicity, is related to venous irritation.

An improved method to prepare an injectable microemulsion of the galanin-receptor 3 selective antagonist, SNAP 37889, using Kolliphor(®) HS 15

Research into the galanin-3 (GAL3) receptor has many challenges, including the lack of commercially available selective ligands. While the identification of non-peptidergic GAL3 receptor-selective antagonists, 1-phenyl-3-[3-(trifluoromethyl)phenyl]iminoindol-2-one (SNAP 37889) and 1-[3-(2-pyrrolidin-1-ylethoxy)phenyl]-3-[3-(trifluoromethyl)phenyl]iminoindol-2-one (SNAP 398299) have implicated a role for GAL3 receptors in anxiety, depression and drug-seeking behaviour, a major limitation of their use is poor aqueous solubility. Previously we have used 5% dimethylsulfoxide (DMSO) with 1% hydroxypropylmethyl cellulose in saline to dissolve SNAP 37889 for intraperitoneal (i.p.) injections of rats; however this produced a micro-suspension that was not ideal. The injectable formulation of SNAP 37889 was improved as follows:•30% (w/v) Kolliphor(®) HS 15 (Solutol HS(®) 15) and sodium phosphate buffer (0.01 M, pH 7.4) were used as vehicles.•A smooth glass mortar and pestle was used to triturate the Kolliphor(®) HS 15 and SNAP 37889 into a paste before addition to the sodium phosphate buffer at room temperature (RT).•The resulting mixture was vortexed until the paste was fully dissolved and the microemulsion was allowed to sit for 20 min to allow air bubbles to coalesce.

Formulation design, preparation, and in vitro and in vivo characterizations of β-Elemene-loaded nanostructured lipid carriers

In the present study, nanostructured lipid carriers (NLCs) were prepared and optimized for the intravenous delivery of β-Elemene (β-E). Aqueous dispersions of NLCs were successfully prepared by high-pressure homogenization method using glycerol monostearate as the solid lipid and a mixture of Maisine 35-1 and Labrafil M1944 CS as the liquid lipid. The results revealed that the morphology of the NLCs was spheroidal. The particle size, zeta potential, and entrapment efficiency (EE) for the optimized formulation were observed as 138.9 nm, -20.2 mV, and 82.11%, respectively. X-ray diffraction analysis revealed the formation of less ordered structures in the inner core of the NLC particles. Moreover, the β-E-loaded NLCs were also less irritating and less toxic compared to Elemene injection. In addition, β-E-NLCs showed a significantly higher bioavailability and anti-tumor efficacy than Elemene injection. Taken together, our data indicate that the β-E-NLCs described in this study are well-suited for the intravenous delivery of β-E.

Preparation of Lipid Nanoemulsions Incorporating Curcumin for Cancer Therapy

The aim of this study was to develop a new formulation of a curcumin lipid nanoemulsion having the smallest particle size, the highest loading, and a good physical stability for cancer chemotherapy. Curcumin lipid nanoemulsions were prepared by a modified thin-film hydration method followed by sonication. Soybean oil, hydrogenatedL-α-phosphatidylcholine from egg yolk, and cosurfactants were used to formulate the emulsions. The resultant nanoemulsions showed mean particle diameter of 47–55 nm, could incorporate 23–28 mg curcumin per 30 mL, and were stable in particle size for 60 days at 4°C. The cytotoxicity studies of curucumin solution and curcumin-loaded nanoemulsion using B16F10 and leukemic cell lines showed IC50values ranging from 3.5 to 30.1 and 22.2 to 53.7 μM, respectively. These results demonstrated the successful incorporation of curcumin into lipid nanoemulsion particles with small particle size, high loading capacity, good physical stability, and preserved cytotoxicity.

Formulation of a stable and high-loaded quercetin injectable emulsion

The purpose of this paper was to prepare a stable and high-loaded quercetin emulsion with the quercetin-phospholipid complex. The complex was analyzed by FT-IR and SEM. Quercetin and soybean lecithin were reacted in dichloromethane at a ratio of 1:2.5 for 2 h at 40°C to prepare the complex. The optimum quercetin emulsion formulation consisted of (according to quality percentage), the complex (quercetin 0.06% in the emulsion), miglyol 812 10%, soybean oil 2%, solutol HS 15 1.2%, cremophor ELP 0.4%, vitamin E 0.2%, oleic acid 0.5%, glycerol 2.5%. The quercetin emulsion was sterilized at 121°C for 15 min. The drug content and particle size distribution of the emulsion before and after sterilization were almost unchanged. The results of accelerate stability (stored at 40°C over one month) and short-time stability (stored at room temperature over six months) tests showed that the quercetin emulsion had enough physicochemical stability to undergo storage. The histopathological examination for rabbit ear vein irritation test indicated that the quercetin emulsion produced no more irritation than normal saline.

An oil-free microemulsion for intravenous delivery of diallyl trisulfide: formulation and evaluation

The aim of the present study was to develop an oil-free o/w microemulsion, Cremophor EL:ethanol-propylene glycol:saline, for diallyl trisulfide (DATS) for intravenous (i.v.) administration to modify the safety and pharmacokinetics of DATS. The ternary diagram was constructed to identify the regions of dilutable microemulsions, and the optimal composition of microemulsion was determined by evaluation of injection safety such as hemolysis, intravenous stimulation and injection anaphylaxis compared to commercial formulation Chentian(®). Promising microemulsion with modified injection safety was developed that could incorporate 100 mg/g of DATS. The droplet size of the microemulsion was about 26 nm in diameter with narrow distribution (polydispersity index: 0.14). Acute toxicity test showed that median lethal dose (LD(50)) of DATS microemulsion was 1.69-fold higher than that of Chentian(®). Pharmacokinetics was assessed by comparing with the commercial injection after intravenous administration to rats at a dose of 30 mg/kg. The developed microemulsion showed significant higher area under the drug concentration-time curve and lower clearance and distribution volume than those of Chentian(®) (p<0.05). This helped DATS to reach higher level in vessel, and circulate in the blood stream for a longer time resulting in better therapeutic effect. In conclusion, microemulsion would be a promising intravenous delivery system for DATS.

The composition of oil phase modulates venous irritation of lipid emulsion-loaded diallyl trisulfide

INTRODUCTION

In this study, a nanoemulsion system (LE) was investigated for intravenous delivery of diallyl trisulfide (DT), which was a lipophilic and venous irritant drug for systemic therapy of bacterial and fungal infection.

METHODS

Egg phospholipid was chosen as the only emulsifier, soybean oil, medium chain triglyceride (MCT), and olive oil were used as the oil phases, forming stable DT LEs (o/w) with small particle sizes. The venous irritation of DT LEs was evaluated by in vitro human umbilical cord endothelial cells (HUV-EC CRL 1730) tolerance model with the intracellular ATP and GTP concentrations as the indices.

RESULTS

The intracellular ATP and GTP reduction changed with the incorporation of a variety of oils, which were strongly related with the free DT concentration of DT LEs.

DISCUSSION

It was deduced that the free DT concentrations of LEs made of various oils depended on the particle sizes of the DT LEs. In conclusion, the oil phases modulated the free DT concentrations by forming DT LEs with different particle sizes, and optimization of the oil phase was an effective method to alleviate the venous irritation of DT LEs.

Pharmacokinetics, tissue distribution and safety of cinnarizine delivered in lipid emulsion

The aim of this study was to assess the potential of cinnarizine loaded in lipid emulsion to modify the pharmacokinetics, tissue distribution and safety of cinnarizine. The cinnarizine-loaded emulsion (CLE) which can remain stable over 18-month storage at 4+/-2 degrees C was prepared by high-pressure homogenization. Nicomp 380 particle sizing system and HPLC were used to evaluate CLE in vitro, while UPLC/MS/MS for pharmacokinetic and tissue distribution study. The pharmacokinetics and tissue distributions of CLE were assessed by comparing with the solution form after intravenous administration to rats at a dose of 2mg/kg. The CLE showed significant higher AUC and lower clearance and distribution volume than those of solution form. This helped cinnarizine to reach higher level in vessel, and circulate in the blood stream for a longer time resulting in better therapeutic effect. The tissue distribution exhibited significant lower uptake of CLE emulsion in lung and brain, indicating the advantage of CLE over the solution form in reducing drug precipitation in vivo and toxicity in CNS. Drug safety assessment studies including hemolysis test, intravenous stimulation and injection anaphylaxis revealed that the CLE was safe for intravenous injection.

Emulsifiers' composition modulates venous irritation of the nanoemulsions as a lipophilic and venous irritant drug delivery system

In this study, a nanoemulsion (NE) system was investigated for intravenous delivery of lipophilic and venous irritant drugs. NEs were prepared to deliver diallyl trisulfide (DT) for systemic therapy of bacterial and fungal infection, egg phospholipid was chosen as the main emulsifier, and two co-emulsifiers were also incorporated, including Poloxamer 188 (P188) and Solutol HS 15 (S15). Soybean oil was used as the dispersed phases, forming stable DT NEs with small particle sizes. The venous irritation of DT NEs was evaluated by in vitro human umbilical cord endothelial cells (CRL 1730) compatibility model with the intracellular adenosine triphosphate (ATP) and guanosine triphosphate (GTP) concentrations as the indices. The intracellular ATP and GTP reduction changed with the incorporation of a variety of co-emulsifiers, which varied in a free DT concentration-dependent manner. It was deduced that the free DT concentrations of NEs containing co-emulsifiers were determined by the partition coefficient of DT between oil and surfactant buffer solution. In conclusion, NE was an appropriate delivery system for lipophilic and venous irritant drug, and optimization of the composition of emulsifiers was an effective method to alleviate the venous irritation of DT NEs.

Formulation of an intravenous emulsion loaded with a clarithromycin-phospholipid complex and its pharmacokinetics in rats

The purpose of this paper is to prepare a new formulation of clarithromycin emulsion (ClaE) with the clarithromycin-phospholipid complex which was analyzed by DSC. High-pressure homogenization, Nicomp 380 Particle Sizing system, and HPLC were used to prepare and investigate ClaE, while UPLC/MS/MS for pharmacokinetic study. Clarithromycin and soybean lecithin were reacted in dehydrated alcohol at a ratio of 1:10 for 3 h at 65 degrees C to prepare the complex. The ClaE formulation consisted of, according to quality percentage, the complex (clarithromycin 0.25% in ClaE), LCT 4%, MCT 16%, soybean lecithin 1.0%, F68 0.2%, Tween80 0.2%, glycerol 2.5%, sodium oleate 0.1% and L-cysteine 0.02%. ClaE was sterilized in a 100 degrees C revolving water bath for 30 min. The drug content, particle size distribution and entrapment efficiency of ClaE before and after sterilization and over 6 months storage at 10 degrees C were almost unchanged, while zeta-potential increased from -20.32 mV to -23.71 mV. These results show that ClaE has enough physicochemical stability to undergo sterilization and storage. The pharmacokinetic study showed that both ClaE and ClaS fitted a three-compartment model, their pharmacokinetic curves were similar and the main parameters showed no significant difference except Vss. ClaE has a great potential for clinical applications and industrial-scale production.