A parenteral docetaxel-loaded lipid microsphere with decreased 7-epidocetaxel conversion in vitro and in vivo

Berberine-10-hydroxy camptothecine-loaded lipid microsphere for the synergistic treatment of liver cancer by inhibiting topoisomerase and HIF-1α

10-HCPT is a topoisomerase I inhibitor effective in the treatment of liver cancer but its use is hampered by its resistance. The expression of hypoxia-inducible factor-1α (HIF-1α) is reportedly upregulated in liver cancer tissues, which is directly linked to the resistance of 10-HCPT. While BBR can significantly decrease the level of HIF-1α according to the literature report. Thus, the aim of this study was to prepare a novel intravenous 10-HCPT-BBR-loaded lipid microsphere (LM) and evaluate their synergistic effect on liver cancer treatment. The optimal preparation mainly included 10.0% oil phase (medium-chain triglyceride:long-chain triglyceride = 1:1), emulsifier (egg lecithin E80 and pluronic F68), antioxidant (0.02% NaHSO₃), and pH regulator (0.1 mol/L Hcl). Then, the behaviors of BBR-10-HCPT loaded LM in vitro and in vivo were systematically investigated. In vitro, it showed an obvious sustained-release effect in different release mediums, good physicochemical stability at accelerated and long-term storage conditions, and great anti-proliferative capability toward human liver cancer Hep-3B cells. In vivo, the prepared LM exhibited a longer half-life and higher AUC compared to BBR injection and 10-HCPT injection. More importantly, it was found that The LM was distributed more in the liver, spleen, and tumors, but less in the lungs and heart, especially in the lung. And then, it showed significant inhibition of tumor growth against nude mouse with Hep-3B tumor, and the tumor inhibition rate reached 91.55%. Thus, the data obtained in our study suggested that BBR combined with 10-HCPT can raise curative effect and reduce the toxicity of 10-HCPT.

Aprepitant Intravenous Emulsion Based on Ion Pairing/Phospholipid Complex for Improving Physical and Chemical Stability During Thermal Sterilization

An aprepitant (APT) cholesteryl hemisuccinate (CHEMS) ion pair complex emulsion (AIPE) with high lecithin content was prepared to improve sterilization stability through the film dispersion homogenization method; therefore, it could be a promising delivery system of APT. Medium-chain triglycerides (MCT) was selected as the oil phase to improve the solubility and stability of APT in oil phase. DSC, XRD, FT-IR, and ¹H-NMR spectroscopies confirmed that the APT-CHEMS ion pair (AIP) was formed between CHEMS and APT. The formation of AIP significantly increased the hydrophobicity of APT, allowing it to be completely embedded in the oil phase core to improve chemical stability and decrease hydrolysis of APT in the water phase. Also, CHEMS had a strong affinity with lecithin and could stabilize lipid membranes, forming a stronger and thicker interface membrane to increase the physical stability of AIPE. As a result, AIPE could withstand autoclaving at 120°C for 8 min without any change of particle size or content. Furthermore, AIPE with a potential of - 53.4 mV remained stable through spatial repulsion during sterilization. The encapsulation efficiency of AIPE was over 90% and the particle size was 106.8 ± 65.62 nm(0.286). Pharmacokinetic study in rats was comparable with that of CINVANTI which yielded a relative bioavailability of 114.31% indicating that the AIPE had similar pharmacokinetic processes in vivo with the analog of CINVANTI®. The AUC0-t of the AIPE was 4.31-fold that of the APT solution.

The modulation of drug-loading stability within lipid membranes via medium chain triglycerides incorporation

The current research aimed to explore medium chain triglycerides (MCT) incorporation in liposomes to overcome stability challenges when drugs with high molecular weight and payload are loaded within lipid membranes. A model drug clarithromycin was loaded in lipid dispersions with various MCT/phospholipids ratios (R_M/P = 0, 0.5, 1.75 and 7.5 w/w). TEM images demonstrated a liposome-to-emulsion structural transformation by MCT incorporation to cause increased particle size (104.3-167.7 nm) but decreased zeta potential (-63.6 to -44.4 mV) of lipid particles. MCT incorporation produced biphasic release in PBS and accelerated released in plasma. The tolerance of liposomes for thermal sterilization, high temperature test and freeze-thaw cycles were significantly improved by MCT incorporation. However, MCT incorporation produced adverse effects on colloidal stability in plasma and pharmacokinetics behavior in vivo to some extent. MCT stabilizing mechanism attributes to the modulation of drug loading area and stability improvement of lipid carriers. MCT incorporated liposomes achieved 2-3 fold cellular uptake level than traditional liposomes without significant cytotoxicity. These results indicated that MCT incorporation could be a promising strategy to apply in liposome production to achieve stable drug loading.

Unravelling the anticancer efficacy of 10-oxo-7-epidocetaxel: in vitro and in vivo results

PURPOSE

To prepare 7-epidocetaxel (7ED) and 10-oxo-7-epidocetaxel (10-O-7ED) formulations as like marketed Taxotere® (TXT) injection and to screen them for in vitro and in vivo anticancer efficacy including their in vivo toxicity behavior.

METHODS

The 7ED and 10-O-7ED formulations were screened for in vitro anti-proliferative, anti-metastatic and cell cycle arresting behaviors. Further, in vivo acute toxicity of TXT injection containing 10% of 7ED and 10-O-7ED separately and the therapeutic study of 10-O-7ED alone were studied in B16F10 experimental metastasis mouse model.

RESULTS

10-O-7ED caused significantly higher cytotoxicity after 48 and 72 h than 22 h study. 10-O-7ED showed significantly increased in vitro anti-metastatic activity than TXT. The TXT caused more arrest of cells at S phase, whereas 10-O-7ED arrested more at G2-M phase and vice versa at higher concentration. In vivo acute toxicity study revealed better therapeutic effect with reduced toxicity of TXT containing 10% 10-O-7ED than TXT alone. Similarly, the therapeutic study revealed significantly less number of surface metastatic nodules formation with 10-O-7ED treated group (107 ± 49) (***p < .0001) than control group (348 ± 56). Also, the control group showed significant weight loss at the end (20th day) of the experiment (*p < .05, p = .041) than 10-O-7ED treated group which showed about 4% increased mean group weight.

CONCLUSION

Our study revealed the significantly higher in vivo anti-metastatic behavior, with no toxicity, of 10-O-7ED. However, it is a preliminary observation being noticed but further investigations are needed to address the potential of 10-O-7ED in cancer treatment with mechanisms behind the improved therapeutic efficacy with no toxicity.

Research progress of self-assembled nanogel and hybrid hydrogel systems based on pullulan derivatives

Polymer nano-sized hydrogels (nanogels) as drug delivery carriers have been investigated over the last few decades. Pullulan, a nontoxic and nonimmunogenic hydrophilic polysaccharide derived from fermentation of black yeast like Aureobasidium pullulans with great biocompatibility and biodegradability, is one of the most attractive carriers for drug delivery systems. In this review, we describe the preparation, characterization, and 'switch-on/off' mechanism of typical pullulan self-assembled nanogels (self-nanogels), and then introduce the development of hybrid hydrogels that are numerous resources applied for regenerative medicine. A major section is used for biomedical applications of different nanogel systems based on modified pullulan, which exert smart stimuli-responses at ambient conditions such as charge, pH, temperature, light, and redox. Pullulan self-nanogels have found increasingly extensive application in protein delivery, tissue engineering, vaccine development, cancer therapy, and biological imaging. Functional groups are incorporated into self-nanogels and contribute to expressing desirable results such as targeting and modified release. Various molecules, especially insoluble or unstable drugs and encapsulated proteins, present improved solubility and bioavailability as well as reduced side effects when incorporated into self-nanogels. Finally, the advantages and disadvantages of pullulan self-nanogels will be analyzed accordingly, and the development of pullulan nanogel systems will be reviewed.

PEGylated lipid microspheres loaded with cabazitaxel for intravenous administration: stability, bioavailability, antitumor efficacy, and toxicity

This paper aimed to develop a novel lipid microsphere delivering cabazitaxel (CTX) using phosphatidylcholine combined with DSPE-PEG2000 as emulsifier, and evaluate its stability, pharmacokinetics, antitumor efficacy, and toxicity. The pegylated cabazitaxel-loaded lipid microspheres (CTX-PLMs) were prepared by high-pressure homogenization methods; the biological samples were analyzed by the UPLC-MS/MS method. CTX-PLMs had a drug concentration of 1.2 mg/ml and a mean particle size of 180.0 ± 51.119 nm. CTX-PLMs showed a superior physical stability as it could remain nearly intact after 1-year storage. The AUC_0-t of the CTX-PLMs was 1562.6 ± 520.1 μg h L^-1 compared with the CTX-solution of 860.734 ± 312.4 μg h L^-1. CTX-PLMs exhibited a strong antitumor efficacy against NCI-N87 and DU145 tumor models with tumor growth inhibition rates of 93.5 and 88.5%, respectively. The LD50 of CTX-PLMs in rats was 20.89 mg/kg. As for the long-term toxicity, the thymus, mesenteric lymph nodes, and bone marrow were the main toxic target organs and systemic toxicity induced by CTX-PLMs was alleviated relative to that of the CTX-solution. Safety assessment studies including hemolysis test, dermal sensitization test, systemic anaphylaxis, and vascular stimulation test indicated that CTX-PLMs is safe enough for intravenous administration. In a word, CTX-PLMs are a promising carrier for intravenous administration with satisfactory stability, stronger tumor inhibition, and superior safety profile.