Synergistic Combination of Irinotecan and Rapamycin Orally Delivered by Nanoemulsion for Enhancing Therapeutic Efficacy of Pancreatic Cancer.

In recent years, combining different types of therapy has emerged as an advanced strategy for cancer treatment. In these combination therapies, oral delivery of anticancer drugs is more convenient and compliant. This study developed an irinotecan/rapamycin-loaded oral lecithin-based self-nanoemulsifying nanoemulsion preconcentrate (LBSNENPir/ra) and evaluated its synergistic combination effects on pancreatic cancer. LBSNENP loaded with irinotecan and rapamycin at a ratio of 1:1 (LBSNENPir10/ra10) had a better drug release profile and smaller particle size (<200 nm) than the drug powder. Moreover, LBSNENPir10/ra10 exhibited a strong synergistic effect (combination index [CI] < 1.0) in cell viability and combination effect studies. In the tumor inhibition study, the antitumor activity of LBSNENPir10/ra10/sily20 against MIA PaCa-2 (a human pancreatic cancer cell line) was significantly increased compared with the other groups. When administered with rapamycin and silymarin, the area under the curve and the maximum concentration of irinotecan significantly improved compared with the control. We successfully developed an irinotecan/rapamycin-loaded oral self-nanoemulsifying nanoemulsion system to achieve treatment efficacy for pancreatic cancer.

CPT11 with P-glycoprotein/CYP 3A4 dual-function inhibitor by self-nanoemulsifying nanoemulsion combined with gastroretentive technology to enhance the oral bioavailability and therapeutic efficacy against pancreatic adenocarcinomas.

Therapeutic efficacies of orally administrated hydrophobic chemodrugs are decreased by poor water solubilities and reduced oral bioavailabilities by P-glycoprotein (P-gp) and CYP450. In this study, CPT11 alone or combined with dual-function inhibitors (baicalein (BA) silymarin (SM), glycyrrhizic acid (GA), and glycyrrhetinic acid (GLA)) of P-gp and CYP450 loaded in a lecithin-based self-nanoemulsifying nanoemulsion preconcentrate (LBSNENP) to improve the solubility and inhibit the elimination by P-gp and CYP450. Results revealed that the LBSNENP composed of Capryol 90, lecithin/Tween 80/Cremophor EL, and propylene glycol at a weight ratio of 18:58:24 (designated PC90C10P0) was optimally selected. Encapsulating CPT11 with PEO-7000K in PC90C10P10/30 further enhanced the resultant hydrogel to be gastro-retainable and to release CPT11 in a sustained manner. Pharmacokinetic study of CPT11-loaded PC90C10P0 administered orally revealed an absolute bioavailability (FAB, vs. intravenous CPT11) of 7.8 ± 1.01% and a relative bioavailability (FRB1, vs. oral solution of CPT11) of 70.7 ± 8.6% with a longer half-life (T1/2) and mean residence time (MRT). Among the dual-function inhibitors, SM was shown to be the most influential in increasing the oral bioavailability of CPT11. SM also increased the plasma concentration of the SN-38 active metabolite, which formed from the enhanced plasma concentration of CPT11. It is concluded that treatment with CPT11 loaded in PC90C10P0 with or without solubilization with SM could expose tumors to higher plasma concentrations of both CPT11 and SN-38 leading to enhancement of tumor growth inhibition with no signs of adverse effects.

Honokiol/Magnolol-Loaded Self-Assembling Lecithin-Based Mixed Polymeric Micelles (lbMPMs) for Improving Solubility to Enhance Oral Bioavailability.

OBJECTIVE: This study was intended to utilize lecithin-based mixed polymeric micelles (lbMPMs) for enhancing the solubility and bioavailability of honokiol and magnolol to resolve the hindrance of their extreme hydrophobicity on the clinical applications. METHODS: Lecithin was selected to increase the volume of the core of lbMPMs, thereby providing a greater solubilization capacity. A series of amphiphilic polymers (sodium deoxycholate [NaDOC], Cremophor®, and Pluronic® series) were included with lecithin for screening and optimization. RESULTS: After preliminary evaluation and subsequentially optimization, two lbMPMs formulations composed of honokiol/magnolol:lecithin:NaDOC (lbMPMs[NaDOC]) and honokiol/magnolol:lecithin:PP123 (lbMPMs[PP123]) in respective ratios of 6:2:5 and 1:1:10 were optimally obtained with the mean particle sizes of 80-150 nm, encapsulation efficacy (EEs) of >90%, and drug loading (DL) of >9.0%. These lbMPMs efficiently stabilized honokiol/magnolol in phosphate-buffered saline (PBS) at room temperature or 4 °C and in fetal bovine serum or PBS at 37 °C. PK study demonstrated that lbMPMs[NaDOC] showed much improvement in enhancing bioavailability than that by lbMPMs[PP123] for both honokiol and magnolol. The absolute bioavailability for honokiol and magnolol after intravenous administration of lbMPMs[NaDOC] exhibited 0.93- and 3.4-fold increases, respectively, compared to that of free honokiol and magnolol. For oral administration with lbMPMs[NaDOC], the absolute bioavailability of honokiol was 4.8%, and the absolute and relative bioavailability of magnolol were 20.1% and 2.9-fold increase, respectively. CONCLUSION: Overall, honokiol/magnolol loaded in lbMPMs[NaDOC] showed an improvement of solubility with suitable physical characteristics leading to enhance honokiol and magnolol bioavailability and facilitating their wider application as therapeutic agents for treating human disorders.

Lecithin-Stabilized Polymeric Micelles (LsbPMs) for Delivering Quercetin: Pharmacokinetic Studies and Therapeutic Effects of Quercetin Alone and in Combination with Doxorubicin.

In this study, lecithin-stabilized polymeric micelles (LsbPMs) were prepared to load quercetin (QUE) in order to improve its bioavailability and increase its antitumor activity. Its combination with doxorubicin (DOX) to minimize DOX-mediated cardiac toxicity and increase the antitumor activity of QUE-loaded LsbPMs was also examined. LsbPMs were prepared following a previously reported procedure. Results demonstrated that optimal QUE-loaded LsbPMs contained quercetin, D-α-tocopheryl polyethylene glycol succinate, and lecithin at a weight ratio of 6:40:80. Drug-release studies showed that QUE released from LsbPMs followed a controlled release pattern. A cytotoxicity assay revealed that QUE-loaded LsbPMs had significant anticancer activities against MCF-7, SKBR-3, and MDA-MB-231 human breast cancer cells and CT26 mouse colon cancer cells. In animal studies, intravenous administration of QUE-loaded LsbPMs resulted in efficient growth inhibition of CT26 colon cancer cells in a Balb/c mice model. In a pharmacokinetics study compared to free QUE, intravenous and oral administration of QUE-loaded LsbPMs was found to have significantly increased the relative bioavailability to 158% and 360%, respectively, and the absolute bioavailability to 5.13%. The effect of QUE-loaded LsbPMs in combination with DOX resulted in efficient growth inhibition of CT26 colon cancer cells and reduced cardiac toxicity in the Balb/c mice model.

Novel application of pluronic lecithin organogels (PLOs) for local delivery of synergistic combination of docetaxel and cisplatin to improve therapeutic efficacy against ovarian cancer.

The synergistic combination of docetaxel (DTX) and cisplatin (CIS) by local drug delivery with a pluronic lecithin organogel (PLO) to facilitate high drug concentrations at tumor sites and less nonspecific distribution to normal organs is thought to be beneficial in chemotherapy. In this study, using Capryol-90 (C90) with the addition of lecithin as the oil phase was developed to carry DTX, which was then incorporated into a PLO-containing CIS to formulate a dual-drug injectable PLO for local delivery. An optimal PLO composite, P13L0.15O1.5, composed of PF127:lecithin:C90 at a 13:0.15:1.5 weight ratio was obtained. The sol-gel transition temperature of P13L0.15O1.5 was found to be 33 °C. Tumor inhibition studies illustrated that DTX/CIS-loaded P13L0.15O1.5 could efficiently suppress tumor growth by both intratumoral and peritumoral injections in SKOV-3 xenograft mouse model. Pharmacokinetic studies showed that subcutaneous administration of P13L0.15O1.5 was able to sustain the release of DTX and CIS leading to their slow absorption into the systemic circulation resulting in lower area under the plasma concentration curve at 0-72 h (AUC0-72) and maximum concentration (Cmax) values but longer half-life (T1/2) and mean residence time (MRT) values. An in vivo biodistribution study showed lower DTX and CIS concentrations in organs compared to other treatment groups after IT administration of the dual drug-loaded P13L0.15O1.5. It was concluded that the local co-delivery of DTX and CIS by PLOs may be a promising and effective platform for local anticancer drug delivery with minimal systemic toxicities.

Formulation and process optimization of multiparticulate pulsatile system delivered by osmotic pressure-activated rupturable membrane.

In this study, a multiparticulate pulsatile drug delivery system activated by a rupturable controlled-release membrane (Eudragit(®) RS) via osmotic pressure (with NaCl as the osmogent) was developed and characterized for omeprazole, omeprazole sodium, and propranolol HCl which have different water solubilities. Multiparticulates in pellet form for incorporation with or without the osmogent were manufactured by three methods and then used to coat a polymeric membrane. Results demonstrated that drug/osmogent-containing pellets manufactured by the extrusion/spheronization method with incorporation of the osmogent were optimal. The lag time (tL) to initiate pulsatile release is regulated by tL=l(2)/(6×D), which is dependent on the coating levels (l(2)) and plasticizer content (D). The pulsatile release pattern was found to be dependent on the osmotic pressure (osmogent), drug solubility, and mechanical properties of the polymeric membrane (elasticity and toughness). Omeprazole with lower water solubility could not generate sufficient osmotic pressure to create a crack in the membrane to activate pulsatile release, whereas the two other model drugs with higher solubilities could. But adsorption of omeprazole sodium on Eudragit(®) RS via charge-charge interactions led the its incomplete release. Finally, with 4% osmogent of NaCl added, a lag time in a range from 0 to 12h proportionally regulated by varying both the membrane thickness and plasticizer level initiated the complete pulsatile release of propranolol HCl. In conclusion, a multiparticulate pulsatile drug delivery system activated by a rupturable controlled-release membrane via osmotic pressure was successfully developed, and clinical applications of chronotherapy with drugs like propranolol HCl are expected.

Efficacy of antioxidants as a Complementary and Alternative Medicine (CAM) in combination with the chemotherapeutic agent doxorubicin.

INTRODUCTION: Although doxorubicin (Dox)-induced cardiac toxicity and pegylated liposomal doxorubicin (PLD)-induced hand-foot syndrome (HFS) were reported to be correlated with reactive oxygen species (ROS) generation, there is no effective preventive treatment at present. Therefore, the aim of this study was to investigate whether antioxidants-resveratrol (RSVL), tetrahydroxystilbene glucoside (THSG), curcumin, and the ethanolic extract of Antrodia cinnamomea (EEAC)-have the ability to reduce Dox-induced ROS and have a synergistic anticancer effect with Dox that could prevent those side effects and enhance the efficacy of cancer treatment. METHODS: 3T3 normal cells were used as a model to evaluate the effects of these antioxidants in reducing ROS accumulation. Furthermore, the synergistic anticancer effect of antioxidants with Dox on the MCF-7 breast cancer model was also evaluated. RESULTS: Pretreatment of cells with RSVL, curcumin, and EEAC increased the cell antioxidant ability by improving the activity of superoxide dismutase (SOD), prevented or limited intracellular damage, and ameliorated the harmful effects of ROS. Additionally, RSVL, curcumin, and EEAC had synergistic effects with Dox against MCF-7 breast cancer cells. CONCLUSION: RSVL, curcumin, and EEAC have the potential to be clinically applied to prevent cardiac toxicity and HFS and enhance the anticancer efficiency of Dox.