• Journal of Pharmaceutical Investigation
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• v.37 no.5
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• pp.311-314
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• 2007

Paclitaxel (PTX) is an antineoplastic agent approved for the treatment of ovarian and breast carcinomas. However, the use of paclitaxel as an anticancer drug is limited by its extremely poor water solubility (below $0.3\;{\mu}g/mL$). Furthermore, it has very low bioavailability when administered orally because paclitaxel is a substrate of P-glycoprotein (P-gp) efflux pump. In this study, buccal delivery of PTX was investigated as one of the alternatives for PTX delivery. Ethanol and glyceryl monooleate (GMO) were selected as permeation enhancing agents to increase solubility and permeation across buccal mucosa of PTX. At the different concentrations of ethanol solution ($30{\sim}70\;w/w\;%$), PTX permeation was studied, followed effects of GMO in the concentration range of $2.5{\sim}25%$ with ethanol vesicle. The transbuccal ability of PTX was evaluated in vitro using Franz diffusion cells mounted with rabbit buccal mucosa. As a result, incorporation of PTX into ethanol vesicle with GMO significantly enhanced the PTX permeation in rabbit buccal mucosa. Particularly, the mixtures of ethanol:water:GMO at the ratio of 50:47.5:2.5 showed the most excellent enhancing ability. The results showed a promising possibility for buccal delivery of PTX.

• Journal of Pharmacopuncture
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• v.22 no.2
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• pp.90-94
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• 2019

Objectives: Paclitaxel (PTX) as an anticancer drug used against solid cancers, possesses adverse reactions such as neuropathic pain which has confined its use. PTX-induced neuropathic pain is mediated via activation of oxidative stress. Berberine (BER), an isoquinoline phytochemical found in several plants, exerts strong antioxidant and painkilling properties. In the current study, we aimed to evaluate pain-relieving effect of BER in a mouse model of PTX-induced neuropathic pain. Methods: This study was done using 42 male albino mice that were randomly divided into 6 groups (n = 7) as follow: Sham-operated (not treated with PTX), negative control group (PTX-treated mice receiving normal saline), BER 5, 10, and 20 mg/kg (PTX-treated mice receiving BER) and positive control group (PTX-treated mice receiving imipramine 10 mg/kg). Neuropathic pain was induced by intraperitoneal administration of four doses of PTX (2 mg/kg/day) on days 1, 3, 5 and 7. Then, on day 7, hot plate test was done to assess latency to heat to measure possible anti-neuropathic pain effect of BER. Results: Four doses of PTX 2 mg/kg/day induced neuropathy that was reduced by BER at all time-points (i.e. 0, 30, 60, 90 and 120 min) after injection (P < 0.001 in comparison to control). The statistical analysis of data showed significant differences between groups (P < 0.001 in comparison to negative control), at 30, 60, 90 and 120 min after injection of BER 5, 10 and 20 mg/kg; in other words, 30, 60, 90 and 120 min after BER administration, neuropathic pain was significantly reduced as compared to normal saline-treated mice. Conclusion: Altogether, our results showed that PTX could induce neuropathic pain as reflected by hyperalgesia and BER could alleviate PTX-induced thermal hyperalgesia.

• Biomolecules & Therapeutics
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• v.25 no.5
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• pp.553-558
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• 2017

Paclitaxel (PTX) is one of the most frequently used anticancer agent for treating refractory ovarian cancer, metastatic breast cancer and non-small cell lung cancer. However, its oral administration is impeded by very low bioavailability (<5%) due to the P-glycopprotein (P-gp) efflux pump effect. This study investigated in vitro and in vivo P-gp inhibitory effects of adamantyl derivatives AC-603 and AC-786 in rats. Two adamantyl derivatives tested in this study increased the cytotoxicity of daunomycin (DNM) in P-gp overexpressed cell line by inhibiting P-gp efflux function. Pharmacokinetics of PTX with orally co-administered P-gp inhibitors were assessed in rats to improve PTX absorption. The pharmacokinetic parameters of PTX were determined in rats after intravenous (2 mg/kg) or oral (25 mg/kg) administration in the presence or absence of verapamil (a positive control), AC-603 or AC-786 (0.5 mg/kg or 5 mg/kg). Compared to control group (PTX alone), experimental groups (PTX with AC-603 or AC-786) significantly increased the area under the plasma concentration-time curve of PTX following oral administration by 1.7-2.2 fold. The volume of distribution and total clearance of PTX were decreased, while other parameters were not significantly changed. In conclusion, co-administration of AC-603 or AC-786 enhanced the relative bioavailability of orally administered PTX as compared to control.

• Journal of Pharmaceutical Investigation
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• v.41 no.6
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• pp.381-386
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• 2011

Multi-drug resistance (MDR) has been known as a major hurdle in cancer chemotherapy. One of the most clinically significant causes of MDR was the efflux of anticancer agents mediated by p-glycoprotein (p-gp) over-expressed in MDR cancer cells. To overcome MDR, there have been several strategies such as co-administration with p-gp inhibitors and encapsulation of anticancer drugs into drug delivery systems. In the present study, curcumin was evaluated for its potential as p-gp inhibitor and MDR reversal activity when combined with paclitaxel incorporated into lipid nanoparticles (PTX/LN). Western blot assay showed curcumin did not modulate the level of p-gp expression in MCF-7/ADR which is a MDR variant of human breast cancer cell line, MCF-7, and over-expresses p-gp. However, curcumin inhibited p-gp-mediated efflux of calcein in a dose-dependent manner even though it showed lower activity compared to verapamil, a well-known p-gp inhibitor. Incorporation of paclitaxel into lipid nanoparticles partially recovered the anticancer activity of paclitaxel in MCF-7/ADR. The combined use of curcumin and PTX/LN exhibited further full reversal of MDR, suggesting susceptibility of PTX/LN to the efflux system. In conclusion, combined approach of using p-gp inhibitors and incorporation of the anticancer agents into nano-delivery systems would be an efficient strategy to overcome MDR.

• Polymer(Korea)
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• v.34 no.2
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• pp.172-177
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• 2010

Although many researchers have studied the efficacy of paclitaxel (PTX) on many cells during the last two decades, little work has been reported on the importance of release kinetics inhibiting cell proliferation. The aim of this study is to examine the release behavior of the PTX on various biodegradable polymers such as poly(lactic-co-glycolic acid)(PLGA), poly-L-lactide (PLLA), and polycaprolactone (PCL) for drug-eluting stents (DES). The PTX from the fabricated films was released for 8 weeks and the degree of degradation of the films was observed by FE-SEM. Although the degradation time of PCL was the slowest, the PTX release rate was the fastest among them and followed by PLGA and PLLA with the equivalent PTX concentration. It suggests that hydrophobic drug such as PTX from polymer with low $T_g$ like PCL could be moved easily and released rapidly in body temperature.

• Macromolecular Research
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• v.17 no.2
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• pp.99-103
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• 2009

We evaluated the efficacy of pH-sensitive micelles, formed by methoxy poly(ethylene glycol)-b-poly($\beta$)-amino ester) (PEG-PAE), as carriers for paclitaxel (PIX), a drug currently used to treat various cancers. PTX was successful encapsulated by a film hydration method. Micelles encapsulated more than 70% of the PTX and the size of the PTX-encapsulated micelles (PTX-PM) was less than 150 nm. In vitro experiments indicated that the micelles were unstable below pH 6.5. After encapsulation of PTX within the micelles, dynamic light scattering (DLS) studies indicated that low pH had a similar demicellization effect. An in vitro release study indicated that PTX was slowly released at pH 7.4 (normal body conditions) but rapidly released under weakly acidic conditions (pH 6.0). We demonstrated the safety of micelles from in vitro cytotoxicity tests on HeLa cells and the in vivo anti-tumor activity of PTX-PM in B16F 10 tumor-bearing mice. We concluded that these pH-sensitive micelles have potential as carriers for anti-cancer drugs.

• Journal of Pharmaceutical Investigation
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• v.35 no.5
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• pp.361-367
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• 2005

In this study, we evaluated and compared the pharmacodynamics of paclitaxel (PTX) in human A549 NSCLC cells grown as monolayers or as three-dimensional histocultures. Growth inhibitory effects were determined after incubating cells in drug free medium until 96 hr post drug exposure initiation. Cell cycle arrest and apoptosis were measured by flow cytometry. The growth inhibition induced by PTX was significantly different in monolayers and histocultures, and PTX showed significantly less cytotoxicity in histocultures where large resistant fractions were observed. Moreover, although PIX induced significant $G_{2}/M$ arrest followed by apoptosis in monolayers in a drug concentration-dependant manner, $G_{2}/M$ arrest was not elicited in histocultures. However, apoptotic cells appeared from the $G_{2}/M$ phase in histocultures. In this study, we provide first evidence that PIX in three-dimensional histocultures, does not induce $G_{2}/M$ arrest, but rather that it induces $G_{2}/M$ phase specific apoptosis. Overall, our data demonstrate different pharmacodynamics of PTX in traditional monolayer and three-dimensional histocultures.

• Biomolecules & Therapeutics
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• v.25 no.4
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• pp.411-416
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• 2017

Paclitaxel (PTX) is a effectively chemotherapeutic agent which is extensively able to treat the non-small cell lung, pancreatic, breast and other cancers. But it is a practically insoluble drug with water solubility less than $1{\mu}g/mL$, which restricts its therapeutic application. To overcome the problem, hyaluronic acid-complexed paclitaxel nanoemulsions (HPNs) were prepared by ionic complexation of paclitaxel (PTX) nanoemulsions and hyaluronic acid (HA) to specifically target non-small cell lung cancer. HPNs were composed of ${\small{DL}}-{\alpha}$-tocopheryl acetate, soybean oil, polysorbate 80, ferric chloride, and HA and fabricated by high-pressure homogenization. The HPNs were $85.2{\pm}7.55nm$ in diameter and had a zeta potential of $-35.7{\pm}0.25mV$. The encapsulation efficiency was almost 100%, and the PTX content was 3.0 mg/mL. We assessed the in vivo antitumor efficacy of the HPNs by measuring changes in tumor volume and body weight in nude mice transplanted with CD44-overexpressing NCI-H460 xenografts and treated with a bolus dose of saline, $Taxol^{(R)}$, PTX nanoemulsions (PNs), or HPNs at a dose of 25 mg/kg. Suppression of cancer cell growth was higher in the PN- and HPN-treated groups than in the $Taxol^{(R)}$ group. In particular, HPN treatment dramatically inhibited tumor growth, likely because of the specific tumor-targeting affinity of HA for CD44-overexpressed cancer cells. The loss of body weight and organ weight did not vary significantly between the groups. It is suggest that HPNs should be used to effective nanocarrier system for targeting delivery of non-small cell lung cancer overexpressing CD44 and high solubilization of poorly soluble drug.

• Journal of Pharmaceutical Investigation
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• v.36 no.1
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• pp.1-9
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• 2006

Human solid tumors exhibit a multicellular resistance (MCR) resulting from limited drug penetration and decreased sensitivity of tumor cells when interacting with their microenvironments. Multicellular cultures represent solid tumor condition in vivo and provide clinically relevant data. There is little data on antitumor effect of paclitaxel (PTX) in multicellular cultures although its MCR has been demonstrated. In the present study, we evaluated antiproliferative effects of PTX in multicellular layers (MCL) of DLD-1 human colorectal carcinoma cells. BrdU labeling index (LI), thickness of MCL, cell cycle distribution and cellular uptake of calcein were measured before and after exposure to PTX at 0.1 to 50 ${\mu}M$ for 24, 48 and 72 hrs. BrdU LI and thickness of MCL showed a concentration- and time-dependent decrease and the changes in both parameters were similar, i.e., 34.2% and 40.6% decrease in BrdU LI and thickness, respectively, when exposed to $50\;{\mu}M$ for 72 hr. The DLD-1 cells grown in MCL showed increase in $%G_{0}/G_{1}$ and resistance to cell cycle arrest and apoptosis compared to monolayers. Calcein uptake in MCL did not change upon PTX exposure, indicating technical problems in multicellular system. Overall, these data indicate that antitumor activity of PTX may be limited in human solid tumors (a multicellular system) and MCL may be an appropriate model to study further pharmacodynamics of PTX.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.15
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• pp.6535-6539
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• 2015

This study was designed to assess, whether a new chemotherapeutic microtubule inhibitor, Epothilone B (EpoB, Patupilone), can induce DNA damage in normal ovarian cells (MM14.Ov), and to evaluate if such damage could be repaired. The changes were compared with the effect of paclitaxel (PTX) commonly employed in the clinic. The alkaline comet assay technique and TUNEL assay were used. The kinetics of DNA damage formation and the level of apoptotic cells were determined after treatment with IC50 concentrations of EpoB and PTX. It was observed that PTX generated significantly higher apoptotic and genotoxic changes than EpoB. The peak was observed after 48 h of treatment when the DNA damage had a maximal level. The DNA damage induced by both tested drugs was almost completely repaired. As EpoB in normal cells causes less damage to DNA it might be a promising anticancer drug with potential for the treatment of ovarian tumors.