mTORC2 promotes pancreatic cancer progression and parp inhibitor resistance.

Pancreatic cancer is one of the most aggressive cancers with a median survival time of less than 5 months, and conventional chemotherapeutics are the main treatment strategy. Poly(ADP-ribose) polymerase (PARP) inhibitors have been recently approved for BRCA1/2-mutant pancreatic cancer, opening a new era for targeted therapy for this disease. However, most pancreatic cancer patients carry wild-type BRCA1/2 with resistance to PARP inhibitors. Here, we reported that mammalian target of rapamycin complex 2 (mTORC2) kinase is overexpressed in pancreatic cancer tissues and promotes pancreatic cancer cell growth and invasion. Moreover, we found that knockdown of the mTORC2 obligate subunit Rictor sensitized pancreatic cancer cells to the PARP inhibitor olaparib. Mechanistically, we showed that mTORC2 positively regulates homologous recombination (HR) repair by modulating BRCA1 recruitment to DNA double-strand breaks (DSBs). In addition, we confirmed that combination treatment with the mTORC2 inhibitor PP242 and the PARP inhibitor olaparib synergistically inhibited pancreatic cancer growth in vivo. Thus, this study provides a novel target and strategy for optimizing PARP inhibitor efficiency in pancreatic cancers.

Preparation and in vivo evaluation of an intravenous emulsion loaded with an aprepitant-phospholipid complex.

In present, there was no detailed report on the formulation optimization and quality evaluation of aprepitant (APT) injectable lipid emulsion (APT-IE). The aim of the present investigation was to prepare and evaluate its properties of APT-IE loaded with an APT phospholipid complex (APT-PC) in vitro and in vivo. APT-PC was obtained by solvent evaporation with APT and phospholipids, then analyzed by X-ray diffraction, Fourier transform infrared spectroscopy and differential scanning calorimetry. Lipid emulsions are a new formulation that can reduce side effects and improve drug loading.APT-IE prepared by High-pressure homogenization and optimized by response surface methodology (RSM). The proportion of sodium oleate, poloxamer 188 and soybean oil were selected as variables for the optimization. The optimal formulation of ATP-IE had the following characteristics: particle size, 82.83 ± 1.89 nm; polydispersity index, 0.243 ± 0.008; zeta potential, -59.0 ± 2.54 mV; encapsulation efficiency, 98.84%±1.43%; drug loading, 7.08 ± 0.16 mg/mL; and osmotic pressure, 301 ± 2.15 mOsmol/kg. Transmission electron microscopy images indicated that the particle diameter of APT-IE was approximately 100 nm, with a morphology of spheroidal or spherical. APT-IE exhibited sufficient stability after storage at 4 ± 2 °C for more than 6 months. The results of the pharmacokinetic study demonstrated that APT-IE had the advantages of better safety, higher bioavailability, and obvious liver targeting than APT solution (APT-SL). The area under the curve (AUC) of APT-IE was 3-fold enhanced compared with APT-SL. The targeted enhancement multiple of APT-IE to liver tissue was greater than that of APT-SL. These results suggested that APT-IE has broad clinical application and industrial production potential.

The enhancing effect and promoting mechanisms of the stereoisomeric monoterpene alcohol esters as enhancers for drugs with different physicochemical properties.

To explore the structure-activity connections of amphiphilic permeation enhancers containing the length of the hydrophobic chains as well as the properties of the polar head, O-acylgeraniol and O-acylnerol derivatives were synthesized from geraniol/nerol (cis-isomer of geraniol) and pharmaceutical excipient acids in this research. Their promotion of the percutaneous absorption of three drugs as the model, flurbiprofen (FP), isosorbide dinitrate (ISDN) and donepezil (DNP), which were selected based on their physicochemical properties, was tested by in vitro skin penetration and in vivo. Molecular simulation, ATR-FTIR, CLSM and histological observation were implement to evaluate the mode of action of the enhancers. The results indicated that (E)-3,7-dimethyl-2,6-octadien-1-yl tetradecanoate (GER-C14, trans-) achieved the highest enhancement ability for the three drugs; additionally, the in vivo results obtained were in good correlation with the in vitro data. Molecular docking results suggested that enhancers loosen the hydrogen bonds between ceramides, and the results of molecular simulation indicated that GER-C14, NER-C14 could insert into the middle of the lipid bilayer to form an independent phase. According to ATR-FTIR and histological evaluation, the enhancers extracted lipids and influenced the protein region, thereby disturbing the skin array. In addition, CLSM described the dynamic effects of enhancers on lipids between stratum corneum (SC) cells. In conclusion, GER-C14 had a better penetration promotion effect, which broadened our understanding of stereoisomeric penetration enhancers.

[Puerarin Inhibits the Proliferation,Invasion,and Migration of Non-small Cell Lung Cancer Cells through Regulating miR-490/Denticleless E3 Ubiquitin Protein Ligase].

Objective To explore the mechanism of puerarin inhibiting the proliferation,invasion,and migration of non-small cell lung cancer cells. Methods A549 cells were cultured and treated with different concentrations of puerarin.The inhibition rate (IR) on cell proliferation was detected by CCK-8,and qRT-PCR was performed to detect the mRNA levels of miR-490 and denticleless E3 ubiquitin protein ligase(DTL).Double luciferase reporter assay was employed to identify the targets of miR-490 and DTL based on the establishment of NC mimic group,miR-490 mimic group,NC inhibitor group,and miR-490 inhibitor group.The cells treated by 20 µmol/L puerarin were classified into six groups:DMSO,puerarin,puerarin+NC inhibitor,puerarin+miR-490 inhibitor,puerarin+miR-490 inhibitor+Si-NC,and puerarin+miR-490 inhibitor+Si-DTL.Transwell was used to detect cell migration and invasion.Western blotting was performed to detect the protein levels of epithelial-mesenchymal transition-related markers E-cadherin,N-cadherin,and Vimentin. Results With the increase in puerarin concentration,the IR gradually elevated (F=105.375,P<0.001),miR-490 expression gradually increased (F=32.919,P<0.001),and DTL expression gradually decreased (F=116.120,P<0.001).Compared with NC mimic group,miR-490 mimic group had decreased luciferase activity (t=7.762,P=0.016),raised miR-490 mRNA level (t=13.319,P<0.001),and declined DTL mRNA level (t=7.415,P=0.002).Compared with those in NC inhibitor group,miR-490 demonstrated decreased mRNA level (t=9.523,P=0.001) and DTL presented increased mRNA level (t=11.305,P<0.001) in miR-490 inhibitor group.Western blotting showed that the protein level of DTL was higher in NC mimic group (t=7.953,P=0.001) than in miR-490 mimic group and higher in miR-490 inhibitor group than in NC inhibitor group (t=10.552,P<0.001).Compared with DMSO group,puerarin group showed up-regulated mRNA level of miR-490 (t=10.255,P=0.001) while down-regulated mRNA level of DTL (t=6.682,P=0.003).Compared with those in puerarin+NC inhibitor group,the mRNA level of miR-490 declined (t=10.995,P<0.001) while that of DTL raised (t=12.478,P<0.001) in puerarin+miR-490 inhibitor group.The mRNA level of miR-490 had no significant difference between puerarin+miR-490 inhibitor+Si-NC group and puerarin+miR-490 inhibitor+Si-DTL group (t=1.081,P=0.341),and that of DTL was lower in the latter group (t=14.321,P<0.001).The protein level of DTL was higher in puerarin+miR-490 inhibitor group than in puerarin+NC inhibitor group (t=11.423,P<0.001),and lower in puerarin+miR-490 inhibitor+Si-DTL group than in puerarin+miR-490 inhibitor+Si-NC group (t=12.080,P<0.001).Compared with DMSO group,puerarin group showed inhibited cell proliferation (F=129.27,P<0.001).The activity of cell proliferation was higher in puerarin+miR-490 inhibitor group than in puerarin+NC inhibitor group (F=75.12,P<0.001),and higher in puerarin+miR-490 inhibitor+Si-NC group than in puerarin+miR-490 inhibitor+Si-DTL group (F=52.59,P<0.001).Compared with DMSO group,puerarin group had suppressed cell migration (t=8.963,P=0.001).The cell migration ability was higher in puerarin+miR-490 inhibitor group than in puerarin+NC inhibitor group (t=12.117,P<0.001) and higher in puerarin+miR-490 inhibitor+Si-NC group than in puerarin+miR-490 inhibitor+Si-DTL group (t=12.934,P<0.001).Puerarin group showed weakened cell invasion ability compared with DMSO group (t=4.710,P=0.009).The cell invasion ability was higher in puerarin+miR-490 inhibitor group than in puerarin+NC inhibitor group (t=13.264,P<0.001) and lower in puerarin+miR-490 inhibitor+Si-DTL group than in puerarin+miR-490 inhibitor+Si-NC group (t=13.476,P<0.001).Compared with DMSO group,puerarin group showed up-regulated protein level of E-cadherin (t=7.137,P=0.002) while down-regulated protein levels of N-cadherin (t=8.828,P=0.001) and vimentin (t=6.594,P=0.003).Compared with those in puerarin+NC inhibitor group,the protein level of E-cadherin (t=12.376,P<0.001) decreased while those of N-cadherin (t=13.436,P<0.001) and vimentin (t=11.467,P<0.001) increased in puerarin+miR-490 inhibitor group.Compared with puerarin+miR-490 inhibitor+Si-NC group,puerarin+miR-490 inhibitor+Si-DTL group up-regulated the protein level of E-cadherin (t=13.081,P<0.001) while down-regulated the protein levels of N-cadherin (t=10.835,P<0.001) and vimentin (t=11.862,P<0.001). Conclusion Puerarin could inhibit the proliferation,invasion,and migration of non-small cell lung cancer cells by up-regulating miR-490 and down-regulating DTL.

Optimization, and in vitro and in vivo evaluation of etomidate intravenous lipid emulsion.

The aim of this investigation was to develop an etomidate intravenous lipid emulsion (ETM-ILE) and evaluate its properties in vitro and in vivo. Etomidate (ETM) is a hydrophobic drug, and organic solvents must be added to an etomidate injectable solution (ETM-SOL) to aid dissolution, that causes various adverse reactions on injection. Lipid emulsions are a novel drug formulation that can improve drug loading and reduce adverse reactions. ETM-ILE was prepared using high-pressure homogenization. Univariate experiments were performed to select key conditions and variables. The proportion of oil, egg lecithin, and poloxamer 188 (F68) served as variables for the optimization of the ETM-ILE formulation by central composite design response surface methodology. The optimized formulation had the following characteristics: particle size, 168.0 ± 0.3 nm; polydispersity index, 0.108 ± 0.028; zeta potential, -36.4 ± 0.2 mV; drug loading, 2.00 ± 0.01 mg/mL; encapsulation efficiency, 97.65% ± 0.16%; osmotic pressure, 292 ± 2 mOsmol/kg and pH value, 7.63 ± 0.07. Transmission electron microscopy images showed that the particles were spherical or spheroidal, with a diameter of approximately 200 nm. The stability study suggested that ETM-ILE could store at 4 ± 2 °C or 25 ± 2 °C for 12 months. Safety tests showed that ETM-ILE did not cause hemolysis or serious vascular irritation. The results of the pharmacokinetic study found that ETM-ILE was bioequivalent to ETM-SOL. However, a higher concentration of ETM was attained in the liver, spleen, and lungs after administration of ETM-ILE than after administration of ETM-SOL. This study found that ETM-ILE had great potential for clinical applications.

circPDSS1 Stimulates the Development of Colorectal Cancer via Activating the Wnt/ß-Catenin Signaling.

OBJECTIVE: This study aims to illustrate the role of circPDSS1 and the Wnt/ß-catenin signaling in the development of colorectal cancer (CRC). PATIENTS AND METHODS: Cancerous mucosa and normal paracancerous mucosa tissues more than 5 cm away from the tumor were surgically collected from 56 CRC patients. circPDSS1 levels in collected tissues and CRC cell lines were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The influence of circPDSS1 on clinical features of CRC patients was analyzed. After knockdown of circPDSS1 in HCT-8 and HCT-116 cells, phenotype changes were examined by Transwell, tube formation and wound healing assay. Western blot and rescue experiments were finally performed to uncover the role of circPDSS1 and the Wnt/ß-catenin signaling in the development of CRC. RESULTS: circPDSS1 was upregulated in CRC mucosa tissues than controls. High level of circPDSS1 predicted high rates of lymphatic metastasis and distant metastasis, and poor prognosis in CRC patients. Knockdown of circPDSS1 attenuated migratory ability and angiogenesis in CRC cells. Protein levels of key genes in the Wnt/ß-catenin signaling, including ß-catenin, GSK-3ß, c-Myc, MMP-9 and cyclin D1 were downregulated in CRC cells transfected with sh-circPDSS1. Overexpression of ß-catenin reversed the role of circPDSS1 in attenuating migratory ability and angiogenesis in CRC cells. CONCLUSION: Upregulated circPDSS1 in CRC is closely linked to lymphatic metastasis, distant metastasis and overall survival. It stimulates the migratory ability and angiogenesis in CRC cells via activating the Wnt/ß-catenin signaling.

Chiral 4-O-acylterpineol as transdermal permeation enhancers: insights of the enhancement mechanisms of a transdermal enantioselective delivery system for flurbiprofen.

In order to devise more effective penetration enhancers, 4-O-acylterpineol derivatives which were expected to be hydrolyzed into nontoxic metabolites by esterase in the living epidermis, were synthesized from 4-terpineol (4-TER) enantiomers and straight chain fatty acids. Their promoting activities on the SR-flurbiprofen and its enantiomers were tested across full-thickness rabbit skin, as well as to correlate under in vitro and in vivo conditions. The permeation studies indicated that both d-4-O-acylterpineol and l-4-O-acylterpineol had significant enhancing effects, interestingly, d-4-O-aclyterpineol had higher enhancing effects than l-4-O-aclyterpineol with the exception of d-4-methyl-1-(1-methylethyl)-3-cyclohexen-1-yl octadec-9-enoate (d-4-T-dC18). The mechanism of 4-O-acylterpineol facilitating the drug penetration across the skin was confirmed by Attenuated total reflection-Fourier transformed infrared spectroscopy (ATR-FTIR) and molecular simulation. The mechanism of penetration enhancers promoting drug release was explored by the in vitro release experiment. Finally, a relative safety skin irritation of enhancers was also investigated by in vivo histological evaluation. The present research suggested that d-4-O-aclyterpineol and l-4-O-aclyterpineol could significantly promote the penetration of SR-flurbiprofen and its enantiomers both in vitro and in vivo, with the superiorities of high flux and low dermal toxicity.

Permeation-enhancing effects and mechanisms of O-acylterpineol on isosorbide dinitrate: mechanistic insights based on ATR-FTIR spectroscopy, molecular modeling, and CLSM images.

The present study aimed to evaluate the penetration activity of O-acylterpineol derivatives both in vitro and in vivo, and to investigate the enhancing mechanism of O-acylterpineol derivatives which were synthesized by α-terpineol and fatty acid. The promoting activities on the isosorbide dinitrate patch were tested across full thickness rabbit skin both in vitro and in vivo. In order to elucidate the permeation mechanism, attenuated total reflection Fourier transform infrared spectroscopy, molecular modeling, and confocal laser scanning microscopy were introduced to investigate the regulation of enhancers in the skin permeability and biophysical properties. With in vitro cytotoxicity test and in vivo erythema model, the skin irritation of enhancers was also evaluated. Permeation studies showed 2-(4-methylcyclohex-3-en-l-yl) propan-2-yl tetradecanoate produced the obvious enhancement activity for ISDN both in vitro and in vivo from patches. These results were supported by ATR-FTIR, molecular modeling, and CLSM studies which revealed that O-acylterpineol could decrease the order of the alkyl chains in the skin lipids. Additionally, it was found that TER-C14 produced a relatively low skin irritation, compared with the TER which was assumed to be a safe compound. The present research suggested that some newly designed acylterpineol derivatives are shown to be suitable permeation enhancers for transdermal drug delivery, and the chain length of C14 seem to be safe and more favorable for the penetration of ISDN from DIA patches.

Two N,N'-bis-(pyridin-4-yl)pyridine-2,6-dicarboxamide coordination compounds.

The molecular structures of tetra-aqua-[N,N'-bis-(pyridin-4-yl)pyridine-2,6-dicar-boxamide]-sulfatomanganese(II) dihydrate, [Mn(SO4)(C17H13N5O2)(H2O)4]·2H2O or [Mn(H2L1)(SO4)(H2O)4]·2H2O, (I), and tetra-aqua-bis[N,N'-bis-(pyridin-4-yl)pyridine-2,6-dicar-boxamide]cadmium(II) sulfate tetra-hydrate, [Cd(C17H13N5O2)2(H2O)4]SO4·4H2O or [Cd(H2O)4(H2L1)2]·SO4·4H2O, (II), both contain a central metal atom in a distorted octa-hedral geometry coordinated equatorially by four oxygen atoms from water mol-ecules. In (I), the axial positions are occupied by a nitro-gen atom from H2L1 and an oxygen atom from the sulfate anion, whereas in (II), the axial positions contain two nitro-gen atoms from two different H2L1 ligands and the sulfate anion acts as the charge-balancing ion. π-π stacking between pyridine rings and a network of hydrogen bonds involving the water molecules and the sulfate anions play a crucial role in the mol-ecular self-assembly of the two structures.

A novel method of combining Periodic Acid Schiff staining with Wright-Giemsa staining to identify the pathogens Penicillium marneffei, Histoplasma capsulatum, Mucor and Leishmania donovani in bone marrow smears.

Penicillium marneffei, Histoplasma capsulatum, Mucor and Leishmania donovani can lead to penicilliosis marneffei, histoplasmosis, mucormycosis and leishmaniasis, respectively, which, to a certain extent, share similar clinical manifestations. These pathogens are approximately the same size, therefore it is relatively difficult to rapidly diagnose the diseases. The aim of the present study was to explore a novel method that attempts to rapidly identify the pathogens of these diseases. In the Wright-Giemsa staining, the four pathogens were approximately the same size and mainly existed in macrophages. The multiplying P. marneffei had two nuclei, which were on both sides of the fungus, and had light cross-walls in the middle. H. capsulatum had a purplish nucleus, which occupied between one-third and one-half of the spore. The cytoplasm was light blue. Peripheral spores were observed in the form of an empty, bright ring without color, like a capsule. Generally, Mucor were observed to have a long and lightly stained area, which could be easily confused with the Wright staining of dinuclear P. marneffei. L. donovani exhibited a deep-staining kinetoplast near the nucleus. In the Periodic Acid Schiff (PAS) staining, the pathogens of P. marneffei and H. capsulatum were distinct and stained red. Differentiation between P. marneffei and H. capsulatum relied on their modes of reproduction: P. marneffei depends on fission, when the pathogens stretch into sausage-shapes and are split by a cross-wall, while H. capsulatum depends on budding so that narrow-necked, single spores can be formed. With PAS staining, the cell walls and intracellular contents of Mucor and L. donovani were not stained, lightly stained or granulated and discontinuous. In conclusion, this method, combining PAS and Wright-Giemsa staining, is simple and rapid, and may contribute to the effective identification of the four pathogens.

The CCND1 G870A gene polymorphism and leukemia or non-Hodgkin lymphoma risk: a meta-analysis.

In recent years, mounting evidence has indicated that the CCND1 G870A gene polymorphism, which impacts the mitotic cell cycle, may influence leukemia or non-Hodgkin lymphoma risk. Unfortunately, the previous results were inconsistent. Therefore, a meta-analysis was performed to obtain a more precise estimation of any association. We conducted a search in PubMed, Embase and CNKI covering all published papers up to March, 2014. A total of 9 publications including 10 case-control studies met the inclusion criteria. Odds ratios (ORs) and their 95% confidence intervals (95%CIs) were applied to assess association. The pooled ORs showed significant association in non-Hodgkin lymphoma (comparison A vs G: OR= 1.114, 95%CI=1.053-1.179, p=0.000; homozygote comparison AA vs GG: OR=1.245, 95%CI=1.110-1.396, p=0.000; heterozygote comparison AG vs GG: OR=1.095, 95%CI=1.000-1.199, p=0.05; dominant model AA/GA vs GG: OR=1.137, 95%CI=1.043-1.239, p=0.003; and recessive model AA vs GA/GG: OR=1.177, 95%CI=1.066-1.301, p=0.001). However, there was no association between the CCND1 G870A polymorphism and leukemia risk. In conclusion, the CCND1 G870A polymorphism may increase risk of non-Hodgkin lymphoma, but not leukemia. However, more primary large scale and well-designed studies are still required to evaluate the interaction of CCND1 G870A polymorphism with leukemia and non-Hodgkin lymphoma risk.

The CCND1 G870A gene polymorphism and brain tumor risk: a meta-analysis.

BACKGROUND: In recent years, numerous studies have been performed to investigate the CCND1 G870A gene polymorphism impact on brain tumors susceptibility. Unfortunately, the results of previous studies were inconsistent. Therefore, we performed a meta-analysis to derive a more precise estimation of any association. MATERIALS AND METHODS: We conducted a search in PubMed, Embase and CNKI covering all published papers up to November, 2013. Odds ratios (ORs) and their 95% confidence intervals (95%CIs) were applied to assess associations. RESULTS: A total of 6 publications including 9 case-control studies met the inclusion criteria. The pooled ORs for the total included studies showed significant association among comparison A vs G (OR= 1.246, 95%CI= 1.092-1.423, p= 0.001), homozygote comparison AA vs GG (OR= 1.566, 95%CI= 1.194-2.054, p= 0.001), heterozygote comparison AG vs GG (OR= 1.290, 95%CI= 0.934-1.782, p= 0.122), dominant model AA/GA vs GG (OR= 1.381, 95%CI= 1.048-1.821, p= 0.022) and recessive model AA vs GA/GG (OR= 1.323, 95%CI= 1.057- 1.657, p= 0.015) especially in glioma. CONCLUSIONS: CCND1 G870A polymorphism may increase brain tumor risk, especially for gliomas. However, more primary large scale and well-designed studies are still required to evaluate the interaction of CCND1 G870A polymorphism with brain tumor risk.

Effect of (E)-2-isopropyl-5-methylcyclohexyl octadec-9-enoate on transdermal delivery of Aconitum alkaloids.

OBJECTIVE: The aim of this work was to evaluate the percutaneous absorption of Aconitum alkaloids using (E)-2-isopropyl-5-methylcyclohexyl octadec-9-enoate (M-OA) as an enhancer as well as to investigate the effect of M-OA in isopropyl palmitate (IPP) solution (5% ethanol in IPP, w/v), with or without an enhancer, on the stratum corneum (SC) barrier properties in vitro. METHODS: The in vitro permeation studies of Aconitum alkaloids were conducted in isopropyl myristate (IPM) solution in side-by-side diffusion cells. In addition, scanning electron microscopy (SEM) and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy were used to evaluate the M-OA biophysical changes in SC barrier function in vitro. RESULTS: The in vitro permeation studies indicated that M-OA had significant enhancing effect on the permeation of mesaconitine (MA) and hypaconitine (HA); however, aconitine (AC) was too low to be detected on the receiver side, and L-menthol had no effect on the penetration of all the Aconitum alkaloids. Morphological changes in the skin after enhancer treatment demonstrated that the extraction of the SC lipids by the enhancers led to disruption of the SC and the desquamation of SC flake. ATR-FTIR spectra of C-H asymmetric/symmetric stretching peak shifts and amide II stretching vibrations were indicative of SC lipid fluidization and changes in protein conformation, respectively. CONCLUSION: The results showed that M-OA was worthy of further investigation as a potential candidate for inclusion in transdermal formulations as a penetration enhancer.

Effect of O-acylmenthol and salt formation on the skin permeation of diclofenac acid.

PURPOSE: To enhance the transdermal delivery of diclofenac acid (DA) by using O-acylmenthol as a penetration enhancer and complexing with amines, or by a combination of the two methods. METHODS: The skin permeability of diclofenac was tested in vitro across rat skin with each of the evaluated permeants in a saturated isopropyl myristate (IPM) donor solution. RESULTS: A 4.5-fold increase in the flux of diclofenac was observed by ion-pair formation with diethylamine; however, the cations with hydroxyl groups had negative effects on the transdermal delivery of diclofenac. 2-isopropyl-5-methylcyclohexyl 2-hydroxypanoate and 2-isopropyl-5-methylcyclohexyl heptanoate produced significant increase in the permeation of diclofenac potassium (D-K); however, both of them were ineffective for the other diclofenac salts, including diclofenac diethylamine (D-DETA), diclofenac ethanolamine (D-EA), diclofenac diethanolamine (D-DEA), diclofenac triethanolamine, and diclofenac N-(hydroxylethyl) piperidine. 2-isopropyl-5-methylcyclohexyl tetradecanoate was effective on the penetration of D-K, D-DETA, D-EA, and D-DEA. Also, it is exciting to note that the combined use of diethylamine with 2-isopropyl-5-methylcyclohexyl tetradecanoate produced a 9.74-fold increase in accumulation amount of diclofenac compared with DA in IPM. CONCLUSIONS: The use of ion pair in combination with O-acylmenthol is necessary to further increase the diclofenac flux to provide better compliance for the patients undergoing clinical therapy.

Transdermal delivery of tolterodine by O-acylmenthol: In vitro/in vivo correlation.

The aim of the present investigation was to evaluate the percutaneous absorption of tolterodine (TOL) using O-acylmenthol derivatives as enhancers as well as to correlate their enhancing activity under in vitro and in vivo conditions. The in vitro permeation studies of TOL were conducted in isopropyl myristate (IPM) solution or from patches in side-by-side diffusion cells. TOL pharmacokinetic parameters were determined after intravenous administration and topical application of patches without enhancer or with l-menthol and (E)-2-isopropyl-5-methylcyclohexyl octadec-9-enoate (M-OA) as enhancers in rats. The in vitro permeation studies indicated that M-OA was the most promising enhancer for transdermal delivery, as 2-isopropyl-5-methylcyclohexyl 2-hydroxypanoate (M-LA) was merely effective in IPM solution. There was no significant difference between the control and l-menthol group in terms of the flux before patches were removed, while the skin reservoir effects of the enhancer-containing groups were significantly greater than that of the control group. The mean steady-state plasma concentrations after applying patches without enhancer or with l-menthol and M-OA as enhancers were 0.89, 0.84 and 1.47 microg/mL, respectively. The in vivo results observed from the three types of patches in rats were in good agreement with the plasma concentrations predicted from the in vitro data.

Design and in vivo evaluation of an indapamide transdermal patch.

The aim of the present study was to develop and evaluate a novel drug-in-adhesive transdermal patch system for indapamide. Initial in vitro experiments were conducted to optimize formulation parameters prior to transdermal delivery in rats. The effects of the type of adhesive and the content of permeation enhancers on indapamide transport across excised rat skin were evaluated. The results indicated that DURO-TAK adhesive 87-2852 is a suitable and compatible polymer for the development of transdermal drug delivery systems for indapamide. The final formulation contained 4% N-dodecylazepan-2-one, 6% l-menthol and 3% isopropyl myristate. For in vivo studies patch systems were administered transdermally to rats while orally administered indapamide in suspension was used as a control. The PK parameters, such as the maximum blood concentration (C(max)), time to reach the peak blood concentration (T(max)), mean residence time (MRT), area under the curve (AUC(0-t)) and terminal elimination half-life (T(1/2)) were significantly (p<0.05) different following transdermal administration compared with oral administration. In contrast to oral delivery, a sustained activity was observed over a period of 48h after transdermal administration. This sustained activity was due to the controlled release of drug into the systemic circulation following transdermal administration.

Effect of O-acylmenthol on transdermal delivery of drugs with different lipophilicity.

To develop more effective compounds as enhancers, O-acylmenthol derivatives which were expected to be enzymatically hydrolyzed into nontoxic metabolites by esterases in the living epidermis were synthesized from l-menthol and pharmaceutical excipient acids (lactic acid, cinnamic acid, salicylic acid and oleic acid) in this study. Their promoting activity on the percutaneous absorption of five model drugs, 5-fluorouracil (5-FU), isosorbide dinitrate (ISDN), lidocaine (LD), ketoprofen (KP), and indomethacin (IM), which were selected based on their lipophilicity represented by log K(O/W), were tested in vitro across full thickness rat skin with each of the evaluated drugs in saturated donor solution. 2-Isopropyl-5-methylcyclohexyl 2-hydroxypanoate (M-LA) provided the highest increase of accumulation of 5-FU (3.74-fold) and LD (4.19-fold) in the receptor phase while 2-isopropyl-5-methylcyclohexyl cinnamate (M-CA) was ineffective for most of the drugs; Both 2-isopropyl-5-methylcyclohexyl 2-hydroxybenzoate (M-SA) and (E)-2-isopropyl-5-methylcyclohexyl octadec-9-enoate (M-OA) had better promoting effects on the drugs with low water-solubility. The four O-acylmenthol enhancers produced parabolic relationship between the lipophilicity (log K(O/W)) of the model drugs (5-FU, ISDN, KP, IM) and their enhancement ratio of the permeation coefficient (ER(P)), indicating that the lipophilicity of the penetrants has significant effect on the permeation results, r = 0.989 (P=0.144) for M-LA, r = 0.965 (P = 0.216) for M-CA, r = 0.786 (P = 0.630) for M-SA, and r = 0.996 (P = 0.088) for M-OA.

Transdermal delivery of penetrants with differing lipophilicities using O-acylmenthol derivatives as penetration enhancers.

To develop more effective compounds as penetration enhancers, O-acylmenthol derivatives were synthesized by l-menthol and saturated fatty acid, O-ethylmenthol (MET), was also synthesized as a reference compound. Their promoting activity on the percutaneous absorption of five model drugs, 5-fluorouracil (5-FU), isosorbide dinitrate (ISDN), lidocaine (LD), ketoprofen (KP), indomethacin (IM), which were selected based on their lipophilicity represented by log KO/W, was tested in vitro across full thickness rat skin with each of the evaluated drugs in saturated donor solution. Only 2-isopropyl-5-methylcyclohexyl tetradecanoate (C14 alkyl chain) had promoting effects on the percutaneous permeation of 5-FU; 2-isopropyl-5-methylcyclohexyl hexanoate (C6 alkyl chain), which increased the permeation coefficient (P) 1.91-fold, had the highest permeation for ISDN; in the case of LD, the highest increase in P was observed with 2-isopropyl-5-methylcyclohexyl heptanoate (C7 alkyl chain), which increased the P by 1.58-fold; MET, which increased the P by 2.02-fold, provided the best enhancement for KP; 2-isopropyl-5-methylcyclohexyl heptanoate (C7 alkyl chain) produced the highest increase in P, 3.70-fold for IM. These results suggest that some newly designed percutaneous absorption enhancers have the potential to enhance drugs with different lipophilicities. A chain length of C6-C10 seemed to be favorable for lipophilic drugs, while C14 was the most effective enhancer for hydrophilic drug (5-FU).

Effect of permeation enhancers and organic acids on the skin permeation of indapamide.

The aim of present study was to investigate the transdermal properties of indapamide and to explore the efficacy of various permeation enhancers and organic acids with regard to the percutaneous absorption of indapamide. Permeation experiments were performed in vitro, using rat abdominal skin as a barrier. In the permeation studies, 2-chamber diffusion cells were used. The results obtained indicate that N-dodecylazepan-2-one, N-methyl-2-pyrrolidone, menthol and oleic acid had a strong enhancing effect on the permeation of indapamide and N-dodecylazepan-2-one exhibited the most potent enhancing effect. All eight of the organic acids chosen had a potent enhancing effect on the permeation of indapamide across rat abdominal skin. Among the organic acids examined, lactic acid had the greatest enhancing effect. The formation of an ion-pair between indapamide and organic acids may be responsible for the enhanced skin permeation of indapamide. Although the exact reason remains unknown, it is worth carrying out further investigations.

Diels-Alder reactions of novel (1'-arylallylidene)cyclopropanes with heterodienophiles.

Palladium-catalyzed cross-coupling of various aryl iodides with bicyclopropylidene provided isolable (1'-arylallylidene)cyclopropanes, which reacted with a number of carbonyl compounds in the presence of Eu(fod)3 under high pressure to furnish oxaspiro[2.5]octene derivatives in moderate to good yields (22-69%). The reactions of the allylidenecyclopropanes with two azo compounds as dienophiles afforded diazaspiro[2.5]octenes in high yields (82 and 99%) even at ambient pressure. When treated with nitrosobenzene, two of the allylidenecyclopropanes gave the Diels-Alder adducts in up to 83 and 40% yield. 2,5-Diiodo-p-xylene coupled twice with bicyclopropylidene, and the product underwent a twofold Diels-Alder reaction with nitrosobenzene to produce the bis(spirocyclopropaneoxazine) derivative in 88% yield. This overall transformation can be brought about in a one-pot, two-step operation by addition of the nitrosoarene to the reaction mixture immediately after formation of the allylidenecyclopropanes to furnish various 5-oxa-4-azaspiro[2.5]oct-7-ene derivatives in 22-77% yield. The coupling of methyl bicyclopropylidenecarboxylate with 2,6-dimethylphenyl iodide produced a mixture of very stable regioisomeric allylidenecyclopropane derivatives in 90% yield. The reaction of this mixture with N-phenyltriazolinedione gave a corresponding mixture of the spirocyclopropanated heterobicycles in 61% yield.