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Objectives@#The stratum corneum (SC) remains an obstacle to the passage of drugs applied topically. Several investigations have focused on enhancing the penetration of drugs through the SC by integrating permeation enhancers (PE) into the drug formulation. Terpenes are among the PE utilized in formulations and are categorized by the regulatory bodies as generally recognized as safe (GRAS). This study aimed to comparatively analyze the skin permeation enhancing effect of terpenes on lipophilic drugs. @*Methods@#The present study reviewed the effects of terpenes on the permeation of lipophilic small-molecule drugs through the skin using original research published between 2000 - 2022 retrieved from PubMed®. The search phrase used was (lipophilic drug) AND (terpene) AND (permeation enhancer). @*Results@#Terpenes increase the percutaneous permeation of lipophilic small molecule drugs by 1.06 – 256.80-fold. Linear correlation analysis of terpenes’ cLog P with enhancement ratio (ER) revealed moderate and strong positive correlations in pig skin (r = 0.21) and mouse skin (r = 0.27), and rat skin (r = 0.41) and human skin (r = 0.67), respectively. Drug cLog P is a poor (r = -0.06) predictor of permeation enhancement. Terpenes with cLog P higher than 2.40 had ER greater than 10. Higher ERs (>30) were recorded for nerolidol, carvacrol, borneol, terpineol, limonene, menthone, pulegone, and menthol among the terpene-chemical penetration enhancers. @*Conclusion@#cLog P of terpene-based chemical permeation enhancers (CPE) is strongly correlated with ER of lipophilic drugs across human skin. Non-polar groups in terpenes and hydrogen bond interactions by terpenes with SC lipid enhance cutaneous drug penetration of lipophilic drugs.
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Terpenes , SkinABSTRACT
Background: The aim of our study is to assess the dose enhancement from scattered radiation due to dental restorative materials used for occlusal and mesio-occlusal-distal (MOD) cavity filling during simulated head and neck radiotherapy. Methods: We have studied the dose enhancement ratio (DER) of conventional amalgam, high-copper amalgam, and resin composite dental restorative materials at cadaver mandible teeth using 2 therapeutic photon energies of 1.25 MeV (Co-60 gamma ray) and 6 MV (Linac X-ray) for irradiation. Results: DER values at buccal position for Co-60 and 6 MV X-ray were 1.250 ± 0.013 and 1.151 ± 0.012, respectively. For dental cavity fillings, DER values for 6 MV X-ray were 1.065 ± 0.021, 1.100 ± 0.014, and 1.162 ± 0.016 for resin composite filling, low-copper amalgam filling, and high-copper amalgam filling, respectively. Our results revealed that DER regarding irradiation energy was minimum for 6 MV X-rays. With respect to dental restorative filling material, DER was minimum for resin composite filling. Regarding the cavity type, our results with standard deviation (SD) calculations revealed that DER was slightly but not significantly different for both Co-60 gamma ray (1.25 MeV) and 6 MV X-ray energies for both occlusal and MOD cavities. Conclusion: Our dosimetric results for a single beam geometry suggest that, among the three types of filling, resin composite filling is an ideal restorative filling material with minimal morbidity-inducing radiation dose enhancement that may result in increased osteoradionecrosis and secondary caries risk. There is a need for further dosimetric studies with actual clinical beam arrangements.
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Objective To explore the effect of oxaliplatin ( OXA) on enhancing radiosensitivity in human hepatocellular carcinoma cell line HepG2 . Methods 50% inhibition concentration ( IC50 ) of HepG2 cells treated with OXA was measured by using MTT method at 6, 12, 24, 48 hours. Then clone formation assay was applied to obtain sensitizing enhancement ratio ( SER) of OXA combing IR, according to the survival fraction of three groups 10?14 days after treatments:placebo?treated group ( C) ,radiation group ( IR, single dose of 1 Gy,2 Gy,4 Gy,6 Gy,8 Gy,10 Gy) and IR synchronizing OXA group ( IR+3 mg/L OXA) . The proportions of cell apoptosis were analyzed using flow cytometry at 24 hours after treatment. At last, we semi?quantitative tested the expression of extracellular regulated protein kinase 1/2 ( ERK 1/2 ) and DNA damage repair protein Ku?70 of the C,IR and IR+OXA groups. Statistical analysis was performed by T test. Results The IC50 of OXA on HepG2 cells is 54?4 mg/L at 6 hours,29?1 mg/L at 12 hours,17?8 mg/L at 24 hours and 10?5 mg/L at 48 hours.3 mg/L was selected in clone formation assay at which 80?90% HepG2 cells survived at 24 hours. The SER ( SF2 ) is calculated as 1?59. Flow cytometry showed the proportion of survival cells in IR+OXA group is significantly lower than those of IR group ( P=0?005) ,OXA group ( P=0?008) and C group ( P=0?001) . The expressions of ERK 1/2 were inhibited in IR and IR+OXA groups compared by that of control group. But the expression of ERK 1/2 in IR group showed increasing after 48 hours which was higher than that of IR+OXA group. For Ku?70,the changes of expression were similar with that of ERK 1/2. Conclusion Oxaliplatin presented enhancing radiosensitivity in human hepatocellular carcinoma cell line HepG2 in vitro.
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OBJECTIVE: To investigate the effects of current, voltage and pH of donor chamber solution on the iontophoretic transport of ciprofloxacin. METHODS: An in vitro study was carried out to determine the iontophoretic permeability of ciprofloxacin through pig skin. Iontophoretic flux of ciprofloxacin through excised pig skin was determined using Valia-Chien two chamber diffusion cells. The permeability enhancement ratios in donor chamber solution of different pH under different currents and voltages were also measured. RESULTS: Iontophoretic flux of ciprofloxacin increased with increasing current and voltage. The effect of ciprofloxacin solution pH in the donor chamber on the iontophoretic transport was observed. When the pH of ciprofloxacin solution was 3.5, there was good iontophoretic permeability. CONCLUSION: The results suggest that electrical factor and pH of the donor chamber solution may be important factors for the iontophoretic permeability of ciprofloxacin.
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Objective: To study the enhancing effects of electret on transdermal delivery of lidocaine patches in vitro. Methods: In vitro rat skin permeation experiment was carried out with lidocaine patches, lidocaine paches with azone, positive/negative electret lidocaine patches, and positive/negative electret lidocaine patches with azone by using Franz diffusion cells. The accumulated lidocaine concentrations in rat skin treated with each kind of patches were examined by HPLC to investigate the influence of electret on transdermal delivery of lidocaine. Results: (1) The enhancement rates of 1%, 3% and 5% azone lidocaine patches 10 h after application were 1. 06, 1. 10 and 1. 66 folds (P<0. 05, 5% azone to lidocaine patch group) that of the lidocaine patch, respectively. (2) Lidocaine patches with negative electret containing 1%, 3% and 5% azone showed similar transdermal behavior to the corresponding chemical enhancer patches. (3) Lidocaine patches with positive electret containing 1%, 3% and 5% azone showed much better enhancing effect than the corresponding chemical enhancer lidocaine patches (P<0. 05). Besides, 5% azone together with positive electret showed a cooperative enhancing effect. Conclusion: Positive electret patch has better effect in enhancing transdermal delivery of lidocaine. Besides, the cooperative enhancing effect of azone with positive electret on transdermal delivery of lidocaine is in a concentration-dependent manner with azone.
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Objective: To explore the role of cytosine-phosphate-guanine oligodeoxynucleotide(CpG ODN)in enhan- cing the radiosensitivity to X-ray in mouse with Lewis lung cancer.Methods: The tumor-bearing mouse model was in- duced by injevting Lewis lung cancer cells into the right infra-axillary dermis.Thirty-two C57BL/6J mice were evenly ran- domized into 4 groups.Group A: the control group;Group B: the X-Ray radiation group;Group C: the CpG group; Group D: the CpG plus X-Ray radiation group.Group B was treated with X-Ray radiation only(3 Gy/F,on day 1,3,5, 8,10,and 12;the total dose was 18 Gy);group C was administered with CpG ODN 0.05 mg on day 1,3,5,8,10, and 12;group D was administered with CpG ODN 6h before X-ray radiation.The tumor growth and tumor growth delay (TGD)were observed in all groups.Meanwhile,the pathological change of the tumor tissue was observed with H-E staining method and the apoptosis of tumor cells were examined with the method of TUNEL.Results: The Lewis hmg cancer-bearing model was successfolly established in mice.The tumor volumes of the treatment groups were smaller than that in lhe control group(P
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The synergistic effect of combining radiation therapy and hyperthermia kills significantly more cells than using either modality alone. The reason for enhanced cell killing from the combined treatment is that the two modalities are complementary. For histopathological exmination, 102 rats were divided into 4 groups as hyperthermia, radiation, hyperthermia combined with radiation and normal control groups. The effect of prior irradiation (6-15 Gy of X-ray) on the response of small and large bowel of rats to 40degree C-44degree C (for 30 minutes) microwave (2450 MHz) hyperthermia was investigated. The musculature of the small and large intestine remained intact and the circumference of the histological sections were not significantly altered by the heated at 43degree C for 30 minutes. Thermal enhancement ratios of normal tissue is 1.0. Thermal enhancement ratio was not increased in combination therapy by evaluation of histopathologic changes in small and large intestine.