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Junhyung Tak - One of the best experts on this subject based on the ideXlab platform.

  • insecticidal activity of 28 essential oils and a Commercial Product containing cinnamomum cassia bark essential oil against sitophilus zeamais motschulsky
    Insects, 2020
    Co-Authors: Yunho Yang, Murray B Isman, Junhyung Tak
    Abstract:

    Maize weevils, Sitophilus zeamais, are stored Product pests mostly found in warm and humid regions around the globe. In the present study, acute toxicity via contact and residual bioassay and fumigant bioassay of 28 essential oils as well as their attraction-inhibitory activity against the adults of S. zeamais were evaluated. Chemical composition of the essential oils was analyzed by gas chromatography-mass spectrometry, and a compound elimination assay was conducted on the four most active oils (cinnamon, tea tree, ylang ylang, and marjoram oils) to identify major active constituents. Amongst the oils examined, cinnamon oil was the most active in both contact/residual and fumigant bioassays, and exhibited strong behavioral inhibitory activity. Based on the compound elimination assay and chemical analyses, trans-cinnamaldehyde in cinnamon oil, and terpinen-4-ol in tea tree and marjoram oils were identified as the major active components. Although cinnamon oil seemed promising in the lab-scale bioassay without rice grains, it failed to exhibit strong insecticidal activity when the container was filled with rice. When a cinnamon oil-based Product was applied both in an empty glass jar and a rice-filled container, all weevils in the empty jar were killed, whereas fewer than 15% died in the rice-filled container.

Yunho Yang - One of the best experts on this subject based on the ideXlab platform.

  • insecticidal activity of 28 essential oils and a Commercial Product containing cinnamomum cassia bark essential oil against sitophilus zeamais motschulsky
    Insects, 2020
    Co-Authors: Yunho Yang, Murray B Isman, Junhyung Tak
    Abstract:

    Maize weevils, Sitophilus zeamais, are stored Product pests mostly found in warm and humid regions around the globe. In the present study, acute toxicity via contact and residual bioassay and fumigant bioassay of 28 essential oils as well as their attraction-inhibitory activity against the adults of S. zeamais were evaluated. Chemical composition of the essential oils was analyzed by gas chromatography-mass spectrometry, and a compound elimination assay was conducted on the four most active oils (cinnamon, tea tree, ylang ylang, and marjoram oils) to identify major active constituents. Amongst the oils examined, cinnamon oil was the most active in both contact/residual and fumigant bioassays, and exhibited strong behavioral inhibitory activity. Based on the compound elimination assay and chemical analyses, trans-cinnamaldehyde in cinnamon oil, and terpinen-4-ol in tea tree and marjoram oils were identified as the major active components. Although cinnamon oil seemed promising in the lab-scale bioassay without rice grains, it failed to exhibit strong insecticidal activity when the container was filled with rice. When a cinnamon oil-based Product was applied both in an empty glass jar and a rice-filled container, all weevils in the empty jar were killed, whereas fewer than 15% died in the rice-filled container.

Murray B Isman - One of the best experts on this subject based on the ideXlab platform.

  • insecticidal activity of 28 essential oils and a Commercial Product containing cinnamomum cassia bark essential oil against sitophilus zeamais motschulsky
    Insects, 2020
    Co-Authors: Yunho Yang, Murray B Isman, Junhyung Tak
    Abstract:

    Maize weevils, Sitophilus zeamais, are stored Product pests mostly found in warm and humid regions around the globe. In the present study, acute toxicity via contact and residual bioassay and fumigant bioassay of 28 essential oils as well as their attraction-inhibitory activity against the adults of S. zeamais were evaluated. Chemical composition of the essential oils was analyzed by gas chromatography-mass spectrometry, and a compound elimination assay was conducted on the four most active oils (cinnamon, tea tree, ylang ylang, and marjoram oils) to identify major active constituents. Amongst the oils examined, cinnamon oil was the most active in both contact/residual and fumigant bioassays, and exhibited strong behavioral inhibitory activity. Based on the compound elimination assay and chemical analyses, trans-cinnamaldehyde in cinnamon oil, and terpinen-4-ol in tea tree and marjoram oils were identified as the major active components. Although cinnamon oil seemed promising in the lab-scale bioassay without rice grains, it failed to exhibit strong insecticidal activity when the container was filled with rice. When a cinnamon oil-based Product was applied both in an empty glass jar and a rice-filled container, all weevils in the empty jar were killed, whereas fewer than 15% died in the rice-filled container.

Hangon Choi - One of the best experts on this subject based on the ideXlab platform.

  • novel fenofibric acid loaded controlled release pellet bioequivalent to choline fenofibrate loaded Commercial Product in beagle dogs
    International Journal of Pharmaceutics, 2015
    Co-Authors: Kyung Soo Kim, Sung Giu Jin, Jong Soo Woo, Dong Wuk Kim, Jong Oh Kim, Chul Soon Yong, Omer Mustapha, Abid Mehmood Yousaf, Young Hun Kim, Hangon Choi
    Abstract:

    Abstract The objective of this study was to develop a novel fenofibric acid-loaded controlled release pellet showing enhanced, or equivalent to, bioavailability compared with two Commercially available Products containing fenofibrate or choline fenofibrate. The effect of solubilizing agents on drug solubility and the impact of fillers on core properties were investigated. Among them, magnesium carbonate most improved drug solubility, and κ-carrageenan provided the best spherical cores. The fenofibric acid-loaded pellet was prepared with magnesium carbonate and κ-carrageenan employing the extrusion/spheronizing technique followed by coating with ethylcellulose. Furthermore, dissolution and pharmacokinetic study in beagle dogs were performed compared to the fenofibrate-loaded Commercial tablet (FCT) and choline fenofibrate-loaded Commercial mini-tablet (CFCM). This fenofibric acid-loaded pellet showed controlled release of the drug in phosphate buffer (pH 6.8) and 0.025 M sodium laurylsulfate within 4 h. Furthermore, this pellet and CFCM exhibited similar dissolution profiles. Plasma concentrations greater than 1000 ng/ml were maintained from 30 min to 8 h, suggesting a sustained release pattern. Also, the fenofibric acid-loaded pellet gave significantly higher AUC and C max values than FCT, indicating that it improved the bioavailability of fenofibrate due to enhanced solubility and sustained release. In addition, this pellet and CFCM were not significantly different in terms of pharmacokinetic parameters including AUC, C max and T max . Thus, this pellet was bioequivalent to CFCM in beagle dogs. In conclusion, this fenofibric acid-loaded controlled release pellet would be a potential alternative to the choline fenofibrate-loaded Commercial Product.

  • development of direct compression entecavir 0 5 mg loaded tablet exhibiting enhanced content uniformity
    Powder Technology, 2014
    Co-Authors: Abid Mehmood Yousaf, Jun-pil Jee, Young-joon Park, Jong Oh Kim, Chul Soon Yong, Hangon Choi, Seung Rim Hwang, Hanjoo Maeng, Kwan Hyung Cho
    Abstract:

    Abstract The aim of the present research was to develop direct compression entecavir 0.5 mg-loaded tablet (DCET) providing enhanced content uniformity. Various compositions and preblending methods were tested at lab-scale, and the optimum composition and method were applied to pilot-scale Production for further confirmation of the entire process. The content uniformity, physical properties and dissolution behavior of the final film-coated DCET were compared to the Commercial Product. In lab-scale preparation, the method involving preblending, micronization of API (d0.5 = 5.13 μm), addition of a larger quantity of colloidal silicon dioxide (1%) and sieving through smaller pores (300 μm) yielded an excellent acceptance value (AV) in the content uniformity criteria compared to a control method and composition (AV 1.0 vs. 9.8). In pilot-scale Production, the film-coated DCET provided better content uniformity than the Commercial Product (AV 1.3 vs. 3.8). Furthermore, both Products exhibited similar dissolution profiles in various media. Thus, direct compression entecavir 0.5 mg-loaded tablet developed in this study would be a promising dosage form with excellent content uniformity that may be bioequivalent to the Commercial Product.

  • novel valsartan loaded solid dispersion with enhanced bioavailability and no crystalline changes
    International Journal of Pharmaceutics, 2012
    Co-Authors: Yidong Yan, Jun Ho Sung, Kun Kook Kim, Dong Wuk Kim, Jong Oh Kim, Beomjin Lee, Chul Soon Yong, Hangon Choi
    Abstract:

    With the aim of developing a novel valsartan-loaded solid dispersion with enhanced bioavailability and no crystalline changes, various valsartan-loaded solid dispersions were prepared with water, hydroxypropyl methylcellulose (HPMC) and sodium lauryl sulphate (SLS). Effects of the weight ratios of SLS/HPMC and carrier/drug on both the aqueous solubility of valsartan and the drug-release profiles of solid dispersions were investigated. The physicochemical properties of solid dispersions were characterized using scanning electron microscope (SEM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The bioavailability of the solid dispersions in rats was evaluated compared to valsartan powder and a Commercial Product (Diovan). Unlike the conventional solid dispersion system, the valsartan-loaded solid dispersion had a relatively rough surface and did not change the crystalline form of the drug. It was suggested that the solid dispersions were formed by attaching hydrophilic carriers to the surface of the drug, thus changing from a hydrophobic to a hydrophilic form without changing the crystalline form. The drug-loaded solid dispersion composed of valsartan/HPMC/SLS at a weight ratio of 3/1.5/0.75 improved the drug solubility by about 43-fold. It gave a higher AUC, C(max) and shorter T(max) compared to valsartan powder and the Commercial Product. The solid dispersion improved the bioavailability of the drug in rats by about 2.2 and 1.7-fold in comparison with valsartan powder and the Commercial Product, respectively. Thus, the valsartan-loaded solid dispersion would be useful for delivering poorly water-soluble valsartan with enhanced bioavailability and no crystalline changes.

  • development of novel sibutramine base loaded solid dispersion with gelatin and hpmc physicochemical characterization and pharmacokinetics in beagle dogs
    International Journal of Pharmaceutics, 2010
    Co-Authors: Hyun Tae Lim, Chul Soon Yong, Hangon Choi, Prabagar Balakrishnan, Kwan Hyung Joe, Young Ran Kim, Doo Hyung Hwang, Yongbok Lee
    Abstract:

    Abstract To develop a novel sibutramine base-loaded solid dispersion with enhanced solubility and bioavailability, various solid dispersions were prepared using a spray drying technique with hydrophilic polymers such as gelatin, HPMC and citric acid. Their solubility, thermal characteristics and crystallinity were investigated. The dissolution and pharmacokinetics of the sibutramine base-loaded solid dispersion were then compared with a sibutramine hydrochloride monohydrate-loaded Commercial Product (Reductil ® ). The solid dispersions prepared with gelatin gave higher drug solubility than those prepared without gelatin, irrespective of the amount of polymer. The sibutramine base-loaded solid dispersions containing hydrophilic polymer and citric acid showed higher drug solubility compared to sibutramine base and sibutramine hydrochloride monohydrate. Among the formulations tested, the solid dispersion composed of sibutramine base/gelatin/HPMC/citric acid at the weight ratio of 1/0.8/0.2/0.5 gave the highest solubility of 5.03 ± 0.24 mg/ml. Our DSC and powder X-ray diffraction results showed that the drug was present in an altered amorphous form in this solid dispersion. The difference factor ( f 1 ) values between solid dispersion and Commercial Product were 2.82, 6.65 and 6.31 at pH 1.2, 4.0 and 6.8, respectively. Furthermore, they had the similarity factor ( f 2 ) value of 65.68, 53.43 and 58.97 at pH 1.2, 4.0 and 6.8, respectively. Our results suggested that the solid dispersion and Commercial Product produced a similar correlation of dissolution profiles at all pH ranges. The AUC, C max and T max of the parent drug and metabolite I and II from the solid dispersion were not significantly different from those of the Commercial Product, suggesting that the solid dispersion might be bioequivalent to the Commercial Product in beagle dogs. Thus, the sibutramine base-loaded solid dispersion prepared with gelatin, HPMC and citric acid is a promising candidate for improving the solubility and bioavailability of the poorly water-soluble sibutramine base.

K Dadkhahipour - One of the best experts on this subject based on the ideXlab platform.

  • Effect of particle size of two Iranian diatomaceous earth deposits and a Commercial Product on Sitophilus granarius (Col.: Dryophthoridae)
    2016
    Co-Authors: Masumeh Ziaee, Saied Moharramipour, K Dadkhahipour
    Abstract:

    Laboratory bioassays were carried out to study the insecticidal efficacy of two Iranian diatomaceous earths (DEs) and SilicoSec ® formulation against Sitophilus granarius (L.). Four different particle sizes of DEs were applied at five concentrations. The mortality was counted 2, 5 and 7 days after exposure. The experiment was carried out at 27 1°C and 55 5 % relative humidity in continuous darkness. For SilicoSec ® and Mamaghan with less than 37 µm particle size,500 ppm was sufficient to cause 100 % mortality after 5 days of exposure. While in case of Maragheh deposit with the same particle size, complete mortality was recorded at 1000 ppm after 5 days. LC50 values indicated that SilicoSec ® and Mamaghan with < 37 µm particle size were the most efficient DE samples against S. granarius. In most cases, the efficacy of DEs increased with decreasing particle size. The visual observation of scanning electron microscopy (SEM) images showed that SilicoSec ® has more attachment to insects body. However, the adhesiveness of DE particles cannot be the main indicative of their insecticidal effectiveness

  • effect of particle size of two iranian diatomaceous earth deposits and a Commercial Product on sitophilus granarius col dryophthoridae
    نامه انجمن حشره شناسی ایران, 2013
    Co-Authors: Masumeh Ziaee, Saied Moharramipour, K Dadkhahipour
    Abstract:

    Laboratory bioassays were carried out to study the insecticidal efficacy of two Iranian diatomaceous earths (DEs) and SilicoSec ® formulation against Sitophilus granarius (L.). Four different particle sizes of DEs were applied at five concentrations. The mortality was counted 2, 5 and 7 days after exposure. The experiment was carried out at 27 � “ � 1°C and 55 � “ ®