• Korean Journal of Dental Materials
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• v.44 no.1
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• pp.21-31
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• 2017

The purpose of this study was to fabricate a biocompatible fluoride varnish with sustained fluoride release, and to compare it with commercial fluoride varnishes. For the experimental fluoride varnish, bis-GMA (BG) or two types of rosin (KR-610: K0, KR-612: K2) were used as bases. Either ethyl acetate or ethanol was added as solvent and 5 wt% NaF was used. 5 mg of experimental F- varnishes and 2 commercial products, Cavity shield (CS) and Flor-opal (FO), were applied on a labial surface of bovine teeth ($10mm{\times}7mm$). The amount of fluoride release was measured at 1 hr, 2 hrs, 3 hrs, 4 hrs, 8 hrs, 12 hrs, 1 day, 3 days, 5 days, 10 days, 15 days, 20 days and 30 days. MTT test was done with diluted F- varnishes using ethanol. Statistical analysis was done with one-way ANOVA and Duncan multiple range test (${\alpha}=0.05$). BG showed the highest fluoride release at 1 hr (P<0.05), while that of K0 was highest at 2 hrs (P<0.05). From 1 day to 5 days, experimental fluoride varnishes showed higher fluoride release than the commercial products (P<0.05), and there were no significant differences after 5 days (P>0.05). For MTT test, K0 and FO showed higher cell viability than other experimental groups (P<0.05), with no significant differences with K2 (P>0.05). Considering the sustained fluoride release and cell viability of the experimental rosin-based fluoride varnishes compared with commercial products, it will be appropriate for clinical application.

• Journal of Pharmaceutical Investigation
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• v.24 no.3
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• pp.139-144
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• 1994

The effect of some formulation variables on the release rate of famotidine, a $H_2$ receptor antagonist, from cellulose matrices containing hydroxypropylcellulose (HPC) in different ratios and types was investigated. The effects of tablet shape and compression pressure on dissolution rate of famotidine were studied. And the effect of the pH of dissolution media was also studied. Increase in the ratio of polymer to drug decreased the release rate of famotidine. Increase of the polymer viscosity also decreased the release rate. The release rate of famotidine was dependent on the pH of dissolution media. The release rate of drug was not much dependent on the compression pressure but dependent on the tablet shape and/or surface area. Consequently, the release rate of famotidine can be modified by changing the HPC contents, types of polymers with different viscosity grades or using appropriate fillers.

• Journal of Pharmaceutical Investigation
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• v.23 no.4
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• pp.213-216
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• 1993

${\kappa}-Carrageenan$, an anionic polysaccharide, was employed in tablet formulations and its function as a drug release sustaining agent was investigated. Tablets composed of ${\kappa}-carrageenan$ and hydroxypropyl methylcellulose were fabricated by using direct compression method. Lactose and sodium alginate were utilized as controls for ${\kappa}-carrageenan$. Drug release experiments performed at pHs 1.2 and 7.4 revealed that ${\kappa}-carrageenan$ retains pH-dependent sustained release effects due to its anionic characteristics. Also, the ionic interaction between ${\kappa}-carrageenan$ and drugs exerted significant affects on drug release kinetics. ${\kappa}-Carrageenan$ was found out to be a useful additive for sustained release tablet formulations.

• Journal of the Korean Society of Physical Medicine
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• v.1 no.1
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• pp.49-57
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• 2006

Purpose : The Purpose of this study was to pain release and power grip in wrist affect of needle TENS(utilized of TENS in electrotherapy with oriental needle) and ultrasound therapy and taping with carpal tunnel syndrome patients. Methods : To study divided of each groups. each groups were apply to ultrasound therapy for 5 mintus, Taping was attached from wrist joint to elbow joint medial epicondly after maximum extension. needle TENS application was following of median nerve in wrist. Result : 1. The pain was released on needle TENS, ultrasound and taping groups of all(p<.05). 2. Power grip was enhanced in needle TENS and taping groups(p<.05) but ultrasound was no difference compared with before therapy. 3. Compared with needle TENS and taping therapy about pain release was needle TENS groups better than ultrasound groups(p<.05) Conclusion : Needle TENS, taping therapy are more effectable than ultrasound therapy for grip power and pain release. Needle TENS therapy is more effectable than taping therapy for pain release. Therefor, neddle TENS therapy is most effectable for pain release with carpal tunnel syndrome patients.

• Journal of Pharmaceutical Investigation
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• v.19 no.2
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• pp.99-107
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• 1989

In order to develop a pediatric liquid preparation with sustained release properties, dextromethorphan hydrobromide (DEXT) was complexed with strong cation exchange resin (CG 120) and the-complex was coated with Eudragit RS using a phase separation method by non-solvent addition. The effect of pH, ionic strength of the release medium and drug/resin ratio on the release rate of DEXT was studied. The release rate of free drug from the uncoated complex, and coated complexes with 9.5 and 18.5% Eudragit RS in artificial gastric juice were measured. The release rate from the uncoated complex was faster with higher pH, higher ionic strength of the release medium and higher drug/resin ratio. The release rate from the coated complex could be controlled by the amount of coating material, and the surface after release did not rupture into.

• Journal of Pharmaceutical Investigation
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• v.19 no.3
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• pp.145-154
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• 1989

Methyl methacrylate-butyl methacrylate copolymer (MMBM)-povidone (PVP) films were investigated as a potential topical drug delivery system for the controlled release of econazole nitrate as a model drug. The effect of changes in film composition, drug concentration, film thickness, pH and temperature of release medium on the in vitro release of econazole nitrate were studied. The release rate constant was found to be increased with increasing povidone content in dry films. Drug release followed zero-order kinetics in the initial stage and then release rate increased gradually with time, espicially in the films having larger proportions of PVP. The release rate was found to be dependent on drug content, film thickness, the pH and temperature of release medium. Antimicrobial test showed that microbial growth was inhibited markedly with increasing proportions of PVP in films. Also drug content and film thickness affected the antimicrobial activity.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.9
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• pp.1003-1012
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• 2007

In this study, we analyzed the release differences for some critical pollution compounds according to the surrounding conditions in order to predict water quality due to the sedimental releases and the release characteristics at different sedimental locations in Lake Leewon, in Tae-An area. COD, nitrogens and phosphates were analyzed using the standard methods for water quality, based on high chloride ion concentration(greater than 2,000 ppm). For COD, the release rate increased in the anoxic basin but almost the same in the oxic basin. For $NH_3$-N, the release rate decreased in the oxic basin as you go A through C point meanwhile, for $NO_3$-N and T-N, the tendency was reversed because of nitrification of them. In the anoxic basin, the release rates of $NH_3$-N and $NO_3$-N went up with A through C path. However, the release rate of T-N was found to decrease. Also, for $PO_4$-P and T-P, the release rates in the oxic basin were lowest at B point mainly because the phosphates were at less released in the highly $O_2$ concentrated environment. In the anoxic reactor, $PO_4$-P was released similarly regardless of the sampling points. In summary, the release rates in the oxic reactor were greater than those in the anoxic reactor for COD and $NO_3$-N. For the other components, the anoxic basin generated the higher release rates.

• Korean Journal of Organic Agriculture
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• v.14 no.3
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• pp.315-323
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• 2006

The potential of the predatory mite Phytoseiulus persimilis (Acarina : Phytoseiidae) to control two spotted spider mite Tetranychus urticae (Acarina : Tetranychidae) was investigated on sustainable strawberry fields in Jeonnam area. The density of T. urticae increased from 4th and 7th weeks after single and two timings release P. persimilis, respectively. On the three timings of release plot, number(density) of T. urticae on a leaf maintained fewer than 10 during the 15 weeks after release. In the 1,000 release of P. persimilis per $100m^2$ plot, P. persimilis could not suppress T. urticae. In the 2,000 release plot, P. persimilis could suppress T. urticae with low density which was the similar in the 3,000 release plot. Two-spotted spider mite, T. urticae, occurred from late March and increased density in Hampyeong area. In the P. persimilis released field, T. urticae inhibited continuously after release. In Boseong area, density of P. persimilis increased 50 per 10 leaves through increasing of T. urticae. Percent of occurrence of T. urticae showed high $10.5{\sim}75.5%$ in none-release predatory mite but not high in release treatment. T. urticae on sustainable strawberry field could be inhibited by P. persimilis.

• Biomolecules & Therapeutics
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• v.5 no.1
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• pp.94-99
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• 1997

Capsaicin is known to be an analgesic agent, affecting the synthesis, storage, , transport and release of substance p, the principal neurotransmitter of pain from periphery to the central nervous system(CNS). DA-5018, a newly synthesized capsaicin derivative has shown potent analgesic effect comparable to that of morphine in various rat models of experimentally inducted acute pairs. In this study the mechanism of analgesic actlvity of DA-5018 was examined. First, the electrically-evoked contraction of guinea pig trachea was inhibited by DA-5018 and these inhibition was recovered by incubation with capsafepine(3$\muM$), capsaicin receptor antagonist and this result suggested that DA-5018 has affinity on capsaicin receptor. The correlation between the norciceptive threshold and the release of substance P was evaluated. In vivo perfusion of slices of the rat spinal cord with DA-5018(10, 100$\muM$) produced a significant increase of the release of substance P and this increase was less than that of capsaicin(10$\muM$). The norciceptive threshold of rat treated with DA-5018(1 mg/kg, p.o) in tall pinch test increased from 2.9$\pm$0.3 to 23.5 $\pm$6.61. Tail pinch latency increased to a maximun at 15 min after DA-5018 treatment and then declined to control values by 120 min. The capsaicin-evoked release ot substance P from the spinal cord slices of rat treated with DA-5018 reduced from 2.38$\pm$ 0.79 to 0.69$\pm$ 0.26 pg/mg wet weight. This reduction reached to a minium at 15 min after DA-5018 treatment and then recovered to control value by 120 min. These results mean that analgesic activity of DA-5018 is due to release of substance P The effect of DA-5018 cream on electrically-evoked neurogenic inflammation of rat saphenous nerve was compared with capsaicin (zostrix-HP). DA-5018 showed 34% inhibition of the neurogenic extravasation while capsaicin showed significant 67% inhibition. This result indicates that the potency of DA-5018 in the release of substance P is less than that of capsaicin. These results suggest that the release of substance P is partially involved in the mechanism of analgesic action of DA-50l8.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.1
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• pp.34-41
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• 2017

Objective: Two experiments were performed to evaluate the effects of coated slow-release urea on nutrient digestion, ruminal fermentation, nitrogen utilization, blood glucose and urea concentration (Exp 1), and average daily gain (ADG; Exp 2) of steers. Methods: Exp 1: Eight ruminally fistulated steers [$503{\pm}28.5kg$ body weight (BW)] were distributed into a d $4{\times}4$ Latin square design and assigned to treatments: control (CON), feed grade urea (U2), polymer-coated slow-release urea A (SRA2), and polymer-coated slow-release urea B (SRB2). Dietary urea sources were set at 20 g/kg DM. Exp 2: 84 steers ($350.5{\pm}26.5kg$ initial BW) were distributed to treatments: CON, FGU at 10 or 20 g/kg diet DM (U1 and U2, respectively), coated SRA2 at 10 or 20 g/kg diet DM (SRA1 and SRA2, respectively), and coated SRB at 10 or 20 g/kg diet DM (SRB1 and SRB2, respectively). Results: Exp 1: Urea treatments (U2+SRA2+SRB2) decreased (7.4%, p = 0.03) the DM intake and increased (11.4%, p<0.01) crude protein digestibility. Coated slow-release urea (SRA2+-SRB2) showed similar nutrient digestibility compwared to feed grade urea (FGU). However, steers fed SRB2 had higher (p = 0.02) DM digestibility compared to those fed SRA2. Urea sources did not affect ruminal fermentation when compared to CON. Although, coated slow-release urea showed lower (p = 0.01) concentration of $NH_3-N$ (-10.4%) and acetate to propionate ratio than U2. Coated slow-release urea showed lower (p = 0.02) urinary N and blood urea concentration compared to FGU. Exp 2: Urea sources decreased (p = 0.01) the ADG in relation to CON. Animals fed urea sources at 10 g/kg DM showed higher (12.33%, p = 0.01) ADG compared to those fed urea at 20 g/kg DM. Conclusion: Feeding urea decreased the nutrient intake without largely affected the nutrient digestibility. In addition, polymer-coated slow-release urea sources decreased ruminal ammonia concentration and increased ruminal propionate production. Urea at 20 g/kg DM, regardless of source, decreased ADG compared both to CON and diets with urea at 10 g/kg DM.