• The Korean Journal of Pesticide Science
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• v.9 no.4
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• pp.401-410
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• 2005

A series of studies involving formulation processes, bubbling activity test, diffusibility test and biological efficacy test was undertaken to develop Jumbo herbicide formulations in paddy rice field. Gas evolution speed from the tablets prepared by different organic acids was in the order of oxalic acid, malonic acid, citric acid, and tartaric acid. The total volume of evolved gas from the tablet and diffusibility of the active ingredient in the submerged water were increased with increase of water temperature; the volume from 1 g of tablet at 10, 15, 25 and $30^{\circ}C$ for 5 minutes after immersion into water was 20, 25, 28, 45, 57 mL, respectively. The concentration of halosulfuron-methyl and pyriminobac-methyl in submerged water at 5, 15, 20 and $30^{\circ}C$ at the 2.4 m distance from the applied spot of the tablet was 20, 48, 85, and 97% of the concentration of treated spot, respectively. The evolved gas volume from the tablets was not affected by pH of submerged water. The concentration of halosulfuron-methyl in different sizes of submerged water within 24 hours after treatment of the tablet was maintained 0.16 ppm, which is ideal concentration at standard dosage regardless of the submerged water area. The concentration of pyriminobac-methyl was also uniformly dispersed in the water within 24 hours after applying it into the submerged water. The wind velocity of 5 m $sec^{-1}$ on concentration distribution of halosulfuron-methyl and pyriminobac-methyl in the submerged water 24 hours after treatment was not influenced; an equal concentration in the up the wind and down the wind from the applied spot was maintained. Spot treatments of one tablet formulations(5 g) including 4 times higher dosage at 4 different spots resulted in even concentration distribution of active ingredient in the water 24 hours after applying it into the submerged water.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2000.04a
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• pp.20-25
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• 2000

아세트아미노펜(파라세타몰)은 p-aminophenol 유도체로서 (그림 1) 두통, 치통, 신경통 등의 통증에 널리 사용되는 해열진통제인데 아스피린과 같은 정도의 해열 진통 효과를 나타내며, 이것은 중추신경계의 체온조절 중추에 작용하여 피부혈관을 확장함으로써 열의 확산을 증가시키는 해열작용과 시상 및 대뇌피질에의 통각역치를 높여 진통작용을 하는 것으로 추정 된다. 아세트아미노펜은 백색의 결정 또는 결성성 가루로 물에 조금 녹고 메탄올 또는 에탄올에 잘 녹으며 수산화나트륨 시액에 녹고 에텔에는 매우 녹기 어렵다 (표1). 대한약전에서는 정제가, 미국약전에는 캅셀제, 좌제, 경구현탁액제, 발포성 건조시럽, 정제 등이 수재되어 있고, 세계 각국에서 OTC 제품으로 1정당 160mg의 츄잉정까지 판매되고 있다. 그러나, 시판되고 있는 정제등은 붕해되어 용출되는데 오랜시간이 소요되어 대한약전에는 약 30분간에 80%이상의 용출기준이 설정되어 있으며, 독특한 쓴맛 때문에 microencapsulation 한 제피세립을 사용하고 있으나 역시 1 정당 300mg 이상의 확산정이나 속용정은 존재하지 않는다. 이것을 개선하기 위하여 붕해속도가 빠르고 특히 진통효과가 빠르며 물없이 구강내에서 간편히 녹여 복용하거나 또는 씹어서 또는 물과 함께 복용할 수 도 있는 $\ulcorner$알카펜$\lrcorner$ 속용정을 개발하게 되었다 (그림2).

• Journal of the Korean Society of Visualization
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• v.19 no.3
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• pp.84-91
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• 2021

Effervescent tablets generate gas bubbles when chemical reaction occurs between water and tablets. Most of previous studies have been focused on pharmaceutical characteristics of tablets. However, for their applications in disinfectants, cleaners, and pesticides, physical characteristics of bubbles released from the effervescent tablets when they are in water are important. In this study, we experimentally investigated the characteristics of microbubbles generated by an effervescent tablet made of sodium bicarbonate and tartaric acid using PDPA and high-speed camera. Microbubbles were generated using different weights of effervescent tablet as well as in different water temperature. The experimental study shows increase in reaction time, bubble concentration and rise velocity as the weight of effervescent tablet increases from 1 to 20 g. The decrease in average bubble diameter was observed when the temperature of water increased from 25 to 45 ℃. Further, reaction time varies inversely with increase in water temperature, while bubble rise velocity is directly proportional to increase in water temperature. Effervescent table continuously generates the bubble with approximately constant diameter (235 ㎛) in the water. However, bubble concentration and bubble rise velocity decreased over time.