• Journal of Pharmaceutical Investigation
• /
• 제30권2호
• /
• pp.119-125
• /
• 2000

In an attempt to develop a non-aqueous liquid formulation of practically insoluble biphenyl dimethyl dicarboxylate (DDB), dissolution and permeation studies were performed. Various non-aqueous DDB solutions were formulated and filled into empty hard capsules. Dissolution rates of a new formulation were compared with those of commercially available DDB preparations using one and eight dose units. Dissolution rates after 2 hr of DDB tablets (DDB 25 mg), hard capsules (DDB 7.5 mg) and soft capsules (DDB 7.5 mg) on market and new formulation (DDB 7.5 mg) were 6.3, 15.0, 84.5 and 98.0%, respectively. Higher doses (8 units) resulted in a supersaturation within one hr of dissolution, and dissolved amounts were reduced markedly. Due to the saturation and precipitation, a directly proportional dose-dissolution relationship was not observed. The addition of copolyvidone and/or glycyrrhizic acid ammonium salt to DDB solution in polyethylene glycol 300 and 400 inhibited the formation of precipitates during dissolution and markedly enhanced the rabbit duodenal permeation of DDB. From the site-specific gastrointestinal permeation studies, it was found that permeation rates of DDB after mixing of non-aqueous DDB solutions with aqueous buffered solutions were faster in the order of $rectal\;<\;colonic\;{\risingdotseq}\;ileal\;{\risingdotseq}\;duodenal\;<\;jejunal\;<\;gastric$.

• Journal of Pharmaceutical Investigation
• /
• 제31권1호
• /
• pp.27-35
• /
• 2001

To evaluate the site-specific permeation of aspalatone (acetylsalicylic acid maltol ester, AM) through gastrointestinal tract, the enzymatic degradation and permeation studies were carried out using gastric, duodenal and jejunal mucosae of rabbits. It was found that $15.2{\pm}11.4%$, $11.6{\pm}5.2$ and $0.8{\pm}0.6%$ of the donor dose of AM, salicylmaltol (SM) and aspirin (ASA) permeated through the upper gastric mucosa after 8 hr of permeation, respectively. After 8 hr of AM permeation, SM and ASA were measured to be $15.0{\pm}1.7$ and $2.6{\pm}0.8%$ of the dose in the donor solutions, respectively, and salicylic acid (SA) was not detected even after 6 hr, suggesting a very low gastric damage. For the gastric mucosa, the increase of donor dose from 100 to $1,000\;{\mu}g/ml$ increased the permeation flux dose-dependently (r=0.9905). For the duodenal and jejunal mucosae, however, AM was fully degraded into SM and SA due to the esterase activities within 30 min. AM and ASA were not detected in the receptor solution. This result indicates that AM is not a prodrug of ASA. Addition of potassium fluoride (0.5%) into the donor solution delayed the degradation of AM, but did not allow the permeation through duodenal mucosa even by the inhibition of esterase activity. The addition of $dimethyl-{\beta}-cyclodextrin$ and $2-hydroxypropyl-{\beta}-cyclodextrin$ (5%) into the donor solutions also did not show favorable effects on the permeation of AM through various mucosae. In comparison of permeation rates of AM and ASA through the upper gastric mucosa, the flux of ASA was 4.2 times faster than AM based on the molar concentration. ASA also was fully degraded in the donor solutions faced with duodenal and jejunal mucosae within 2 hr, and was not detected in the receptor solution, suggesting a slower metabolism compared with AM.

• Journal of Pharmaceutical Investigation
• /
• 제32권4호
• /
• pp.291-297
• /
• 2002

For preventing and curing the stretching mark, TECA Niosome/W/O system creams were formulated using Titrated Extract of Centella Asiatica (TECA) which is well known for its excellent wound healing effect. The lipid-water partition coefficients and the stabilities of TECA were evaluated and TECA Niosome/W/O system (TECA N/W/O) creams were prepared with different concentrations of cetyl alcohol and ceramide. TECA N/W/O cream was evaluated with respect to their rheological properties, permeation through excised skin of hairless mouse and in vitro and in vivo accumulation in the skin of hairless mouse. In addition, dermal thicknesses of hairless mouse skins were determined following the in vivo application of TECA N/W/O cream and control cream. TECA N/W/O creams showed pseudoplastic flow and hysteresis loop. The permeation of TECA from formulations through excised skin of hairless mouse did not observed. Amount of accumulated drug in the excised skin of hairless mouse was deσeased with an increase in the concentration of cetyl alcohol and showed no relationship with concentration of ceramide. Amount of accumulated drug in formulation A-3 was higher than in niosome suspension and other formulations. In in vivo experiment, amount of accumulated drug in formulation A-2 and A-3 was much higher than that of niosome suspension. Being treated with the N/W/O cream for 8 weeks, the dermal thickness of hairless mouse skin was increased 3.2 times than that of 16 weeks-control group.

• 대한화학회지
• /
• 제54권5호
• /
• pp.567-572
• /
• 2010

닭의 간으로부터 5,10-methenyltetrahydrofolate synthetase를 30-70% 황산암모늄 분획, Q Sepharose Fast Flow anion exchange and Source 15Phe hydrophobic interaction chromatography을 이용하여 정제하였다. 세포 추출물, 황산암모늄 분획, Q Sepharose Fast Flow와 Source 15Phe 단계에서의 비활성은 각각0.0085, 0.031, 0.80 및 1.27 U/mg 이었다. 세포 추출물, 황산암모늄 분획, Q Sepharose Fast Flow와 Source 15Phe 단계에서의 정제도는 각각 1, 3.7, 94.1 및 149.4 이었다. HPLC gel permeation chromatography와 SDS-polyacrylamide electrophoresis 실험으로부터 5,10-methenyltetrahydrofolate synthetase는 분자량이 22.8 kDa인 단량체임을 알 수 있었다. 5-methyl THF과 Mg-ATP의 Km은 각각 $7.1\;{\mu}M$ 및 $63\;{\mu}M$ 이었다. 최적온도와 최적pH는 각각 $30^{\circ}C$ 및 6.0 이었다. 금속이온에 대한 특이성과 스토키오메트리 실험으로부터 최고속도가 $Mg^{2+}$과 1:1일 때 얻어진다는 것을 알 수 있었다. ATP와 Km은 MgATP, MgCTP, MgUTP 및 MgGTP의 순서로 증가하였으며 최고 역가는 같은 순으로 감소하였는데, 이는 MgATP 가 가장 효과적인 기질임을 증명한다. 이 효소는 tetranitrometane 및 1-ethyl-3-(3-dimethyl aminopropyl)-carbodiimide에 의해서만 수식되었는데, 이는 tyrosine and carboxylate 잔기가 효소의 활성부위에 존재함을 나타낸다.

• Parasites, Hosts and Diseases
• /
• 제27권3호
• /
• pp.161-170
• /
• 1989

Toxeplasma의 추출액을 3H-casein을 기질로 반응시켰을 때, pH 6.0과 PH 8.5에서 casein을 분해하였으며, pH 6.0에서는 cysteinyl protease의 억제제 인 iodoacetamide(rAh)에 의해 억제되 었고, 활성제 인 dithiothreitol (DTT)에 의해 환성이 증가하였다. 또 pH 8.5에서는 serine protease의 억제제인 phenylmethylsulfonil fluoride (PMSF)에 의해 활성이 억제되었으며, ATP를 첨가할 때 그 활성이 증가하여 ATP 의존성 효소임을 알 수 있었다. 위의 단백질 분해 효소를 부분 정제하기 위해 여러 chromatography를 실시하였는데, 먼저 DE52 (2.Sfx40 cm)에 통과시켰을 때, 0.05M-0.IM NaCl에 의해 유출되는 분획이 pH 6.0에서 황성을 나타내었으며, 0.25V- 0.3M에서 유출되는 분획이 pH 8.5에서 황성을 나타내었다. 이 분회들을 각각 Sephadex G-200 ($2.50{\phi}{\times}40cm$) 에 통과시켜 pH 6.0에서 활성을 나타내는 분획은 exclusion limit내에서, pH 8.5의 분획은 exclusion limit 외에서 분획을 얻었다. 이들을 각각 hydroxylapatite ($2.50{\phi}{\times}10cm$과 $2.5{\phi}{\times}20cm$)를 통과시켜 각각을 0.05M Phosphate로 유출되는 분회에서 높은 환성을 얻었다. 부분 정제된 분획들의 특성을 검토하기 위하여 억제제를 농도별로 처리하였을 때, pH 0.0에서의 분해 효소는 10-3M IAA에 의해 활성이 반감되어 cysteinyl acid protease임을 알 수 있었다. pH 8.5에서의 분해 효소는 10-5M PMSF에 의해 활성이 반감되었고, ATP에 의해 활성이 증가(ATP의 농도가 2.0mM 이상에서는 억제)하여 ATP-dependent neutral serine protease임을 알 수 있었다.