• 한국응용약물학회:학술대회논문집
• /
• 한국응용약물학회 1997년도 춘계학술대회
• /
• pp.118-118
• /
• 1997

Solid dispersions were used to increase the dissolution rate of biphenyl dimethyl dicarboxylate (DDB) in water, with the ultimate goal of optimizing its bioavailability when incoporated into pharmaceuticals. Carriers used were Kollidon 30, Kollidon VA 64, 2-hydroxypropyl-${\beta}$-cyclodextrin (HPCD), sodium salicylate or sodium benzoate. DDB solid dispersions were prepared at drug to carrier proportions ranging from 1 : 5 to 1 : 20 (w/w) by solvent evaporation method. DDB tablets (7.5 mg) were prepared by compressing the powder mixture composed of solid dispersions, lactose, corn starch, crospovidone and magnesium stearate using a single-punch press. DDB capsules (7.5 mg) were prepared by filing the mixture into empty hard gelatin capsules (size #1). Dissolution studies of DDB from powdered solid dispersions, tablets and capsules were performed in 900 $m\ell$ of water at 100 rpm and 37$^{\circ}C$ by the paddle method. The dissolved amount was assayed by HPLC and expressed as the mean(%)of three determinations.

• Applied Microscopy
• /
• 제18권1호
• /
• pp.92-102
• /
• 1988

살리실산이 백서 와우의 나선신경절의 미세구조에 미치는 영향을 전자현미경으로 관찰하였다. 생후 $4{\sim}5$주의 Sprague-Dawley계 백서에 $500{\sim}600mg/kg$의 용량으로 살리실산 나트륨을 7일간 피하주사한 후에 각각 24시간(1군), 6주(2군), 10주(3군) 경과 후에 와우조직을 얻어 나선신경절에 나타나는 미세구조의 변화를 관찰하였다. 1. 1군에서는 신경절세포와 위성세포 그리고 Schwann cell의 세포질내에 다양한 크기의 막소구의 팽창이 나타났으며 Schwann cell 내에서는 미토콘드리아가 팽윤되거나 다낭성 세포소체를 형성하였다. 2. 2군에서는 신경절세포나 위성세포내의 막소구들이 더욱 팽창하고 그 일부는 융합하여 세포질이 감소하였다. Type I 세포의 신경 세포체나 신경섬유 주위를 싸고 있는 수초는 각층 사이의 거리가 멀어지거나 일부는 소실되었고, Type II 세포내에는 신경미섬유가 증가하였다. 3. 3군에서는 수초의 변형 및 파괴로 신경절세포의 세포질 이탈이 관찰되었고 Corti기 및 골성 나선판에 위치하는 신경섬유들의 소실이 관찰되었다. 이상의 결과를 종합하면 나선신경절세포와 그 주위를 둘러싸는 위성세포 및 Schwann cell은 과량의 살리실산 나트륨 투여후에 미세구조의 변화를 보였으며 1군에서 2군, 3군으로 갈수록 변화가 더욱 현저하였다.

• Journal of Pharmaceutical Investigation
• /
• 제29권3호
• /
• pp.227-234
• /
• 1999

Solid dispersions were prepared to increase the dissolution rate of biphenyl dimethyl dicarboxylate (DDB) using water-soluble carriers such as povidone, copolyvidone, $2-hydroxypropyl-{\beta}-cyclodextrin (HPCD)$, sodium salicylate or sodium benzoate by solvent evaporation method. Solid dispersions were characterized by infrared spectrometry, differential scanning calorimetry (DSC) and powder X-ray diffractometry, dissolution and permeation studies. DDB tablets (7.5 mg) were prepared by compressing the powder mixtures composed of solid dispersions, lactose, com starch, crospovidone and magnesium stearate using a single-punch press. DDB capsules (7.5 mg) were also prepared by filling the mixtures in empty hard gelatin capsules (size No.1). From the DSC and powder x-ray diffractometric studies, it was found that DDB was amorphous in the HPCD or copolyvidone solid dispersions. Dissolution rates after 10 min of DDB alone and solid dispersions (1 : 10) in sodium benzoate, sodium salicylate and copolyvidone were 11.8, 23.5, 22.8 and 82.5%, respectively. Dissolution rates of DDB after 30 min from 1 : 10 and 1 : 20 copolyvidone solid dispersions were 80.5 and 95.0%, respectively. For the DDB tablets prepared using solid dispersions (1 : 20), the initial dissolution rate was dependent on carrier material, and was ranked in order, $Kollidon\;30\;{\ll}$ copolyvidone < HPCD. For the HPCD solid dispersion tablets, dissolution rate reached 97.4% after 15 min, but thereafter slowly decreased to 80.7% after 2 hr due to the precipitation of DDB. However, in the case of copolyvidone solid dispersion tablets, dissolution increased linearly and reached 93.4% after 2 hr. Reducing the volume of test medium from 900 to 300 ml markedly decreased the dissolution rate of the tablets containing 1 : 20 HPCD solid dispersions and 1 : 10 copolyvidone solid dispersion. For 1 : 20 copolyvidone solid dispersion tablets, there was no significant change in dissolution rate up to 1 hr with different volumes of test medium. Preparation of the copolyvidone solid dispersion (1 : 20) in capsules markedly delayed the dissolution (31.2 % after 2hr) due to the limited diffusion within capsules. The permeation rate $(13.4\;g/cm^2\;after\;8\;hr)$ of DDB through rabbit duodenal mucosa from copolyvidone solid dispersion (1 : 10) was markedly enhanced, when compared with drug alone or physical mixtures. From overall findings, DDB formulations containing copolyvidone solid dispersions (1 : 20) could be used to remarkably improve the dissolution rate in dosage form of powders and tablets.

• Journal of Pharmaceutical Investigation
• /
• 제24권4호
• /
• pp.251-256
• /
• 1994

Polypropylene glycol (M.W. 4000) was crosslinked and chain-extended by using triisocyanate and diisocyanate to synthesize rubbery and water swellable hydrogels. Model drugs, i.e., sodium salicylate and indomethacin were incorporated in the polymer matrices by swelling loading. The drug release rates of drugs could be regulated by varying the degrees of crosslinking and chain-extension. Whereas, no correlation was observed between the drug release profiles and the swelling behaviours of the matrices. The release of drugs from the matrices was considered to be governed by the mobility and mesh size of the polymer chains in the matrices.

• Journal of Pharmaceutical Investigation
• /
• 제26권2호
• /
• pp.119-124
• /
• 1996

To develop oral controlled release dosage forms, ionic interactions between polymers and drugs were evaluated. Hydroxypropylmethyl cellulose and carboxymethylene were used as model nonionic and ionic polymers, respectively. 5-fluorouracil, propranolol-HCl and sodium salicylate were selected as model nonionic, cationic and anionic, respectively. Polymer-drug mixtures were compressed into tablets and drug release kinetics from these tablets were determined. Drug release from the tablets made of the nonionic polymer was not affected by the charge of drugs, rather, was regulated by the solubility of drugs in different pH releasing media. However, drug release kinetics were significantly affected when drug-polymer ionic interactions exist. Enhanced drug release was observed from anionic drug-anionic polymer tablets due to ionic repulsion, whereas drug release was retarded in cationic drug-anionic polymer tablets owing to ionic attractive force. Therefore, the results suggested that the polymer-drug interactions are important factors in designing controlled release dosage forms.

• 한국고분자학회:학술대회논문집
• /
• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
• /
• pp.258-258
• /
• 2006

Electrospun fibers of poly(vinyl alcohol) (PVA) were successfully prepared and applied as drug carriers for transdermal drug delivery system. Sodium Salicylate (SS) was the model drug and it was incorporated in the PVA fibers by adding 20 % of SS in a PVA solution prior to electrospinning. Electrospinning of SS-containing PVA solution resulted in the formation of beaded fibers. In order to control the rate of SS release and decrease water solubility of PVA, the SS-loaded electrospun PVA mat was cross-linked by either glutaraldehyde or glyoxal vapor. The morphology, thermal behavior, swelling behavior, release characteristic, kinetics of drug release and also toxicity of the cross-linked sample were investigated.

• Bulletin of the Korean Chemical Society
• /
• 제25권8호
• /
• pp.1202-1206
• /
• 2004

Novel naphthyl-containing biphenyl analogues were prepared by Suzki reaction for the chemiluminescent blue fluorophores. UV-Vis absorption, photoluminescence, chemiluminescence and CIE chromaticities were measured. The fluorophores displayed blue photoluminescence in solution with a maximum intensity around 378-415 nm. Sodium salicylate-catalyzed reaction of them with bis(2 carbopentyloxy-3,5,6-trichlorophenyl)-oxalate with hydrogen peroxide provided a strong chemiluminescent red light emission with wavelengths of 398-427 nm; these were similar to the photoluminescent spectra. The chemiluminescent intensity decayed exponentially and the glow of chemiluminescence, which was visible with naked eyes, was maintained for more than 4 h.

• Journal of Pharmaceutical Investigation
• /
• 제21권2호
• /
• pp.91-95
• /
• 1991

Polyethylene glycol, polypropylene glycol and block copolymer of ethylene glycol and propylene glycol were crosslinked by triisocyanate to form water swellable, rubbery polymer. The equilibrium swelling of the hydrogels ranged from 3% to 60% according to the hydrophobic-hydrophilic properties of the prepolymers. Model drugs, sodium salicylate and prednisolone were incorporated in the polymer matrices by swelling loading. Physical properties of the drugs affected the drug release mechanisms due to the change in the swelling behaviors of the polymeric devices. Zero order release was observed in the case of relatively hydrophobic polymer matrices.

• Bulletin of the Korean Chemical Society
• /
• 제21권7호
• /
• pp.701-704
• /
• 2000

Fluorene and carbazole-containing distyrylarylene model and polymeric fluorophores were prepared by reacting 2,7-dibromo-9-butylfluorene and 3,6-dibromo-9-butylcarbazole with styrene and divinylbenzene using the Heck reaction for the chemiluminesc ence. The UV-vis absorbance, photoluminescence (PL) as well as the chemiluminescence (CL) characteristics of the model and polymeric fluorophores were measured. Sodium salicylate-catalyzed reaction of bis(2,4,6-trichlorophenyl)oxalate (TCPO) with hydrogen peroxide produced a strong chemiluminescent blue light emission with 439-489 nm in the presence of the fluorophore. The wave-length of CL light was similar to that of photoluminescence. The chemiluminescent intensity was decayed according to the exponential equation.The glow of CL maintained more than 12 hr and was visible with naked eye.

• Bulletin of the Korean Chemical Society
• /
• 제22권7호
• /
• pp.727-731
• /
• 2001

Conjugated-non-conjugated alternating block copolymers containing distyrylarylene units were synthesized via Wittig reaction for chemiluminescent fluorophores. The polymers were differentiated from others by the presence of aromatic unit in the chromophoric block. When UV-VIS, photoluminescence and chemiluminescence spectra of these materials were compared with copolymers, a strong bathochromic effect was observed. A more pronounced red shift and higher chemiluminscence efficiency were observed in the polymer with anthracene ring. Sodium salicylate-catalyzed reaction of bis(2-carbopentyloxy-3,5,6-trichlorophenyl) oxalate with hydrogen peroxide produced a strong chemiluminescence from blue to yellow-green light emission with wavelength of 450-537 nm in the presence of the fluorophore. The chemiluminescent intensity decayed exponentially. The glow of chemiluminescence maintained more than l2 hr and was visible with the naked eye.