• Journal of Pharmaceutical Investigation
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• 제37권2호
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• pp.101-106
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• 2007

Venlafaxine, 1-[2-(dimethylamino)-1-(4-methoxyphenyl)ethyl] cyclohexanol hydrochloride is a novel, nontricyclic antidepressant. venlafaxine is a unique antidepressant that differs structurally from other currently available. The aim ot the study was to formulate sustained-release venlafaxine granules and assess their formulation variables. It consists of two layers, venlafaxine drug layer and sustained release coating layer and manufactured by fluidized bed process. The sustained release of drug could be increased by double-control rising various components in venlafaxine drug layer and sustained-release layer. The drug-containing granules were coated with cellulose acetate, cetyl alcohol and Eudragit RS along with plastisizer such as dibuthyl sebacate as an nano-pore former The release oi venlafaxine depended on the type of Eudragit such as RS, and RL used in the formulation of controlled release layer. These results obtained clearly suggest that the sustained release oral delivery system for venlafaxine could be designed with satisfying drug release profile approved.

• 대한의용생체공학회:의공학회지
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• 제41권1호
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• pp.62-66
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• 2020

Controlled drug release is important for effective treatment of cancer. Poly(DL-lactide-co-glycolide) acid (PLGA) is a Food and Drug Administration (FDA) approved polymer and have been extensively studied as drug delivery carriers with biodegradable and biocompatible properties. However, PLGA drug delivery carriers are limited due to the initial burst release of drug. Certain drugs require an early rapid release, but in many cases the initial rapid release can be inefficient, reducing therapeutic effects and also increasing side effects. Therefore, sustained release is important for effective treatment. Poly Lactic Acid stereo complex (PLA SC) is resistant to hydrolysis and has high stability in aqueous solutions. Therefore, in this work, PLGA based discoidal polymeric particles are modified by Poly Lactic Acid stereocomplex (PLAsc DPPs). PLAsc DPPs are 3 ㎛ in diameter, also showing a relatively sustained release profile. Fluorescein 5(6)-isothiocyanate (FITC) released from PLAsc DPPs was continuously observed until 38 days, which showed the initial release of FITC from PLAsc DPPs was about 3.9-fold reduced as compared to PLGA based DPPs at 1 hour.

• Journal of Pharmaceutical Investigation
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• 제27권3호
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• pp.225-231
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• 1997

For the effective administration of naloxone, we attempted to investigate the naloxone sustained-release implants. Using the biodegradable polymer, poly[(diethyl glutamate)-co-(ethyl glycinate)phosphazenes](PGGP), the implantable devices containing naloxone hydrochloride(NLX HCl) and naloxone base(NLX) were prepared. The release rates of NLX and NLX HCl were compared. Influences of NLX contents on release rates were examined. For pharmacokinetic studies, NLX and NLX HCl loaded devices were implanted subcutaneously in rabbits and then the plasma concentrations of NLX were determined by HPLC(ECD). NLX-containing devices were implanted with various doses and pharmacokinetic parameters according to dose were calculated. The relative bioavailabilities were evaluated and compared. Incorporation of NLX in the polymer leaded to a slow release. There were no differences of release rates based on drug contents. In pharmacokinetic parameters determined in 216 hours, NLX loaded devices resulted in enhanced bioavailability with the higher AUC (p<0.01) than NLX HCl loaded devices and MRT was significantly (p<0.05) increased. This result demonstrates that NLX is more suitable for sustained release devices than NLX HCl. Therefore it is anticipated that the effective concentrations of naloxone could be maintained for longer periods and bioavailabilities could be improved by naloxone sustained-release implants, with varying drug base/hydrochloride.

• 약학회지
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• 제8권4호
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• pp.89-93
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• 1964

Sustained-release dosage form of ferruginous hematinics which can be absorbed effectively without forming "iron block" that caused by high concentration of Iron in the gastrointestinal tract, was studied. Gelatinized micropellets containing medicament were prepared according to the method of N. Tanaka et al. and hardened in 10% formalin-isopropanol in various time. Gelatinized micropellets were digested with artificial gastric juice and prepared a graph of iron concentration determined by Hong's method. As a result, it is assumed that gelatinized sustained-release dosage form can be a good ferruginous hematinics and it is shown that the preparation of 72-hour-hardening in 10% formalin-isopropanol has a suitable sustained release.d release.

• 약학회지
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• 제57권6호
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• pp.442-447
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• 2013

The aim of the present study was to improve commercial twice-a-day Acebrophylline formulation to once-a-day new formulation to improve patient compliances. To develop the double-layered tablet, the sustained release layer was prepared using Eudragit$^{(R)}$ L100-55 and Carnauba wax. The sustained release layer has shown delayed release rates in pH 1.2 which comparable to that of performed in pH 6.8 buffer. In the comparative pharmacokinetic study with commercialized Surfolase$^{(R)}$, the present double-layered Acebrophylline tablet has shown similar pharmacokinetic parameters of AUC, $C_{max}$ and $T_{max}$ values.

• Journal of Pharmaceutical Investigation
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• 제20권1호
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• pp.13-18
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• 1990

Hydrocortisone (HC) sustained-release suppositories were prepared by using a solid matrix of methacrylic acid-methacrylic acid methyl ester copolymer $(Eudragit\;L_{100}^{R}:\;EL)$ as a poorly water soluble carrier and polyethylene glycole 1540 (PEG) as an water soluble carrier. HC release rate was controlled by complexation with ${\beta}-cyclodextrin$ $({\beta}-CyD)$ which was confirmed by X-ray diffractometry, IR-spectroscopy and differential scanning calorimetry. Release rate of HC from the EL-PEG matrix suppositories decreased with increase of EL contents. The release rale from $HC-{\beta}-CyD$ complex decreased in the following order: $HC-{\beta}-CyD/PEG$ > HC/PEG > $HC-{\beta}-CyD/EL_{10%}-PEG$ > $HC/EL_{10%}-PEG$ > $HC-{\beta}-CyD/EL_{15%}-PEG$ > $HC/EL_{15%}-PEG$ > $HC-{\beta}-CyD/EL_{20%}-PEG$ > $HC/EL_{20%}-PEG$. The crystallinity of HC in polymer matrix was identified using X-ray diffractometer and the surface of matrix suppositories after release test was examined by scanning electron microscopy. The sustained release of HC from these matrix suppositories was attributed to the network structure of EL.

• Macromolecular Research
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• 제8권2호
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• pp.80-88
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• 2000

Biodegradable microspheres were prepared with poly(L-lactide-co-glycolide) (PLGA, 75 : 25 by mole ratio) by an oil/oil solvent evaporation method for the sustained release of anti-AIDS virus agent, AZT The microspheres of relatively narrow size distribution (7.6$\pm$ 3.8 ㎛) were obtained by controlling the fabrication conditions. The shape of microspheres prepared was smooth and spherical. The efficiency of AZT loading into the PLGA microsphere was over 93% compared to that below 15% for microspheres by a conventional water/oil/water method. The effects of Preparation conditions on the morphology and in vitro AZT release pattern were investigated. in vitro release studies showed that different release pattern and release rates could be achieved by simply modifying factors in the fabrication conditions such as the type and amount of surfactant, initial amount of loaded drug, the temperature of solvent evaporation, and so on. PLCA microspheres prepared by 5% of initial drug loading, 1.0% (w/w) of surfactant concentration, and 25$\^{C}$ of solvent evaporation temperature were free from initial burst effect and a near-zero order sustained release was observed. Possible mechanisms of the near-zero order sustained release for our system have been proposed.

• 한국산학기술학회논문지
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• 제11권7호
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• pp.2451-2458
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• 2010

고혈압 치료제인 카르베딜롤을 모델약물로 하여 새로운 서방성 방출 제어형 매트릭스 정제를 제조하기 위하여 소수성 서방성 부형제인 Compritol 888 ATO와 친수성 고분자인 hydroxypropyl methyl cellulose (HPMC) 또는 polyethylene oxide (PEO)를 이용하여 방출 제어형 매트릭스 정제를 제조하였다. 카르베딜롤 방출 제어형 매트릭스 정제의 제조 시 Compritol 888 ATO의 비율과 친수성 고분자의 종류 및 비율, hot melt coating coagglutination (HMCC) rocess의 적용 유무에 따른 카르베딜롤의 방출 양상을 위하여 용출시험기를 사용하여 pH 1.2의 인공위액과 pH 6.8의 인공장액에서 24시간 동안 $37^{\circ}C$, 50 rpm으로 용출시험을 실시하였다. 그 결과, HMCC process를 적용한 모든 제제가 약물의 방출 제어에 매우 효과적인 것을 확인하였다. 또한 소수성 서방성 부형제인 Compritol 888 ATO의 비율에 따라 약물의 방출 양상 및 시간이 기존 일반정제에 비하여 약 95%의 용출률을 나타내었으며 24시간까지 지연됨을 확인할 수 있었다.

• Journal of Pharmaceutical Investigation
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• 제15권1호
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• pp.32-39
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• 1985

Bioavailability studies in guinea pigs and dissolution tests of sustained release capsules of ascorbic acid were investigated comparing with those of solution. The results were as follows; 1. In the dissolution test sustained release capsules released 90% of ascorbic acid after 12 hours, and ascorbic acid in the chewable tablet was dissolved. completely within 10 minutes. 2. In the determination of total ascorbic acid concentration in serum, the area under the curve between 0 and 24 hours $(AUC\;0{\sim}24h)$ ana the maximum serum concentration $(C_{max})$ did not show any significant difference between solution and sustained release capsule. The time to the maximum concentration $(C_{max})$ and the time over $50{\mu}g/ml$ concentration showed significant difference. 3. The time reached to maximum excretion rate $(T_{max})$ in sustained release capsule was longer than that of solution.

• 대한수의학회지
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• 제49권1호
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• pp.9-15
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• 2009

The present study was carried out to examine the sustained release effect of the implantable bovine somatotropin (SRI-BST) formula. In the blood profile test in steers, the bovine somatotropin concentration in serum by radioimmunoassay showed the peak concentration on the first day after the implantation of the SRI-BST formula, and concentration proceeded for 5 days (p < 0.05). The insulin-like growth factor-1 concentration showed the peak concentration on the seventh day after implantation of the SRIF-BST formula, and concentration proceeded for 10 days (p < 0.05). The glucose showed the peak concentration on the first day after implantation of the SRI-BST formula, and concentration continued for 3 days (p < 0.05). The blood urea nitrogen showed the lowest concentration on the third day after implantation of the SRI-BST formula, and concentration continued for 7 days (p < 0.05). These results proved that the SRIF-BST formula was the sustained release effects in steers.