• 약학회지
• /
• 제40권4호
• /
• pp.400-410
• /
• 1996

In oder to develop the controlled release of drugs from the suppositories, in vitro drug release and in vivo absorption in rabbits were investigated. Various suppo sitory forms with hollow cavities, into which drugs in the form of fine powder or solid dispersion system(SDS) could be placed, were utilized. The oleaginous Witepsol H-15 (WH-15) as a base, and indomethacin (IDM) of a very slightly soluble drug and propranolol-HCL (PPH) of a very soluble drug were employed as model drugs. The in vitro drug release showed that the cumulative release amount of PPH from PPH-(methylcellulose) MC-SDS and PPH-(ethylcellulose) EC-SDS hollow type suppositories reached 40% and 12% in 6 hrs,respectively. On the other hand, the drug release for a conventional suppository was 80% in 6 hrs. For the IDM suppositories,the cumulative drug release from IDM-(polyvinylpyrrolidone) PVP-SDS hollow type suppositories reached 99% in 24 hrs, whereas that from a conventional suppository reached 85%. An in vivo experiment with rabbits showed that IDM-PVP-SDS hollow type suppository delayed the absorption of IDM, significantly. The $t_{max},\;C_{max}\;and\;AUC_{0{\to}8}$ of IDM-PVP-SDS suppository were 60 min, 12.12${\mu}g$/ml and 2657${\mu}g$/ml/min, respectively. The $t_{max},\;C_{max}\;and\;AUC_{0{\to}8}$ of controlled group were 20 min, 15.49${\mu}g$/ml and 2190${\mu}g$/ml/min, respectively.

• Journal of Pharmaceutical Investigation
• /
• 제22권3호
• /
• pp.205-210
• /
• 1992

In order to develop a controlled-release oral drug delivery system (DDS) of theophylline (TP), microporous membrane-coated tablets were prepared and evaluated in vitro and in vivo. Rapidly water-soluble core tablets of TP (300 mg) were prepared by wet granulation and compression technique, Then the core tablets were spray-coated with polyvinylchloride (PVC) in which micronized sucrose particles were dispersed. Effect of formula compositions of coating suspensions on the pharmaceutical characteristics such as membrane strength and dissolution was investigated in vitro. The membranes remained unbroken in pH 1.2 buffer at $37^{\circ}C$ at least for 2 hours after the disintergration test. TP was released from the coated-released tablets at a zero-order rate over 8 hours. The release at pH 1.2 and 4.0 was similar in rate but a little more rapid than that at pH 6.8. The coated tablets were administered to three healthy male volunteers and their saliva profiles of TP were compared with those from the commercial sustained release TP tablets such as Slobid and Asconthin. Saliva TP concentrations from the coated tablets were successfully sustained over 48 hours after the dosing and were comparable to those of the commercial sustained-release tablets. The membrane-coating technique is very simple and does not need any sophisticated equipments. In this respect, the membrane-coated tablets may be superior to the commercial sustained-release tablets and this technique is worth adopting by the pharmaceutical industries.

• Archives of Pharmacal Research
• /
• 제9권4호
• /
• pp.193-199
• /
• 1986

The release of heparin from monolithic devices composed of different ratios of polythylene oxide (PEO MW 20,000) and hydrophobic polydimethylsiloxane or polyurethane was investigated. Water soluble PEO blended into the polymers provided a controlled release of heparin. The release rate of heparin could be controlled by varying the content of PEO. The heparin release rate from the devices increased as the content of PEO in the devices increased. The release mechanism may be associated with the creation of pore of domain through the devices following the swelling and the change in the physical structure of the polymer network. Hydrophobic polydimethylsiloxanes and polyurethanes containing PEO can provide an antith rombogenic material for prologed release of heparin from blended system.

• Journal of Korean Neurosurgical Society
• /
• 제63권1호
• /
• pp.45-55
• /
• 2020

Objective : Fibrin sealants have been used for hemostasis, sealant for cerebrospinal fluid leakage, and adhesive barrier in neurosurgery. Further, as its clinical use and role of an effective drug delivery vehicle have been proposed. This study was performed to measure antibacterial activity and continuous local antibiotic release from different concentrations of vancomycin-impregnated fibrin sealant in vitro. Methods : Antibacterial activity was investigated by disk diffusion test by measuring the diameter of the growth inhibition zone of bacteria (methicillin-resistant Staphylococcus aureus, ATCC29213) from vancomycin-embedded fibrin sealant disc diluted at five different concentrations (C1-C5; 8.33, 4.167, 0.83, 0.083, and 0.0083 mg/disc, respectively). Continuous and conditioned release of vancomycin concentration (for 2 weeks and for 5 days, respectively) were also measured using high-performance liquid chromatography (HPLC) method. To mimic the physiologic wound conditions with in vitro, conditioned vancomycin release in phosphate buffer solution (PBS) was measured and replaced PBS for five consecutive days, half a day or completely daily. Results : In the disk diffusion test, the mean diameters of bacterial inhibition zone were 2.54±0.07 cm, 2.61±0.12 cm, and 2.13±0.15 cm (C1, C2, and C3 respectively) but 1.67±0.06 cm and 1.23±0.15 cm in C4 and C5, respectively. Continuous elution test elicited the peak release of vancomycin from the fibrin sealant at 48 hours, with continued release until 2 weeks. However, conditioned vancomycin release decreased to half or more on day 2, however, the sustainable release was measured over the therapeutic dose (10-20 ㎍/mL) for 5 days and 4 days in assays of half and total exchange of PBS. Conclusion : This study suggests that fibrin sealant can provide an efficient vehicle for antibiotic drug release in a wide range of neurosurgical procedures and the safe and effective therapeutic dose will be at the concentration embedded of 4.167 mg/disc or more of vancomycin.

• Journal of Pharmaceutical Investigation
• /
• 제29권4호
• /
• pp.349-353
• /
• 1999

A novel polymeric tablet of tinidazole (TD) was formulated to treat Helicobacter pylori and Giardia lambria more efficiently with reduced hepatotoxicity by controlling the release of TD after oral administration. TD tablets containing various concentrations of either xanthan gum (XG, viscosity enhancer) and/or polycarbophil (PC, mucoadhesive) were prepared by the wet granulation method. In vitro release of TD into pH 2.0 and pH 5.0 buffer solutions was observed at 37°C by using an USP dissolution tester and an UV (313 nm) spectrophotometer. In vivo absorption of TD tablets was investigated in rabbits by measuring the blood concentration of TD after oral administration using a HPLC. Compared to a commercial TD tablet, in vitro release of TD in both pH 2.0 and pH 5.0 buffer solutions significantly decreased as the concentration: of XG or PC in the tablet increased up to 30%. However, when XG and PC was added in combination, TD was completely released in a pH 5.0 buffer solution within 8 hours, whereas the release of TD in pH 2.0 buffer solution significantly decreased. TD in a commercial tablet was rapidly absorbed after oral administration in rabbits. After oral administration of the polymeric tablets that contain both XG and PC, plasma concentration of TD dramatically decreased. Since the oral absorption of TD significantly decreased by the addition of XG and PC in the tablets while TD completely released in a pH 5.0 buffer solution, it was speculated that more TD was retained in the gastrointestinal tract. Thus, it was possible to control the release of TD by changing the content of XG and/or PC in the tablet, thereby manipulating the release rate and the gastrointestinal retention of TD after oral administration in rabbits.

• Journal of Pharmaceutical Investigation
• /
• 제41권5호
• /
• pp.279-288
• /
• 2011

The Dexamethasone (DEX) loaded chitosan microspheres were prepared by thermal denaturation and chemical cross-linking method using a dierent concentration of glutaraldehyde as chemical cross-linking agent. The prepared microspheres were evaluated for the percentage of Drug Loading (DL), Encapsulation Efficiency (EE) and surface morphology by Scanning Electron Microscopy (SEM). DL and EE were found to be maximum range of 10.0 to 10.79 % and 58.19 to 64.73 % respectively. The SEM Photographs of the resultant microspheres exhibited fairly smooth surfaces and predominantly spherical in appearance. In addition, Fourier Transform Infrared Spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC) shown that there was no interaction between the drug and polymer. In vitro and in vivo release studies revealed that the release of dexamethasone was sustained and extended up to 63 days and effectively controlled by the extent of cross-linking agent. Non-clinical parameters such as paw volume, hematological parameters like Erythrocyte Sedimentation Rate (ESR), Paced Cell Volume (PCV), Total Leucocytes Count (TLC), Hemoglobin (Hb), Differential Cell Count (DCC) were investigated in Fruend's Complete Adjuvant (FCA) induced arthritic rats. Radiology and histopathological studies were also performed in order to evaluate the therapeutic efficacy of the DEX-loaded microspheres in extenuating the rat arthritic model.

• The Korean Journal of Physiology
• /
• 제28권2호
• /
• pp.225-231
• /
• 1994

The present study was undertaken to investigate the role of endogenous nitric oxide in renin release under different physiological conditions. In the first series of experiments, renin release was either inhibited by acute volume-expansion (VE) or stimulated by clipping one renal artery in the rat. VE was induced by intravenous infusion of saline (0.9% NaCl) up to 5% of the body weight over 45 min under thiopental (50 mg/kg, IP) anesthesia. VE caused a decrease of plasma renin concentration (PRC). With $N^G-nitro-L-arginine$ methyl ester $(L-NAME,\;5\;{\mu}g/kg\;per\;min)$ superadded to VE, PRC decreased further. The magnitude of increase in plasma atrial natriuretic peptide levels following VE was not affected by the L-NAME. In two-kidney, one clip rats, L-NAME-supplementation resulted in a decrease, and L-arginine-supplementation an increase of PRC. Plasma atrial natriuretic peptide levels were significantly lower in the L-arginine group than in the control. Blood pressure did not differ among the L-NAME, L-arginine, and control groups. In another series of experiments, the renin response to a blockade of NO synthesis was examined using in vitro preparations from isolated renal cortex. L-NAME significantly increased basal renin release, although it was without effect on the isoproterenol-stimulated release. These findings suggest that endogenous nitric oxide significantly contributes to the renin release. Since many factors may affect the renin release in vivo, an interaction between NO and renin under various pathophysiological states is to be further defined.

• Journal of Dairy Science and Biotechnology
• /
• 제39권1호
• /
• pp.27-35
• /
• 2021

본 연구에서는 CPP와 CSO를 사용하여 제조한 나노 복합체의 유식품 적용성 및 포집된 생리활성물질인 비타민 D의 in vitro release를 평가하였다. 그 결과, CPP/CSO 나노 복합체는 model milk 및 model yogurt 적용 후 12일간의 저장기간 동안 높은 물리적 안정성을 지녀 식품 적용성이 뛰어남을 규명하였다. 또한 제조 공정 요인인 CPP 농도와 pH 조절을 통해 비타민 D를 90% 이상 포집할 수 있었으며, in vitro release 평가를 통해 비타민 D를 위에서 보호하고, 장에서 release 하는 나노 복합체의 특성을 규명하였다. 결론적으로 본 연구에서 제조된 CPP/CSO 나노 복합체는 뛰어난 유식품 적용성을 지닐 뿐만 아니라, 칼슘흡수 증진을 위한 비타민 D를 효과적으로 포집할 수 있으며, 포집된 비타민 D를 소장까지 안전하게 전달할 수 있는 효과적인 나노 전달체로 활용될 수 있을 것으로 기대된다.

• 대한한방소아과학회지
• /
• 제19권2호
• /
• pp.175-195
• /
• 2005

Objective: This experimental study was performed to examine the in vitro and in viva anti-inflammatory and anti-allergic effects of Mori Cortex. Methods: Water extract of Mori Cortex was studied to its ability to stimulate or inhibit macrophage 264.7 cells to produce inflammatory and allergic mediators. Cytokines such as $IL-1{\beta}$, IL-6, IL-10 and $TNF-{\alpha}$ were measured by immunochemical assay. In vitro, the macrophages 264.7 were classified into four groups. One group was a normal group. The other group was a (-) control group stimulated with LPS. And the third group was a (+) control group pretreated for 1 hour with hydrocortisone. And the fourth group was a sample group pretreated for 1 hour with Mori Cortex. After pretreatment, macrophage were incubated with lipopolysaccharide(LPS) $100\;ng/m{\ell}$ for 12 hour and media collected and $IL-1{\beta}$, IL-6, IL-10 and $TNF-{\alpha}$ concentrations in supernatants were measured each by Enzyme linked immuno-soubent assay. Mori Cortex were used $50\;{\mu}g/m{\ell},\;100\;{\mu}g/m{\ell},\;250\;{\mu}g/m{\ell},\;500\;{\mu}g/m{\ell},\;and\;1,000\;{\mu}g/m{\ell}$. Hydrocortisones were used $10^{-8}M,\;10^{-7}M,\;10^{-6}M,\;10^{-5}M\;and\;10^{-4}M$. In vivo, the SD rats were classified into three groups. One group was a normal group injected with normal saline into the abdominal cavity. The other was a control group prescribed to compound 48/80 after normal saline injection. And the third was a sample group prescribed to compound 40/80 after Mori Cortex injection. Then, the release of histamine, IL-6 and $TNF-{\alpha}$ were measured. Results : In vitro, Man Cortex significantly increased the release of $IL-1{\beta}\;and\;TNF-{\alpha}$ by LPS-stimulated macrophage 264.7 cells. And it significantly decreased the release of IL-10. In IL-6, Mori Cortex of low concentration significantly decreased the release of IL-6, but that of high concentration acted in reverse. In vivo, Man Cortex didn't show significant inhibitory effects on the release of histamine and IL-6 in comparison with that of the control group. But it significantly increased the release of $TNF-{\alpha}$ in comparison with that of the control group.

• Journal of Pharmaceutical Investigation
• /
• 제36권3호
• /
• pp.175-184
• /
• 2006

Poly(D,L-lacic acid)(PLA) microshperes containing loazepam were prepared by a solvent-emulsion evaporation method and their release patterns were investigated in vitro. Various batches of microspheres with different size and drug content were obtained by changing the ratio of lorazepam to PLA, PLA concentration in the dispersed phase and stirring rate. Rod-like lorazepam crystals on microsphere surface, which were released rapidly and could act as a loading dose, were observed with increasing drug content. The release rate was increased with increase in drug contents and decrease in the molecular weight of PLA. The release rate of lorazepam for long-acting injectable delivery system in vitro, which would aid in Predicting in vivo release Profile, could be controlled by properly optimizing various factors affecting characteristics of microspheres.