• Advances in Traditional Medicine
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• v.7 no.1
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• pp.51-64
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• 2007

Mucus is an aqueous gel complex with a constitution of about 95% water, high molecular weight glycoprotein (mucin), lipid, salts etc. Mucus appears to represent a significant barrier to the absorption of some compounds. Natural mucoadhesive agent was isolated and purified from the aqueous extract of the seeds of prosopis pallida (PP). Formulated tablet with the isolated material by wet granulation method. Some natural edible substances are in consideration for candidates as mucoadhesive agents to claim more effective controlled drug delivery as an alternative to the currently used synthetic mucoadhesive polymers. Subjected the materials obtained from natural source i.e. PP and standard synthetic substance, sodium carboxymethyl cellulose for evaluation of mucoadhesive property by various in vitro and in vivo methods. Through standard dissolution test and a model developed with rabbit, evaluated in vitro controlled release and bioadhesive property of theophylline formulation. Mucoadhesive agent obtained from PP showed good mucoadhesive potential in the demonstrated in vitro and in viνo models. The results suggest that the mucoadhesive agent showed controlled release properties by their application, substantially. In order to assess the gastrointestinal transit time in vivo, a radio opaque X-ray study performed in healthy rabbit testing the same controlled release formulation with and without bioadhesive polymer. Plasma levels of theophylline determined by the HPLC method and those allowed correlations to the in vitro mucoadhesive study results. Better correlation found between the results in different models. PP may acts as a better natural mucoadhesive agent in the extended drug delivery system.

• Journal of Pharmaceutical Investigation
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• v.11 no.3
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• pp.14-20
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• 1981

One of the major objectives in the developments of a progesterone I.U.D. is to prepare devices which release drug at a constant rate for extended periods. A constant release rate is achived by maintaining drug concentration at a constant valve via the introduction of rate limiting membrane to solute diffusion at the surface of the devices. In this study, progesterone dispersed at monolithic device were prepared from polyhydroxy ethyl methacrylate. Constant release rate were obtained with device which were soaked in on ethanol-hexan solution. The release rate was dependant upon the concentration of the ethanolic solution in the soaking solution. This devices offer significant potential for futher development of hydrogel in the intrauterine contraception device for controlled release of progesterone.

• Journal of Pharmaceutical Investigation
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• v.21 no.2
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• pp.111-116
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• 1991

Dextromethorphan HBr (DMP HBr) ion exchange albumin microcapsules were prepared by the interfacial polymerization method. The incorporation of drugs in empty albumin microcapsules was more increased in case of glutaraldehyde (GA) and formaldehyde (FA) than terephthaloyl chloride (TC) as a cross linking agent. The amount of DMP HBr incorporated into empty albumin micorcapsules was augemented with increasing DMP HBr concentration and the amount of empty microcapsules in the incorporation medium. Increasing the salt concentration in the release medium, the release rate and the DMP HBr amount released from microcapsules were increased. The release rates of DMP HBr from microcapsules retarded considerably compared with DMP HBr powder.

• Biomolecules & Therapeutics
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• v.9 no.3
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• pp.218-223
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• 2001

In the present study, we intended to investigate whether polycationic peptides including poly-L-lysine (PLL) and poly-L-arginine (PLA) specifically inhibit the mucin release and do not affect significantly the release of the other releasable glycoproteins with less molecular weight than mucin's from cultured airway goblet cells. Confluent primary hamster tracheal surface epithelial (HTSE) cells were metabolically radiolabeled with 3H-glucosamine for 24 hr and chased for 30 min in the presence of varying concentrations of either poly-L-arginine (PLA) or poly-L-lysine (PLL) to assess the effects on 3H-mucin release and on the total elution profile of the treated culture medium. The results were as follows : (1) PLL 78,000, PLL 9,600 and PLA 8,900 inhibited mucin release in a dose-dependent manner; (2) These polycationic peptides did not inhibit the release of the other releasable glycoproteins with less molecular weights than mucin's. We conclude that these polycationic peptides 'specifically'inhibit mucin release from airway goblet cells. This finding suggests that these polycationic peptides might be used as a specific airway mucin-regulating agent.

• Macromolecular Research
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• v.8 no.2
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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.

• Journal of Pharmaceutical Investigation
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• v.36 no.6
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• pp.371-375
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• 2006

Neomycin coupled to a polymer matrix via a metal linker was prepared and evaluated for prolonging antibacterial activity. Microcrystallized cellulose was chemically modified to cellulose xanthate(MCX) to afford metal binding sites. MCX was treated with Cu(II), Fe(III) or Zn(II) followed by reaction with neomycin (Ne). The release of Ne from MCX-Zn(II)-Ne was investigated and its activity duration was measured by ditch plate method. The amount of metal bound to MCX was 0.36 mmol/g matrix, 0.26 mmol/g matrix and 0.56 mmol/g matrix for Cu(II), Zn(II) and Fe(III), respectively. Ne bound to MCX-metal chelates was 0.006 mmol, 0.07 mmol and 0.01 mmol per g MCX for Cu(II), Zn(II) and Fe(III), respectively. The Ne release from MCX-Zn(II)-Ne was sustained even after seven washes, whereas Ne from MC/Zn(II)/Ne mixture was almost completely released in two washes. Antibacterial activity was prolonged with MCX-Zn(II)-Ne and MCX-Fe(III)-Ne, but not with MCX-Cu(II)-Ne when compared with that of free Ne. Taken together, these results suggest that neomycin coupled to MCX via a proper metal linker has a potential as a polymeric antibacterial agent with sustained activity.

• Journal of Korean Society for Quality Management
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• v.51 no.4
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• pp.735-749
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• 2023

Purpose: The purpose of this study is to derive solutions and prevent similar cases from occurring by analyzing the causes of cracks found in temperature cycling tests of rocket motor. Methods: By combining the results of the current state confirmation test, non-destructive test, domestic and foreign rocket motor comparison test, cutting test, and adhesion test according to the number of times to apply mold release agent, a Cause and Effect Diagram analysis was performed to derive the cause of cracks. Results: Through this study, 26 factors that could cause cracking in rocket motors during temperature cycling tests were identified. Through various additional test results, a total of five causes were identified, including chemical and structural design of the joint between the propellant and stress relief insert, omission of procedure in the manufacturing procedures, natural aging due to temperature, and load accumulation due to temperature changes. The fundamental cause was confirmed to be insufficient consideration of the release properties of the propellant and stress relief insert. Conclusion: During the design process, it was confirmed that this could be solved by structurally or chemically designing the insert so that it does not combine with the propellant, or by applying a mold release agent during the manufacturing process.

• The Journal of Internal Korean Medicine
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• v.27 no.2
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• pp.295-304
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• 2006

Objectives : This study was done to investigate whether two oriental prescriptions, saganmahwang-tang (SMT) and prescription C (P-C) significantly affect mucin release from cultured hamster tracheal surface epithelial (HTSE) cells. Methods : Cofluent HTSE cells were metabolically radiolabeled with 3H-glucosamine for 24 hrs and chased for 30 min in the presence of SMT or P-C to assess the effect of each agent on 3H-mucin release. Possible cytotoxicities of each agent were assessed by measuring lactate dehydrogenase (LDH) release. Also, the effects of SMT and P-C on contractility of isolated tracheal smooth muscle were investigated. Results : SMT significantly inhibited mucin release from cultured HTSE cells, without cytotoxicity. P-C significantly increased mucin release from cultured HTSE cells, with significant cytotoxicity. SMT inhibited Ach-induced contraction of isolated tracheal smooth muscle. P-C did not affect Ach-induced contraction of isolated tracheal smooth muscle. Conclusion : Results su99est that SMT and P-C have regulating effects on mucin secretion from airway goblet cells. Further investigation is needed, because of the value in finding novel agents to this purpose, and these oriental medical prescription have potential for such a role.

• The Journal of Internal Korean Medicine
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• v.26 no.1
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• pp.221-228
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• 2005

The intent of this study is to investigate whether two oriental medical prescriptions named haengsotang(HST) and gami-palmihwan(GPMH) significantly effect mucin release from cultured hamster tracheal surface epithelial(HTSE) cells, Confluent HTSE cells were metabolically radiolabeled with $^3H-glucosamine$ for 24 hrs and chased for 30 min in the presence of HST or GPMH to assess the effect of each agent on $^3H-mucin$ release. Possible cytotoxicities of each agent were assessed by measuring lactate dehydrogenase(LDH) release. Also, the effects of HST and GPMH on contractility of isolated tracheal smooth muscle were investigated. The results are consistant with the following assertions: (1) HST significantly inhibited mucin release from cultured HTSE cells, without cytotoxicity; (2) GPMH did not effect mucin release without cytotoxicity; (3) HST and GPMH did not effect contractility of isolated tracheal smooth muscle. These results suggest a need for further investigation of HST and its components, for its potential in oriental medicine prescriptions and novel agents that effectively regulate (inhibit) mucin secretion from airway goblet cells.

• The Korea Journal of Herbology
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• v.20 no.4
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• pp.53-60
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• 2005

Objectives : This study was carried out to determine if Dendrobii Herba have protective effect against cell injury induced by various toxic agents in rat kidney slices. Water(DWe) and methanol(DMe) extracts were prepared for this experiment. Methods : Cell injury was estimated by measuring lactate dehydrogenase(LDH). Lipid peroxidation was examined by measuring malondialdehyde, a product of lipid peroxidation. Results : DMe prevented the LDH release by $CCl_4$, menadione, tert-butyl hydroperoxide and mercury treatment in vitro in kidney slices, but DWe prevented the LDH release by $CCl_4$ and mercury. DMe also prevented reduction in GSH and lipid peroxidation induced by $CCl_4$ and mercury. Conclusion : Thus, DMe may have more powerful efficacy on anti-oxidative effects when compared with DWe. And further studies have to be followed concerned with extraction of Dendrobii Herba and its change of effects.