• Proceedings of the PSK Conference
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• 2002.10a
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• pp.424.2-424.2
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• 2002

The in vivo release characteristics of rhGH-loaded PLGA microsphere prepared using a double emulsion process from hydrophilic 50:50 poly(D.L-lactide-co-glycolide) (PLGA) polymers were analyzed. This formulation showed particle size of ca 53.1$\mu\textrm{m}$ with high drug incorporation efficiency. To investigate in vivo release kinetics without the interference of formation of antibodies to rhGH in the experimental animals, the animals were immunosuppressed by treatment with Cyclosporin. (omitted)

• Journal of Society of Preventive Korean Medicine
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• v.18 no.2
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• pp.89-100
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• 2014

Objective : The co-administration effects of Gongjindan (GJD) on the pharmacokinetics (PK) of sorafenib were observed as a process of the comprehensive and integrative medicine. Methods : After sorafenib treatment, GJD was administered within 5 min. The plasma were collected at 30min before administration, 30min, 1, 2, 3, 4, 6, 8 and 24hrs after end of GJD treatment, and plasma concentrations of sorafenib were analyzed using LC-MS/MS methods. PK parameters of sorafenib ($T_{max}$, $C_{max}$, AUC, $t_{1/2}$ and $MRT_{inf}$) were analysis as compared with sorafenib single administered rats. Results : The absorption of sorafenib were significantly increased at 30min, 1, 6 and 6hrs after co-administration with GJD as compared with sorafenib single treated rats. Accordingly, the $AUC_{0-t}$ (47.20%) of sorafenib was significantly increased but $t_{1/2}$ (-30.63%) and $MRT_{inf}$ (-34.11%) in co-administered rats were non-significantly decreased. These findings are considered as direct evidences that GJD increased the oral bioavailability of sorafenib through increase of the absorption, when they co-administered within 5min. Conclusion : Based on the results, co-administration of GJD increased the oral bioavailability of sorafenib through increase of the gastrointestinal absorption. It is considered that the more detail pharmacokinetic studies should be tested to conclude the effects of GJD on the pharmacokinetics of sorafenib, when they were co-administered, like the effects after co-administration with reasonable intervals considering the $T_{max}$ of sorafenib (about 3.5hr-intervals) and after repeated co-administrations.Hence, concomitant uses of GJD with sorafenib may require close monitoring for potential drug interactions.

• Archives of Pharmacal Research
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• v.21 no.6
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• pp.645-650
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• 1998

The dual drug-loaded alginate beads simultaneously containing drug in inner and outer layers were prepared by dropping plain (single-layered) alginate beads into $CaCl_2$ solution. The release characteristics were evaluated in simulated gastric fluid for 2 h followed by intestinal fluids thereafter for 12 h. The surface morphology and cross section of dual drug-loaded alginate beads was also investigated using scanning electron microscope (SEM). The poorlv water-soluble ibuprofen was chosen as a model drug. The surface of single-layered and dual drug-loaded alginate beads showed very crude and roughness, showing aggregated particles, surface cracks and rough crystals. The thickness of dual drug-loaded alginate beads surrounded by outer layer was ranged from about 57 to 329mcm. The distinct chasm between inner and outer layers was also observed. In case of single-layered alginate bead, the drug was not released in gastric fluid but was largely released in intestinal fluid. However, the release rate decreased as the reinforcing $Eudragit^{\circledR}$ polymer contents increased. When the plasticizers were added into polymer, the release rate largely decreased. The release rate of dual drug-loaded alginate beads was stable in gastric fluid for 2 h but largely increased when switched in intestinal fluid. The drug linearly released for 4 h followed by another linear release thereafter, showing a distinct biphasic release characteristics. There was a difference in the release profiles between single-layered and dual drug-loaded alginate beads due to their structural shape. However, this biphasic release profiles were modified by varying formulation compositions of inner and outer layer of alginate beads. The release rate of dual drug-loaded alginate beads slightly decreased when the outer layer was reinforced with $Eudragit^{\circledR}$ RS1OO polymers. In case of dual drug-loaded alginate beads with polymer-reinforced outer layer only, the initial amount of druc released was low but the initial release rate (slope) was higher due to more swellable inner cores when compared to polymer-reinforced inner cores. The current dual drug-loaded alginate beads may be used to deliver the drugs in a time dependent manner.

• Journal of Pharmaceutical Investigation
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• v.36 no.6
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• pp.355-361
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• 2006

Intraarticular corticosteroid injections for therapy of rheumatic arthritis are administered with the aim of optimal local anti-inflammatory effect at the injection site. Since the side effects of corticosteroidal drug, dexamethasone(DEX), administered at hish dose limited the therapeutic efficacy, there was a need to design a new drug delivery system for controlled release of dexamethasone. As a prodrug for continuous therapeutic efficacy, dexamethasone-21-palmitate(DEX-PAL) was prepared via esterification of palmitoyl chloride and dexamethasone. DEX-PAL was identified by NMR and MASS analysis. DEX-PAL or DEX was entrapped in lipid nanosphere which could be prepared by using a self emulsification-solvent evaporation method. Physicochemical characteristics such as mean particle diameter, zeta potential and drug loading efficiency of the lipid nanospheres were investigated with variation of either the kind of lipid or the lipid composition. The lipid nanospheres had a mean diameter $83{\sim}95$ nm and DEX-PAL loading efficiency of up to 95%. The drug loading efficiency increased with the increase of aliphatic chain length attached to the phospholipid. The incorporation of cationic lipid was very efficient for both reducing particle size of lipid nanospheres and enhancing drug loading efficiency. The lipid nanospheres containing DEX-PAL may be a promising novel drug carrier for the controlled release of the poorly water-soluble drugs.

• Journal of the Korean Applied Science and Technology
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• v.29 no.4
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• pp.552-560
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• 2012

Drug delivery technologies are patent protected formulation technologies that modify drug release profile, absorption, distribution, and elimination for the benefit of improving product efficacy and safety, as well as patient convenience and compliance. The most commonly used transdermal system is the skin patch using various types of technologies. Compared with other method of dosage, it is possible to use for a long term. It is also possible to stop the drug dosage are stop if the drug dosage lead to side effect. Polysaccharide, such as karaya gum and locust bean gum(LBG)/water-soluble chitosan oligomer(WSCO) were selected as base materials of TDS. Also, these polymers were characterized in terms of enhancers, tacrine contents. Among these polysaccharide, the permeation rate of karaya gum matrix was fastest in tacrine such as lipophilic drug in vitro. We used glycerin, PEG 400, and PEG 800 as enhancers. Therefore, transdermal absorption of tacrine could be improved by changing vehicle composition or by using penetration enhancers. Especially it would be anticipated that the high permeation efficacy could be obtained by using vehicle that has enhancing effect for itself and by adding enhancers to it.

• KSBB Journal
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• v.22 no.4
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• pp.213-217
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• 2007

It has been reported that hydrophobic additives generally decrease the release rate of protein drugs from drug delivery systems (DDS) and hydrophilic additives increase the release rate. In many cases, however, the addition of hydrophilic molecule is necessary for improving the stability of protein drugs. In the present work, the effects of hydrophilic additives on the release profiles, and micelle formation of protein drug formulations were investigated to develop a novel method for protein drug delivery. For model protein drug, bovine serum albumin (BSA) was employed and several hydrophilic additives were used in the release experiments. Hydrophilic additive D-sorbitol showed the lower release rates of BSA than other hydrophobic additives due to the gel strengthening ability of the additive and the optimum concentration of D-sorbitol was 3 w/v % for the retarded release rate. In addition, it was found that the addition of D-sorbitol was very effective for obtaining homogeneous and stable DDS. The results were discussed in terms of the micelle formation and the micelle structure, i.e., the differences in gel structure and the distribution of drugs in micelles.

• KSBB Journal
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• v.11 no.6
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• pp.676-680
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• 1996

The characteristics of controlled drug release were studied for a biodegradable drug delivery system. A biodegradable chitosan matrix was prepared after swelling chitosan with 10%-acetic acid and adding sulfadiazine. The release behavior of sulfadiazine from the chitosan matrix was studied using the Higuchi's diffusion controlled model in phosphate buffer solutions of pH 7.4 and pH 1.2. The drug release time was delayed by increasing the content of sulfadiazine. The drug release at pH 7.4 was more delayed than that at pH 1.2. The reason is that chitosan has greater swelling abilities at low pH than at high pH. The apparent release rate constant(K) increased as the concentration of drug increased. In shoat, the formulation the biodegradable chitosan matrix to suppress the burst effect of drug release mechanism, which led to a sustained release pattern.

• Archives of Pharmacal Research
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• v.28 no.4
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• pp.488-492
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• 2005

The purpose of this study is to investigate the bioequivalence of two haloperidol 5 mg tablets, Myung In haloperidol (Myung In Pharm. Co., Ltd., test drug) and $Peridol^{R}$(Whanin Pharm. Co., Ltd., reference drug), and also to estimate the pharmacokinetic parameters of haloperidol in Korean volunteers. The bioavailability and pharmacokinetics of haloperidol tablets were examined on 24 healthy volunteers who received a single oral dose of each preparation in the fasting state in a randomized balanced 2 way crossover design. After an oral dosing, blood samples were collected for a period of 60 h. Plasma concentrations of haloperidol were determined using a liquid chromatographic electrospray mass spectrometric (LC-MS) method. The pharmacokinetic parameters were calculated with noncompartmental pharmacokinetic analysis. The geometric means of $AUC_{0-60h} and C_{max}$ between test and reference formulations were $17.21\pm8.26 ng\cdot/mL vs 17.31\pm13.24 ng\cdot/mL and 0.87\pm0.74 ng/mL vs 0.85\pm0.62 ng/mL$. respectively. The $90\%$ confidence intervals of mean difference of logarithmic transformed $AUC_{0-60h} and C_{max} were log0.9677{\sim}log1.1201 and log0.8208{\sim}log1.1981$, respectively. It shows that the bioavailability of test drug is equivalent with that of reference drug. The geometric means of other pharmacokinetic parameters ($AUC_{inf}. t_{1/2}, V_{d}/F, and CL/F$) between test drug and reference drug were $21.75\pm8.50 ng{\cdot}h/mL vs 21.77\pm15.63 ng{\cdot}h/mL, 29.87\pm8.25 h vs 29.60\pm7.56 h, 11.51\pm5.45 L vs 12.90\pm6.12 L and 0.26\pm0.09 L/h vs 0.31\pm0.17 L/h$, respectively. These observations indicate that the two formulation for haloperidol was bioequivalent and, thus, may be clinically interchangeable.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2001.11a
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• pp.93-93
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• 2001

Loxoprofen sodium is an orally used anti-inflammatory, analgesic and antipyretic agent. For alleviation or inhibition of the pain symptoms regardless of referred or superficial pain, the prompt absorption of a drug and its immediate bioavailability might be generally required for a formulation or development of a new drug. Therefore, in intramuscular administration, its anti-inflammatory, analgesic, and antipyretic effects were evaluated compared with an oral administration in animals. The occurrence of gastric damages which is common in nonsteroidal anti-inflammatory drugs was also observed.

• Natural Product Sciences
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• v.13 no.1
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• pp.6-10
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• 2007

The ethanolic (50% v/v) extracts of Carissa carandas (fruits) (Apocynaceae) and Microstylis wallichii (tubers) (Orchidaceae) were examined for anti-inflammatory and analgesic activities in experimental animals. Carissa carandas and Microstylis wallichii (50-200 mg/kg) caused a dose dependent inhibition of swelling caused by carrageenin significantly in cotton pellet induced granuloma in rats (P < 0.05 to P < 0.001). There was a significant increase in the analgesy meter induced pain in rats. The extracts of Carissa carandas and Microstylis wallichii resulted in an inhibition of stretching episodes and percentage protection was 16.05-17.58%respectively in acetic acid induced writhing.