• Archives of Pharmacal Research
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• v.28 no.3
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• pp.370-375
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• 2005

The objective of this study was to develop a new reverse micelle-based microencapsulation technique to load tetracycline hydrochloride into PLGA microspheres. To do so, a reverse micellar system was formulated to dissolve tetracycline hydrochloride and water in ethyl formate with the aid of cetyltrimethylammonium bromide. The resultant micellar solution was used to dissolve 0.3 to 0.75 g of PLGA, and microspheres were prepared following a modified solvent quenching technique. As a control experiment, the drug was encapsulated into PLGA microspheres via a conventional methylene chloride-based emulsion procedure. The micro­spheres were then characterized with regard to drug loading efficiency, their size distribution and morphology. The reverse micellar procedure led to the formation of free-flowing, spherical microspheres with the size mode of 88 ~m. When PLGA microspheres were prepared follow­ing the conventional methylene chloride-based procedure, most of tetracycline hydrochloride leached to the aqueous external phase: A maximal loading efficiency observed our experimental conditions was below $5\%$. Their surfaces had numerous pores, while their internal architecture was honey-combed. In sharp contrast, the new reverse micellar encapsulation technique permitted the attainment of a maximal loading efficiency of 63.19 $\pm$$0.64\%$. Also, the microspheres had smooth and pore-free surfaces, and hollow cavities were absent from their internal matrices. The results of this study demonstrated that PLGA microspheres could be successfully prepared following the new reverse micellar encapsulation technique.

• Nanomaterials
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• v.9 no.12
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• pp.1652-1663
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• 2019

Osteosarcoma (OSA) is a difficult cancer to treat due to its tendency for relapse and metastasis; advanced methods are therefore required for OSA treatment. In this study, we prepared a local drug-delivery system for OSA treatment based on doxorubicin·hydrochloride (DOX·HCl)/cisplatin (CP)-loaded visible light-cured glycol chitosan (GC) hydrogel/(2-hydroxypropyl)-beta-cyclodextrin (GDHCP), and compared its therapeutic efficiency with that of DOX·HCl- and CP-loaded GC hydrogels (GD and GHCP). Because of diffusion driven by concentration gradients in the swollen matrix, the three hydrogels showed sustained releases of DOX·HCl and CP over 7 days, along with initial 3-h bursts. Results of in vitro cell viability and in vivo animal testing revealed that GDHCP had a stronger anticancer effect than GD and GHCP even though there were no significant differences. Body weight measurement and histological evaluations demonstrated that the drug-loaded GC hydrogels had biocompatibility without cardiotoxicity or nephrotoxicity. These results suggested that GDHCP could be a good platform as a local drug-delivery system for clinical use in OSA treatment.

• Nanomaterials
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• v.12 no.17
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• pp.2945-2957
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• 2022

In this work, the growth of extended tri-s-triazine units (melem units) on g-C₃N₄ (CN) by hydrothermal treatment and its effect on the photodegradation efficiency of tetracycline hydrochloride (TC) is investigated. The CN-180-x and CN-200-6 samples were prepared using different hydrolysis times and temperatures, and they were characterized by multiple physicochemical techniques. In addition, their photodegradation performance was evaluated under visible light irradiation. Compared to the CN, CN-180-6 possesses remarkable photocatalytic degradation efficiency at 97.17% towards TC removal in an aqueous solution. The high visible-light-induced photo-reactivity of CN-180-6 directly correlates to charge transfer efficiency, numerous structural defects with a high specific surface area (75.0 m² g^-1), and sufficient O-functional groups over g-C₃N₄. However, hydrothermal treatment at a higher temperature or during a longer time additionally induces the growth of extended melem units on the surface of g-C₃N₄, resulting in the inhibition of the charge transfer. In addition, the superoxide radical is proven to be generated from photoexcited reaction and plays a key role in the TC degradation.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.4
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• pp.525-531
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• 2013

Purpose: To identify the apoptosis caused by Proparacaine hydrochloride (PPC), a topical anesthesia, applied to conjunctival cell lines and determine whether pigallocatechin-gallate (EGCG), has protective effects on. Methods: The conjunctival cell lines were treated with 0.5% of Alcaine$^{(R)}$, 0.5% of PPC and 0.01% of Benzalkonium chloride (BAC) for 15 minutes, respectively in order to investigate the effects of topical anesthesia on cells, and followed by cultured for 12 and 24 hours. The recovery effects were investigated by measuring level of cellular proliferation inhibiting using MTT assay and LDH assay. The conjunctival cell lines were pre-treated with EGCG $10{\mu}M$ for 3 hrs and post-treated with 0.5% PPC for 15 mins in order to investigate whether EGCG has protective effects, flow cytometry were performed in order to observe apoptosis. Results: A result of the additional culture of 12 and 24 hours and again immediately after the treatment for 15 minutes 0.5% of Alcaine$^{(R)}$, 0.5% of PPC, the 0.01% of BAC, cell viability was not increased in all groups (p<0.05). The cell viabilities were higher than in cells 3 hours post-treated with $10{\mu}M$ of EGCG and pre-treated PPC 0.5% (68.2%), compared to cells ($32.2{\pm}2.0%$) treated only with 0.5% of PPC. PPC 0.5% also induced apoptosis in the treated group was reduced by the addition of EGCG. Conclusions: It is considered that the EGCG has cell protective effects when it is added to PPC, a topical anesthesia, by improving cell viability and inhibiting apoptosis.

• Korean Chemical Engineering Research
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• v.40 no.6
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• pp.659-663
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• 2002

The crystallization of NaF driven by adding ethanol was monitored using quartz crystal analyzer (QCA). Adding ethanol to NaF solution reduced the solubility of NaF and consequently led to nucleation and growth of NaF crystals. To investigate the crystallization behavior of NaF, a gold electrode of QCA was modified by anchoring with 2-mercaptoethylamine hydrochloride based on a self-assembly method. Frequency of QCA varied with the amount of NaF adsorbed on the self-assembled layer of 2-mercaptoethylamine hydrochloride, and thereby the process of NaF crystallization could be analyzed indirectly by monitoring the frequency change of QCA. To change the extent of supersaruration of NaF, the amount of ethanol added to the solution was varied from 1 to 5 ml. Then, the effect of the extent of the supersaturation on the crystallization was examined by analyzing the frequency changes of QCA coated with 2-mercaptoethylamine hydrochloride. It was shown that the QCA technique could be well applied for the characterization and analysis of the crystallization behavior of NaF.

• Journal of Dental Anesthesia and Pain Medicine
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• v.18 no.1
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• pp.19-25
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• 2018

Background: Third molar extraction is associated with considerable pain and discomfort, which is mostly managed with oral analgesic medication. We assessed the analgesic effect of benzydamine hydrochloride, a topical analgesic oral rinse, for controlling postoperative pain following third molar extraction. Methods: A randomized controlled trial was conducted in 40 patients divided into two groups, for extraction of fully erupted third molar. Groups A received benzydamine hydrochloride mouthwash and group B received normal saline gargle with oral ibuprofen and paracetamol. Oral ibuprofen and paracetamol was the rescue analgesic drug in group A. Patients were evaluated on the $3^{rd}$ and $7^{th}$ post-operative days (POD) for pain using the visual analogue score (VAS), trismus, total number of analgesics consumed, and satisfaction level of patients. Results: The VAS in groups A and B on POD3 and POD7 was $4.55{\pm}2.54$ and $3.95{\pm}1.8$, and $1.2{\pm}1.64$ and $0.95{\pm}1.14$, respectively and was statistically insignificant. The number of analgesics consumed in groups A and B on POD3 ($5.25{\pm}2.22$ and $6.05{\pm}2.43$) was not statistically different from that consumed on POD7 ($9.15{\pm}5.93$ and $10.65{\pm}6.46$). The p values for trismus on POD3 and POD7 were 0.609 and 0.490, respectively and those for patient satisfaction level on POD3 and POD7 were 0.283 and 0.217, respectively. Conclusions: Benzydamine hydrochloride oral rinses do not significantly reduce intake of oral analgesics and are inadequate for pain relief following mandibular third molar extraction.

• Journal of the Korean Chemical Society
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• v.54 no.2
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• pp.198-207
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• 2010

The construction and performance characteristics of doxepin hydrochloride selective electrodes were developed. Three types of electrodes: plastic membrane I, coated wire II, and coated graphite rod III were constructed based on the incorporation of doxepin hydrochloride with ammonium reineckate. The influence of membrane composition, kind of plasticizer, pH of the test solution, soaking time, and foreign ions on the electrodes was investigated. The electrodes showed a Nernstain response with a mean slope of 57.41 ${\pm}$ 0.5, 56.22 ${\pm}$ 0.2 and 52.88 ${\pm}$ 0.7 mV at $25^{\circ}C$ for electrode I, II and III respectively, over Doxepin hydrochloride concentration range from $1{\times}10^{-2}-1{\times}10^{-6}M$, $5{\tims}10^{-2}-1{\times}10^{-6}M$ and $1{\times}10^{-3}-5{\times}10^{-6}M$, and with a detection limit $5.0{\times}10^{-7}M$, $6.3{\times}10^{-7}M$ and $2.5{\times}10^{-6}M$ for electrode I, II and III respectively. The constructed electrodes gave average selective precise and usable within the pH range 3 - 7. Interferences from common cations, alkaloids, sugars, amino acids and drug excipients were reported. The results obtained by the proposed electrodes were also applied successfully to the determination of the drug in pharmaceutical preparations and biological fluids.

• YAKHAK HOEJI
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• v.54 no.5
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• pp.348-353
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• 2010

The dissolution test method and an analytical procedure by HPLC were developed and validated for viquidil hydrochloride capsules and alibendol tablets. These drugs were not yet characterized by the dissolution specifications in Korean Pharmaceutical Codex. So, with each reference and test drugs, we did the preliminary and standard experiments based on the Korean Pharmacopeia Guideline of dissolution testing for solid oral dosage forms. The dissolution test for viquidil hydrochloride capsules was carried out under sink conditions as follows: dissolution medium water, paddle rotation speed 50 rpm and vessel volume 900 ml. More than 90% of its label amount was released within 30 min in this method. Also the dissolution test for alibendol tablets was carried out under sink conditions as follows: dissolution medium water, paddle rotation speed 100 rpm and vessel volume 900 ml. More than 90% of its label amount was released within 45 min in this method. The dissolution samples were analyzed with a precise and accurate HPLC method. The developed dissolution test showed specificity, linearity, precision and accuracy within the acceptable range. The dissolution testing method described above was adequate for the purpose and may be proposed as a pharmacopeial standard to assess the performance of viquidil hydrochloride capsules and alibendol tablets.

• YAKHAK HOEJI
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• v.55 no.5
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• pp.411-418
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• 2011

The dissolution test method and an analytical procedure by HPLC were developed and validated for nafronyl oxalate capsules and tramadol hydrochloride capsules. These drugs were not yet characterized by the dissolution specifications in the Korean Pharmaceutical Codex. So, with each reference and test drugs, we did the preliminary and standard experiments based on the Korean Pharmacopeia Guideline of dissolution testing for solid oral dosage forms. The dissolution test for nafronyl oxalate capsules was carried out under sink conditions as follows: dissolution medium phosphate buffer pH 6.8, paddle rotation speed 100 rpm and vessel volume 900 ml. More than 80% of its label amount was released within 30 min in this method. Also the dissolution test for tramadol hydrochloride capsules was carried out under sink conditions as follows: dissolution medium water, paddle rotation speed 50 rpm and vessel volume 900 ml. More than 90% of its label amount was released within 15 min in this method. The dissolution samples were analyzed with a validated HPLC analytical procedure. The analytical methodology showed acceptable values in terms of specificity, linearity, precision and accuracy. The dissolution test methods described above were adequate for the purpose and may be proposed as a pharmacopeial standard to assess the performance of nafronyl oxalate capsules and tramadol hydrochloride capsules. Furthermore, the outcomes of this study were expected to help create an environment where safe and high quality drugs would be distributed on the domestic market making contributions to advancing public health.

• Journal of Veterinary Science
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• v.22 no.6
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• pp.41.1-41.14
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• 2021

Background: Our previously prepared ceftiofur (CEF) hydrochloride oily suspension shows potential wide applications for controlling swine Streptococcus suis infections, while the irrational dose has not been formulated. Objectives: The rational dose regimens of CEF oily suspension against S. suis were systematically studied using a pharmacokinetic-pharmacodynamic model method. Methods: The healthy and infected pigs were intramuscularly administered CEF hydrochloride oily suspension at a single dose of 5 mg/kg, and then the plasma and pulmonary epithelial lining fluid (PELF) were collected at different times. The minimum inhibitory concentration (MIC), minimal bactericidal concentration, mutant prevention concentration (MPC), post-antibiotic effect (PAE), and time-killing curves were determined. Subsequently, the area under the curve by the MIC (AUC_0-24h/MIC) values of desfuroylceftiofur (DFC) in the PELF was obtained by integrating in vivo pharmacokinetic data of the infected pigs and ex vivo pharmacodynamic data using the sigmoid E_max (Hill) equation. The dose was calculated based on the AUC_0-24h/MIC values for bacteriostatic action, bactericidal action, and bacterial elimination. Results: The peak concentration, the area under the concentration-time curve, and the time to peak for PELF's DFC were 24.76 ± 0.92 ㎍/mL, 811.99 ± 54.70 ㎍·h/mL, and 8.00 h in healthy pigs, and 33.04 ± 0.99 ㎍/mL, 735.85 ± 26.20 ㎍·h/mL, and 8.00 h in infected pigs, respectively. The MIC of PELF's DFC against S. suis strain was 0.25 ㎍/mL. There was strong concentration-dependent activity as determined by MPC, PAE, and the time-killing curves. The AUC_0-24h/MIC values of PELF's DFC for bacteriostatic activity, bactericidal activity, and virtual eradication of bacteria were 6.54 h, 9.69 h, and 11.49 h, respectively. Thus, a dosage regimen of 1.94 mg/kg every 72 h could be sufficient to reach bactericidal activity. Conclusions: A rational dosage regimen was recommended, and it could assist in increasing the treatment effectiveness of CEF hydrochloride oily suspension against S. Suis infections.