• Journal of Pharmaceutical Investigation
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• v.34 no.4
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• pp.275-281
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• 2004

We have studied the effect of polarity, current density, current duration, crosslinking density, swelling ratio, and permeation enhancers on the transdermal flux of ketoprofen from acrylamide hydrogel. Hydrogel was prepared by free radical crosslinking polymerization of acrylamide. Drug loading was made just before transport experiment by soaking the hydrogel in solution containing drug. In vitro flux study using hairless mouse skin was performed at $36.5^{\circ}C$ using side-by-side diffusion cell, and the drug was analysed using HPLC/UV system. The result showed that, compared to passive flux, the total amount of drug transported increased about 18 folds by the application of $0.4\;mA/cm^2$ cathodal current. Anodal delivery with same current density also increased the total amount of drug transported about 13 folds. It seemed that the increase in flux was due to the electrorepulsion and the increase in passive permeability of the skin by the current application. Flux increased as current density, the duration of current application and loading amount (swelling duration) increased. As the cross linking density of the hydrogel increased, flux clearly decreased. The effect of hydrophilic enhancers (urea, N-methyl pyrrolidone, Tween 20) and some hydrophobic enhancers (propylene glycol monolaurate and isopropyl myristate) was minimal. However, about 3 folds increase in flux was observed when 5% oleic acid was used. Overall, these results provide some useful information on the design of an optimized iontophoretic delivery system of ketoprofen.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1259-1264
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• 2007

Microstereolithography technology has potential capability for fabrication of 3D microstructures. It evolved from conventional SLA which is one of the RP processes. In a microstereolithography process, 3D microstructures can be easily fabricated by continuously stacking 2D layer which is photopolymerized using a liquid prepolymer. Combination between biocompatible/biodegradable photocurable prepolymer and 3D complex fabrication in microstereolithography makes broad application areas such as medical, pharmaceutic, and bio devices. In particular, a 3D microneedle for transdermal drug delivery and a scaffold for tissue engineering are fabricated using this technology. In this paper, the authors address development of microstereolithography system adapted to large surface and fabrication of various microstructures. In addition, to apply human body we suggest a biodegradable 3D microneedle and a scaffold using biodegradable photocurable prepolymer.

• Journal of Pharmaceutical Investigation
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• v.33 no.2
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• pp.79-84
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• 2003

The effects of various pressure sensitive adhesives (PSA) and enhancers on the percutaneous absorption of tulobuterol were investigated. The permeation rate of tulobuterol through hairless mouse skin from various adhesives was evaluated using a flow-through diffusion cell system at $37^{\circ}C$. The permeability of tulobuterol was variable depending on the physicochemical property of the PSA. The permeation rate of tulobuterol from polyethylene oxide grafted acrylic adhesive matrix was higher than that from other PSA matrices. The flux of tulobuterol was $4.37{\pm}0.34\;{\mu}g/hr/cm^2$ from polyethylene oxide grafted acrylic adhesive matrix. When the effects of various enhancers on the percutaneous absorption of tulobuterol from grafted acrylic adhesive were evaluated, Plurol $oleique^{\circledR}$ showed higher flux than all other enhancers tested.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.258-258
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• 2006

Electrospun fibers of poly(vinyl alcohol) (PVA) were successfully prepared and applied as drug carriers for transdermal drug delivery system. Sodium Salicylate (SS) was the model drug and it was incorporated in the PVA fibers by adding 20 % of SS in a PVA solution prior to electrospinning. Electrospinning of SS-containing PVA solution resulted in the formation of beaded fibers. In order to control the rate of SS release and decrease water solubility of PVA, the SS-loaded electrospun PVA mat was cross-linked by either glutaraldehyde or glyoxal vapor. The morphology, thermal behavior, swelling behavior, release characteristic, kinetics of drug release and also toxicity of the cross-linked sample were investigated.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.622-627
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• 2001

Microjet flows are often encountered in many industrial applications of micro-electro-mechanical systems as well as in medical engineering fields such as a transdermal drug delivery system for needle-free injection of drugs into the skin. The Reynolds numbers of such microjets are usually several orders of magnitude below those of larger-scale jets. The supersonic microjet physics with these low Reynolds numbers are not yet understood to date. Computational modeling and simulation can provide an effective predictive capability for the major features of the supersonic microjets. In the present study, computations using the axisymmetic, compressible, Navier-Stokes equations are applied to understand the supersonic microjet flow physics. The pressure ratio of the microjets is changed to obtain both the under- and over-expanded flows at the exit of the micronozzle. Sonic and supersonic microjets are simulated and compared with some experimental results available. Based on computational results, two microjets are discussed in terms of total pressure, jet decay and supersonic core length.

• YAKHAK HOEJI
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• v.56 no.3
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• pp.158-163
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• 2012

Lidocaine has been studied for many chronic pain conditions, including postherpetic neuralgia (PHN) and recently it has also been increasingly used in transdermal drug delivery systems. In this study, pharmacokinetics of a lidocaine patch was studied in four hairless male rats. The plasma concentration was determined by a validated LC/MS/MS method after applying a $3{\times}2cm^2$ (30mg) patch for 12 hours. From the plasma lidocaine concentration vs time curves, $AUC_{0-20h}$, Cmax, and Tmax of lidocaine patch were $2,926.32{\pm}335.28ng{\cdot}h/ml$, $256.86{\pm}29.63ng/ml$, and $6.00{\pm}2.31h$, respectively.

• Archives of Pharmacal Research
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• v.28 no.2
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• pp.243-248
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• 2005

To improve the skin permeability of piroxicam, a new oil-in-water microemulsion containing $0.5\%$ piroxicam was developed. Among various oils investigated for their suitability as an oil phase for the microemulsion system, oleic acid showed both excellent solubility and skin permeation enhancing effect for piroxicam. Microemulsion existence ranges were identified through the construction of the pseudo-ternary phase diagram. The effect of the content of oleic acid and the ratio of the surfactant/cosurfactant on skin permeation of piroxicam were evaluated with excised rat skins. The optimum formulation with the highest skin permeation rate ($47.14\;{\mu}g/cm^2/h$) consisted of $0.5\%$ piroxicam, $10\%$ oleic acid, $60\%$ Labrasol/ethanol (1:5) and water.

• The Journal of Korean Physical Therapy
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• v.14 no.2
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• pp.219-233
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• 2002

스테로이드성 소염진통제인 트리암시놀론 겔의 피부투과도를 향상시키기 위하여 초음파를 조사하여 약물의 투과도에 미치는 영향을 비교하였다. 트리암시놀론을 함유한 수용성 겔을 제조하여 물리화학적 시험을 실시하였으며 carbopol을 기제로한 겔이 우수한 제제학적 특성을 보였다. 초음파 조사가 약물의 투과도에 미치는 영향을 알아보기 위하여 hairless mouse의 적출 피부에 대한 in vitro 흡수 실험을 실시하였다. 트리암시놀론 겔 음파영동군이 트리암시놀론겔 단독 처치군에 비하여 투과도가 유의적으로 향상되었다. 특히 주파수가 1MHz인 지속초음파를 고 강도로 적용시 피부투과도의 향상이 더욱 두드러졌다. 따라서 트리암시놀론 겔 도포 후 초음파를 이용한 음파영동 경피흡수가 단독의 겔 처치보다 피부투과에 유용할 것으로 사료된다.

• Journal of the Korean Applied Science and Technology
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• v.28 no.2
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• pp.170-177
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• 2011

Transdermal drug delivery(TDS) offers many important advantages. For instance, it is easy and painless, it protects the active compound from gastric enzymes, and it avoids the hepatic first-pass effect. Also, it is simple to terminate the therapy if any adverse or undesired effect occurs. But skin is a natural barrier, and only a few drugs can penetrate the skin easily and in sufficient quantities to be effective. Therefore, in recent years, numerous studies have been conducted in the area of penetration enhancement. 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 stopped if the drug dosage lead to side effect. Polysaccharide, such as xanthan gum and algin were selected as base materials of TDS. Also, these polymers were characterized in terms of enhancers and drug contents. Among these polysaccharide, the permeation rate of Paroxetine such as lipophilic drug was the fastest in xanthan gum matrix in vitro. We used glycerin, PEG400 and PEG800 as enhancers. Since dermis has more water content(hydration) than the stratum corneum, skin permeation rate at steady state was highly influenced when PEG400 was more effective for lipophilic drug. Proper selection of the polymeric materials which resemble and enhance properties of the delivering drug was found to be important in controlling the skin permeation rate.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.411.1-411.1
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• 2014

This study evaluates the utility of an antibacterial microneedle composed of green tea extract (GT) and hyaluronic acid (HA), for the efficient delivery of GT. These microneedles have the potential to be a patient-friendly method for the conventional sustained release of drugs. In this study, a fabrication method using a mold-based technique to produce GT/HA microneedles with a maximum area of ${\sim}60mm^2$ with antibacterial properties was used to manufacture transdermal drug delivery systems. Fourier transform infrared (FTIR) spectrometry was carried out to observe the potential modifications in the microneedles, when incorporated with GT. The degradation rate of GT in GT/HA microneedles was controlled simply by adjusting the HA composition. The effects of different ratios of GT in the HA microneedles were determined by measuring the release properties. In HA microneedles loaded with 70% GT (GT70), a continuous higher release rate were sustained for 72 h. The in vitro cytotoxicity assays demonstrated that GT/HA microneedles are not generally cytotoxic to chinese hamster ovary cells (CHO-K1), human embryonic kidney cells (293T), and mouse muscle cells (C2C12), which were treated for 12 and 24 h. Antimicrobial activity of the GT/HA microneedles was demonstrated by ~95% growth reduction of gram negative [Escherichia coli (E. coli), Pseudomonas putida (P. putida) and Salmonella typhimurium (S. typhimurium)] and gram positive bacteria [Staphylococcus aureus (S. Aureus) and Bacillus subtilis (B. subtilis)], with GT70. Furthermore, GT/HA microneedles reduced bacterial growth in the infected skin wound sites and improved skin wound healing process in rat model.