Biomedical subjects

Myung-Kwan Chun

Publications and source records attributed to Myung-Kwan Chun.

4 recordsLinked to original sources

PubMed2005

Preparation of mucoadhesive microspheres containing antimicrobial agents for eradication of H. pylori.

Mucoadhesive microspheres containing either amoxicillin or clarithromycin were prepared via the interpolymer complexation of poly(acrylic acid) (PAA) with poly(vinyl pyrrolidone) (PVP) and solvent diffusion method. The complexation between the PAA and PVP in an ethanol/water mixture was confirmed by the change in the transmittance of the solution as a function of repeating PAA and PVP unit ratio. The loading efficiency of clarithromycin in the complex microspheres was higher than that of amoxicillin due to the stronger interaction of clarithromycin with the PAA. The microspheres had a spherical shape with a smooth surface and the inside of the microspheres was completely filled. The dissolution rate of the complex microspheres was significantly slower than that of the PVP microspheres, particularly at pH 2.0. Amoxicillin and clarithromycin degraded significantly during the release study at pH 2.0. Therefore, their release rates were corrected using first order degradation rate constants. The amoxicillin release rates were similar regardless of the pH of the medium, while those of clarithromycin differed depending on the pH. The release mechanism of amoxicillin was mainly by a diffusion process and that of clarithromycin was via a dissolution process. The drug release rate from the complex microspheres was significantly lower than that from the PVP microspheres.

Adhesives↗

PubMed2004

Mucoadhesive microspheres prepared by interpolymer complexation and solvent diffusion method.

Mucoadhesive microspheres were prepared to increase gastric residence time using an interpolymer complexation of poly(acrylic acid) (PAA) with poly(vinyl pyrrolidone) (PVP) and a solvent diffusion method. The complexation between poly(acrylic acid) and poly(vinyl pyrrolidone) as a result of hydrogen bonding was confirmed by the shift in the carbonyl absorption bands of poly(acrylic acid) using FT-IR. A mixture of ethanol/water was used as the internal phase, corn oil was used as the external phase of emulsion, and span 80 was used as the surfactant. Spherical microspheres were prepared and the inside of the microspheres was completely filled. The optimum solvent ratio of the internal phase (ethanol/water) was 8/2 and 7/3, and the particle size increased as the content of water was increased. The mean particle size increased with the increase in polymer concentration. The adhesive force of microspheres was equivalent to that of Carbopol. The release rate of acetaminophen from the complex microspheres was slower than the PVP microspheres at pH 2.0 and 6.8.

Adhesives↗

PubMed2004

Preparation and characterization of enrofloxacin/carbopol complex in aqueous solution.

Since the bitter taste of enrofloxacin apparently limit the patient compliance in the oral formulations of the antibacterial agent, the masking of the taste is essential for the improvement of the therapeutic effectiveness. Therefore, this study was carried out to examine the feasibility of taste masking of enrofloxacin by the retardation of its dissolution rate using the formation of complex between the drug and Carbopol. The complexation between Carbopol and enrofloxacin was confirmed by turbidity, UV spectrophotometry, wide angle X-ray diffraction, and differential scanning calorimetry. The enrofloxacin content in the complexes was 34% (Carbo-enrofloxacin complex I) and 57% (Carbo-enrofloxacin complex II) depending on the preparation method. The dissolution rate of enrofloxacin from the complex increased as the pH was reduced. The dissolution rate of enrofloxacin from the Carbo-enrofloxacin complex I was significantly lower than that of the enrofloxacin powder. Therefore, these observations suggest that Carbo-enrofloxacin complex I can be used to mask the taste of enrofloxacin.

Acrylic Resins↗

PubMed2003

Preparation of buccal patch composed of carbopol, poloxamer and hydroxypropyl methylcellulose.

A polymeric film composed of Carbopol, Poloxamer and hydroxypropyl methylcellulose was prepared to develop a buccal patch and the effects of composition of the film on adhesion time, swelling ratio, and dissolution of the film were studied. The effects of plasticizers or penetration enhancers on the release of triamcinolone acetonide (TAA) were also studied. The hydrogen bonding between Carbopol and Poloxamer played important role in reducing swelling ratio and dissolution rate of polymer film and increasing adhesion time. The swelling ratio of the composite film was significantly reduced and the adhesion time was increased when compared with Carbopol film. As the ratio of Poloxamer to hydroxypropyl methylcellulose increased from 0/66 to 33/33, the release rate of TAA decreased. However, no further significant decrease of release rate was observed beyond the ratio of 33/33. The release rate of TAA in the polymeric film containing polyethylene glycol 400, a plasticizer, showed the highest release rate followed by triethyl citrate, and castor oil. The release rate of TAA from the polymeric film containing permeation enhancers was slower than that from the control without enhancers. Therefore, these observations indicated that a preparation of a buccal patch is feasible with the polymeric film composed of Cabopol, Poloxamer and hydropropyl methylcellulose.

Acrylic Resins↗