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Search Results: 1 - 10 of 12 matches for " Ryosei Kamaguchi "
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Preparation and Characteristics of Film Dosage Form Natural Polysaccharides  [PDF]
Yoshifumi Murata, Kyoko Kofuji, Norihisa Nishida, Ryosei Kamaguchi
Pharmacology & Pharmacy (PP) , 2011, DOI: 10.4236/pp.2011.23028
Abstract: We investigated preparation of film dosage form (FD) from natural polysaccharides using the casting method without organic solvents, heating or pH control. Ferulic acid (FA) and catechin were employed as model compounds incorporated in the FD, and the release profile of each compound from the form was investigated in the limited medium. Film formation was affected by the addition of the model compound to the polysaccharide solution. Rigid FD was obtained with 2% low-molecular-weight alginate (L-ALG; thickness, 65 µm), and it hardened after the addition of 0.5% polygalacturonic acid, although the thickness of the film did not change. The FDs immediately released the model compound, and the forms dissolved in phosphate-buffered saline. FD modification did not affect the FA release rate except in the early stage. FD would be a useful dosage form, especially for preventing or treating localized problems in the oral cavity.
Development of Oral Dissolving Gelatin Beads Containing Allopurinol for the Prevention and Treatment of Mucositis  [PDF]
Yoshifumi Murata, Takashi Isobe, Kyoko Kofuji, Masafumi Mizutani, Ryosei Kamaguchi
Pharmacology & Pharmacy (PP) , 2012, DOI: 10.4236/pp.2012.33039
Abstract: Oral dissolving gelatin beads (GBs) containing allopurinol (AP) were prepared by the seamless capsule method and their rheological properties were examined. The release profiles of both gelatin and AP from GBs were also investigated in limited dissolution medium. GBs containing AP provided an easy-to-handle dosage form, but the physical strength of the beads immediately decreased upon contact with physiological saline at 37℃. Gelatin was released from the outer layer of GBs in physiological saline, with almost all the gelatin dissolved after 5 min, together with approximately 30% of the AP contained in the inner layer of the GB. The oral administration of GBs likely results in immediate softening of the GB upon contact with saliva. The released AP acts directly at inflammation sites, in a manner similar following oral rinsing with an AP suspension. Therefore, GBs are a useful dosage form for preventing or treating localized problems in the oral cavity, such as mucositis.
Development of Film Dosage Forms Containing Miconazole for the Treatment of Oral Candidiasis  [PDF]
Yoshifumi Murata, Takashi Isobe, Kyoko Kofuji, Norihisa Nishida, Ryosei Kamaguchi
Pharmacology & Pharmacy (PP) , 2013, DOI: 10.4236/pp.2013.43047
Abstract:

Film dosage forms (FDs) containing miconazole (MCZ) for the treatment of oral candidiasis were prepared using water-soluble polysaccharides, and the dissolution profiles of MCZ from the FDs were investigated. In addition, the forms were modified by the addition of a surface active agent to accelerate the drug dissolution rate. Circular films incorporating MCZ were obtained using each polysaccharide. Most FDs were easy to handle and resistant to tearing. No diffraction peaks were observed in the X-ray diffractograms of FDs. FDs prepared with sodium alginate or pullulan immediately swelled and disintegrated in aqueous medium, whereas MCZ incorporated in the FD gradually dissolved. A marked acceleration in the MCZ dissolution rate was observed when FD was prepared with polysaccharide containing a surfactant. These results confirmed that modified FDs are useful for treating localized conditions in the oral cavity, such as oral candidiasis, and that FDs can simplify the administration of drugs to patients.

Uptake of Bile Acid into Calcium-Induced Alginate Gel Beads Containing β-Chitosan Weak Acid Salt  [PDF]
Yoshifumi Murata, Kyoko Kofuji, Norihisa Nishida, Ryosei Kamaguchi
Pharmacology & Pharmacy (PP) , 2014, DOI: 10.4236/pp.2014.54042
Abstract:

Recently, potential applications for β-chitosan (β-CS) have been examined. In the present study, calcium-induced alginate gel beads (Alg-Ca) containing weak acid salts of β-CS were prepared and examined with regard to their ability to adsorb bile acids in vitro. More than 70% of taurocholate dissolved in solution was taken up by Alg-Ca containing 100 mg β-CS, sim. ilar to the degree of uptake observed with Alg-Ca containing α-CS salt. The adsorption of bile acid was affected by the absolute amount of β-CS and/or the acid concentration of the preparation. A secondary bile acid, taurodeoxycholate, was also adsorbed by Alg-Ca containing weak acid salts of β-CS. Therefore, β-CS might be used to adsorb bile acids within the gastrointestinal tract in the same manner as an anion-exchange resin, and thus serve as a complementary means by which to prevent hyperlipidemia.

Cyclodextrin-Modified Film Dosage Forms for Oral Candidiasis Treatment  [PDF]
Yoshifumi Murata, Kyoko Kofuji, Shushin Nakano, Ryosei Kamaguchi
Pharmacology & Pharmacy (PP) , 2015, DOI: 10.4236/pp.2015.65027
Abstract: Oral candidiasis is a common disease in patients with dry mouth. In this study, film dosage forms (FD) incorporating miconazole nitrate, an antifungal agent, were prepared with water-soluble polysaccharide and cyclodextrin (CD). The dissolution profiles of the drug from the FDs were investigated in limited dissolution medium. Soft films were obtained from sodium alginate containing 0.5% α-CD, β-CD, or γ-CD. Most FDs were easy to handle, though the film tearing resistance was lower than that of CD-free FDs. Addition of CD to the FD accelerated the drug dissolution rate. Interestingly, this phenomenon was also observed in FDs prepared with pullulan. In contrast, acceleration of the drug dissolution rate was not observed when CD polymer was added to the base solution. The initial drug dissolution rate was controllable by the amount of CD added to the FD. Therefore, FDs prepared with these materials are useful to treat oral candidiasis in patients with dry mouth syndrome.
Preparation of Fast Dissolving Films for Oral Dosage from Natural Polysaccharides
Yoshifumi Murata,Takashi Isobe,Kyoko Kofuji,Norihisa Nishida,Ryosei Kamaguchi
Materials , 2010, DOI: 10.3390/ma3084291
Abstract: Fast-dissolving films (FDFs) were prepared from natural polysaccharides, such as pullulan, without heating, controlling the pH, or adding other materials. The release profiles of model drugs from the films were investigated. In the absence of a drug, the casting method and subsequent evaporation of the solvent resulted in the polysaccharide forming a circular film. The presence of drugs (both their type and concentration) affected film formation. The thickness of the film was controllable by adjusting the concentration of the polysaccharide, and regular unevenness was observed on the surface of 2% pullulan film. All films prepared with polysaccharides readily swelled in dissolution medium, released the incorporated compound, and subsequently disintegrated. The release of dexamethasone from the films was complete after 15 min, although this release rate was slightly slower than that of pilocarpine or lidocaine. Therefore, FDFs prepared from polysaccharides could be promising candidates as oral dosage forms containing drugs, and would be expected to show drug dissolution in the oral cavity.
Development of Film Dosage Form Containing Allopurinol for Prevention and Treatment of Oral Mucositis
Yoshifumi Murata,Kyoko Kofuji,Norihisa Nishida,Ryosei Kamaguchi
ISRN Pharmaceutics , 2012, DOI: 10.5402/2012/764510
Abstract:
Development of Film Dosage Form Containing Allopurinol for Prevention and Treatment of Oral Mucositis
Yoshifumi Murata,Kyoko Kofuji,Norihisa Nishida,Ryosei Kamaguchi
ISRN Pharmaceutics , 2012, DOI: 10.5402/2012/764510
Abstract: Film dosage forms (FDs) containing allopurinol (AP) were prepared using a casting method with water-soluble polysaccharides, such as sodium alginate (ALG), and the release profile of AP from FDs was investigated in limited dissolution medium. Some ALGs were able to form FDs incorporating AP, and the thickness was about 50?μm. All FDs were easy to handle, though the rheological properties varied with ALG species. AP was homogenously present throughout the FDs and was released with disintegration in 10?mL of physiological saline. These results confirmed that FDs are useful for preventing or treating localized problems in the oral cavity, such as mucositis. FDs are also useful for administering drugs to cancer patients receiving chemotherapy and/or radiotherapy. 1. Introduction The xanthine oxidase inhibitor allopurinol (AP) is a drug used for the treatment of gout. AP has also been used to prevent and treat oral mucositis (mouth ulcers) in cancer patients receiving chemotherapy and/or radiotherapy [1–3]. In the treatment of mucositis, direct application of AP to the oral mucosa is necessary to avoid the systemic action seen after gastrointestinal absorption as the antioxidant activity of AP will result in lowering the activity of anticancer drug such as methotrexate. For example, AP suspensions (1?mg/mL) are freshly prepared in the hospital, and the patient gargles with the preparation [4]. This method for preventing mucositis is simple and effective; however, these preparations are not stable for long-term preservation, and it is difficult to control the amount of AP during gargling, although the dose is not sufficiently high to induce systemic effects in the event of erroneous swallowing. Recently, oral disintegration (OD) dosage forms such as OD tablets have become widely utilized, as they are useful in patients who have difficulty swallowing regular tablets [5, 6]. Film dosage forms (FDs) are also anticipated to be useful in oral care [7–9]. The active compound present in FDs is spread in the oral cavity as the form disintegrates on contact with saliva, and the disintegration profile of FDs can be varied by modifying the film base [10]. However, the drug loading capacity of FDs is typically very low, and the drug incorporated into FDs should be selected carefully. FDs are generally prepared using a water-soluble polymer base for immediate dissolution in saliva. As various polysaccharides have been used as additives for drug preparation or food ingredients because of the safety on peroral administration, they are candidate materials for FD preparation.
The Role of Immediate Recurrent Laryngeal Nerve Reconstruction for Thyroid Cancer Surgery
Tetsuji Sanuki,Eiji Yumoto,Ryosei Minoda,Narihiro Kodama
Journal of Oncology , 2010, DOI: 10.1155/2010/846235
Abstract: Unilateral vocal fold paralysis (UVFP) is one of the most serious problems in conducting surgery for thyroid cancer. Different treatments are available for the management of UVFP including intracordal injection, type I thyroplasty, arytenoid adduction, and laryngeal reinnervations. The effects of immediate recurrent laryngeal nerve (RLN) reconstruction during thyroid cancer surgery with or without UVFP before the surgery were evaluated with videostroboscopic, aerodynamic, and perceptual analyses. All subjects experienced postoperative improvements in voice quality. Particularly, aerodynamic analysis showed that the values for all patients entered normal ranges in both patients with and without UVFP before surgery. Immediate RLN reconstruction has the potential to restore a normal or near-normal voice by returning thyroarytenoid muscle tone and bulk seen with vocal fold denervation. Immediate RLN reconstruction is an efficient and effective approach to the management of RLN resection during surgery for thyroid cancer. 1. Introduction Unilateral vocal fold paralysis (UVFP) is one of the most serious problems in the management of thyroid cancer. The vocal folds may be paralyzed at the time of presentation, or the recurrent laryngeal nerve (RLN) may need to be sacrificed even when the RLN is functioning preoperatively. UVFP causes breathy voice, shortening of phonation, and aspiration. The negative impact of UVFP on a patient’s quality of life has been confirmed by several outcome measurements [1, 2]. Different treatments are available for the management of UVFP including intracordal injection [3], type I thyroplasty [4], arytenoid adduction [5], and laryngeal reinnervations [6–9]. Laryngeal reinnervation has several advantages over other techniques. It has the potential of restoring a normal or near normal voice. RLN reinnervation can prevent the progressive loss of thyroarytenoid muscle tone and bulk [7, 9, 10] as seen with vocal fold denervation, which can limit the long-term results of the conventional static laryngoplasty procedure. We report on cases involving the immediate reconstruction of the RLN during thyroid cancer surgery in patients with or without UVFP preoperatively and voice outcomes following the procedure with videostroboscopic, aerodynamic, and perceptual analyses. 2. Materials and Methods During the period from 2000 to 2008, at Kumamoto University Hospital, Japan, we reconstructed the RLN in 12 patients who had UVFP or whose unilateral RLN needed to be sacrificed due to thyroid cancer (Table 1). In 12 patients with thyroid cancer
Wide and Fast Wavelength-Swept Fiber Laser Based on Dispersion Tuning for Dynamic Sensing
Shinji Yamashita,Yuichi Nakazaki,Ryosei Konishi,Osamu Kusakari
Journal of Sensors , 2009, DOI: 10.1155/2009/572835
Abstract: We have developed a unique wide and fast wavelength-swept fiber laser for dynamic and accurate fiber sensing. The wavelength tuning is based on the dispersion tuning technique, which simply modulates the loss/gain in the dispersive laser cavity. By using wideband semiconductor optical amplifiers (SOAs), the sweep range could be as wide as ~180 nm. Since the cavity contains no mechanical components, such as tunable filters, we could achieve very high sweep rate, as high as ~200 kHz. We have realized the swept lasers at three wavelength bands, 1550 nm, 1300 nm, and 800 nm, using SOAs along with erbium-doped fiber amplifiers (EDFAs), and in two laser configurations, ring and linear ones. We also succeeded in applying the swept laser for a dynamic fiber-Bragg grating (FBG) sensor system. In this paper, we review our researches on the wide and fast wavelength-swept fiber lasers.
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