Characterization of Itraconazole Semisolid Dosage Forms Prepared by Hot Melt Technique

Shim, Sang-Young,Ji, Chang-Won,Sah, Hong-Kee,Park, Eun-Seok,Lee, Beom-Jin The Pharmaceutical Society of Korea 2006 Archives of Pharmacal Research Vol.29 No.11

The objective of this study was to formulate itraconazole semisolid dosage forms and characterize their physicochemical properties. Itraconazole and excipients such as polysorbate 80, fatty acids, fatty alcohols, oils and organic acids were melted at $160^{\circ}C$. The fused solution was then cooled immediately at $-10^{\circ}C$ to make wax-like semisolid preparations. Their physicochemical attributes were first characterized using differential scanning calorimetry, Fourier transform infrared spectroscopy and nuclear magnetic resonance spectrometry. The solubility of itraconazole in semisolid preparations and their dispersability in the simulated gastric fluid were also determined. Our semisolid preparations did not show any distinct endothermic peak of a crystalline form of itraconazole around $160-163^{\circ}C$. This suggested that it was changed into amorphous one, when it was formulated into semisolid preparations. In addition, the distinctive functional peaks and chemical shifts of itraconazole were well retained after processing into semisolid preparations. It could be inferred from the data that itraconazole was stable during incorporation into semisolid preparations by the hot melt technique. In particular, itraconazole semisolid preparations composed of polysorbate 80, fatty acids and organic acids showed good solubility and dissolution when dispersed in an aqueous medium. It was anticipated that the semisolid dosage forms would be industrially applicable to improving the bioavailability of poorly water-soluble drugs.

Characterization of Itraconazole Semisolid Dosage Forms Prepared by Hot Melt Technique

Sang-Young Shim,Chang-Won Ji,사홍기,박은석,이범진 대한약학회 2006 Archives of Pharmacal Research Vol.29 No.11

The objective of this study was to formulate itraconazole semisolid dosage forms and characterize their physicochemical properties. Itraconazole and excipients such as polysorbate 80, fatty acids, fatty alcohols, oils and organic acids were melted at 160oC. The fused solution was then cooled immediately at -10oC to make wax-like semisolid preparations. Their physicochemical attributes were first characterized using differential scanning calorimetry, Fourier transform infrared spectroscopy and nuclear magnetic resonance spectrometry. The solubility of itraconazole in semisolid preparations and their dispersability in the simulated gastric fluid were also determined. Our semisolid preparations did not show any distinct endothermic peak of a crystalline form of itraconazole around 160-163oC. This suggested that it was changed into amorphous one, when it was formulated into semisolid preparations. In addition, the distinctive functional peaks and chemical shifts of itraconazole were well retained after processing into semisolid preparations. It could be inferred from the data that itraconazole was stable during incorporation into semisolid preparations by the hot melt technique. In particular, itraconazole semisolid preparations composed of polysorbate 80, fatty acids and organic acids showed good solubility and dissolution when dispersed in an aqueous medium. It was anticipated that the semisolid dosage forms would be industrially applicable to improving the bioavailability of poorly water-soluble drugs.

Microstructural Investigation and High Temperature Mechanical Behavior of AXE622 Cast Mg Alloy

A. Habibi Eftekhar,S. Mohsen Sadrossadat,M. Reihanian 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.5

The microstructure and high temperature properties of the AXE622 Mg alloy were investigated after the conventional andsemisolid casting processes. The tensile test was conducted at room temperature, and 473 K. Impression creep test was performedat a temperature range of 423–498 K under the stress range of 450–600 MPa. The microstructure of the conventionaland semisolid alloys contains α-Mg dendrites, the eutectic phase, secondary phases including (Mg–Al)2Ca, eutectic Mg17Al12,and Al11RE3. During semisolid processing, coarse dendrites of the α-Mg became fine, globular, and Rosetta shape. Theaverage length of the secondary phases in the semisolid alloy decreased from 4.21 to 2 μm and the average grain size of theα-Mg reduced from 113 to 96 μm. Semisolid processing caused a significant improvement in the tensile and creep resistanceof the AXE622 Mg alloy. The stress exponent for creep was calculated in the range 5.6–7.7 for the conventional alloy andin the range 10.3–11 for the semisolid alloy. The activation energy for conventional and semisolid alloy was determined as71.4 kJ/mol and 78.3 kJ/mol, respectively. It was concluded that the dominant creep mechanism in the conventional alloywas the grain boundary diffusion-controlled dislocation climb, while in the semisolid alloy was the power-law breakdown.

Influence of Time Evolution of Particle Shape on Rheological Behavior of Semisolid Slurries of Magnesium Alloy AZ91D

Liang Li,Mian Zheng 대한금속·재료학회 2016 METALS AND MATERIALS International Vol.22 No.2

To gain the insights into the influence of the morphology of solid particles on rheological behavior of semisolid metal slurries, the time evolution of Hausdorff dimensionality describing the particle morphology is deduced in order to quantitatively analyze the time evolution of the particle morphology. In consideration of the role of the liquid entrapped by non-spherical solid particles, the non-spherical solid particles with the entrapped liquid are treated as spherical solid particles, and the equivalent solid volume fraction is defined as the sum of solid volume fraction and the volume fraction of the entrapped liquid. This model could be used to analyze the rheological behavior of the semisolid metal slurries containing the non-spherical particles with Hausdorff dimensionality less than 3. Moreover, the rheological behavior of semisolid magnesium alloy AZ91D is theoretically analyzed by this model during isothermal shearing and continuous cooling. The calculated results are found coinciding with the experimental results and the calculated results also reveal that the shear rate and cooling rate could influence the rheological behavior of semisolid metal slurries by changing the morphology of solid particles except by affecting agglomeration degree.

Microstructural Evolution in Semisolid Forging of A356 Alloy

강병근,홍준표,최병희,장영수,손일 대한금속·재료학회 2015 METALS AND MATERIALS International Vol.21 No.1

A semisolid forging study using A356 alloy was carried out to investigate the evolution of microstructuresaffected by the solid fraction, the forging pressure and the addition of Sr. The semisolid slurry for forgingwas made by an electromagnetic stirring method. Microstructures were evaluated at two typical positions of thesemisolid forged specimens: one is the region, where direct forging pressure is applied, and the other is theregion, where the slurry was squeezed and extruded indirectly. Microstructural characteristics, such as themorphology of the primary Al particles and the eutectic Si, were changed with the positions observed. Asthe solid fraction increased, the morphology of the primary Al particles was transformed from rosette-like toglobular. As the forging pressure increased, the size of eutectic Si became fine. An increase of the forgingpressure is speculated to improve the interfacial heat transfer coefficient between the semisolid slurry andthe mould wall, leading to an increase of the cooling rate on the growth of eutectic Si. The addition of Sris effective in modifying the morphology for eutectic Si, especially when the forging pressure was low.

정상인에서 반고형식 Lactulose 수소호기검사법을 이용한 구강맹장 통과시간의 측정

강영우(Young Woo Kang),박승국(Soong Kook Park) 대한소화기학회 1994 대한소화기학회지 Vol.26 No.4

N/A Lactulose hydrogen breath test has been used for rneasurement of orocecal transit time (OCTT) because of its non invasiveness and simplicity. Recently, the lack of reproducibility of OCTT which measured by hydrogen breath test using water diluted lactulose resulted in the need to develop a new semisolid or solid meal combined lactulose hydrogen breath test. We measured OCTT in 47 norrnal subjects(male 17, female 30, age 24 69 years, average 35.5 years) after ingestion of semisolid meal including potato soup and lactulose syrup 20g. OCTT was defined as the time from test meal ingestion to a sustained increase of more than 10pprn above the baseline in end expiratory hydrogen concentration with 10 minutes interval for 3 hours. OCTT was 79.2+11.9(mean+SD) minutes in male, 81.5+15.2 minutes in female, and average 81.9+13.3 minutes. Although there was no significant difference according t,o sex, OCTT in sixth and seventh decades were delayed compared to third decades(P<0.05). These results will be useful for comparison of OCTT in different group of patients.(Korean J Gastro- enterol 1994; 26: 619 624)

Separation Technology of Tramp Elements in Aluminium Alloy Scrap by Semisolid Processing

Thet Thet Cho,Yi Meng,Sumio Sugiyama,Jun Yanagimoto 한국정밀공학회 2015 International Journal of Precision Engineering and Vol. No.

A growing number of studies suggest that the accumulation of unwanted elements is a growing problem in all recycled materialstreams. Thus, the separation of tramp elements from aluminium alloy scrap is very important in the aluminium recycling process. In this paper, a new technique of backward extrusion in the semisolid state is reported for separating the tramp elements fromaluminium alloy scrap and obtaining high-purity aluminium easily and quickly. In this process, partial solidification is adopted tocondense tramp elements in the liquid phase on the grain boundary. In experimental trials, four aluminium alloys were selected: castaluminium alloy (AC4C), two kinds of wrought aluminium alloy (A7N01, A7075) and aluminium beverage can scraps. From theresults of macro- and optical microscopic analysis, Rockwell hardness testing and electron probe micro-analyser (EPMA) analysis,it was confirmed that the backward extrusion in the semisolid state could separate the tramp elements from the aluminium alloy scrapeasily and high-purity aluminium was obtained.

Investigation of the controlled atmosphere of semisolid metal processing of A356 aluminium alloy

A. Kolahdooz,S. Nourouzi,M. Bakhshi Jooybari,S. J. Hosseinipour 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.10

The cooling slope (CS) method is one of the semi-solid methods in which the molten alloy with a suitable amount of superheat ispoured on a cooling slope to achieve a fine and non-dendritic structure. After pouring, the melt, which becomes semisolid at the end ofthe plate, is subsequently poured into a cylindrical steel mold with different mold temperatures. Also, the process has been done in differentcooling slopes and different cooling lengths. This work, at first discusses the effect of these parameters on the final microstructure ofA356 aluminum alloy and then the effect of the controlled atmosphere is discussed. Also, in this research, the advantages of using thecontrolled atmosphere system are discussed by tests such as XRD, SEM and ultrasonic test. Results indicate that the pouring temperature,mold temperature, cooling slope and cooling length have significant effects on the size and morphology of α-Al phase. Also, the controlledatmosphere could optimize the process as well and increase the mechanical properties of alloy.

Microstructure Formation Mechanism and Properties of AZ61 Alloy Processed by Melt Treatment with Vibrating Cooling Slope and Semisolid Rolling

Zhan Yong Zhao,Ren Guo Guan,Xiang Wang,Yang Li,Lei Dong,이종수,Chun Ming Liu 대한금속·재료학회 2013 METALS AND MATERIALS International Vol.19 No.5

A melt treatment with a vibrating cooling slope and a semisolid rolling process to produce an AZ61 alloy strip was proposed. The microstructure formation mechanism and the properties of the AZ61 alloy produced by the proposed process were investigated. Due to the high cooling rate and stirring action caused by the vibration cooling slope, the nucleation rate was greatly improved, which caused the formation of fine spherical or rosette primary grains. During the rolling process, the solid fraction increased from the entrance to the exit of the roll gap, and under the shearing action of the roller, the distribution of solute in the melt was homogenous, and the primary grains grew further. When the casting temperature was 680 °C,a strip with a cross section of 4 mm×160 mm was produced and a homogeneous microstructure was obtained. The ultimate tensile strength of the AZ61 alloy strip produced by the proposed method reached 242 MPa, and the corresponding elongation to failure was 4%, which were better than those achieved in previous similar studies.

Effect of forming conditions on mechanical properties of rheoformed thin plates with microchannels using electromagnetic stirring

Jang, Chang Hyun,Jin, Chul Kyu,Bolouri, Amir,Kang, Chung Gil Professional Engineering Publishing Ltd. 2014 Proceedings of the Institution of Mechanical Engin Vol. No.

<P>Rheoforming is a near net-shape manufacturing technology for fabricating components from light alloys in their semisolid states with improved mechanical properties. In this work, a feasibility study on the fabrication of Silafont 36 aluminum thin plates via rheoforming was conducted. The thin plates were fabricated under different experimental conditions, such as different solid fractions and punch pressures. Electromagnetic stirring was used to prepare a semisolid slurry of Silafont 36 aluminum alloy. Subsequently, the slurry was transferred to die sleeve and injected into the die cavity of the thin plate. The thin plates were successfully fabricated under the optimal conditions of 50% solid fraction and a rheoforming pressure of 130 MPa.</P>