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RISS 인기검색어
- 검색키워드
- 저자 : Heng Paul Wan Sia (검색결과 3 건)
- 무료
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Role of dwell on compact deformation during tableting: an overview
Parthiban Anbalagan,Celine Valeria Liew,Paul Wan Sia Heng 한국약제학회 2017 Journal of Pharmaceutical Investigation Vol.47 No.3
Tablet compaction is an important unit operation in the pharmaceutical industry. Among the compaction parameters, dwell time is a key parameter that has been consistently been shown to impact the mechanical quality of tablets. Compacts experience a state of relatively constant strain during the dwell phase and this allows time dependent reactions such as viscoelastic flow to take place within the tablet microstructure. The importance of time dependent compact deformation during the dwell phase has been extensively researched over the years. The amount of plastic flow during the dwell phase has been quantified by researchers by calculating the amount of compaction force decay from stress relaxation curves and by determining certain deformation parameters from compaction force–time profiles during high speed tableting. Dwell time prolongation often led to significant enhancements in the mechanical strength of the tablets, due to a favorable timedependent shift in the elastic–plastic equilibrium in the compact. The influence of dwell phase on tablet properties is governed by the predominant deformation properties of constituents being compressed along with other coexisting compaction parameters such as strain rate during the consolidation phase of the compaction cycle. Research work on the impact of dwell time on tablet compaction in conjunction with formulation and process variables are useful as the findings that are representative of manufacturing conditions would be useful for understanding of the compaction process especially in high speed tableting. Press or tool designs may also be accentuated at increasing dwell time without compromising tablet production rate.
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Veronica Natalia,Loh Yi Ying,Loh Lydia Xiu Ying,Heng Paul Wan Sia,Liew Celine Valeria 한국약제학회 2024 Journal of Pharmaceutical Investigation Vol.54 No.2
Purpose This study aimed to elucidate the effects magnesium stearate (MgSt) with different physical properties have on powder flow and tablet physical properties. The effects of variation in MgSt chemical properties were also investigated with a focus on the palmitate to stearate (C16/C18) ratio. Methods Lactose blended with 0.25, 0.5 and 1%, w/w of different MgSt grades were evaluated for flow properties. Tablets produced from the mixtures were assessed for tensile strength and ejection force. Results Pearson correlation analysis of high C16/C18 ratio (1.09–1.29) MgSt suggested that increasing C16/C18 ratio could improve flowability and reduce tablet mechanical strength. For low C16/C18 ratio (0.41–0.53) MgSt, increasing C16/C18 ratio only resulted in better flowability. Multivariate analysis showed that the MgSt properties influenced the flowability and tablet physical properties of formulations containing 1%, w/w MgSt. The C16/C18 ratio affected flowability. However, its effect was confounded by MgSt particle size, morphology, crystallinity, and moisture content. Contrastingly, tablet tensile strength was mainly influenced by MgSt particle size, crystallinity, and moisture content, while tablet ejection force was minimally affected by the MgSt properties. Conclusion While the C16/C18 ratio could affect the powder flow properties, the effect was confounded by other MgSt properties. The C16/C18 ratio also had minimal effect on tablet physical properties. The results further showed that although MgSt with smaller particle size, higher crystallinity and moisture content provided better flowability, the resultant tablets had lower tensile strength. These findings highlighted the importance of MgSt properties for formulations of good flowability and tablet physical properties.
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Examining the effect of spatial distribution of disintegrant particles on tablet disintegratability
Zheng Audrey Yi,Huang Wei Wei,Poon Li Ying Jolene,Wong Eunice Siying,Heng Paul Wan Sia,Chan Lai Wah 한국약제학회 2024 Journal of Pharmaceutical Investigation Vol.54 No.2
Purpose Superdisintegrants are typically used at low concentrations in tablets. As a result, the spatial distribution of disintegrant particles within the tablet may be inhomogeneous, resulting in varied disintegration times. This study aimed to investigate the effect of disintegrant spatial distribution on tablet disintegratability. Methods Tablets with various degrees of disintegrant spatial distribution were engineered using a novel experimental design. The effects of relative spatial distribution of disintegrant particles on tablet tensile strength, liquid penetration rate and disintegration time were investigated. Results It was observed that increased clustering of disintegrant particles generally promoted faster tablet disintegration due to more localized swelling and strain recovery of sodium starch glycolate and crospovidone, respectively. However, for tablets with insoluble fillers and sodium starch glycolate, a high degree of disintegrant clustering prolonged disintegration due to the formation of gel plugs which impeded liquid penetration into the tablet and caused the tablet to break up into floccules instead. Tablets made with insoluble fillers were also found to be more sensitive to changes in disintegrant spatial distribution compared to those containing soluble fillers. Conclusion Overall, the effects of disintegrant spatial distribution were dependent on the type of disintegrant and filler used.
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