Displaying all 12 publications

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  1. Goh YY, Keshavarzi F, Chew YL
    Dermatitis, 2018 5 16;29(3):151-161.
    PMID: 29762208 DOI: 10.1097/DER.0000000000000376
    BACKGROUND: Atopic dermatitis (AD) is a chronic relapsing, noncontagious skin inflammation characterized by dry skin and itch. Mutation in filaggrin gene leads to defective skin barrier, allowing entry of allergen and eliciting immunological response.

    OBJECTIVES: The aims of this study were to investigate the prevalence of AD in Malaysian children and to understand the pattern of drug therapy. Such information could be useful to establish the relationship between ethnicity and family history of atopy and the development of associated signs and symptoms.

    METHODS: A cross-sectional survey was conducted among children attending kindergartens and nurseries. Standardized questionnaires were filled out by parents.

    RESULTS: Overall prevalence of AD was 13.4%. Of 384 participants recruited, the highest prevalence was observed in males, Malays, participants younger than 2 years, and those with atopic background such as asthma, hay fever, and family history of atopic diseases. Calamine and white soft paraffin were the preferred choice of nonprescription drugs, whereas topical hydrocortisone seemed to be the preferred choice of prescription drug in the management of AD.

    CONCLUSIONS: The overall prevalence is comparable to that reported in the International Study of Asthma and Allergies in Childhood Phase One. There is an association between ethnicity and AD prevalence. Topical corticosteroids and emollients are the mainstay of AD management among Malaysians.

  2. Chew YL, Khor MA, Lim YY
    Heliyon, 2021 Mar;7(3):e06553.
    PMID: 33855234 DOI: 10.1016/j.heliyon.2021.e06553
    Stability indicating assay describes a technique which is used to analyse the stability of drug substance or active pharmaceutical ingredient (API) in bulk drug and pharmaceutical products. Stability indicating assay must be properly validated as per ICH guidelines. The important components in a stability indicating assay include sensitivity, specificity, accuracy, reliability, reproducibility and robustness. A validated assay is able to measure the concentration changes of drug substance/API with time and make reliable estimation of the quantity of the degradation impurities. The drug substance is separated and resolved from the impurities. Pros and cons of HPLC, GC, HPTLC, CE and SFC were discussed and reviewed. Stability indicating assay may consist of the combination of chromatographic separation and spectroscopic detection techniques. Hyphenated system could demonstrate parallel quantitative and qualitative analysis of drug substances and impurities. Examples are HPLC-DAD, HPLC-FL, GC-MS, LC-MS and LC-NMR. The analytes in the samples are separated in the chromatography while the impurities are chemically characterised by the spectroscopy in the system. In this review, various chromatographic methods which had been employed as stability indicating assays for drug substance and pharmaceutical formulation were systematically reviewed, and the application of hyphenated techniques in impurities characterisation and identification were also discussed with supporting literatures.
  3. Chew YL, Mahadi AM, Wong KM, Goh JK
    BMC Complement Altern Med, 2018 Feb 20;18(1):70.
    PMID: 29463252 DOI: 10.1186/s12906-018-2137-5
    BACKGROUND: Bauhinia kockiana originates from Peninsular Malaysia and it is grown as a garden ornamental plant. Our previous study reported that this plant exhibited fairly strong antioxidant and antimicrobial activities. This paper focused on the assessment of the antibacterial activity of B. kockiana towards methicillin-resistance Staphylococcus aureus (MRSA), to purify and to identify the antibacterial compounds, and to determine the mechanism of antibacterial activity.

    METHODS: Antibacterial activity of B. kockiana flower was evaluated qualitatively and quantitatively using disc diffusion assay and microbroth dilution method. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of extracts were examined. Phytochemical analysis was performed to determine the classes of phytochemicals in the extracts. Bioactivity guided isolation was employed to purify the antibacterial agents and identified via various spectroscopy methods. Scanning electron microscopy (SEM) technique was used to evaluate the antibacterial mechanism of extract and compounds isolated.

    RESULTS: B. kockiana flower was found to exhibit fairly strong antibacterial activity towards both strains of MRSA bacteria used, MIC varies from 62.5-250 μg/mL. Tannins and flavonoids have been detected in the phytochemical analysis. Gallic acid and its ester derivatives purified from ethyl acetate extract could inhibit MRSA at 250-500 μg/mL. SEM revealed that the cells have undergone plasmolysis upon treatment with the extract and compounds.

    CONCLUSION: Tannins and polyphenols are the antibacterial components towards MRSA in B. kockiana. Massive leakage of the cell content observed in treated cells showed that the phytochemicals have changed the properties of the cell membranes. Amphiphilic nature of the compounds exhibited the antibacterial activity towards MRSA via three stages: (1) cell membrane attachment; (2) cell membrane fluidity modification; and (3) cell membrane structure disruption.

  4. Leong RZL, Lim LH, Chew YL, Teo SS
    Anim Biotechnol, 2023 Dec;34(9):4474-4487.
    PMID: 36576030 DOI: 10.1080/10495398.2022.2158094
    Sea cucumber is a bioremediator as it can composite organic matter and excrete inorganic matter. Sea cucumber has the potential to serve as a bioindicator in marine habitat as they provide an integrated insight into the status of their environment over long periods. Sea cucumbers are sensitive to the organic concentration in the marine environment and can effectively provide an early warning system for any organic contamination that can negatively impact the ecosystem. The availability of a reference transcriptome for sea cucumber would constitute an essential tool for identifying genes involved in crucial steps of the defence pathway. De novo assembly of RNA-seq data enables researchers to study the transcriptomes without needing a genome sequence. In this study, sea cucumbers fed with Kappaphycus alvarezii powder were treated with 0.20 mg/L copper concentration comprehensive transcriptome data containing 75,149 Unigenes, with a total length of 20,460,032 bp. A total of 8820 genes were predicted from the unigenes, annotated, and functionally categorized into 25 functional groups with approximately 20% cluster in signal transduction mechanism. The reference transcriptome presented and validated in this study is meaningful for identifying a wide range of gene(s) related to the bioindication of sea cucumber in a high copper environment.
  5. Chew YL, Lim YY, Stanslas J, Ee GC, Goh JK
    PMID: 25371595
    BACKGROUND: Flowers of Bauhinia kockiana were investigated for their anticancer properties.

    METHODS: Gallic acid (1), and methyl gallate (2), were isolated via bioassay-directed isolation, and they exhibited anticancer properties towards several cancer cell lines, examined using MTT cell viability assay. Pyrogallol (3) was examined against the same cancer cell lines to deduce the bioactive functional group of the phenolic compounds.

    RESULTS: The results showed that the phenolic compounds could exhibit moderate to weak cytotoxicity towards certain cell lines (GI50 30 - 86 µM), but were inactive towards DU145 prostate cancer cell (GI50 > 100 µM).

    CONCLUSION: It was observed that pyrogallol moiety was one of the essential functional structures of the phenolic compounds in exhibiting anticancer activity. Also, the carboxyl group of compound 1 was also important in anticancer activity. Examination of the PC-3 cells treated with compound 1 using fluorescence microscopy showed that PC-3 cells were killed by apoptosis.

  6. Chew YL, Chan EW, Tan PL, Lim YY, Stanslas J, Goh JK
    PMID: 21306653 DOI: 10.1186/1472-6882-11-12
    Many medicinal plants from Leguminosae family can be found easily in Malaysia. These plants have been used as traditional medicines by local ethnic groups, where they are prepared as decoction, pastes for wound infections, and some have been eaten as salad. This paper focused on the assessment of antioxidant potential, antibacterial activity and classes of phytochemicals of nine plants from the Leguminosae family.
  7. Wiart C, Tan PL, Rajagopal M, Chew YL, Leong MY, Tan LF, et al.
    BMC Complement Med Ther, 2024 Jul 12;24(1):268.
    PMID: 38997637 DOI: 10.1186/s12906-024-04548-5
    Wound is defined as the damage to biological tissues including skin, mucous membranes and organ tissues. The acute wound heals in less than 4 weeks without complications, while a chronic wound takes longer than 6 weeks to heal. Wound healing occurs in 4 phases, namely, coagulation, inflammatory, proliferative and remodeling phases. Triclosan and benzalkonium chloride are commonly used as skin disinfectants in wound healing. However, they cause allergic contact dermatitis and antibiotic resistance. Medicinal plants are widely studied due to the limited availability of wound healing agents. The present review included six commonly available medicinal plants in Malaysia such as Aloe barbadensis Miller, Carica papaya Linn., Centella asiatica Linn., Cymbopogon nardus Linn., Ficus benghalensis Linn. and Hibiscus rosa sinensis Linn. Various search engines and databases were used to obtain the scientific findings, including Google Scholar, ScienceDirect, PubMed Central and Research Gate. The review discussed the possible mechanism of action of medicinal plants and their active constituents in the wound healing process. In addition, their application in nanotechnology and wound dressings was also discussed in detail.
  8. Sang SH, Akowuah GA, Liew KB, Lee SK, Keng JW, Lee SK, et al.
    Heliyon, 2023 Nov;9(11):e21876.
    PMID: 38034771 DOI: 10.1016/j.heliyon.2023.e21876
    Hair shampoos containing botanical ingredients without synthetic additives, such as parabens, petrochemicals, sulfates and silicones are more skin- and environmentally friendly. In recent years, there is a growing demand for shampoo products with botanical extracts. Shampoos with botanical extracts are well-known for their perceived health benefits. They are also generally milder, non-toxic, natural, and less likely to disrupt the hair and scalp's natural pH and oil balance. Many also believe that shampoos with botanical origins have higher standards of quality. Numerous botanical extracts had been used as natural active ingredients in cosmetic formulations to meet consumer demands. In this review, we have revisited six tropical plants commonly added as natural active ingredients in shampoo formulations: Acacia concinna, Camellia oleifera, Azadirachta indica, Emblica officinalis, Sapindus mukorossi, and Garcinia mangostana. These plants have been traditionally used for hair care, and scientific research has shown that they exhibit relevant physicochemical properties and biological activities that are beneficial for hair care and scalp maintenance.
  9. Hazdi SN, Phang HC, Ng ZQ, Chew YL, Uddin AH, Sarker ZI, et al.
    Int J Pharm Compd, 2023;27(6):522-527.
    PMID: 38100670
    Orally disintegrating tablets, which were originally developed in the pharmaceutical field to improve the compliance of patients who had difficulty swallowing tablets, have become a preferable choice in solid dosage forms since it brings advantages to the patients and consumers in the healthcare system. Among the advantages of this novel dosage form are a faster onset of action, improved bioavailability, and the ease of administration as it can be taken without water. However, there are still some limitations of orally disintegrating tablets that need to be overcome, including a lack of mechanical strength, an unpleasant taste of the drug in the mouth, and a stability issue due to its hygroscopicity nature. This objective of this study was to identify the composition of co-processed excipients comprising of mannitol, microcrystalline cellulose, xylitol, and crospovidone or croscarmellose sodium in order to formulate orally disintegrating tablets containing memantine hydrochloride. This study was carried out in two stages. Firstly, orally disintegrating tablets containing memantine hydrochloride with 6 different formulations, which differed in the percentage of crospovidone or croscarmellose sodium, were formulated and manufactured. Secondly, the orally disintegrating tablets obtained were evaluated through pre- and post-compression tests based on the standard for orally disintegrating tablets. Formulation 3, which consisted of 10% xylitol, 10% mannitol, 72% microcrystalline cellulose, and 8% crospovidone, was chosen as the optimum formulation for the co-processed excipient since it was the fastest disintegration process among all the formulations in the study. In addition, Formulation 3 also showed the acceptable and satisfying results in other evaluation tests such as - weight variation test, hardness test, and friability test. The co-processed excipient comprising of 10% xylitol, 10% mannitol, 72% microcrystalline cellulose, and 8% crospovidone, which is characterized by improved functionalities such as a fast disintegration process, plays a crucial role in the application of orally disintegrating tablets.
  10. Loke YH, Phang HC, Mohamad N, Kee PE, Chew YL, Lee SK, et al.
    Planta Med, 2024 Jul 23.
    PMID: 39043195 DOI: 10.1055/a-2359-8097
    For decades, cocoa butter has been extensively used in food industries, particularly in the production of chocolate confectioneries. The composition of fats within cocoa butter, such as stearic acid, palmitic acid, and oleic acid, determines its properties. Studies have indicated the existence of at least six polymorphic forms of cocoa butter, each possessing distinct characteristics and melting points. Recently, cocoa butter has garnered attention for its potential as a delivery system for pharmaceutical products. This review thoroughly explores cocoa butter, encompassing its production process, composition, properties, and polymorphism. It delves into its diverse applications across various industries including food, cosmetics, and pharmaceuticals. Additionally, the review investigates cocoa butter alternatives aiming to substitute cocoa butter and their roles in different drug delivery systems. The unique properties of cocoa butter have sparked interest in pharmaceutical industries, particularly since its introduction as a drug delivery system and excipient. This has prompted researchers and industry stakeholders to explore novel formulations and delivery methods, thereby expanding the range of options available to consumers in the pharmaceutical market.
  11. Mod Razif MRF, Chan SY, Widodo RT, Chew YL, Hassan M, Hisham SA, et al.
    Cancers (Basel), 2023 Jul 24;15(14).
    PMID: 37509402 DOI: 10.3390/cancers15143741
    BACKGROUND: Luteolin is a flavonoid compound that has been widely studied for its various anti-cancer properties and sensitization to multidrug-resistant cells. However, the limited solubility and bioavailability of Lut hindered its potential clinical use. Theoretically, the combination of this compound with vitamin E TPGS and poloxamer 407 can produce a synergistic effect to enhance tumor apoptosis and P-glycoprotein inhibition. This study aimed to develop and optimize vitamin E TPGS/Poloxamer 407 micelles loaded with luteolin through investigating certain factors that can affect the encapsulation efficiency and particle size of the micelle.

    METHODS: A micelle was prepared using the film hydration method, and the micellar solution was lyophilized. The cake formed was analyzed. The factors investigated include the concentrations of the surfactants, ratio of vitamin E TPGS/Poloxamer 407, temperature of the hydrating solution, duration of hydration, and freezing temperature before lyophilization. The effects of these factors on the encapsulation efficiency and particle size of the micelle were also studied. The encapsulation efficiency was measured using a UV-Vis spectrophotometer, while particle size was measured using dynamic light scattering.

    RESULTS: The optimized micelle was found to have 90% encapsulation efficiency with a particle size of less than 40 nm, which was achieved using a 10% concentration of surfactants at a vitamin E TPGS/Poloxamer 407 ratio of 3:1. The optimized temperature for hydrating the micellar film was 40 °C, the optimized mixing time was 1 h, and the optimized freezing temperature was -80 °C. The solubility of the luteolin-loaded micelles increased 459-fold compared to pure Lut in water. The critical micelle concentration of the vitamin E TPGS/Poloxamer 407 micelle was 0.001 mg/mL, and the release study showed that luteolin-loaded micelles exhibited sustained release behavior. The release of luteolin from a micelle was found to be higher in pH 6.8 compared to pH 7.4, which signified that luteolin could be accumulated more in a tumor microenvironment compared to blood.

    CONCLUSION: This study demonstrated that several factors need to be considered when developing such nanoparticles in order to obtain a well-optimized micelle.

  12. Loke YH, Chew YL, Janakiraman AK, Lee SK, Uddin ABMH, Goh CF, et al.
    Drug Dev Ind Pharm, 2024 Jan;50(1):36-44.
    PMID: 38149637 DOI: 10.1080/03639045.2023.2294095
    INTRODUCTION: Orally disintegrating tablets (ODTs) are designed to dissolve in the oral cavity within 3 min, providing a convenient option for patients as they can be taken without water. Direct compression is the most common method used for ODTs formulations. However, the availability of single composite excipients with desirable characteristics such as good compressibility, fast disintegration, and a good mouthfeel suitable for direct compression is limited.

    OBJECTIVE: This research was proposed to develop a co-processed excipient composed of xylitol, mannitol, and microcrystalline cellulose for the formulation of ODTs.

    METHODS: A total of 11 formulations of co-processed excipients with different ratios of ingredients were prepared, which were then compressed into ODTs, and their characteristics were thoroughly examined. The primary focus was on evaluating the disintegration time and hardness of the tablets, as these factors are important in ensuring the ODTs meet the desired criteria. The model drug, Mirtazapine was then incorporated into the chosen optimized formulation.

    RESULTS: The results showed that the formulation comprised of 10% xylitol, 10% mannitol and 80% microcrystalline cellulose demonstrated the fastest disintegration time (1.77 ± 0.119 min) and sufficient hardness (3.521 ± 0.143 kg) compared to the other formulations. Furthermore, the drug was uniformly distributed within the tablets and fully released within 15 min.

    CONCLUSION: Therefore, the developed co-processed excipients show great potential in enhancing the functionalities of ODTs, offering a promising solution to improve the overall performance and usability of ODTs in various therapeutic applications.

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