Rahimah Othman
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Preferred name
Rahimah Othman
Official Name
Rahimah, Othman
Alternative Name
Othman, Rahimah
Othman, R.
Main Affiliation
Scopus Author ID
24348849600
Researcher ID
DWI-3419-2022

Research Output
Now showing 1 - 3 of 3
  • Publication
    Intensification of antioxidant-rich extract from Moringa Oleifera leaves using different solvents: optimization and characterization
    (Springer, 2023)
    Monisha Devi Elan Solan Marimuthu
    ;
    Rahimah Othman
    ;
    Siti Pauliena Mohd Bohari
    ;
    Wei Jinn Ooi
    Natural antioxidants have gained a huge amount of interest due to their ability to combat devastating ailments such as obesity and hypercholesterolemia. Rich in phenolics and flavonoids, Moringa Oleifera (MO) has piqued the interest of many researchers. MO plants have numerous nutritional and therapeutic advantages. The current study aims to maximize yield by optimizing the conditions of MO leaves extraction with the help of a few organic second solvents. Central Composite Design (CCD) of Response Surface Methodology (RSM) was used to optimize total phenolic content (TPC) and total flavonoid content (TFC) of MO extract. Four independent variables (A) type of second solvents, (B) solvent to second solvent ratio, (C) extraction temperature, and (D) extraction time were studied. TPC was evaluated using the Folin–Ciocalteu colorimetric technique, and extract solutions were measured at 765 nm. TFC was determined by aluminium chloride colorimetric test at wavenumber of 416 nm. The functional group of the optimized MO extract was subsequently studied using Fourier Transform Infrared Spectroscopy (FTIR). The optimization studies indicated that the optimum TPC was 313.265 µg · GAE ·mg−1 and TFC was 90.268 µg · QE · mg−1 which were achieved at formulation conditions of (A) acetone, (B) at 1:3, (C) of 100 °C, and (D) of 240 min. The most intense stretching peak of FTIR spectra was detected at 3262.79 cm−1 revealed the characteristics absorption of hydroxyl groups from phenolic content of MO extract. This simulated finding proved that the best extraction solvent elucidates that MO leaves are rich in valuable antioxidants with tremendous therapeutic potency for obesity and hypercholestrolaemia treatment.
  • Publication
    Smart self-assembled polymeric-MMT/Moringa Oleifera L. particles by solvent replacement method
    ( 2024-10)
    Rahimah Othman
    ;
    Koh Qi Sheng
    ;
    Mohd Irfan Hatim Mohamed Dzahir
    ;
    Monisha Devi
    ;
    Siti Pauliena Mohd Bohari
    Obesity, stemming from metabolic syndrome and energy imbalance, is a common health concern characterized by excess energy consumption and fat buildup. Moringa Oleifera L. (MO), known for its anti-obesity properties, is extracted via Soxhlet extraction. MO is extracted using the Soxhlet extraction method. To evaluate the antioxidant properties of MO powder, several analyses were conducted, including the assessment of total phenolic content (TPC), total flavonoid content (TFC), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) activity, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) activity. The TPC and TFC, DPPH activity, and ABTS activity values were determined to be 386.7 mg GAE/g and 82.33 mg QE/g, 32.86 %, and 49.4 % respectively. To improve drug delivery, the freeze-dried MO powder was encapsulated within a polymeric carrier, poly(-caprolactone) (PCL). Moreover, the incorporation of montmorillonite (MMT) into the MO-loaded PCL nanoparticles enhanced the encapsulation efficiency and drug loading of MO. Nanoprecipitation was employed as a method to produce the nanoparticles, and the effects of four key parameters were studied: the ratio of aqueous phase volume to organic volume (1.5 – 10), stirring speed (400 rpm – 1200 rpm), mass weightage of MO (1 % -5 %), and mass weightage of MMT (2 % - 5 %). Design Expert was utilized for full factorial analysis to assess the impact of these parameters on encapsulation efficiency and drug loading. The optimal formulation was achieved at the ratio of aqueous phase volume to the organic volume of 1.5, stirring speed of 400 rpm, mass weightage of MO at 1 %, and mass weightage of MMT at 5% The expected encapsulation efficiency is 91.33 % and drug loading is 6.49 %.
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  • Publication
    Formation of bioresorbable PCL-loaded Moringa Oleifera L./Natural clay functional particles by solvent displacement method for pharmaceutical applications
    (Springer, 2024)
    Monisha Devi
    ;
    Rahimah Othman
    ;
    Mohd Irfan Hatim Mohamed Dzahir
    ;
    Siti Pauliena Mohd Bohari
    Bioresorbable functional particles offer unique advantages based on different synthetic strategies, with the activated moiety may achieve various targeted drug delivery to minimize side effects. Thus, in this study, a highly MO-loaded adsorptive smart-assembled natural clay (montmorillonite, MMT) dispersion onto poly (ε-caprolactone) nanoparticles matrix (hereafter known as MO-loaded MMT/PCL NPs) is formed by solvent displacement method. MMT is selected due to its great drug loading ability due to high specific surface area and grants mucoadhesive properties with tortuous pathway needed for drug delivery across the gastrointestinal barrier. The MO-loaded MMT/PCL NPs are synthesized by self-solvation interaction between the organic phase that composed of dissolved 1 g L−1 PCL, 2–20 wt % of MMT, and 0.6–3.0 g L−1 of MO in acetone and the aqueous phase consisted of 0.2 wt% poly (vinyl alcohol) surfactant solution. The injection rate of organic phase was fixed at 5 mL min−1 with volume ratio aqueous phase to organic phase (Vaq/Vor) between 3–10, and 600–1200 rpm of stirring speed. The inclusion of MMT in polymer was found to improve the entrapment of hydrophilic MO, hence hindering untimely drug leakage. Particle size decreased with increasing the stirring rate and the aqueous-to-organic volumetric ratio as well as the concentration MMT, thus resulting in drug encapsulation efficiency and drug loading up to 30–50 and 5–10%, respectively. The encapsulation of MMT and MO in the NPs was confirmed by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy.