Li Yoke Ho

7 Questions 25 Answers 0 Followers

Questions related from Li Yoke Ho

Can anyone explain what is this EXTRA retention time of the polyphenolic compound in HPLC? Help!

Hi, I Have a very basic knowledge on HPLC. I am studying on a crystalline, hydrophobic/low aqueous solubility polyphenolic compound. I bought it from a supplier at >98% purity. HPLC info:HPLC...

07 July 2017 8,035 12 View

Any way to check encapsulated oil oxidative stability?

Hi,So I encapsulated some oil. Any suggestions to check the oil oxidative stability besides extracting it (via soxhlet) and run peroxide test?There's very little encapsulated oil (around 1.0%...

10 October 2016 3,090 1 View

ABTS Antioxidant activity assay via HPLC?

Hi,Most antioxidant assay for ABTS are done via spectrophotometric method. I am still a noob in all this antioxidant assay. But it should be fine to quantify it using HPLC? Is the below method...

10 October 2016 5,955 2 View

How do I solubilize samples in aqueous solutions?

Hi, I am not from pharmacology background. But I would like to determine my sample aqueous solubility after spray-drying. I chance upon paper belowPaper:Solid Dispersions of α-Mangostin Improve...

07 July 2015 667 9 View

Can anyone help with an entrapment efficiency/encapsulation efficiency calculation?

Is my calculation correct? Lets say my drug system is matrix/microsphere; dried and obtained powder. Entrapment/Encapsulation Efficiency %= (Experimental drug content/total drug content) x...

08 August 2014 7,358 24 View

Can anyone explain why I got weird results on two antioxidant Assays (ABTS & DPPH)?

This is my first time doing an antioxidant assay. I did 2 tests: DPPH & ABTS. 1) DPPH Antioxidant concentration: 0-3mg/ml DPPH Conc: 0.135mM (trial 1) & 0.059mg/ml (trial 2) Trial 1: Sample: 2ml...

03 March 2014 2,182 15 View

Solubility of solute in solvent. What do my results tell me?

My solute which is an antioxidant (0.25g) dissolves easily in acetone (25ml) (99.5%). Whereas my solute (0.25g) does not dissolve in 25ml methanol (99.9%). However it only dissolves when 0.25g in...

02 February 2014 7,321 5 View