Norah
★    

Tunisia,
2018-12-11 12:30
(1934 d 04:43 ago)

Posting: # 19677
Views: 2,599
 

 aspirin degradation [Bioanalytics]

Hi Dears
I'm preparing a BE protocol regarding, enteric delaying release aspirin (acide acetyl salicilique) but because of the instability of ASPIRIN in plasma,
we must take some precautions with anticoagulant, and in sample preparation too.
Could you please tell me what are you recommendations to avoid the degradation of active ingredient in metabolite.
Helmut
★★★
avatar
Homepage
Vienna, Austria,
2019-02-02 17:56
(1880 d 23:17 ago)

@ Norah
Posting: # 19848
Views: 1,848
 

 ASS stabilization

Hi Norah,

❝ I'm preparing a BE protocol regarding, enteric delaying release aspirin […] Could you please tell me what are you recommendations to avoid the degradation of active ingredient in metabolite.


In my CRO we had two methods (anticoagulant K3EDTA or Li-heparin). Example for 10 mL vacutainers.
  1. Stabilizer H3PO4
    Prepare 5% orthophosporic acid (59 mL 85% o-H3PO4 p.a. diluted to 1000 mL).
    Caution: Even diluted phosphoric acid is strongly acidic; wear gloves and eye protection.
  2. Stabilizer potassium fluoride
    Prepare cold saturated KF solution (100 g KF p.a. in 100 ml water).
    Caution: KF is poisonous. Observe the usual rules.
Penetrate the stopper of 10 mL vacutainers (e.g., by a 200–500 µL HPLC syringe with a thin needle) and inject 100 µl of the respective stabilizer. Use these for all samples.

Handling & storage

Put blood samples immediately after draw in an ice-bath. Allow 10 minutes for equilibration and centrifuge at ~2000×g at +4 ℃ for 20 minutes.

  1. Mix plasma with 5% H3PO4 1:1 (exactly!). Store at ≤20 ℃.
  2. Store at ≤70 ℃.
If you have no problems with sensitivity I would suggest #1. However, the final dilution step is labour-intensive. #2 gives a ~2times lower LOQ but the deep-freezer will suck up a lot of electricity…

Dif-tor heh smusma 🖖🏼 Довге життя Україна! [image]
Helmut Schütz
[image]

The quality of responses received is directly proportional to the quality of the question asked. 🚮
Science Quotes
UA Flag
Activity
 Admin contact
22,957 posts in 4,819 threads, 1,638 registered users;
69 visitors (0 registered, 69 guests [including 6 identified bots]).
Forum time: 17:14 CET (Europe/Vienna)

Nothing shows a lack of mathematical education more
than an overly precise calculation.    Carl Friedrich Gauß

The Bioequivalence and Bioavailability Forum is hosted by
BEBAC Ing. Helmut Schütz
HTML5