PRAVASTATIN ASSAY

The Analysis of Pravastatin in Human Plasma

Chemical structure of Pravastatin. Source: https://en.wikipedia.org/wiki/Pravastatin

What is Pravastatin?

“Pravastatin belongs to a group of medicines called statins, it is used to lower cholesterol if you’ve been diagnosed with high blood cholesterol, it is also taken to prevent heart disease including heart attacks and strokes” (1)

1 in 1000 people taking pravastatin may have serious side effects such as: muscle pain, tenderness, weakness or cramps, severe stomach pain. In rare cases its possible to have a serious allergic reaction (anaphylaxis).

Method:

The first objective of this project was to validate a method for the quantitation of pravastatin residues in human plasma by LCMS analysis.  The second objective was to validate a method for the quantitation of pravastatin lactone in human plasma by LCMS analysis.

The LLOQ and ULOQ were established for the method as 1ng/ml and 100ng/ml respectively for Pravastatin and defined as the lowest and highest validated concentration that meet all acceptance criteria. Accuracy and precision were established at the LLOQ.
.The Limit of Detection for Pravastatin was calculated as 0.885654ng/ml in human plasma.

It was not possible to validate the method for Pravastatin Lactone as it was too unstable, however the Limit of Detection was established to be 11.81485ng/ml in human plasma.

This project took seven years from initial discussion to receipt of samples, so patience is sometimes required!

References.

(1) Pravastatin: a medicine used to lower cholesterol [Internet]. nhs.uk. 2020 [cited 13 November 2020]. Available from: https://www.nhs.uk/medicines/pravastatin/

WHAT ARE CANNABINOIDS?


They are chemicals found in cannabis, the most notable is phytocannabinoid tetrahydrocannabinol (THC), the primary psychoactive compound in cannabis plants. Cannabidiol (CBD) is another major constituent of the plant and these are just two of at least 144 known different cannabinoids isolated from cannabis all exhibiting various affects.(1)

Why use CBD?

CBD oil has been studied for its potential medical role in easing symptoms of many common health issues including anxiety, depression, acne, and heart disease as well as being put into various non-medical products from beers to soaps.(2)

How can B-AC help?

Say a product such as soap has a claimed level CBD, we have an assay to determine the actual level of CBD present, as well as checking that the level of THC is below the legal limit.

What are the legal restrictions?

There is no maximum level of CBD so long as it cannot be easily separated from other compounds in the product, however your product can only contain 0.01% (not detected) THC and no more than 1mg in any CBD product.(3)

The packaging must have clear labelling; no medical claims; its CBD content; manufacturing details and ingredients. This is vigorously tested to ensure companies are not lying about the THC content as it can have the most dangerous psychoactive affects.

Examples

A 200g block of soap has been manufactured with 100mg of CBD and 20mg of THC, are these levels acceptable for it to be sold?

CBD

200g:100mg

200,000mg:100m

(100/200,000) x 100 = 0.05% or 500ppm

THC

200g:20mg

200,000mg:20mg

(20/200,000) x 100 = 0.01% or 100ppm

 

That level of THC is above the legal requirement as there are traces of other cannabinoids so can be no higher than 1mg:

(0.5/200,000) x 100 = 0.00025 or 2.5ppm

The THC levels would need to be tested at an accredited lab to ensure they are at the legal and displayed level.

 

What can we do for you?

We have an assay which can determine the level of the 13 main cannabinoids. We can also develop methods for synthetic or unusual cannabinoids unique to your requirements.

 

HPLC graph with 13 peaks for tested cannabinoids

 

Regulations

https://www.theextract.co.uk/is-cbd-legal-uk/

References:

1) Cannabinoid [Internet]. En.wikipedia.org. 2020 [cited 11 September 2020]. Available from: https://en.wikipedia.org/wiki/Cannabinoid

2)  7 Benefits and Uses of CBD Oil (Plus Side Effects) [Internet]. Healthline. 2020 [cited 11 September 2020]. Available from: https://www.healthline.com/nutrition/cbd-oil-benefits#:~:text=CBD%20oil%20has%20been%20studied,for%20pain%20and%20symptom%20relief.

3) CBD Regulation UK – – Explained – – Medic Pro Limited [Internet]. Medic Pro. 2020 [cited 11 September 2020]. Available from: https://www.medicpro.london/cbd-regulation-laws-uk/#:~:text=So%20the%200.2%25%20limit%20does,limit%20of%20detection%20of%200.01%25.

 

WHAT IT’S LIKED TO BE TRAINED AT THE BIO ANALYSIS CENTRE.

Alongside analytical services we also provide training courses on Shimadzu Nexera XP HPLC and Shimadzu LCMS-8040, these include:

  • 3 day HPLC analysis
  • 5 day LCMS analysis
  • 1 day HPLC refresher course
  • 1 day general laboratory skills

To get an understanding of the benefits of our courses, we asked those who had been previously trained questions about their experience here. Some answers where extracted from previously submits surveys, shown with Anonymous (Anon).

  1. Which training course did you follow?

E: I came in on a summer internship to gain some relevant experience for my degree and was trained up to run all the instruments in the lab.

M: LC-MS 5 day course.

  1. Why did you choose the Bio Analysis Centre for training?

E: It is a small team so I knew I would get good 1 on 1 training in a quiet setting where I could learn.

M: Course content and excellent reviews.

  1. How did the training received compare to what knowledge you previously had?

E: I had very little previous knowledge, maybe some basics of the principles behind the techniques but no idea how to run the machines or how to set up a practical on them.
In that sense I was taught everything from scratch, even my basic lab skills where greatly improved during this training.

M: It was an intensive 5-day course that covered all aspects of MS thoroughly and in great depth.

  1. What did you hope to gain from your training course?

E: Some new skills to be able to add to my CV, they are such unusual skills to have for someone my age and I was very grateful for the opportunity to learn new things.

M: My aim was to gain hands-on experience in Mass Spectrometry. I wanted to be able to run analysis independently.

  1. Was there anything else you would’ve liked to have learnt?

E: No Comment

M: The course covered everything I needed.

Anon: More on the Mass Spectrometer if had more time and more method development on LC + LCMS

Anon 2: General lab practice such as pipettes and weights calibration

  1. Were there any areas that could’ve been improved?

E: No not that I can think of.

M: No comment.

Anon: Some basic theory at the beginning of the course to cater for beginners, however it was addressed as we went along

  1. Would you recommend our training programmes to a colleague?

E: Definitely, if anyone said they need this sort of work doing I would encourage them to come learn how to do it themselves, it’s a great thing to know how to do.

M: I would highly recommend this course to colleagues and other PhD students who would want to gain experience in Mass Spectrometry.

For the Following statements:

Q8 Services Provided,
Q9 Quality of training,
Q10 Interaction with trainer,
Q11 Understanding of the topic,

we asked the participants in the survey to rate on a scale from 1 – 5, 1 being very bad and 5 very good, how their training was. All results, which can be seen in Graph 1 below, came back with very good (5) as the answer to all.

Graph 1

 

Graph 2

 

Graph 2 above shows previously gathered information along side the new data of the participant’s overall enjoyment of training at the BAC, with an average of 4.5 / 5 between 10 participants.

Alongside the overall enjoyment these comments where left:

Great training course in a great facility, enjoyed my time being trained there by Cali and Amy. Thank you!

Thanks to Cali and the team for a great training course. It has been really informative and useful for our research, Cali’s expertise allowed us to tailor the training to our specific need.

Our experience with Cali at the Bio Analysis Centre was really constructive, she provided us with a lot of insight and tips for our type of experiment. Highly recommended.

Dr Carolyn Hyde is very experienced teaching expert on this programme and a great manager too! We will talk more on all possible collaborations. Many thanks for sharing all the information and knowledge!

METABOLITES ASSAY

Simultaneous Analysis of 97 Primary Metabolites on a Pentafluorophenylpropyl Column (PFPP). This assay was performed by Shimadzu (1), the manufacturer of the equipment used, all information shown is from them unless otherwise stated.

What are Metabolites?

‘Metabolites are substances made or used when the body breaks down food, drugs, chemicals, or its own tissue (for example, fat or muscle tissue). This process, called metabolism, makes energy and the materials needed for growth, reproduction, and maintaining health. It also helps get rid of toxic substances’ (2).

Energy at the cellular level is derived by various metabolic processes, including the glycolytic system and the TCA cycle. In order to investigate the metabolites of living systems it is important to quantify the amount of each metabolite.

 

Table 1: List of Metabolites detected taken from Shimadzu paper (1)

Method and Sampling

Many primary metabolites are hydrophilic and difficult to analyse by reverse phase chromatography.  Usually, Ion pair chromatography is used for hydrophilic compounds, but this is not compatible with LCMS analysis due to the ion pair reagents causing high background signals and sensitivity deterioration.

A method using a PFPP column has been developed to overcome these limitations, it allows not only hydrophobic interaction but also retention of hydrophilic compounds, which is essential for successful analysis of primary metabolites.

The samples provided to Shimadzu were tissue extracts and all measurements were done on a Shimadzu LCMS – 8040 Triple Quadrupole UFMS.

Liver and Heart tissue samples where extracted and immediately frozen in liquid nitrogen, each frozen sample was weighed and homogenised in methanol containing internal standards. After homogenisation, a methanol-chloroform extraction was carried out, the metabolites were collected, and the extracts concentrated.

After preparation, 3 µl of the solution was injected onto the column using the gradient shown in Table 2 at a flow rate of 0.25ml / min.

Table 2: Gradient used for Metabolite Analysis (1)

In each extract over 80 metabolites were detected, the PFPP column was especially effective at separating the amino acids and organic acids (1).

References:

  1. Simultaneous Analysis of 97 Primary Metabolites By PFPP: Pentafluorophenylpropyl Column [Internet]. Shimadzu Excellence in Science. 2014 [cited 16 March 2020]. Available from: https://www.shimadzu.com/an/literature/lcms/jpo114088.html
  2. NCI Dictionary of Cancer Terms [Internet]. National Cancer Institute. [cited 16 March 2020]. Available from: https://www.cancer.gov/publications/dictionaries/cancer-terms/def/metabolite

 

 

 

MYCOTOXIN ASSAY

This assay was performed by Shimadzu (1), the manufacturer of the equipment used, all information shown is from them unless otherwise stated.

Mycotoxins are severely toxic contaminants which can be found in grains, they’re naturally occurring and are produced by certain moulds found on food (fungi) and present a risk to human health. The most common are Aflatoxins and Ochratoxin A. The World Health Organisation set the maximum level for Aflatoxin in food at 0.5 – 15 µg/kg (2) and for Ochratoxin-A at 1 – 50 µg/mg for food and 100 – 1000 µg/kg for animal feed (3).

Due to the toxicity of Mycotoxins, the rapid determination of their presence is essential. UHPLC-MS/MS offers the best combination of selectivity, sensitivity, and speed for detecting these compounds in complex matrices. In this study (1), a high throughput method for the quantitation of 23 Mycotoxins in various matrices was established.

Method:

5g of dry food (such as grain or animal feed) was mixed with 10ml of water to produce the sample. 10g of wet food (such as fruit) produced the sample.

10ml Acetonitrile was added and the sample macerated, before salts were added to allow phase separation.  The solution was then centrifuged to pellet the solids. The supernatant was transferred to a clean tube and 5 fold diluted with Mobile Phase A (Water + 0.5% acetic acid) and internal standard.

20 µl of the solution was injected onto the column using the gradient shown in Table 1 at a flow rate of 0.4ml / min.

Table 1: Gradient used for Mycotoxin Analysis

This assay could be used for any type of food, and as the method is developed by the manufacturer on the exact machine, we can run this assay. If you have a similar project would like analysed, then please get in contact.

 

References

  1. Rapid simultaneous assay of 23 mycotoxines in a variety of food samples by UHPLC-MS/MS using fast polarity switching [Internet]. 2013 [cited 2 March 2020]. Available from: https://www.shimadzu.com/an/literature/lcms/fro113069.html
  2. Mycotoxins [Internet]. World Health Organisation. 2018 [cited 2 March 2020]. Available from: https://www.who.int/news-room/fact-sheets/detail/mycotoxins
  3. Egmond V. Worldwide regulations for Ochratoxin A [Internet]. 1991 [cited 2 March 2020]. Available from: https://www.ncbi.nlm.nih.gov/pubmed/1820350

GUT MALABSORPTION ASSAY

Gut permeability is an issue when there are changes and the absorption of nutrients is altered.

The Theory:

A solution of 3 sugars are given to patients at a set concentration, then either urine or blood samples are taken at set time points for analysis. The ratio of the Lactulose (disaccharide) to either Rhamnose or Mannitol (monosaccharides) indicates if and where there is a problem in the gut. These 3 sugars are not metabolised by the body, they just permeate across the gut wall.

How we are involved:

We have developed two analysis methods, based on published work, to measure these sugars in either urine or plasma. We have a lower limit of quantitation of 15µg/ml in Urine and 7.5µg/ml in Plasma, however we would advise that the actual lower levels should be 25µg/ml for urine and 15µg/ml for plasma to ensure that the lowest levels do not fall outside the calibration range. Figure 1 shows the timing and peaks for the sugars being sent round the HPLC.

Figure 1: Graph from the HPLC showing the 3 sugars separation and their associated retention times.

We are working with Mike Hewetson from the Royal Veterinary College to adapt the plasma method for use with equine serum. At present, there is no easy way of determining where a problem is in the equine gut and it is hoped that this test will offer an alternative to submitting the horse for a surgical procedure.

WHAT CAN WE DO FOR YOU?

Here at the Bio Analysis Centre we have the capability to run samples through our UHPLC (Ultra High Performance Liquid Chromatograph) or LCMS (Liquid Chromatograph Mass Spectrometer). Shimadzu (1), the manufacture of the machinery, ran a Multiple Residue Analysis of 210 Pesticides in Food Samples by Triple Quadrupole UHPLC – MS/MS.

 

Pesticide residue on food can severely affect human health, so governments and food manufacturers established regulations which set the limits in a range of 0.01 – 10 mg / kg depending on the toxicity of the pesticide. For food used in the production of baby foods, the detectable level of pesticide must be less than 0.01 mg / kg along with prohibiting the use of certain toxic pesticides.

 

Linearity was investigated over a nine point calibration, with samples ranging from 0.5 μg / kg – 0.2mg / kg or 0.5 – 200 parts per billion (ppb) analysed in duplicate; calibration samples were injected once in increasing order and once in decreasing order. From that the Mass Spectrometer calculated from the area of the peak the concentration by correlating to the calibration curve associated with the specific pesticide.

 

This exact assay can be conducted here at the Bio Analysis Centre, if you have a similar project or any enquiries for any other assay, please contact us.

 

References

  1. Multi-Residue Analysis of 210 Pesticides in Food Samples by Triple Quadrupole UHPLC-MS/MS [Internet]. Shimadzu; [cited 29 January 2020]. Available from: https://www.shimadzu.com/an/literature/lcms/jpo113017.html?fbclid=IwAR0vWv-SXKE4BKlRmm_RgKE7JkAFXR9i-JJn3KsZRGb2sYxMwxiyaWKkNWk