Accuracy of enteral syringes for liquid medicines prescribed in children Karuna Gurung, UCL School of Pharmacy

Accuracy of enteral syringes for liquid

medicines prescribed in

childrenKaruna Gurung, UCL School of Pharmacy

UCL SCHOOL OF PHARMACYBRUNSWICK SQUARE

Accuracy of enteral syringes for liquid medicines prescribed in children

Arenas-Lopez S, Gurung K , Wei Li , Tibby S, Tuleu C

http://www.guysandstthomas.nhs.uk/Home.aspx


Liquid dosage form (e.g. Solutions, suspensions)

Oral administration devices: Example :Measuring spoons, measuring cups, droppers,

oral syringes

Oral syringes are better than other devices but…

Paediatrics

Image source: www.rxlist.com/onfi-drug

http://www.theannals.com/cgi/content/full/42/1/46/FIG1


Aims

A. To compare the dosing accuracy of oral syringes from different brands :

Baxa and Medicina Of different syringe sizes for each brands At different volumes size for each brands and each

sizes

B. To investigate the influence of physical characteristics of oral liquid drugs on the accuracy of oral syringes


Materials & Methods

Aqueous

1) Calcium Carbonate BP suspension

2) Amoxicillin 125mg/5ml suspension

3) Peppermint water BP 1974

4)Nifedipine oral drops

Lipidic

9)Neoral oral solution

(ciclosporin)

10) Ciproxin (Ciprofloxacin)

suspension

Hydro-alcoholic

5) Lanoxin PG elixir (Digoxin)

6)Sytron elixir

7) One-alpha (alfacalcidol)

8) Epanutin(phenytoin) suspension

Liquid drugs were chosen according to their foreseeable differences in characteristics

Water = control


Characterisation of Liquids

ViscosityAt shear rate of

100 s-1Rotational rheometer

(Gemini HR nano by Malvern)

DensityDensity=

mass/volume

Measuring cylinders/

Balance (Precisa 180A balance)

Surface Tension

Tensiometer (Delta-8

multichannel microtensiometer

by Kibron Inc.)

Conductivity

Conductivity meter (Primo 5

Hanna ®)

pHpH

pH meter (pH 209 Hanna®)

n=3


Oral syringes’ brands and sizesBAXA

MEDICINA

1ml 2.5ml 5ml

5ml3ml1ml

widerTips

taperedTips

1ml 2.5ml 5ml

1ml 3ml 5ml

0.01ml 0.1ml 0.2ml

Oral Syringe sizes – smallest graduations


6 Drugs : Lanoxin, Amoxicillin, Ciproxin, Peppermint water, Calcium Carbonate BP, Sytron

5 Drugs: Amoxicillin, Ciproxin, Peppermint water, Calcium Carbonate BP, Sytron

1ml Syringes

2.5ml/3ml syringes

5ml syringes

All 10 liquid drugs

Drugs used

Water = control


Volume Measured

0.05ml 0.1ml 0.25ml 0.5ml 1ml

0.1ml 0.25ml 0.5ml 1ml 2ml

0.2ml 0.5ml 1ml 2ml 3ml 5ml

1ml Syringe

2.5ml/3ml syringe

5ml syringe

• 10 measurements were carried out with each volume of liquid

n=10New syringe at each measurement


(measured) density d=m/V

Volume

mean +/- Standard deviation n= 10

Data analysed by ANCOVA (Stata)Significance: 0.05

Dead spacevolume

Dose volume

weight

Method


Irrespective of syringe size, volume and liquid delivered, the dead space was fairly constant

• Baxa [0.07+/-0.05ml] • Medicina (wider tip) [0.13+/-0.08ml]

• However for the accuracy of volumes, all 2- and 3-way interactions (brand ± syringe size ± drug volume) were examined and all were very significant

Results


Baseline model : brand, syringe size and drug volume

M


Comparison between brands: 1ml syringe

INCREASING VISCOSITY


Comparison between brands: 2.5ml/3ml syringe




Surface Tension

Viscosity

B


• Dosing accuracy with enteral syringes commonly found in the HealthCare systems was heterogenous for different brands, sizes and liquid characteristics especially for small volumes (0.25ml and less) which are not uncommon doses in paediatrics

• To improve medication safety in paediatrics, carers should choose the right syringe size for the dose (for small volumes <0.5ml use 1ml size syringes or less if available)

• Manufacturers need to include as part of the pharmaceutical development plan the validation of the syringes to use with their products specially if dosing volumes are envisaged to be <0.5ml

Conclusion

0.5ml


Future work

• Clinical significance of these variabilities?- Including possibility of rounding the dose volumes to

the next accurate volume (if the Therapeutic index of the drugs permits)

• What is the accuracy of devices supplied as part of the packaging of licensed products? Are they any better?– Neoral (1 and 4ml syringes)


Thank you for listening

Any questions?

AcknowledgementsThe Evelina London Paediatric Pharmacy Team for their kind donations of Oral Liquid Medicines

http://www.guysandstthomas.nhs.uk/Home.aspx



Model Simulation 1 ml syringes


2.5ml/3ml syringe

0.2ml 0.5ml 1ml 2ml 3ml 5ml

0.05ml 0.1ml 0.25ml 0.5ml 1ml

0.1ml 0.25ml 0.5ml 1ml 2ml

1ml Syringe

5ml syringe

Volume measurements

UCL SCHOOL OF PHARMACYBRUNSWICK SQUARE Comparison between sizes

MEDICINA


Comparison between sizes: 1ml and 2.5ml/3ml syringe size





UCL SCHOOL OF PHARMACYBRUNSWICK SQUAREComparison between brands: 2.5ml/3ml syringe

UCL SCHOOL OF PHARMACYBRUNSWICK SQUAREComparison between brands: 2.5ml/3ml syringe






1ml Syringe Volume measured Medicina Baxa

0.05ml ✖ ✖0.1ml ✖ ✖0.25ml ✖ ✔0.5ml ✔ ✔1ml ✔ ✔

2.5ml/3ml syringe

5ml syringe

Volume measured Medicina Baxa

0.1ml ✖ ✖0.25ml ✖ ✖0.5ml ✔ *Except Ciproxin ✔1ml ✔ ✔2ml ✔ ✔

Volume measured Medicina Baxa

0.2ml ✖ ✖

0.5ml ✔ ✖

1ml ✔ ✔

2ml ✔ ✔

3ml ✔ ✔

5ml ✔ ✔

Documents

Accuracy of enteral syringes for liquid medicines prescribed in children Karuna Gurung, UCL School of Pharmacy