Reference Standards

British Pharmacopoeia Chemical reference substances (BPCRS)

These Primary standards are established using absolute methods and the declared content figures are determined without comparing to another substance. You should use BPCRS to perform the tests in the British Pharmacopoeia (BP) or BP (Veterinary). Do not eat BPCRS or feed them to animals – you should only use BPCRS for chemical analysis. They are not suitable for any other use.

07 August 2025

We are pleased to update that products affected by the recent electrical freezer fault are now available following their temporary withdrawal.

This follows a detailed quality assessment of vialled stock and re-vialing product from our reserved bulk supplies.

Thank you again for your patience while we worked to resolve this matter.

Search within this catalogue

951 items

  • Search result 1

    Category Number 1154
    Pack size 10 mg
    Substance name citalopram impurity standard
    Declared content Not applicable
    Current batch 3765
    QTY (Max 25)

  • Search result 2

    Category Number 833
    Pack size 100 mg
    Substance name clarithromycin
    Declared content
    98.1% of C38H69NO13
    Current batch 4570
    QTY (Max 25)

  • Search result 3

    Category Number 834
    Pack size 20 mg
    Substance name clarithromycin impurity E
    Declared content Not applicable
    Current batch 3028
    Discontinued

  • Search result 4

    Category Number 747
    Pack size 1
    Substance name clavulanate polymer
    Declared content Not applicable
    Current batch
    Discontinued

  • Search result 5

    Category Number 525
    Pack size 200 mg
    Substance name clemastine fumarate
    Declared content
    74.7% of C21H26ClNO
    Current batch 3457
    QTY (Max 25)

  • Search result 6

    Category Number 1220
    Pack size 100 mg
    Substance name clenbuterol hydrochloride
    Declared content
    99.4 % of C12H18Cl2N2O,HCl
    Current batch 4065
    Out of Stock

  • Search result 7

    Category Number 1231
    Pack size 25 mg
    Substance name clenbuterol impurity D
    Declared content Not applicable
    Current batch 4107
    QTY (Max 25)

  • Search result 8

    Category Number 419
    Pack size 100 mg
    Substance name clindamycin phosphate
    Declared content
    88.2% of C18H34CIN2O8PS
    Current batch 4586
    QTY (Max 1)

  • Search result 9

    Category Number 84
    Pack size 200 mg
    Substance name clioquinol
    Declared content
    99.9% of C9H5ClINO
    Current batch 3107
    QTY (Max 25)

  • Search result 10

    Category Number 507
    Pack size 100 mg
    Substance name clobazam
    Declared content
    100.0 % of C16H13CIN2O2
    Current batch 4341
    Out of Stock

  • Search result 11

    Category Number 522
    Pack size 25 mg
    Substance name clobetasol impurity A
    Declared content Not applicable
    Current batch 2459
    Discontinued

  • Search result 12

    Category Number 521
    Pack size 100 mg
    Substance name clobetasol propionate
    Declared content
    99.5% of C25H32ClFO5
    Current batch 4336
    QTY (Max 25)

  • Search result 13

    Category Number 482
    Pack size 100 mg
    Substance name clobetasone butyrate
    Declared content
    99.3% of C26H32ClFO5
    Current batch 4563
    QTY (Max 25)

  • Search result 14

    Category Number 406
    Pack size 100 mg
    Substance name clocortolone hexanoate
    Declared content Not applicable
    Current batch 1885
    E-mail to order:  bpcrs@mhra.gov.uk

  • Search result 15

    Category Number 663
    Pack size 100 mg
    Substance name clofazimine
    Declared content
    99.6% of C27H22Cl2N4
    Current batch 2240
    QTY (Max 1)

  • Search result 16

    Category Number 543
    Pack size 100 mg
    Substance name clomethiazole edisilate
    Declared content
    100.0% of (C6H8ClNS)2C2H6O6S2
    Current batch 1842
    QTY (Max 25)

  • Search result 17

    Category Number 445
    Pack size 25 mg
    Substance name clomethiazole impurity A
    Declared content Not applicable
    Current batch 4244
    E-mail to order:  bpcrs@mhra.gov.uk

  • Search result 18

    Category Number 446
    Pack size 25 mg
    Substance name clomethiazole impurity B
    Declared content Not applicable
    Current batch 1631
    QTY (Max 25)

  • Search result 19

    Category Number 444
    Pack size 25 mg
    Substance name clomethiazole impurity C
    Declared content Not applicable
    Current batch 1630
    QTY (Max 25)

  • Search result 20

    Category Number 980
    Pack size 100 mg
    Substance name clomipramine hydrochloride
    Declared content
    99.6% of C19H23ClN2, HCl
    Current batch 3815
    QTY (Max 25)

  • Search result 21

    Category Number 981
    Pack size 10 mg
    Substance name clomipramine impurity C
    Declared content Not applicable
    Current batch 3260
    Discontinued

  • Search result 22

    Category Number 982
    Pack size 10 mg
    Substance name clomipramine impurity D
    Declared content Not applicable
    Current batch 4366
    QTY (Max 25)

  • Search result 23

    Category Number 983
    Pack size 10 mg
    Substance name clomipramine impurity F
    Declared content Not applicable
    Current batch 3262
    QTY (Max 1)

  • Search result 24

    Category Number 484
    Pack size 100 mg
    Substance name clonazepam
    Declared content
    100.0% of C15H10ClN3O3
    Current batch 4061
    Out of Stock

  • Search result 25

    Category Number 85
    Pack size 100 mg
    Substance name clonidine hydrochloride
    Declared content
    99.9 % of C9H9Cl2N3,HCl for HPLC
    100.0 % of C9H9Cl2N3,HCl for UV
    Current batch 4609
    QTY (Max 1)