Page 31 - A guide to dosage form 1_full v3

ACTIVE INGREDIENTS (POISON AND NON-POISON)

Poison are actives that are regulated by the Poison Act 1952 (and Regulation) and Dangerous Drug
Act 1952 (and Regulations). Thus, it is important that if a poison is required in a preparation, the
amount of the poison taken be recorded. A form will be available in the lab next to the poison.

You are also required to obtain a counter-signature from a pharmacist. The signature should be on
the prescription next to the amount of poison that you weighed. REMEMBER that the pharmacist
need to see the amount of powder that you weighed on the weighing balance, so that he/she can be
sure that you weigh the accurate amount.

Hence the process:

Go to the poison area  Fill in the form  Take the poison bottle  Weigh the exact amount on your
weighing balance (5% tolerance permitted)  Leave the weighed powder on the weighing balance 
Find a pharmacist to counter sign  The pharmacist will check the weighed amount  Counter
signed  Return the poison bottle to the designated area

EXCIPIENTS

Excipients are other ingredients that is needed to prepare your formulation. These include emulsifying
agent, suspending agent, vehicles, preservatives, colouring agent and flavouring agents, among
others.

In the dispensing lab, these ingredients are available in their designated racks, at the middle area of
the lab. They are arranged based on their physical characteristics (liquid and solid materials are
separated) and are alphabetically arranged.

REMEMBER that the number of bottles containing each excipient available on the racks are limited. It
is very important to return the bottle to its respective places immediately after you have taken the
necessary amount.

If you need something that is not available on the rack, please ask the lecturer in-charge or any of the
graduate assistant/lab staff available.

WEIGHING
You will have a weighing balance available on your bench. Each time before you start your practical,
ensure that the balance is in good condition and is functioning properly. The resting point of the
balance must be stable at 0 mg when not in use. At all time, please ensure that your balance is clean
and free from any residual powder or liquid. Always use a weighing boat/paper to weigh the
necessary ingredients. Use a new weighing boat/paper for each ingredient.

Your balance is labelled with its minimum and maximum weighable quantity, besides its
decimal points (sensitivity). Usually, your balance’ minimum weighable quantity (MWQ) is 200 mg.
Hence, you could only weigh accurately at 200 mg or more, meaning to say that if your formula
requires an amount smaller than 200 mg, a dilution method will be necessary. You will learn this
technique as we go through this course.

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