How to Dilute?
How to Dilute?
Dilution is an important aspect in pharmacy.
Today, we'll share a bit of insight on dilution method of a solution.
Before that, let us have a bit of examples on when will the dilution method be applied.
In pharmacy services, some of the solution, or cream that we have were purchased in bulk or in concentrated form for their cost-effectiveness as well as ease of transportation.
For example, benzyl benzoate emulsion (EBB) used in pediatrics. For children above 2 years of age up until 12, EBB 12.5% is recommended. In some facilities, you may also find EBB 6.25%, indicated for pediatric 6 months up to 2 years old.
*Do note that 6.25% is not listed in BlueBook*
In most of the facilities, we will be getting EBB 25%. So, further dilution is required to prepare an emulsion of 6.25%.
Taking this as an example, the preparation can be done through the following formula:
M1V1 = M2V2
Where
M1 = stock solution concentration
V1 = volume of stock solution required
M2 = final solution concentration
V2 = volume of final solution
Hence, to prepare 6.25% of EBB, one must dilutes 25ml of 25% EBB with 75ml of water to make a 100ml of 6.25% EBB.
Another example that can be commonly seen in public healthcare facilities would be Chlorhexidine 0.05% Mouthwash.
Chlorhexidine mouthwash can be prepared from a 2% stock solution through 1:40 parts dilution. So, to prepare a 100ml of 0.05%, one can take 2.5ml pf 2% stock solution and top up it until 100ml.
Dilution is easy isn't it?
Hope this helps out to those who are new to compounding pharmacy.