Sometimes an easy and common question arise from beginner what are excipients and what can they do for pharma companies?
Pharmaceutical Excipients: Pharmaceutical excipients are substances other than the active pharmaceutical ingredient (API) that have been used for design a stable and effective dosage form.
Selection of Pharmaceutical Excipients: Prior to develop a drug product a scientist need to complete literature and reference product (RLD) study. After successfully completing the study he/she can easily select the excipients (qualitative formula). During selection of any excipients following parameters should be considered –
- Appearance/Description
- Identification
- Solubility
- Loss on drying/ water content
- Particle size distribution (PSD)
- pH
- Heavy metals
- Related substances (if required)
- Residual solvents (if required)
- Loss on ignition
- Assay (if required)
- Microbial Enumeration Test (if required)
After selecting the correct excipients for the drug product, Scientist will target to fix the formula with proper quantity selection of excipients. Here he/she can conduct drug-excipients compatibility study to ensure the proper selection of excipients as well as minimize the stability study failure after a while.
After fix the tentative formula, few trials need to be conducted for comparing with reference product (RLD). Where physical and chemical properties will compare between test product and reference product. And the excipients quantity need to be adjusted depending on the trials result.
Following physical & chemical parameters should be compare between test product and reference product:
Physical Parameters –
- Appearance & Description
- Tablet/Capsule weight
- Size&Shape
- Disintegration Time (DT)
- Hardness, Thickness & Friability
Chemical Parameters –
- Dissolution profile
- F2 calculation
- Related substances/ Impurities
- Assay
After evaluating the test results a scientist may need to change/adjust the excipients quantity. Finally when the desired results obtain from trials then the formula subjected for stability study and PO/Exhibit batch will be conducted.
After successfully optimization of formula, the process need to be validated in commercial area in commercial scale. Where also excipients adjustment needed for desired results. If this scenario occurred, you should follow SUPAC guideline.
Pharmaceutical regulations and standards require that all ingredients in drugs, as well as their chemical decomposition products, be identified and shown to be safe. From this aspect all excipients used in the drug product should be identified as a safe material.
This is an overview of excipients selection for pharmaceutical product development. To get more information for each excipients you can read an awesome book ‘Handbook of Pharmaceutical Excipients’ – by Paul J Sheskey, Bruno C Hancock, Gary P Moss, David J Goldfarb.
You can also see a list of pharmaceutical excipients and their uses from below links –
