P.CEUTICS1: Formulation Decisions for Cancer Drugs

Question 1

Formulation choices for anti-cancer drugs depend upon…

Answer 1

• Physicochemical + biopharmaceutical properties of drug candidate
• Intended dose + Route of Admin.
• Disease factors
• Patient (ADME)

Question 2

Why are injectable formulations preferred to oral formulations for cancer drugs?

Answer 2

Parenteral formulations avoids problems with oral admin.

• Nausea + vomiting = common side effects of most cytotoxic agents

For IV admin.:

• accurate dosing (100% bioavailability)
• rapid onset of action
• rapid withdrawal
• avoids 1^st pass metabolism
• no fed/fasted effect
• dose flexibility + dosing schedule

Oral admin:

• subject to 1^st pass metabolism
• drug absorbed via gut
• drug stays in stomach for 30-40 minutes
• 90% of oral medicines metabolised by liver before reaching bloodstream
• Drug rapidly transported round body
• Portal circulation blood from intestines taken to liver for detoxification

Question 3

List parenteral routes

Answer 3

• IV
• IM
• SC
• Minor = intrathecal, intrarticular, intracardiac, intraplural

Question 4

What are the requirements for IV formulation?

Answer 4

• Sterile production
• Formulation stability
  
  • particle size
  • solubility
  • clearance time
  • targeting
• No preservatives, low excipients
  
  • ​reduce incompatibilities