Excipients play an important role in drug formulations by acting as bulking agents, protective agents, and improving drug bioavailability. Excipients can interact with active pharmaceutical ingredients through physical, chemical, and biopharmaceutical interactions. These interactions can affect properties like drug stability, release, and absorption. It is important to select excipients that do not interact with drugs and understand how excipients may influence drug performance and safety after administration.

1. Excipients
Interaction

2. Excipients Interaction
 Excipients play an important role in formulating a dosage
form. These are ingredients which along with active
pharmaceutical ingredients make up the dosage forms.
 Excipients act as protective agents, bulking agents and
can also be used to improve bioavailability of drug.
 Excipients as like other active pharmaceutical
ingredients need to be stabilized and standardized.

3. Excipients Interaction
 An excipient is an inactive substance formulated alongside the
active ingredient of a medication, for the purpose of bulking-up
formulations that contain potent active ingredients”.
 The resultant biological, chemical and physical properties of the
drug product are directly affected by the excipient chosen, their
concentration and interactions with the API:
 Consistency of drug release and bioavailability
 Stability including protection from degradation
 Ease of administration to the target patient population(s) by sthe
intended route

4. Ideal properties of Excipient
 No interaction with drug
 Cost effective
 Pharmacologically inert
 Stable for handling

5. Drug excipient interaction
 In pharmaceutical dosage forms the active
pharmaceutical ingredients are in intimate
contact with the excipient which are greater
quantity excipient and drugs may have certain
incompatibility which lead to drug excipient
interaction

6. Types of drug excipient Interactions
 Physical interactions.
 Chemical interactions.
 Biopharmceutical interactions.
 Excipient –Excipient interactions

7. Physical interactions
 Physical interactions alter physical properties of
dosageform like the rate of dissolution , dosage
uniformity ,etc.
 Physical interactions do not involve chemical changes
thus permitting the components in the formulation to
retain their molecular structure .physical interactions are
difficult to detect

8. Physical interactions

9. Chemical interaction
 Active pharmaceutical ingredients and
excipients react with each other to form
unstable compounds.

10. Chemical interaction

11. Chemical interaction

12. Biopharmaceutical interactions
 These are the interaction observed after
administration of the medication.
 Interaction within the body is between medicine
and body fluids which influence the rate of
absorption .
 All excipient physiological way when they are
administered along with active pharmaceutical
ingredients.

13. Biopharmaceutical interactions
 Premature breakdown of enteric coat-The enteric
coating polymers like cellulose acetate phthalate and
hydroxyl propyl cellulose acetate phthalate.
 Are soluble more at basic pH, but antacids raise pH of
stomach resulting in breakdown of the enteric coat in
stomach and release of active pharmaceutical
ingredient in stomach itself , which results in degradation
of drug in stomach.
 In case of NSAID’s premature breakdown of enteric coat
may cause side effects like gastric bleeding

14. Biopharmaceutical interactions
 Many of the excipients like Sorbitol ,xylitol
have tendency to increase the
gastrointestinal motility thus reducing the
time available for absorption of drugs like
metoprolol.

15. Excipient –excipient interaction
 Excipient –excipient interaction though
observed very rarely. These are prime
importance in determining the stability of the
dosage forms excipient –excipient interactions
can be undesirable as well as some interactions
are used in the formulations to get the desired
product attributes