The pink color of this drug serves as an indicator of the acidity of the medium, since the color has changed, it means that the acidity has also changed (increased in this case). This may be due to a violation of the tightness of the bottle (even if we do not see it), that is, the drug is no longer sterile, it contains and divides on this nutrient medium that microorganism that is not provided by the manufacturer there. So we are not talking about the use of I / O here. What about drinking? I either look bad, or gamavit is really not prescribed per os, which means that most likely the drug is not resistant to the acidic environment of the stomach and all that is "valuable" into the systemic circulation - it will not get there. That is, watering is simply not effective, although in the case of gamavit and hardly toxic.
And even taking into account all of the above, I would not dare to give you a direct recommendation to violate the instructions for use of any medical product. Well, at least for cultural reasons, follow the prescriptions of doctors. Although all of the above may encourage you to make a decision in the direction of per os, because you read about drinking in some source, perhaps authoritative for you. Difficult, evasive, but as it is.
The instructions for the preparation state that as soon as it changes color, it is no longer suitable for use.
And many doctors believe that there is zero sense from it - this is homeopathy, holy water and nothing more.