22. What are the characteristics of colonic release systems?
a) Release the drug along the entire length of GIT
b) Prolonged their residence in the GIT and release
c) Usage of polymers that dissolves only in the alkaline pH of colon
d) Use of enteric coating

23. The duration of action of parental controlled release systems can be extended up to whattime?
a) 1 day
b) 1 week
c) 1 month
d) Day, week, month even a year

24. What is the drawback of parental controlled release systems?
a) Injecting is a difficulty
b) The drug cannot be easily removed once administered
c) Can get easily precipitated in the injection site
d) Rapid onset but fast excretion

25. Which one of the following should not be a characteristic of the vehicles or polymerswhich are used for parenteral formulations?
a) Sterile
b) Consists of pyrogen
c) Nonirritating
d) Biodegradable

26. With aqueous solutions, the drug releases can be controlled. Which of the following is notthe right method of controlling?
a) Increasing the viscosity
b) By forming complexes with macromolecules
c) Reducing the solubility of the parent drug
d) Increasing the pH to make it highly basic

27. Release of water-soluble drugs can be retarded by presenting it as ____________suspension.
a) Oil
b) Water
c) Colloidal
d) Freezing