Review questions answers

Review questions

24.1 Suppositories are solid dosage forms intended for insertion into body

orifices and are used for

A.      Rectal and vaginal drug delivery

B.      Oral drug delivery

C.      Nasal drug delivery

D.      Skeletal drug delivery

E.       All of the above

24.2 The rate of drug release from an aerosol depends on

A.      The power of a compressed or liquefied gas to expel the container

B.      Particle size of the formulation

C.      The type of drug

D.      The type of container

E.       All of the above

24.3 Which of the following statements is not true about aerosols?

A.      Dry powders can be dispensed.

B.      Contamination is avoided.

C.      Emulsions cannot be dispensed.

D.      More patient compliance compared to injectables.

E.       None of the above

24.4 What are Ocuserts? Mention a marketed drug product using this dos-age form.

24.5 Enlist factors that affect drug bioavailability from a suppository. What are the different kinds of suppository bases?

24.6 Identify clinical considerations important to the development of all implantable drug delivery systems. What are the differences in the principle of drug delivery between an osmotic minipump and a diffusion-controlled implant?

Answers:

24.1 A.

24.2 E.

24.3 C.

24.4 Occusert™ is a device consisting of a drug reservoir (e.g., pilocar-pine HCl in an alginate gel) enclosed by two release-controlling mem-branes made of ethylene–vinyl acetate copolymer and enclosed by a white ring, allowing positioning of the system in the eye.

21.5 Factors affecting the bioavailability of suppository dosage forms include the retention time of the suppository in the cavity, the size, and the shape of the suppository, and its melting point.

Types of suppository base: Oleaginous bases

Water-soluble or water-miscible suppository bases

24.6 Diffusion-controlled implants and osmotic minipumps differ in mechanism of drug release. The rate of drug delivery from diffusion-controlled implant is controlled by drug diffusion or dissolution through an insoluble matrix and/or the use of a rate-controlling membrane. Minipumps, on the other hand, are osmotically-controlled devices consisting of an impermeable membrane with well-defined openings for drug release, encasing a drug- containing core.