Powder for suspension
| Home | | Pharmaceutical Drugs and Dosage | | Pharmaceutical Industrial Management |Chapter: Pharmaceutical Drugs and Dosage: Dosage forms - Suspensions
The inherent physical instability of suspensions and the desirability of a relatively long shelf life have led to the popularity of powder for suspension (PFS) dosage forms.
Powder for
suspension
The
inherent physical instability of suspensions and the desirability of a
relatively long shelf life have led to the popularity of powder for suspension
(PFS) dosage forms. These dosage forms are developed as powder mixtures of
typical ingredients required for an aqueous suspension and are marketed in unit
dose sachet or multidose bottles. The pharmacist reconstitutes these dosage
forms with water before dispensing to the patient. The reconstituted suspension
has a limited shelf life under designated storage conditions, such as 14 days
under refrigeration.
1. Unit dose powder
for suspension:
A unit dose sachet of powder could be
administered to a patient by sprinkling on the top of a semisolid food, such as
jelly or ice cream, or by suspending in a suitable vehicle, such as water or
juice, immediately before administration. This mode of administration is
preferred for pediatric and geriatric populations, who may have swallowing
difficulty, and for high dose compounds. A key requirement for this dosage form
is the palatability of the drug. Extremely bitter or unpleasant tasting drugs
are generally not suitable for formulation as PFS.
2. Multidose powder
for suspension:
The multidose PFS are dispensed as
powders in a suitable-sized bottle for reconstitution with water by the pharmacist
immediately before dispensing. This allows the advantage of custom flavoring by
the pharmacist to increase patient compliance and the reduced requirement for
the duration of physi-cal and chemical stability of the formulation. For
example, the com-bination of amoxicillin and potassium clavulanate is dispensed
as multidose PFS in a bottle. Superior stability of the powder dosage form
allows long shelf life of the commercial product at room tem-perature of a drug
that is very unstable in the presence of water. The pharmacist reconstitutes
this PFS immediately before dispensing. The reconstituted suspension is
required to be stored by the patient under refrigerated conditions and consumed
within 14 days.
