Biomedical Engineering Reference
In-Depth Information
8.4.2
Reformulations
Reformulations of a drug use the same active ingredient as the original drug, but the
formulation is changed to improve compliance, side effects or effi cacy. This strat-
egy can involve new forms or dosages and requires new clinical tests. Reformulations
have a shorter approval path than NMEs (Fleming and Ma
2002
) and upon approval
receive at least three additional years of market exclusivity through a sNDA (Bhat
2005
). Reformulations often involve technical challenges, which sometimes can be
patented, making it harder for generic fi rms to copy or design around.
Time-release versions of a drug are a popular reformulation and make up 8 % of
unit sales of prescription drugs in the United States (Danzon and Furukawa
2008
).
7
They ensure a slow and controlled release of the drug in the body and provide the
advantage of fewer dosages per day (compared to instant-release formulations) and
fewer side effects. Other emerging technologies are site-specifi c drug delivery,
depot formulation, and inhalation drug delivery (Dubey and Dubey
2009
).
Sixty percent of newly approved drugs are reformulations (Dubey and Dubey
2009
; Huskamp et al.
2008
; Sandner and Ziegelbauer
2008
). The cost of introducing
a reformulation is estimated to be $10-50 million (Bhat
2005
). The reformulation
typically builds on the brand name of the original drug (e.g., Effexor XR is a refor-
mulation of Effexor). When the reformulation is approved, only the reformulation
receives the additional market exclusivity. Hence it is important for fi rms to differ-
entiate their reformulation from the original drug and switch patients to the refor-
mulation in order to benefi t from the additional market exclusivity. Huskamp et al.
(
2008
) fi nd that promotional expenditures for the original brand decrease substan-
tially when a reformulation is introduced.
8.4.3
Combination Drugs
Combination drugs are an increasingly popular lifecycle extension strategy (e.g.,
Advair, Caduet, Vytorin), with worldwide sales in 2009 of over $30 billion.
Combination drugs are two or more active ingredients that are physically or chemi-
cally combined to produce a single pill, inhaler, injection, or patch (Herrick and
Million
2007
). In some circumstances, fi rms are allowed to co-package drugs
(Evans and Salinger
2007
); however, this is more common for OTC drugs.
Combination drugs are often based on two or more ingredients already on the mar-
ket and qualify for a new patent. It is required for approval that the combination
drug provides an improved treatment for at least some type of patient, compared to
the single components. The approval process of a combination drug depends on the
7
Time-release technology is also referred to as sustained release (SR), sustained-action (SA),
extended release (ER, XR or XL), controlled-release (CR), modifi ed-release (MR), or continuous-
release (CR).
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