Biomedical Engineering Reference
In-Depth Information
Commercial Aspects of Iontophoretic Delivery
FDA requirements, regulatory issues in
combination products, and patient compliance are some of the important market fac-
tors. Ease of use, device adhesion, dosing and rate factors, electrode design, power
requirements and battery technology, and prefilled disposable device designs are fac-
tors which depend upon design of iontophoretic delivery device. Initial products (from
Iomed, Empi, Life-Tech, Vyteris, and ALZA) have not achieved market success, per-
haps because of drawbacks in some medical devices or unoptimized formulations for
iontophoresis.
Several pharmaceutical companies are trying to commercialize iontophoretic
skin delivery. Major companies that are involved in the development of iontopho-
resis equipment include Iomed Inc. (Salt Lake City, UT), Empi Inc. (St Paul, MN),
Life-Tech Inc. (Houston, TX), Alza Corporation (Pala Alto, CA), and Beckton and
Dickinson (Franklin Lakes, NJ). Iontophoresis makes a positive contribution to the
transport of cations and a negative contribution to the transport of anions under nor-
mal physiological conditions. Iontophoresis is a major mode of transport for neutral
molecules design but requires further research today in order to build convenient,
efficient, and cost-effective devices. Many devices are already on the market and typ-
ically include a current-controlling mechanism primarily incorporating a micropro-
cessor, a pulse controller with timer, and electrodes.
An New Drug Application has been filed for a prefilled iontophoretic fentanyl
patch. The iontophoretic patch from Alza is expected to be an integrated device.
The lidocaine patch from Vyteris has a prefilled patch, a wearable battery-powered
controller, and an interconnect module, and has been approved for marketing by the
FDA. Elan Corporation (Ireland) investigated a device (Panoderm) that was designed
like a watch and contained a disposable drug cartridge. Empi Inc. has announced
FDA approval of a lidocaine HCl 2% and epinephrine 1:100,000 solution for use
with the company's Action Patch Smart Iontophoresis System for the iontophoretic
induction of local analgesia during superficial dermatologic procedures. Although an
iontophoretic patch is expected to be more costly than a passive transdermal patch,
this may not be a disadvantage for a proteinous or peptide drug due to their higher
initial cost. Also, passive transdermal or other alternative delivery systems may not
be possible, so it is important to verify the efficiency of delivery.
As shown earlier, iontophoresis has been approved for the topical delivery of local
anesthetics and corticosteroids. Gel drug-delivery systems containing proteins and
peptides have been fabricated by preparing a formulation of the peptide or protein
drug with the monomer and inducing polymerization by the application of electro-
magnetic radiation. Use of hydrogel formulations in units available in the market will
allow dosage replacement by the removal and replacement of a drug-loaded hydrogel
patch that reuses the same iontophoretic device. Studies have shown that polypep-
tide drugs are reliably loaded into the aqueous environment of a hydrogel, and their
release from the hydrogel is controlled and modulated by controlling the iontopho-
resis parameters, such as the current density. Feasibility of the commercialization
of iontophoretic delivery and any long-term effects of current on skin will need to
be carefully evaluated. The only short-term effects experienced following iontopho-
retic delivery are a feeling of tingling or warmth and possibly general irritation and
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