Excipient analysis by GPC/SEC and other LC techniques (zbirka aplikacij)

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Investigating excipients
Traditionally, excipients were inactive substances used in
pharmaceutical and personal care formulations to carry
active ingredients. At their most basic, excipients were
employed to make a drug tablet or capsule large enough to
be easily handled, because the active ingredient is present
in small quantities. Thus a common painkiller may contain
80 percent or more inert filler. Other drug excipients ease
the administration or uptake of active ingredients, or make
them more palatable, or add color to aid identification. As
well as these patient-friendly attributes, excipients can
be used during manufacturing to assist handling of the
active ingredient, for example by preventing it sticking to
machinery or degrading during processing or storage. Many
compound classes are used as excipients, including synthetic
and natural polymers, saccharides, and proteins. However,
similar compounds may have different functions in different
formulations. Thus, carboxymethyl cellulose is used as a
binder, a suspending agent and a disintegrant.
In the past, excipients were thought of as cheap and
inert substances whose sole purpose was to carry active
ingredients. However, it is now recognized that they can
influence the rate and extent of uptake of actives. Moreover,
there is a move away from synthetic excipients, for which it
may be problematic to obtain regulatory approval, towards
‘natural’ compounds that are potentially less toxic, more
easily accessible, cheaper, and more acceptable to consumers
in this age of health scares associated with synthetic
products.
The value of excipients has therefore led to extensive
research by the pharmaceutical industry to improve their
efficacy. This list shows some excipients released since
20061
.
• Modified excipients – Polyplasdone Ultra (ISP), Lμtrol
micro 68 & 127; Kollidon CL-F & CL-SF (all BASF),
Swelstar MX 1 (Asahi Kasei), GalenIQ 721 (Palatinit)
• Co-processed excipients – Spectrablend HS (Sensient),
Prosolv ODT (JRS), Ludiflash (BASF), Aquarius (Ashland),
Avicel DG (FMC), Sepitrap (Seppic), Starcap 1500
(Colorcon)
• Novel excipients – Solutol HS 15, Soluplus, Kollicoat
Smartseal 30 D (all BASF)
The exact nature and formulation of many excipients are
considered trade secrets. However, commercial confidentiality
has quality implications for drug companies when using
these compounds, particularly because of new regulatory
requirements. For example, under ICH M4Q (Quality)2
, novel
excipients now require characterization of their functionality
(pharmaceutical assessment and drug delivery properties)
and physicochemistry (physicochemical properties and
impurities).