Curve stripping

Figure 1. Typical chromatograms for (- -)F-PHEA in the presence of serum albumin (-o-) serum albumin in perfusate and (-x-)F-PHEA following curve stripping of the data.

Radionuclidic analyses are performed with either a lithium-drifted germanium or intrinsic germanium detector. The assay for Sr-82 is based upon its 777 keV photon of 13.6% abundance. Strontium-85, which is often present in amounts comparable to that of Sr-82, is assayed by its 514 keV photopeak, which must be resolved from prominent 511 keV annihilation radiation by a curve stripping procedure (12). 

Other approaches have been used for more complex models. These include curve stripping or the method of residuals,either manually or using a computer program such as CSTRIP and ESTRIF. These techniques can separate a multiexponential curve into its component parts for initial estimates. Other techniques include deconvolution methods specific to the one and two compartment pharmacokinetic models. The objective of the deconvolution method is to mathematically subtract the results obtained after IV administration from the oral or extravascular data. This results in information about the input or absorption process alone. More general methods have been presented by various researchers that do not rely on a particular compartmental model. ... 

Peeling, curve stripping, or the method of residuals is an old technique advocated in some of the classic textbooks on pharmacokinetics (Gibaldi and Perrier, 1982) as a method to obtain initial estimates. The method will not be described in detail the reader is referred to the references for details. Its use will be briefly illustrated. Consider the biexponential model... 

From Equation 12.8 a plot of Qater - C vs. time on semilog graph paper provides an estimate of k, the absorption rate constant. The technique of curve stripping or method of residuals can be applied to equations involving multiple exponential terms when they differ by at least fivefold. 

The absorption rate constant is determined by a method known as "feathering," "method of residuals" or "curve stripping." The method allows the separation of the monoexponential constituents of a biexponential plot of plasma concentration against time. From the plasma concentration... 

The method of residuals is a commonly employed technique for resolving a curve into various exponential terms. This method is also known as feathering or curve stripping (see p.l02). The curve from the observed data and that for the extrapolated line are depicted in Fig. 13.11. Table 13.2 gives the headings for the data that can be extracted from the figure. 

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