A rotating iterative procedure (RIP) for estimating hybrid constants in multi-compartment analysis on desk computers.

The rotating iterative procedure (RIP) is a programming concept for non-linear least squares fitting of multiexponential equations to experimental data in pharmacokinetics. The method is economical in its use of program and active register capacity and can be employed in modern electronic desk-top computers. The algorithms necessary for obtaining primary estimates of various logarithmic components and their subsequent correction are presented, with as little higher mathematics as appeared permissible. The procedure is described in the sequence that would actually be followed in a pharmacokinetic analysis, and an example is included, as well as a skeleton version of a program written in BASIC. Some instructions for obtaining overall statistical parameters are given.