Erratum to: J Pharmacokinet Pharmacodyn DOI 10.1007/s10928-009-9147-3

In the original online publication, under the sub-section ‘Multidimensional compartmental model’, the matrix equation above the paragraph ‘Thus \( {\hat{\text{q}}}\left( {\text{s}} \right) = \left( {{\text{A}}_{\text{s}} } \right)^{ - 1} {\text{Q}}^{0} \) and the further…’ is incomplete. However the print version is correct. The complete online version is given below:

$$ \begin{gathered} {\text{A}} = \left[ {\begin{array}{*{20}c} {{\text{a}}_{ 1 1} } & {{\text{a}}_{ 1 2} } & \ldots & {{\text{a}}_{{ 1 {\text{n}}}} } \\ {{\text{a}}_{ 2 1} } & {{\text{a}}_{ 2 2} } & \ldots & {{\text{a}}_{{ 2 {\text{n}}}} } \\ \vdots & \vdots & \ddots & \vdots \\ {{\text{a}}_{\text{n1}} } & {{\text{a}}_{\text{n2}} } & \ldots & {{\text{a}}_{\text{nn}} } \\ \end{array} } \right],\,{\text{q}} = \left[ {\begin{array}{*{20}c} {{\text{q}}_{ 1} } \\ {{\text{q}}_{ 2} } \\ \vdots \\ {{\text{q}}_{\text{n}} } \\ \end{array} } \right],\,{\text{Q}}^{ 0} = \left[ {\begin{array}{*{20}c} {{\text{s}}^{{\alpha_{ 1} - 1}} {\text{q}}_{1}^{0} } \\ {{\text{s}}^{{\alpha_{ 2} - 1}} {\text{q}}_{2}^{0} } \\ \vdots \\ {{\text{s}}^{{\alpha {\text{n}} - 1}} {\text{q}}_{\text{n}}^{0} } \\ \end{array} } \right]\hfill \\ {\text{D}}^{\alpha } = \left[ {\begin{array}{*{20}c} {{\text{D}}^{{\alpha_{ 1} }} } & 0& \ldots & 0\\ 0& {{\text{D}}^{{\alpha_{ 2} }} } & \ldots & 0\\ \vdots & \vdots & \ddots & \vdots \\ 0& 0& \ldots & {{\text{D}}^{{\alpha_{\text{n}} }} } \\ \end{array} } \right], \,{\text{A}}_{\text{s}} = - \left[ {\begin{array}{*{20}c} {{\text{a}}_{ 1 1} - {\text{s}}^{{\alpha_{ 1} }} } & {{\text{a}}_{ 1 2} } & \ldots & {{\text{a}}_{{ 1 {\text{n}}}} } \\ {{\text{a}}_{ 2 1} } & {{\text{a}}_{ 2 2} - {\text{s}}^{{\alpha_{ 2} }} } & \ldots & {{\text{a}}_{{ 2 {\text{n}}}} } \\ \vdots & \vdots & \ddots & \vdots \\ {{\text{a}}_{\text{n1}} } & {{\text{a}}_{\text{n2}} } & \ldots & {{\text{a}}_{\text{nn}} - {\text{s}}^{{\alpha_{\text{n}} }} } \\ \end{array} } \right] \hfill \\ \end{gathered} $$