Oral Reference Design

The Getting started example uses an IV bolus as the reference formulation for UIR fitting. This guide shows how to use an immediate-release (IR) oral formulation instead, using strip_ka=true to mathematically separate first-order absorption from the underlying disposition — useful when IV data is unavailable.

Simulated data

The data is identical to the Getting started example except that the reference formulation is an IR oral product with first-order absorption (rate constant $K_a$) and a lag time, rather than an IV bolus. Twenty subjects in a crossover design receive the IR reference and three oral test formulations.

first(pk_df, 8)

first(diss_df, 8)

Running the pipeline with strip_ka

The key difference from the Getting started example: strip_ka=true tells the pipeline that the reference formulation ("IR") is an oral formulation whose first-order absorption must be mathematically stripped to recover the underlying disposition. time_lag=true adds a lag-time parameter, and n_exp=1 sets the number of disposition exponentials.

result = run_ivivc(
    pk_df,
    diss_df;
    fast_formulation = "IR",
    strip_ka = true,
    time_lag = true,
    n_exp = 1,
    validation_formulation = "FormB",
    times = collect(range(0.0, 48.0, length = 101)),
);

UIR fits

first(result.uir_df, 8)

Model parameters

coeftable(result.model)

Plots

concentration_profiles(result)

dissolution_profiles(result)

absorption_profiles(result)

levy_plot(result)

ivivc_correlation(result)