get_f1: Get the f1 dissimilarity factor
In disprofas: Non-Parametric Dissolution Profile Analysis

Description Usage Arguments Details Value References See Also

The function get_f1() calculates the dissimilarity factor f_1 for the assessment of dissolution profiles.

1	get_f1(data, ins, tcol, grouping)

`data`	A data frame with the dissolution profile data in wide format.
`ins`	A vector of indices generated regarding the grouping.
`tcol`	A vector of indices specifying the columns in `data` that contain the % release values. The length of `tcol` must be three or longer.
`grouping`	A character string specifying the column in `data` that contains the group names (i.e. a factorial variable, e.g., for the differentiation of batches or formulations of a drug product).

Similarity of dissolution profiles is often assessed using the similarity factor f_2, as recommended by the EMA guideline (European Medicines Agency 2010) “On the investigation of bioequivalence”. The evaluation of the similarity factor is based on the following constraints:

A minimum of three time points (zero excluded).
The time points should be the same for the two formulations.
Twelve individual values for every time point for each formulation.
Not more than one mean value of > 85% dissolved for any of the formulations.
The relative standard deviation or coefficient of variation of any product should be less than 20% for the first time point and less than 10% from the second to the last time point.

The dissimilarity factor, or difference factor, f_1, is the counterpart of the similarity factor f_2. The difference factor f_1 is a measure of the relative error between two curves. Current FDA guidelines suggest that two profiles can be considered similar if f_1 is less than 15 (0 - 15) and f_2 is greater than 50 (50 - 100), which is equivalent to an average difference of 10% at all sampling time points. The dissimilarity factor f_1 is calculated by aid of the equation

f_1 = 100 (sum(abs(R.bar(t) - T.bar(t))) / sum(R.bar(t))) .

In this equation

f_1: is the dissimilarity factor,
n: is the number of time points,
R.bar(t): is the mean percent reference drug dissolved at time t after initiation of the study, and
T.bar(t): is the mean percent test drug dissolved at time t after initiation of the study.

The function returns the f_1 value.

United States Food and Drug Administration (FDA). Guidance for industry: dissolution testing of immediate release solid oral dosage forms. 1997.
https://www.fda.gov/media/70936/download

United States Food and Drug Administration (FDA). Guidance for industry: immediate release solid oral dosage form: scale-up and post-approval changes, chemistry, manufacturing and controls, in vitro dissolution testing, and in vivo bioequivalence documentation (SUPAC-IR). 1995.
https://www.fda.gov/media/70949/download

European Medicines Agency (EMA), Committee for Medicinal Products for Human Use (CHMP). Guideline on the Investigation of Bioequivalence. 2010; CPMP/EWP/QWP/1401/98 Rev. 1.
https://www.ema.europa.eu/en/documents/scientific-guideline/guideline-investigation-bioequivalence-rev1_en.pdf

get_f2.

disprofas documentation built on Dec. 8, 2021, 5:10 p.m.