Description Usage Arguments Details Value References See Also Examples
The function f2()
calculates the similarity factor f_2.
1 |
data |
A data frame with the dissolution profile data in wide format. |
tcol |
A vector of indices specifying the columns in |
grouping |
A character string specifying the column in |
use_EMA |
A character string indicating if the similarity factor
f_2 should be calculated following the EMA guideline “On the
investigation of bioequivalence” ( |
bounds |
A numeric vector of the form |
Similarity of dissolution profiles is assessed using the similarity factor f_2 according to 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 similarity factor f_2 is calculated by aid of the equation
f_2 = 50 log(100 / (sqrt(1 + (sum((R.bar(t) - T.bar(t))^2) / n)))) .
In this equation
is the similarity factor,
is the number of time points,
is the mean percent reference drug dissolved at time t after initiation of the study, and
is the mean percent test drug dissolved at time t after initiation of the study.
Dissolution profiles are regarded as similar if the f_2 value is
between 50 and 100.
A list with the following elements is returned:
f2 |
A numeric value representing the similarity factor f_2. |
Profile.TP |
A named numeric vector of the columns in |
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
f1
.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 | # Dissolution data of one reference batch and one test batch of n = 6
# tablets each:
str(dip1)
# 'data.frame': 12 obs. of 10 variables:
# $ type : Factor w/ 2 levels "R","T": 1 1 1 1 1 1 2 2 2 2 ...
# $ tablet: Factor w/ 6 levels "1","2","3","4",..: 1 2 3 4 5 6 1 2 3 4 ...
# $ t.5 : num 42.1 44.2 45.6 48.5 50.5 ...
# $ t.10 : num 59.9 60.2 55.8 60.4 61.8 ...
# $ t.15 : num 65.6 67.2 65.6 66.5 69.1 ...
# $ t.20 : num 71.8 70.8 70.5 73.1 72.8 ...
# $ t.30 : num 77.8 76.1 76.9 78.5 79 ...
# $ t.60 : num 85.7 83.3 83.9 85 86.9 ...
# $ t.90 : num 93.1 88 86.8 88 89.7 ...
# $ t.120 : num 94.2 89.6 90.1 93.4 90.8 ...
# Use of defaults, i.e. 'use_EMA = "yes"', 'bounds = c(1, 85)'
# Comparison always involves only two groups.
f2(data = dip1, tcol = 3:10, grouping = "type")
# $f2
# [1] 40.83405
#
# $Profile.TP
# t.5 t.10 t.15 t.20 t.30 t.60 t.90
# 5 10 15 20 30 60 90
# Use of 'use_EMA = "no"', 'bounds = c(5, 80)'
f2(data = dip1, tcol = 3:10, grouping = "type", use_EMA = "no",
bounds = c(5, 80))
# $f2
# [1] 39.24385
#
# $Profile.TP
# t.5 t.10 t.15 t.20 t.30 t.60
# 5 10 15 20 30 60
# Use of 'use_EMA = "no"', 'bounds = c(1, 95)'
f2(data = dip1, tcol = 3:10, grouping = "type", use_EMA = "no",
bounds = c(1, 95))
# $f2
# [1] 42.11197
#
# $Profile.TP
# t.5 t.10 t.15 t.20 t.30 t.60 t.90 t.120
# 5 10 15 20 30 60 90 120
# In this case, the whole profiles are used. The same result is obtained
# when setting 'use_EMA = "ignore"' (ignoring values passed to 'bounds').
f2(data = dip1, tcol = 3:10, grouping = "type", use_EMA = "ignore")
# Passing in a data frame with a grouping variable with a number of levels that
# differs from two produces an error.
tmp <- rbind(dip1,
data.frame(type = "T2",
tablet = as.factor(1:6),
dip1[7:12, 3:10]))
tryCatch(
f2(data = tmp, tcol = 3:10, grouping = "type"),
error = function(e) message(e),
finally = message("\nMaybe you want to remove unesed levels in data."))
# Error in f1(data = tmp, tcol = 3:10, grouping = "type") :
# The number of levels in column type differs from 2.
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