get_wcs_limit {expirest} | R Documentation |
Determination of the “worst case scenario” (wcs) limit
Description
The function get_wcs_limit()
calculates “worst case scenario”
(wcs) limit following the ARGPM Guidance “Stability testing for
prescription medicines”.
Usage
get_wcs_limit(
rl,
sl,
intercept,
xform = c("no", "no"),
shift = c(0, 0),
ivl_side = "lower"
)
Arguments
rl |
A numeric value that specifies the release specification limit(s),
on the same scale as |
sl |
A numeric value that specifies the specification limit, on the same
scale as |
intercept |
A numeric value representing the intercept of a linear
regression model fitted to sample data, on the same scale as |
xform |
A vector of two character strings that specifies the
transformation of the response and the time variable. The default is
“no” transformation, i.e. |
shift |
A vector of two values which will be added to the variables
|
ivl_side |
A character string that specifies if the specification
limit, given that the limit has only one side, is an “upper” or a
“lower” bound, i.e. it is specified as either |
Details
The function get_wcs_limit()
determines the “worst
case scenario” (wcs) limit as is proposed by the Australian Regulatory
Guidelines for Prescription Medicines (ARGPM) guidance “Stability
testing for prescription medicines”. According to this guideline, the shelf
life or expiry limit is estimated as the point where the upper or lower
limit of the 95% confidence interval of the linear model fitted to the
data intersects the wcs limit. The wcs limit is obtained by
adding/subtracting the absolute difference of specification limit and
release limit to/from the common intercept of the test batches or the
intercept of the worst performing batch.
If data have been linearised by transformation, all elements, i.e. rl
,
sl
and intercept
must be on the same, i.e. transformed, scale.
The results are returned on the transformed scale and on the original scale.
Value
A list with the following elements is returned:
xform |
A vector of two character strings that specifies the transformation of the response and the time variable. |
shift |
A vector of two values which has been added to the values of
the transformed |
delta.lim |
A numeric value or a numeric vector of the absolute
difference(s) between |
delta.lim.orig |
A numeric value or a numeric vector of the absolute
difference(s) between |
wcs.lim |
A numeric value or a numeric vector of the worst case
scenario (wcs) limit(s), if |
wcs.lim.orig |
A numeric value or a numeric vector of the worst case scenario (wcs) limit(s) on the original scale. |
References
Therapeutic Goods Administration (TGA) of the Department of Health of the Australian Government, Australian Regulatory Guidelines for Prescription Medicines (ARGPM), Stability testing for prescription medicines, Version 1.1, March 2017
See Also
extract_from_ll_wcsl
,
get_wisle_poi_list
, expirest_wisle
.