Dissolution time, mean

S. Yamamura, F. Aida, Y. Momose, and E. Fukuoka, Analysis of mean disintegration time and mean dissolution time by moment analysis microcalorimetric curves, Drug Dev. Ind. Pharm., 26, 1 (2000). 

Mean residence time, mean dissolution time, mean absorption time... 

Since g (t) /goo is a distribution function, it can be characterized by its statistical moments. The first moment is defined as the mean dissolution time (MDT) and corresponds to the expectation of the time up to dissolution for an individual drug fraction from the dosage form ... 

In parallel, the current dissolution specifications [223] are not correlated with the drug s dimensionless solubility-dose ratio 1/0, which has been shown [90] to control both the extent of dissolution as well as the mean dissolution time, MDT, which is a global kinetic parameter of drug dissolution. 

Figure 6.19 The mean dissolution time MDT in the intestines as a function of Peff for parameter values qo = 10 mg, (1/0) = 0.2, and p(0) = lO/rm. MDT is calculated as the area under the curve of the undissolved fraction of dose using...

Lansky, P. and Weiss, M., Does the dose-solubility ratio affect the mean dissolution time of drugs Pharmaceutical Research, Vol. 16, No. 9, 1999, pp. 1470-1476. 

All apparatus must be calibrated and the variables standardized and known. Experimental design in dissolution testing to examine residual variation between experimental runs and individual dissolution vessels is feasible. The objective is to minimize errors in experimental set-up, achieved by using mean dissolution times and partial balancing. Lower coefficients of variation occur at higher hydrodynamic intensities. 

B Statistical moments mean dissolution time (MDT) Statistical moments mean residence time (MRT), mean absorption time (MAT), etc... 

Collier, P.S. The interpretation of in vivo mean dissolution time data. In Pharmacokinetics A Modem View, Benet, L.Z., Levy, G., Eds. New York Plenum Press, 1984 403-406. 

Fig. 8 D-optimal mixture design. (A) definition of the design space. (B) Contour plot of mean dissolution time at 25% polymer content. (From Ref . )...

The spherical nature of the pellets provides the minimum surface/volume ratio for the application of a coating, which is usually a polymer. The shape of the pellets was not found to be critical for pellets coated with a solution of a polymer in non-aqueous solvent (114). There was, however, a relationship between the specific surface area of the pellets and the mean dissolution time (MDT) for a series of pellets which had been prepared by different techniques (15) the higher the value of the specific surface area, the lower the value of the MDT. For pellets coated with polymer dispersion, there was a complex relationship between drug, the level of drug and the excipients used as filler (115). For a... 

Another approach to obtain a parameter that describes the dissolution rate is to use statistical moments to determine the mean dissolution time (MDT) (von Hattingberg 1984). This method has the advantage of being applicable to all types of dissolution profiles, and it does not require fitting to any model. The only prerequisite is that data points are available close to the final plateau level. The MDT can be interpreted as the most likely time for a molecule to be dissolved from a solid dosage form. In the case of zero- and first-order dissolution processes, the MDT corresponds to the time when 50 and 63.2 percent have been released, respectively. The MDT is determined from ... 

Experimental results for the mean dissolution time, the shape factor of the dissolution curve, and hardness and friability of the tablets, are also given in table... 

The normal tablet properties were measured, but of these only the mean dissolution time, equal to the first statistical moment of the release profile, is analysed here. This parameter is often close to the time for 50% dissolution (the median), but all the data of the dissolution profile are used in its determination. 

In all cases the effect of polymer A, relative to that of the more permeable polymer B, was to slow down the release rate, but the maximum delay in dissolution, expressed as mean dissolution time, was still only about 3 hours. 

Figure 10.13 Ternary diagram of the effect on the dissolution profile (mean dissolution time) of varying proportions of polymer A, polymer B, and diluent.

Mean dissolution times simulated using data of table 10.15... 

MDT mean dissolution time in vivo of a solid oral dosage form administered to a human subject... 

The mean dissolution time (t ) determined by the Weibull distribution function was shortened as the surface tension of the surfactant aqueous solution decreased (Table 3). In accordance with the contact angle decreasing, greater water uptake can be observed, parallel to the drug release rate increasing. 

Figure 21 Dependency of different concentrations of povidone and cellulose on the mean dissolution times of tablets containing ibuprofen.

Table 3 Influence of Nitrogen Pressure on the Disintegration Times, the Mean Dissolution Times of the Tablets, and the Contact Angle between Water and Granules...

---