Physical stability tablets

Bindschaedler and Gurny [12] published an adaptation of the simplex technique to a TI-59 calculator and applied it successfully to a direct compression tablet of acetaminophen (paracetamol). Janeczek [13] applied the approach to a liquid system (a pharmaceutical solution) and was able to optimize physical stability. In a later article, again related to analytical techniques, Deming points out that when complete knowledge of the response is not initially available, the simplex method is probably the most appropriate type [14]. Although not presented here, there are sets of rules for the selection of the sequential vertices in the procedure, and the reader planning to carry out this type of procedure should consult appropriate references. 

The hydration state of risedronate sodium was monitored continuously in a fluidized bed dryer and correlated to data on the physical stability of tablets made from the monitored material [275]. The final granulation moisture was found to affect the solid-state form, which in turn dictated the drug s physical stability over time. The process of freeze-drying mannitol was monitored continuously with in-line Raman and at-line NIR spectroscopies [276]. The thin polymer solvent coatings, such as poly(vinyl acetate) with toluene, methanol, benzene, and combinations of the solvents, were monitored as they dried to generate concentra-tion/time profiles [277]. 

D.S. Hausman, R.T. Cambron and A. Sakr, Application of on-line Raman spectroscopy for characterizing relationships between drug hydration state and tablet physical stability, Int. J. Pharm., 299, 19-33 (2005). 

THE USE OF A FACTORIAL DESIGN TO EVALUATE THE PHYSICAL STABILITY OF TABLETS AFTER STORAGE UNDER TROPICAL CONDITIONS... 

The studies described in this chapter are restricted to the physical stability of tablets. Physical properties that are of interest are e.g. crushing strength, friability, disintegration time and dissolution profile. One of the causes of... 

Section 8.2 describes the feasibility of the use of the Storage to Initial Ratio as a measure to express the physical stability of tablets. By expressing the stability as the relative value after storage related to the initial value, it is... 

In section 8.3 a study is described in which the SIR of crushing strength and the SIR of disintegration time are used to evaluate batches of tablets prepared for several combinations of filler-binders and disintegrants, with respect to their physical stability after storage under tropical conditions. 

Since the aim of this study was to evaluate the use of the change in the tablet properties during storage as a parameter to express the physical stability of tablet formulations, the Storage to Initial Ratio of the crushing strength (SIR(S)) and of the disintegration time (SIR(D)) were calculated and used as response values for equation (2). The calculations of SIR(S) and SIR(D) were performed as in equation (1). The mean of the measurements directly after preparation were used as initial value. 

Since the SIR of disintegration time after storage depends on the compression load as well as on the disintegrant concentration, these factors should both be taken into account, when the SIR of disintegration time is used as a measure for the physical stability of tablets after storage, in the developing stage of tablet formulations. 

With the aid of multiple linear regression, model coefficients were calculated, which describe the effect of the variables pn the physical stability of the tablets. Since two levels of each variable were studied it was possible to calculate the linear contribution of the variables. The general form of the model which describes the effect of the variables is given by the following formula ... 

P. York, A preliminary study of the physical stability of tablets prepared from powders stored under tropical conditions. Pharm., 31 (1976) 383. 

Bos CE, Bolhuis GK, Smilde AK, DeBoer JH. The use of a factorial design to evaluate the physical stability of tablets after storage under topical conditions. In Hendriks MMWB, DeBoer JH, Smilde AK, eds. Robustness of analytical chemical methods and pharmaceutical technological products. Amsterdam Elsevier, 1996 309-341. 

Special attention should be given to the physical stability of the tablets manufactured by direct compression because some fillers/binders are known to soften or harden on storage. 

The effect of environmental moisture on the physical stability of effervescent tablets in foil-laminate packages containing microscopic imperfections was examined. Physical stability, after storing at different RH and temperature conditions, was assessed by noting whether the tablet components reacted prematurely. 

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