The random vibration effects on dissolution testing with USP apparatus 2

The Effect of Sampling Cannula on In Vitro Dissolution Testing with USP Paddle Method

In vitro dissolution tests are widely used as quality control tools for drug products in development and manufacturing. Dissolution acceptance criteria are one of the important factors assessed during the regulatory review process. Understanding potential sources of variability is critical and a key to assuring reliable results are obtained when using a standardized system for in vitro dissolution testing. Sampling cannulas are commonly used to withdraw sample aliquots from dissolution medium and are potentially one of the testing factors that can contribute to variabilities in dissolution testing. However, there are still no clear requirements on the size or setting (intermittent or stationary) of sampling cannulas for dissolution testing. Thus, the objective of this study is to evaluate whether various sizes and sampling cannula settings yield different dissolution results using the USP 2 apparatus. Sampling cannulas with outer diameter (OD) ranging from 1.6 mm to 9.0 mm were used in dissolution testing with either intermittent or stationary setting to collect sample aliquots at multiple time points. The dissolution results at each time point were statistically analyzed for effects of both OD and setting of sampling cannula on drug release from 10 mg prednisone disintegrating tablets. Dissolution results indicated both size and setting of the sampling cannula may cause significant systematic errors, even though the dissolution apparatus has been calibrated. The degree of interference in dissolution results was directly related to the OD of the sampling cannula. Size of sampling cannula and setting of sampling procedure should be documented in standard operating procedures (SOP)  for dissolution testing during method development.

Impact of vibration and agitation speed on dissolution of USP prednisone tablets RS and various IR tablet formulations

Dissolution testing is an in vitro procedure which is widely used in quality control (QC) of solid oral dosage forms and, given that real biorelevant test conditions are applied, can also be used as a predictive tool for the in vivo performance of such formulations. However, if a dissolution method is intended to be used for such purposes, it has to deliver results that are only determined by the quality of the test product, but not by other variables. In the recent past, more and more questions were arising on how to address the effects of vibration on dissolution test results. The present study was performed to screen for the correlation of prednisone dissolution of USP Prednisone Tablets RS with vibration caused by a commercially available vibration source as well as to investigate how drug release from a range of immediate release formulations containing class 1-4 drugs of the biopharmaceutical classification scheme is affected by vibration when performing dissolution experiments at different agitation rates. Results of the present study show that the dissolution process of oral drug formulations can be affected by vibration. However, it also becomes clear that the degree of which a certain level of vibration impacts dissolution is strongly dependent on several factors such as drug properties, formulation parameters, and the design of the dissolution method. To ensure the establishment of robust and predictive dissolution test methods, the impact of variation should thus be considered in method design and validation.

Vibration effects of lab equipment on dissolution testing with USP paddle method

Environmental vibration induced by laboratory equipment, building construction, or even by the analysts themselves is one of the more complicated factors affecting dissolution testing. It is difficult to control and/or calibrate by mechanical means or performance-based methods. In this study, dissolution apparatus vibration levels were measured in the frequency range from 10 to 270 Hz along all three axes using commercially available, single-axis accelerometers. The vibration distribution on the dissolution vessel plate was mapped, and acceleration was subsequently measured during dissolution runs involving NCDA#2 (10 mg prednisone) tablets using the paddle method. Several types of laboratory equipment were used to induce vibration during dissolution testing and vibration levels along the X-, Y-, and Z-axes of the vessel plate were measured in an attempt to establish possible correlation with dissolution results. In the frequency range studied, root mean square (RMS) acceleration values above 0.01 g, in either vertical or horizontal direction, typically affected dissolution results.