There is disclosed a method and apparatus for standardizing, in terms of a pre-established range of acceptable in vitro release and/or in vivo response, production of tabletted formulations which have a dependency on tablet hardness, through control of the maximum tabletting compression force developed by the tablet press employed, and for providing an individual momentary as well as permanent readout in digital form of the maximum compression force developed for each tabletting event. One or more tablets are compressed from a particular batch of formulation at selected different press compression force settings. These tablets are processed to derive data regarding in vitro release and/or in vivo response with a determination of an optimum value being made directly from or by interpolation of the resulting data. This optimum value is correlated to a press setting and the press is then set thereat for the tabletting of the bulk of the batch of formulation. Transducer means are appropriately mounted on the press to effect a signal output indicative of the compression force developed for each tabletting event. The transducer output is processed to derive only the true maximum developed compression force for each tabletting event. The derived force is then displayed and recorded in digital form.

A rheometer and method of making rheological measurements are disclosed, in which a sample is supported between plates and an alternating movement is applied by a driver, support rod and plate. Force and displacement measurements are taken and the property determined from those measurements. The vibrating signal which is applied is in the form of a frequency sweep signal having a monotonic group delay function. The top plate is provided with a surface which causes a meniscus to form up a side edge of the plate to reduce the spring nature of the sample when the movement is supplied to the sample, and a supporting rod which supports the top plate is preferably formed from a material having a low coefficient of thermal expansion so that the gap between the plates is maintained substantially constant if the sample is heated to take measurements at different temperatures.

A fast and reliable method is disclosed for measuring the dynamic mechanical properties of a material, particularly its modulus of elasticity and loss factor. By this method the acoustic characteristics of a material can be determined. An elongate strip of material, whose properties are desired to be known, is provided with miniature accelerometers fixedly secured to its opposite ends. One end of the strip is excited by a random noise source which travels toward the other end where that end and accelerometer is allowed to move freely (unrestrained). The accelerometers measures the ratios of acceleration at two locations over an extended frequency range of 0.2 Hz to 25 KHz, and the information is processed through a fast fourier transform spectrum analyzer for determining amplitude of acceleration ratio and phase difference between the two accelerometers from which Young's modulus and loss factor for that material are determined.

A method and apparatus for measuring the dynamic material constants of rur compounds. The rubber compound is tested in strip form by attaching one end of the strip to an electromechanical shaker while the opposite end of the strip is suspended under constant tension. The electromechanical shaker propagates an acoustic wave in the test strip and a piezoelectric transducer positioned at a first point on the test strip measures the mechanical response of the strip for phase and amplitude. The shaker is programmed to step piecewise over the frequency range from 100 Hz to 40 KHz by a frequency synthesizer. The distance between the shaker and the transducer is changed and data is obtained for a second point on the strip. The test values obtained are used to calculate Young's Modulus and the loss factor for the rubber compound.

A rheometer and method of making rheological measurements is disclosed, in which a sample is supported between plates and an alternating movement is applied by a driver, support rod and plate. Force and displacement measurements are taken and the property determined from those measurements. The vibrating signal which is applied is in the form of a frequency sweep signal having a monotonic group delay function. The top plate is provided with a surface which causes a meniscus to form up a side edge of the plate to reduce the spring nature of the sample when the movement is supplied to the sample, and a supporting rod which supports the top plate is preferably formed from a material having a low coefficient of thermal expansion so that the gap between the plates is maintained substantially constant if the sample is heated to take measurements at different temperatures.