Online Evaluation of Paracetamol Antisolvent Crystallization Growth Rate with Video Imaging in an Oscillatory Baffled Crystallizer

Abstract

We report a method for observing and quantifying antisolvent crystallization (acetone/water system) of paracetamol in an oscillatory baffled crystallizer (OBC). With the help of optical means, paracetamol crystals passing the light sheet are recorded by a CCD camera. This allows the mass of crystals to be tracked with time and in turn the instantaneous and overall averaged crystal mass growth rates to be evaluated. By the standard sampling method, the overall averaged crystal growth rate and the percentage recovery of crystals were also determined. This work shows that there is a high correlation in data between the optical and the sampling techniques, validating the accuracy and reliability of the system. Our data are also consistent with previous work in this field.

Determination of metastable zone width, mean particle size and detectable number density using video imaging in an oscillatory baffled crystallizer

“…5 were found to range from 3.6 to 17.4 C (AE0.55 C, error associated with the thermocouple) with an average of 10.5 C. Initial observations from Fig. 2,3,11,12,14 This adds to the validity of our analysis method as a potential tool for determining the metastable zone width along with the mass 26 and growth kinetics 28 described in our previous work. This is contrary to previous work by Ni and Laio 9 who reported that, for the same power density, OBCs had a narrower metastable zone compared to STRs.…”

“…[26][27][28] In summary, the apparatus consists of a 200 ml (32 mm internal diameter) oscillatory baffled crystallizer (OBC) fitted with a square jacket (to correct for the curvature of the reactor internal when taking optical measurements). [26][27][28] In summary, the apparatus consists of a 200 ml (32 mm internal diameter) oscillatory baffled crystallizer (OBC) fitted with a square jacket (to correct for the curvature of the reactor internal when taking optical measurements).…”

Precipitation of hydroxyapatite at 37 °C in a meso oscillatory flow reactor operated in batch at constant power density

“…Imaging-based and colorimetric techniques for crystallization monitoring have been investigated, in particular, for the evaluation of growth kinetics [16][17][18][19] and mixing. 20 The present work focuses on mixing and pH monitoring, as both are key parameters when studying calcium phosphates precipitation.…”

Application of inline imaging for monitoring crystallization process in a continuous oscillatory baffled crystallizer

“…14 The step following the object detection focuses on refining the detected boundaries or filling in the gaps in the object boundaries and rejecting the unwanted objects by classification method. [25][26][27] As application of COBC for continuous crystallization is an area of ongoing development, the use of an inline imaging tool provides an the additional advantage that more, qualitative information is obtained which helps to get a better insight in the crystallization process in this flow crystallizer. The final pool of identified objects is then characterized to determine the shape and the size descriptors.…”