Scale-up in centrifugal partition chromatography: The “free-space between peaks” method

Abstract

Centrifugal Partition Chromatography (CPC) is a purification technique using a biphasic liquid system. As a preparative separation technique, scale-up is of primary concern. Once the separation is optimized on a lab-scale instrument, the scale-up transfer is quite straightforward simply using the instrument volume ratio as the linear transfer factor, thanks to the absence of solid support. Such linear transfer underestimates the performances of large-scale CPC rotors that are usually better than that of small rotors. It means that more material than predicted by the linear estimation could be purified. A fully practical method based on experimental observations is proposed. The first step is to determine experimentally the free space volume available between the two peaks of interest doing two analytical separations, one with the small analytical CPC instrument, giving ΔV1, and the second with the large preparative one, giving ΔV2. The second step is to determine on the small CPC instrument how much material can be loaded to reach the maximum mass load still giving the required purity and recovery ratio of the desired compound. Then, an accurate prediction of the maximal quantity of sample that the large-scale rotor can purify is simply obtained by multiplying the maximum mass load on the analytical CPC instrument by the free-space between peaks ΔV2/ΔV1 ratio. For demonstration purposes, the method is applied to the transfer of the CPC separation of a synthetic three-GUESS-compound mixture from a 35mL-rotor to a semi-prep 239-mL rotor. The paper addresses also the operating condition optimization depending on industrial production strategy (maximal load per run or maximal productivity).

Evaluation of Inter-Apparatus Separation Method Transferability in Countercurrent Chromatography and Centrifugal Partition Chromatography

“…Moreover, the results of this study show that the After the transferability of the separation method has been determined, an experimental validation at the particular flow rate at which the previous criteria are fulfilled can be performed and by this time, the separation method is transferred. A further improvement of the transferred method could follow by applying the space between the peaks method [13] or additional simulations as part of theoretical parameter studies. This can be done by a parameter study, where different flow rates and injection volumes can be evaluated by applying the linear correlations of S F and N i from the short-cut method as input, e.g., as part of a simulation study based on the equilibrium cell model [30,45].…”

“…Commercial columns are usually standardized and have a fix size. Therefore, this approach is not directly applicable for the separation method transfer in standardized and non-adjustable columns.Bouju et al proposed the free-space between the peaks method for the intra-apparatus method transfer between differently sized CPC columns with same cell geometry [13]. With this strategy, a separation method developed at lab scale can be easily transferred to large scale columns using the relation of the space between the peaks determined by pulse injections with low injection volumes ( V inj = 1% V C on the two columns.…”

Continuous Synthesis and Purification by Coupling a Multistep Flow Reaction with Centrifugal Partition Chromatography

“…The throughput could be easily increased by scaling up the column capacity or by converting it into a true moving‐bed system by introducing the sample solution continuously into the intermediate point of the column (e.g., between two columns). This system is the first continuous‐flow adsorbent‐free final‐product purification technique, and should find wide applicability in the synthesis of APIs or intermediates thereof.…”

Gram-Scale Purification of Dihydrorobinetin from Robinia pseudoacacia L. Wood by Centrifugal Partition Chromatography

“…Five grams of the S phase were successfully dissolved in 8 mL of the biphasic system and injected. Taking into account the column volume ratio between both columns used (50/200) and the average of loading sample (7.3 mg/column·mL) commonly used in CPC [32,34] this represents a high sample loading, limited by the solubility of the sample in the biphasic system. The CPC chromatogram obtained is presented on Figure 4.…”

“…Interestingly, CPC separations rely on the use of a liquid stationary phase that presents numerous advantages such as (i) no irreversible adsorption of samples; (ii) no compound degradation; (iii) high column loading capacity; (iv) high sample recovery; (v) lower cost; and (vi) shorter separation time [30,31]. Hence, this technique is particularly well adapted to the purification of various natural compounds from mg to g scale with standard laboratory equipment [32][33][34].…”