Step-wise screening

The rational development of a drug delivery system can be timely and costly. Formulation development and optimization requires a step-wise approach by Lrst screening and evaluating various formulationsin vitro before one initiates formulations/dosage forms tesfringvo. 

The procedure is divided into two steps, bromination and work-up. The critical step is the bromination. A maximum conversion in this step is necessary for a maximum final yield. Hence, variables involved in the first step will be the most important. A first screening can therefore be limited to these. An overall optimization can possibly be achieved through a step-wise approach First optimize the yield of the bromination step, then adjust the work-up procedure to fit an optimum bromination. This is not always true, sometimes by-products interfere with the work-up procedure. 

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