Application of Attribute Control Chart in the Monitoring of the Physical Properties of Solid Dosage Forms

Mostafa Eissa


Quality control monitoring of the critical inspection characteristics in the pharmaceutical dosage forms in the pharmaceutical industry is crucial prerequisite for an effective and safe drug release in the medical market. Part of these monitored properties includes in-process control  tests that is necessary during different manufacturing stages. Apart from the ordinary quality control tests, statistical process control tools provide indispensible methodologies to judge the manufacturing processes efficacy and stability. The current study focused on trending of two properties namely: moisture content and friability of oral antibacterial tablet from the initial 31 manufactured batches. The film coated tablet includes Fluoroquinolone compound, Levofloxacin as an active pharmaceutical ingredient. The approach involved the use of commercial statistical software package for data analysis and the construction of control charts. Interpretation of results showed unexplained outlier batches, although they did not exceed specification values. This finding was assigned and detected chronologically using attribute-type of control chart after applying Laney modification. Laney C΄ chart was approached to correct for either over- or under- dispersion of data. The detected outliers were found in the corresponding control charts of both moisture content and friability in 29th to 31th batches and 1st batch, respectively. Interestingly, 19th batch showed exceptionally low moisture content if compared with other batches. The present methodology applied herein for the evaluation of both inspection properties was very useful in the monitoring of the product quality and the process stability in the drug manufacturing facility. In addition attribute control charts may provide an opportunity to improve the manufacturing process control and the dosage form quality subsequently by investigating the sources of out-of-control and correct them before any true excursion could occur which may lead to out-of-specification product.


Friability; Laney C΄ chart; Moisture Content; Quality Control; Statistical Process Control.

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