**3. Case study: process flow diagram for the manufacturing process of amoxicillin**

Amoxicillin oral suspension is an antibiotic which most commonly utilised for first line treatment of middle ear infections and for pneumonia, skin infections and strep throat as well. Active compound used in its formulation has chemical formula C16H19N3O5S with molar mass of 365.4. It is also called phenoxymethyl penicillin. **Figure 6** shows a variety of Amoxicillin capsules and tablets while **Figure 7** shows the structural formula of Amoxicillin. **Figure 8** is GSK Manufacturing Plant at Irvine.

**Figure 9** shows the process flow diagram for manufacture of Amoxicillin [20]. The process starts from stage A involving the reaction of the relevant raw materials [6-aminopenicillanic acid (6 APA), water and hydroxy phenyl glycine methyl ester (HPGME) and phenyl glycine acylase (PGA)] necessary for manufacture and finishes at stage O which is the drying process. Quality control of the manufacturing process takes place at every stage to ensure that the finished product in a dried form has the target consistency of 100% amoxicillin with minimum impurity. Most of the unit operations up till this stage are mainly batch manufacturing processes. The dried amoxicillin powder would need to be quality tested by acceptance sampling using relevant analytical techniques to establish conversion consistency and consequently any impurities beyond the recommended concentration in parts per million (ppm).

**Figure 6.** *Amoxicillin capsules and tablets.*

**Figure 7.** *Structural formula of amoxicillin (6-aminopenicillanic acid).*

**Figure 8.** *GSK manufacturing Plant at Irvine (GSK Website).*
