Stability of folic acid in extemporaneously compounded suspensions

Some drugs required by paediatric patients are not commercially available in those dosage forms appropriate for their use. These drugs may be needed to be prepared extemporaneously for use in each specific patient. Although the suspension is extensively used in hospital and pharmacy, there is still lack of appropriate formulation for extemporaneously preparation. The objective of this study was to assess the stability of extemporaneously compounded folic acid solution based on physical, chemical and microbiological qualities. For physical and chemical study, the sampling time is 60 days and the samples were kept at 25°C and 4°C. There was no notable changes of colour was observed of the suspension. However, the suspension started to demonstrate signs of caking and change of viscosity after 7 days of storage. There was no significance change between the pH at day 0 and day 60 for both conditions (p > 0.05). On average, the mean particle size of suspension was found to be stable at 4°C (p > 0.05). No significance change of zeta potential and concentration of suspension at day O and day 60 (p > 0.05). The preparations were also free from E. coli and S. aureus over 14 days of microbial testing. In conclusion, based on physical, chemical and microbiological study, folic acid suspensions 1 mg/ml, are expected to remain stable for 60 days.