Dissolution of Extemporaneous Paracetamol Capsules

Abstract

Aim: To investigate the dissolution characteristics of extemporaneously prepared capsules containing hypromellose and paracetamol tablets.Method: Capsules of varying sizes containing paracetamol (powdered tablets) with varying amounts of hypromellose (4–20% w/w) were extemporaneously prepared. Dissolution was investigated using a USP dissolution testing apparatus. Paracetamol dissolution was quantitated using UV absorption spectrophotometry. The impact of hypromellose content, tablet excipients, capsule size, content weight and mixing methods were investigated.Results: Over a 4‐hour period, paracetamol dissolution decreased with increasing hypromellose content. Paracetamol dissolution was 100% from capsules containing 4% hypromellose and 52 ± 3% from capsules containing 20% hypromellose. Reformulated tablets with different formulations resulted in different dissolution rates. The dissolution rate was faster from small capsules and slower from capsules with a lower content weight. The method used to mix the powders also had a significant effect on the dissolution rate.Conclusion: Modified‐release delivery systems can be extemporaneously prepared from reformulated tablets using hypromellose. Hypromellose content, tablet excipients, capsule size, content weight and mixing methods have an impact on the dissolution rate.J Pharm Pract Res 2004; 34: 276–81.