Effect of lignin as natural polymer on the release rate of acetylsalicylic acid tablets

The main focus of this paper is on the improvement of formulations utilising non-conventional bio-based excipients to improve tablet release rates. Two different formulations were considered. The first formulation contains Alcell lignin, lactose monohydrate and microcrystalline cellulose as excipients and acetylsalicylic acid (aspirin) as active pharmaceutical ingredient (API). The second formulation contains lactose monohydrate and microcrystalline cellulose as excipients and aspirin as API. The prepared formulations were roller compacted followed by milling, sieving, and tableting. The tablets were then characterised in terms of dissolution rate in order to compare the release rates. Results indicated that tablets containing Alcell lignin have quicker release, faster disintegration times and higher tablet hardness for all samples with differing process parameters. Higher API dissolution has been attributed to the amorphous structure of lignin and its interaction with aspirin, which increases dissolution of the API.