Stability Studies of Daucus carota (Apiaceae) Extracts as Colourant in Paracetamol Syrup Formulation

Abstract

Background: Colouring agents are pharmaceutical excipients used in imparting a distinctive appearance on pharmaceutical dosage forms thereby making them appealing, appetizing and distinctive. The stability of colourants is signifificantly affffected by environmental factors such as light, temperature, relative humidity and atmospheric oxygen. The study was carried out to determine the stability of Daucus carota (carrot) extracted pigment which was used as a colourant in paracetamol syrup formulation. Method: The dried plant material was macerated using ethanol as the extractive solvent. Paracetamol syrup was formulated using formula from the British Pharmacopoeia (BP), and the extracted pigment (20% and 40%) was added as the colourant and stored in both plain and amber coloured bottles and subsequently compared to amaranth, a synthetic colourant which was used as the standard. The effect of light and temperature at 37°Cand 52°Con the colourant was also determined over a period of 14 days. Results: All coloured formulations used for drug stability studies showed a signifificant decrease in concentration of the colourant over the study period. The result obtained from light stability studies showed better stability when stored in amber bottles than in plain bottles for all colourants however, there was a gradual decrease in the concentration of D. Carota and amaranth with increase in temperature. Conclusion: The stability and physicochemical properties of Daucus carota extract have shown its potential as a natural colourant in the formulation of liquid pharmaceutical dosage forms.