THE POTENTIAL OF THE FRUIT PULP OF PARKIA BIGLOBOSA (AFRICAN LOCUST BEAN) AS AN EXCIPIENT IN SOLID PHARMACEUTICAL DOSAGE FORMS

Marcel Tunkumgnen Bayor*, Paul Lambon and Eric Tuffour

ABSTRACT

Nature has provided us with a wide variety of materials and the world today is increasingly interested in natural drugs and excipients. Parkia biglobosa (African locust bean) fruit pulp was processed into flour and its physicochemical and functional properties evaluated as a potential pharmaceutical excipient for use in solid dosage forms. The effects of the fruit pulp as a binder and disintegrant were investigated on Paracetamol tablet formulations, using Acacia gum and Sodium starch glycolate as reference binder and disintegrant, respectively. The P. biglobosa fruit pulp was soluble in water with a resultant pH of 6.31; but insoluble in organic solvents. By all the indicators, Tapped density (0.24 g/ml), Bulk density (0.18 g/ml), Angle of repose (45.0o), Hausner‟s ratio (1.67), Carr‟s index (40 %); the fruit pulp did not show satisfactory inherent flow properties. The P. biglobosa fruit pulp had a very high water binding capacity (446 %) and swelling profile (4.25), holding up to about five times its own weight of water, which suggested it could serve as a good disintegrant. The proximate data (moisture content 8.66 % , ash value 2.40 % , crude fat 0.13, crude fibre 8.75 %, protein 6.64 % , carbohydrate 76.80 %, and sugar 3.66oBrix); showed it could be a good source of macronutrients. However, it‟s pasting profile (pasting temperature 60.70oC, breakdown viscosity 7.5 RVU, setback viscosity 15 RVU, peak viscosity 9.0 RVU and final viscosity 15.50 RVU); indicated the absence of starch and lack of inherent viscosity. The appearance, tensile strength, friability and disintegration of Paracetamol tablets formulated with the fruit pulp as binder were not significantly different from compacts containing acacia gum at similar binder concentrations (>3 %w/w), but released the drug significantly faster (P < 0.05) (96 % in 30 minutes) compared to formulations with acacia gum (94 % in 45 minutes). The results established the potential of P. biglobosa fruit pulp as a thickener and an effective pharmaceutical binder, at least comparative to the commercially available Acacia gum.

Keywords: Parkia biglobosa, fruit pulp, excipient, binder, diluent, disintegrant.