acta 2_2015

362 OLADAPO A. ADETUNJI et al.Figure 2. Plots of time of detachment (min) of ibuprofen tablets containing different concentrations of Entandophragma angolense gumformulated by wet granulation and direct compression techniquesC-O, C=O, C-N and C-F stretches, and weak P-Hbending groups, which are present in materials likecarbohydrates, starch, and natural polymers (21).The results revealed the presence of methyl, amine,phosphine and hydroxyl groups, inEntandophragma angolense gum. The presence ofthe characteristic peaks for the drug and polymersafter mixing suggests the absence of a chemicalreaction between Entandophragma angolense gumand ibuprofen.The UV analysis of the various mixtures ofEntandophragma angolense gum or hydroxypropylcelluloseand/or ibuprofen showed no significantshift in wavelength of maximum absorption due tointeraction between the polymers and the drug. Theresults of the peaks at wavelength range 190-300 nmfor Entandophragma angolense gum powder incombination with ibuprofen powder at 221 nm suggestthe absence of any reaction betweenEntandophragma angolense gum powder andibuprofen.The results of the factorial experimental design(Tables 3 and 4) provide a clear indication of theeffects of the four independent process parameters:nature of binder (X 1 ), concentration of binder (X 2 ),relative density of tablet (X 3 ), and tabletting technique(X 4 ), on the four responses studied. The rankingof the individual effects on disintegration timewas X 2 > X 3 > X 1 > X 4 , on tensile strength, was X 3> X 2 > X 1 > X 4 on BFI, X 2 > X 3 > X 1 > X 4 and onmucoadhesion time, X 2 > X 1 > X 4 > X 3 . The rankingsshow the relative magnitudes of the effects ofthe factors on these variables. A positive effect signifiesthat the response variable has increased invalue or magnitude, while a negative effect shows adecrease. Concentration of binder (X 2 ) had thelargest positive effect on disintegration time of thetablets. This effect shows that changing the concentrationfrom lower (2.5% w/w) to higher value (10%w/w) caused an increase in the disintegration time ofthe tablet formulations. This effect was significant(p < 0.05) and show that more compact tablets wereformed as the binder concentration was increased,thus causing a reduction in the rate of disintegration.Two other factors (relative density of tablet, X 3 andnature of binder, X 1 ) also had positive effects on disintegrationtime. However, changing the binder fromEntandophragma angolense gum to hydroxypropylcellulosecaused an insignificant increase in both tensilestrength and mucoadhesion time. Relative densi-