RESUMEN
Purpose: This study aimed at determining the optimum concentration of hydroxypropyl methylcellulose (HPMC) as hydrogel matrix and citric acid-locust bean gum (CA-LBG) as negative matrix for controlled release tablet formulation. In addition, the study was to determine the effect of CA-LBG and HPMC. CA-LBG accelerates the disintegration of tablets into granules so that the HPMC granule matrix swells immediately and controls drug release. The advantage of this method is that the tablets do not produce large HPMC gel lumps without drug (ghost matrix) but form HPMC gel granules, which can be rapidly degraded after all of the drug is released. Methods : The experiment followed the simplex lattice design to obtain the optimum tablet formula with CA-LBG and HPMC concentrations as optimization factors. Tablet production by the wet granulation method and ketoprofen is the model of the active ingredient. The kinetics of ketoprofen release was studied using several models. Results : Based on the coefficients of each polynomial equation that HPMC and CA-LBG increased the value of angle of repose (29.91:27.87), tap index (18.99:18.77), hardness (13.60:13.32), friability (0.41:0.73), and release of ketoprofen (52.48:99.44). Interaction of HPMC and CA-LBG increased the value of angle of repose (3.25), tap index (5.64), and hardness (2.42). Interaction of HPMC and CA-LBG too decreased the friability value (-1.10) and release of ketoprofen (-26.36). The Higuchi, Korsmeyer-Peppas, and Hixson-Crowell model is the kinetics of eight experimental tablet formulas. Conclusions : The optimum concentrations of HPMC and CA-LBG for controlled release tablets are 32.97 and 17.03%, respectively. HPMC, CA-LBG, and a combination of both affect the physical quality of tablet and tablet mass. CA-LBG is a new excipient candidate that can control drug release from tablets by the matrix disintegration mechanism on the tablet.
RESUMEN
Esterification of citric acid (CA) with locust bean gum (LBG) was prepared by hydrochloric acid (HCl) as a catalyst and UV irradiation (254 nm) as esterification energy. This study aims to determine the best conditions of esterification. Other than that, it is to know the effect of amount HCl and UV irradiation time for the esterification process of CA with LBG. The amounts of HCl are 0.18 and 0.30 M, while the variations of UV irradiation time are 75 and 100 minutes. Polyester (CA-LBG) were characterized by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), X-ray diffractometer (XRD), esterification degree, and viscosity. Parameters for determining the best conditions for esterification are esterification degree and viscosity. The best conditions of esterification were obtained by using 0.30 M mL HCl and 100 minutes of UV irradiation time resulted in CA-LBG having a value of esterification degree 9.69 % and viscosity 7.46 cPs. HCl accelerates protonation on the O atoms and the formation of positive C atoms of carbonyl groups of citric acid. The time of UV irradiation gives the longer energy for the bond formation between the positive C atoms of the carbonyl group and the O atoms of the hydroxyl group at C-6 atoms of mannose and galactose.