RESUMEN
OBJECTIVE: To optimize the formula and preparation technology of gel-matrix sustained release tablet of nicotinic acid(GSTNA).METHODS: The formula of GSTNA was optimized by orthogonal experiment with the amount of hydrophilic gel-matrix material HPMC(K15M,E15-LV) and that of adjuvant calcium hydrogen phosphate(CHP) as factors and with the in vitro release rates as index.Meanwhile,the verification test on the intra-and inter-batch release rates of the samples was performed.RESULTS: The optimum formula could be seen as follows: the ratios of HPMC(K15M,E15-LV) and CHP were 4%,40% and 25% respectively.The GSTNA prepared in this formula achieved a sustained drug release of up to 12 h,and both the intra-batch homogenicity and the inter-batch reproducibility were satisfactory.CONCLUSION: The GSTNA is reasonable in formula and simple in preparation technology.