Effect of Excipients on Disintegration, Viability and Activity of Fast Disintegrating Tablets Containing Probiotic and Starter Cultures

The effect of excipients on viability, activity and disintegration time of fast disintegrating tablets of probiotic and starter cultures were studied. Active ingredients (AI) of freeze dried cultures in three different combinations viz., Streptococcus thermophilus MTCC 5460 + Lactobacillus helveticus MTCC 5463(AI1); Streptococcus thermophilus MTCC 5460 + Lactobacillus rhamnosus MTCC 5462(AI2); Streptococcus thermophilus MTCC 5460 + Lactobacillus bulgaricus NCIM 2358 (AI3) were mixed with excipients such as spray dried lactose, super starch 200, sodium starch glycolate, PVP K-30, croscarmelos sodium, cros povidone at varying levels. Direct compression method with 1–2 kg/cm² pressure was used for tablet preparation. Tablets were assessed for their viability, activity and disintegration time. Viability of the tablets was measured as log cfu/tablet and activity assessed based on its ability to form curd and its acidity and pH. Further, the interaction of active ingredients and excipients selected were studied using Fourier Transform Infrared (FTIR) Spectroscopy at a resolution of 2 cm⁻¹, over a frequency range of 4000 to 400 cm⁻¹. Excipients and their levels had a significant (P <0.05) effect on disintegration time, viability and activity of tablets. For all the three active ingredients, tablets made using combination of excipients crospovidone, super starch 200 and PVP K-30 was found to be superior in terms of viability (>8.5 log cfu/tablet) and disintegration time (32.56 sec). Further, the Infrared spectra of active ingredients with excipients depicted the same characteristic peaks of probiotics in physical mixtures without any markable change in their position indicating no chemical interaction between probiotics and excipients used and hence proved their compatibility and suitability for preparation of probiotic and starter tablets.