Survivability of freeze-dried probiotic Pediococcus pentosaceus strains GS4, GS17 and Lactobacillus gasseri (ATCC 19992) during storage with commonly used pharmaceutical excipients within a period of 120 days

Objective: To examine the survivability and stability of probiotic strains in presence and absence of pharmaceutical excipients for a long period of time at (4 ± 1) °C. Methods: The survival rates of probiotic strains, Pediococcus pentosaceus GS4 (MTCC12683) (NCBI HM044322), GS17 (NCBI KJ608061) and Lactobacillus gasseri (ATCC 19992), were evaluated. Probiotic strains were lyophilized individually and in combination of excipients (sorbitol, ascorbic acid, fructose and skim milk). The preparation was monitored for 120 d storing at (4 ± 1) °C. During storage, all the preparations were evaluated for viability and stability of probiotic properties like lactic acid production, antimicrobial effect, water activity, and adherence to epithelial cells. Results: Sorbitol, ascorbic acid and skim milk favoured the viability of freeze-dried cells and sustained probiotic properties during storage. Without excipients (control group), strains showed percentage of survivability not more than 70% while strains with excipients survived for 73%–93% for a long period of time. Conclusions: Commonly used excipients can be considered as a vehicle for delivering active principle in probiotic formulation and for sustaining the viability and stability of probiotic strains for a period of 120 d