Assessment of essential probiotic properties of lyophilized Limosilactobacillus reuteri 29B for the development of probiotic vaginal Pessary.

This study is aimed to utilize the lyophilized Limosilactobacillus reuteri 29B (L29B) strain with a high percentage of viable cells and essential probiotic properties in the development and evaluation of the probiotic vaginal pessary. Skim milk was identified as the optimal cryoprotectant for L29B giving 80.18% ± 0.123 viability after lyophilization. Hollow and solid type pessaries were formulated using polyethylene glycol (PEG) at different ratios. Both type of vaginal pessaries was detailed in further with regard to their physical properties. The hollow type vaginal pessary had an excellent stability and viability over a 24-month period at cold storage (68.22% ± 0.13) compared to solid type pessary (49.7% ± 0.59). It also completely disintegrated in the synthetic vaginal environment (pH 4.5) in less than 60 min and offered sustained in vitro release. It is demonstrated that the lyophilized process did not deteriorate the essential probiotic properties of L29B. These findings confirmed that the development of probiotic vaginal pessaries that involved the incorporation of lyophilized L29B into PEG 4000:400 (ratio 1:1) did not result in significant loss of viable cells and as a potential probiotic vaginal delivery system.