PerioChip® (Chlorhexidine Gluconate) 2.5mg releases chlorhexidine in vitro in a biphasic manner, initially releasing approximately 40% of the chlorhexidine within the first 24 hours and then releasing the remaining chlorhexidine in an almost linear fashion for 7-10 days. This enzymatic release rate assay is an experimental collagenase assay that differs from the Regulatory Specification’s Agar Release Rate Assay. This release profile may be explained as an initial burst effect, dependent on diffusion of chlorhexidine from the chip, followed by a further release of chlorhexidine as a result of enzymatic degradation.
The results of two studies confirm a high degree of intersubject variability in chlorhexidine release from the PerioChip® matrix in vivo that was not seen in vitro. Due to the nature and clinical use of the PerioChip® dosage form, dose proportionality was not and would not be expected to be demonstrated between the two studies.