Ruzu® Herbal Bitters and Glibenclamide Tablets: Dissolution and In Vitro Release Kinetics Studies
Background: The concomitant intake of poly-herbal medicines with orthodox drugs raises huge concerns about
herb-drug interactions and patient safety, especially as the pharmacokinetic properties of these herbal medicines are
Objectives: This study aimed to determine the effect of Ruzu® herbal bitters on the dissolution profile and release
kinetics of glibenclamide (Daonil®) in pH simulated dissolution media in order to predict possible herb-drug
Method: The assay of glibenclamide was carried out as described in the British Pharmacopeia (2014). In
vitro dissolution of glibenclamide tablets was studied alone and with Ruzu® herbal bitters in phosphate buffer pH
6.8 using USP dissolution apparatus II at 75 rpm. Analysis of glibenclamide was done using High Performance
Liquid chromatography coupled with a UV detector. Dissolution data were analysed and percentage glibenclamide
released in the dissolution medium determined; dissolution data were compared using a model independent
approach. Different mathematical models were adopted to explore the release kinetics.
Result: The glibenclamide tablets studied showed satisfactory drug content as per BP specifications. Ruzu® herbal
bitters caused a significant reduction in the amount of glibenclamide released in vitro at gastrointestinal pH 6.8
(P < 0.001). The release of glibenclamide alone and with Ruzu® herbal bitters showed Higuchi mathematical model
as their best fitting model.
Conclusion: Ruzu® Herbal Bitters significantly decreased the dissolution of glibenclamide tablets at gastrointestinal
pH of 6.8. This could reflect on in vivo bioavailability performance with potential for causing sub-therapeutic levels
of glibenclamide in vivo. Further studies are needed to assess herb-drug interaction in vivo.
Keywords: Glibenclamide; Ruzu herbal Bitters; Dissolution; Release Kinetics
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