Pterodon pubescens Benth: Stability study of microencapsulated extract and isolated compounds monitored by antinociceptive assays

We previously reported the antinociceptive properties 6α, 7β-dihydroxy-vouacapan-17β-oate methyl ester, isolated from Pterodon pubescens Benth seeds. This report describes the antinociceptive properties of isomers 6α-hydroxy-7β-acetoxy-vouacapan-17β-oate methyl ester and 6α-acetoxy-7β-hydroxy-vouacapan-17β-oate methyl ester (C1) isolated from P. pubescens crude extract, and furthermore the influence of microencapsulation process as a tool for maintaining stability of both the crystals and extracts. Therefore, microencapsulated, free samples of C1 and the crude extract on the antinociceptive assays were evaluated. The most relevant findings were that: sample C1 i) possess antinociceptive activity revealed by writhing test; ii) showed significantly anti-allodynic, but not antihyperalgesic effect; iii) the microencapsulation kept the activity and integrity of both sample C1 and Pp crude extract; iv) microencapsulation by spray drying is a useful alternative to increase shelf life time. The free and microencapsulated C1sample maintained stability even when stored in drastic temperature and humidity conditions. Whereas the crude Pp extract only maintained stability with the microencapsulation process, not only preserving the content, but also solving the inconvenience of low aqueous solubility.