Pterodon pubescens Benth (sucupira) microencapsulation influence on formulation stability outcome compared to non-encapsulated extract

Abstract

Pterodon pubescens Benth is a Brazilian native species, used in folk medicine for chronic pain relief. The anti-inflammatory, antinociceptive, and antiproliferative activities attributed to the species have a straight relationship with vouacapans (furanditerpenes) and geranylgeraniol (acyclic diterpenes), identified in P. pubescens extracts. Nevertheless, scarce reports are found on product development and stability studies containing this species. This gap prompted the stability outcome evaluation of carbomer-940 gel-based formulations containing P. pubescens microencapsulated extract compared to non-encapsulated extract reported herein. Seeds were extracted with dichloromethane providing 46.6% (w/w) crude extract yield. Phytochemical markers were monitored by High Pressure Liquid Chromatography with Diode Array Detector (HPLC-DAD) and Gas Chromatography coupled to Mass Detection (GC-MS) using the vouacapans 1:1 ratio isomers 6α-hydroxy-7β-acetoxy-vouacapan-17β-oate methyl ester and 6α-acetoxy-7β-hydroxy-vouacapan-17β-oate methyl ester for quantification and identification purposes. Spray-dried microcapsules were produced with cashew gum as wall material with structure confirmed by scanning electron microscopy (SEM) and size distribution by light scattering parameters. The particles presented a bimodal size distribution ranging from 0.2 to 500 μm, vouacapans content and encapsulation efficiency of 55.6% and 44.4% respectively, with an overall spray-drying yield of 82.6% (w/w). The formulation containing microencapsulated extract did not achieve an acceptable outcome under test condition, with further studies needed for optimization. Nevertheless, the gel containing 2.5% (w/v) of non-encapsulated extract stored at 25 °C protected from light presented the best results within 180 days in stability study. P. pubescens incorporation maintained rheological properties with better performance when exposed to light during storage time compared to the gel base formulation. The formulation delivered vouacapans throughout a synthetic membrane. This formulation is the first step to achieve a novel topical gel-based product containing P. pubescens beneficial activities.