Etching patterns on the monoclinic and orthorhombic paracetamol

M.A Mikhailenko,V.V Boldyrev,T.N Drebushchak,T.P Shakhtsneider,Mikael Begtrup

doi:10.3998/ark.5550190.0005.c11

Abstract

The initial stages of etching the monoclinic (I) and the orthorhombic (II) polymorphs of paracetamol crystals by a series of agents (10%-solutions of acetic anhydride, pyridine, 1,4- dioxane, morpholine, N-methylmorpholine in carbon tetrachloride) were studied and the corresponding etching patterns were compared. For the first time, it was possible to observe different etching patterns when dissolving not only the faces of the crystals parallel to molecular layers, but also the faces normal to the molecular layers.

Highlights

The dissolution of crystals is a complex heterogeneous catalytic process, which attracts much attention because of its importance for many practical applications.[1]
The etching patterns observed at the initial stages of the dissolution of crystals are a manifestation of the anisotropy of the crystal structure and of the interactions in this structure.[1,2,3,4]
The factors affecting the shapes of the etching pits formed at the initial stages of dissolution were studied in details for the halides of alkali metals, silicon, or AIIIBV compounds

Summary

Introduction

The dissolution of crystals is a complex heterogeneous catalytic process, which attracts much attention because of its importance for many practical applications.[1]. The etching patterns on the faces of the paracetamol crystals were observed using a Neophot[2] optical microscope (Karl Zeiss Jena) with a scanning photodevice (Canon G1 2048 x 1536 (3.3 MPix))

Results

Discussion

Conclusions