Coating and Density Distribution Analysis of Commercial Ciprofloxacin Hydrochloride Monohydrate Tablets by Terahertz Pulsed Spectroscopy and Imaging

Tomoaki Sakamoto,Yukio Hiyama,Donald D Arnone,Philip F Taday,Toru Kawanishi,Alessia Portieri

doi:10.1007/s12247-012-9130-1

Abstract

Terahertz pulsed spectroscopy was used to qualitatively detect ciprofloxacin hydrochloride monohydrate (CPFX·HCl·H2O) in tablets, and terahertz pulsed imaging (TPI) was used to scrutinize not only the coating state but also the density distribution of tablets produced by several manufacturers. TPI was also used to evaluate distinguishability among these tablets. The same waveform, which is a unique terahertz absorption spectrum derived from pure CPFX·HCl·H2O, was observed in all of the crushed tablets and in pure CPFX·HCl·H2O. TPI can provide information about the physical states of coated tablets. Information about the uniformity of parameters such as a coating thickness and density can be obtained. In this study, the authors investigated the coating thickness distributions of film-coated CPFX·HCl·H2O from four different manufacturers. Unique terahertz images of the density distributions in these commercial tablets were obtained. Moreover, B-scan (depth) images show the status of the coating layer in each tablet and the density map inside the tablets. These features would reflect differences resulting from different tablet-manufacturing processes.

Highlights

The electro-magnetic wave on terahertz region is generally defined from 0.1 THz to 10 THz (3.3 to 333 cm−1)
According to the enclosed documents for the products, CPFX·HCl·H2O is the active ingredient in each product. These results suggest that terahertz spectroscopy can be used to identify active pharmaceutical ingredients (APIs) in tablets
In the image obtained from tablet C, small areas having comparatively small changes in refraction of terahertz pulsed wave appear in the center of the tablet

Summary

Introduction

The electro-magnetic wave on terahertz region is generally defined from 0.1 THz to 10 THz (3.3 to 333 cm−1). TPI can produce images or maps which are obtained by detecting reflected pulses from each pixel on a tablet or Terahertz pulses are irradiated at each pixel on a tablet and penetrate, and echoes or reflections from layers are measured.

Results

Conclusion