Emergence of 3D Printed Dosage Forms: Opportunities and Challenges

The recent introduction of the first FDA approved 3D-printed drug has fuelled interest in 3D printing technology, which is set to revolutionize healthcare. Since its initial use, this rapid prototyping (RP) technology has evolved to such as extent that it is currently being used in a wide range of applications including in tissue engineering, dentistry, construction, automotive and aerospace. However, in the pharmaceutical industry this technology is still in its infancy and its potential yet to be fully explored. This paper presents various 3D printing technologies such as stereolithographic, powder based, selective laser sintering, fused deposition modelling and semi-solid extrusion 3D printing. It also provides a comprehensive review of previous attempts at using 3D printing technologies on the manufacturing dosage forms with a particular focus on oral tablets. Their advantages particularly with adaptability in the pharmaceutical field have been highlighted, including design flexibility and control and manufacture which enables the preparation of dosage forms with complex designs and geometries, multiple actives and tailored release profiles. An insight into the technical challenges facing the different 3D printing technologies such as the formulation and processing parameters is provided. Light is also shed on the different regulatory challenges that need to be overcome for 3D printing to fulfil its real potential in the pharmaceutical industry

Nondestructive and on-line monitoring of tablets using light-induced fluorescence technology

A system using light-induced fluorescence (LIF) technology was developed for rapid and nondestructive analysis of active pharmaceutical ingredients on tablet surfaces. Nonhomogenous tablets with defined layer of active ingredients were made by 3-Dimensional Printing technology to determine penetration depths of the light source and the resultant fluorescence responses. The LIF method of analysis showed penetration to depths of up to 3 mm into tablets. A correlation between LIF signals from analysis of tablet surfaces and the total drug content of the respective tablets was established. This method of surface analysis was verified with UV spectrometric methods for the total drug content of each respective tablet. The results from a small sample population of tablets made from both homogeneous and nonhomogeneous powder mixtures established good correlation between LIF surface monitoring and total tablet content. The use of on-line monitoring of the individual tablet for surface content demonstrated consistent LIF profiles from simulated production rates up to 3000 tablets a minute. The instrument was also field tested successfully on a tablet analyzer