pharmaceutics Article Liqui-Mass Technology as a Novel Tool to Produce Sustained Release Liqui-Tablet Made from Liqui-Pellets Matthew Lam *, Nour Nashed and Ali Nokhodchi   Citation: Lam, M.; Nashed, N.; Nokhodchi, A. Liqui-Mass Technology as a Novel Tool to Produce Sustained Release Liqui-Tablet Made from Liqui-Pellets. Pharmaceutics 2021, 13, 1049. https://doi.org/10.3390/ pharmaceutics13071049 Academic Editors: Samantha Meenach and Jie Shen Received: 21 April 2021 Accepted: 6 July 2021 Published: 9 July 2021 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). Pharmaceutics Research Laboratory, Arundel Building, School of Life Sciences, University of Sussex, Brighton BN1 9QJ, UK; N.Nashed@sussex.ac.uk (N.N.); A.Nokhodchi@sussex.ac.uk (A.N.) * Correspondence: M.Lam@sussex.ac.uk; Tel.: +44-(0)1273-877639 Abstract: The Liqui-Mass technology (also known as Liqui-Pellet technology) has shown promising results in terms of enhancing the drug release rate of water insoluble drugs in a simplistic approach. However, there is no current study on sustained-release formulation using the Liqui-Mass technology. In this study, an attempt was made to produce a sustained-release Liqui-Tablet for the first time using a matrix-based approach. The non-volatile co-solvent used in the investigation included Tween 80, Tween 20 and Kolliphor EL. The production of sustained-release propranolol hydrochloride Liqui- Tablet was successful, and data from the saturation solubility test and dissolution test did not show much difference among the mentioned non-volatile co-solvent. The best Liqui-Tablet formulation took 24 h for drug release to reach at around 100%. There seemed to be a synergistic retarding drug release effect when a non-volatile co-solvent and Eudragit RS PO were used together. The increase of Eudragit RS PO concentration increased the retardant effect. Kinetic drug release analysis suggests that the best formulation followed the Higuchi model. The flowability of pre-compressed Liqui-Tablet pellets had no issues and its size distribution was narrow. Liqui-Tablet was generally robust and most formulations passed the friability test. The study revealed that Liqui-Mass technology can be employed to sustain drug release. Keywords: liqui-tablet; liqui-mass technology; liqui-pellet technology; sustained release; eudragit rs po; kinetic model; matrix pellet 1. Introduction Liqui-Mass technology, or sometimes referred to as Liqui-Pellet technology, is a re- cently developed oral drug delivery system, which was first filed for a patent in 2018 and published internationally in 2020 [1]. It was developed in response to bringing the concepts from liquisolid technology into a commercially feasible direction. Experimental data in terms of enhanced dissolution rate and manufacturability have been shown to be very promising [2–6]. The idea of an active pharmaceutical ingredient (API) being in a solubilised state in a solid matrix carrier system has not yet been seen in the current market according to the authors’ current knowledge. This is due to major technical issues with liquisolid technology, which are still persisting after more than two decades. Such drawbacks include issues with flow property, compressibility and inability to exist as a rea- sonably sized dosage form when high-dose formulation is required [7–10]. In terms of flow property, the incorporation of liquid medication in dry powder excipients is problematic because it makes the powder cohesive, giving rise to issue concerning flowability. This in turn creates an issue with attaining uniform feed and reproducible filling [11], which is a major concern when considering large-scale production. High-dose drug typically needs more liquid vehicle, which in turns need more excipients powder to improve formulation flowability. However, this would result in an end product being too large for actual use in patients. With the development of Liqui-Mass technology, such an issue is resolved, leading to a presumption that Liqui-Pellet and Liqui-Tablet are highly feasible in a commercial sense [2–6]. Pharmaceutics 2021, 13, 1049. https://doi.org/10.3390/pharmaceutics13071049 https://www.mdpi.com/journal/pharmaceutics