• Additive Manufacturing of a Point-of-Care “Polypill:” Fabrication of Concept Capsules of Complex Geometry with Bespoke Release against Cardiovascular Disease

      Pereira, B.C.; Isreb, Abdullah; Isreb, Mohammad; Forbes, R.T.; Oga, E.F.; Alhnan, M.A. (2020-07)
      Polypharmacy is often needed for the management of cardiovascular diseases and is associated with poor adherence to treatment. Hence, highly flexible and adaptable systems are in high demand to accommodate complex therapeutic regimens. A novel design approach is employed to fabricate highly modular 3D printed “polypill” capsules with bespoke release patterns for multiple drugs. Complex structures are devised using combined fused deposition modeling 3D printing aligned with hot-filling syringes. Two unibody highly modular capsule skeletons with four separate compartments are devised: i) concentric format: two external compartments for early release while two inner compartments for delayed release, or ii) parallel format: where nondissolving capsule shells with free-pass corridors and dissolution rate-limiting pores are used to achieve immediate and extended drug releases, respectively. Controlling drug release is achieved through digital manipulation of shell thickness in the concentric format or the size of the rate limiting pores in the parallel format. Target drug release profiles are achieved with variable orders and configurations, hence confirming the modular nature with capacity to accommodate therapeutics of different properties. Projection of the pharmacokinetic profile of this digital system capsules reveal how the developed approach can be applied in dose individualization and achieving multiple desired pharmacokinetic profiles.
    • From ‘fixed dose combinations’ to ‘a dynamic dose combiner’: 3D printed bi-layer antihypertensive tablets

      Sadia, M.; Isreb, Abdullah; Abbadi, I.; Isreb, Mohammad; Aziz, D.; Selo, A.; Timmins, P.; Alhnan, M.A. (2018-10)
      There is an increased evidence for treating hypertension by a combination of two or more drugs. Increasing the number of daily intake of tablets has been reported to negatively affect the compliance of patients. Therefore, numerous fixed dose combinations (FDCs) have been introduced to the market. However, the inherent rigid nature of FDCs does not allow the titration of the dose of each single component for an individual patient's needs. In this work, flexible dose combinations of two anti-hypertensive drugs in a single bilayer tablet with a range of doses were fabricated using dual fused deposition modelling (FDM) 3D printer. Enalapril maleate (EM) and hydrochlorothiazide (HCT) loaded filaments were produced via hot-melt extrusion (HME). Computer software was utilised to design sets of oval bi-layer tablets of individualised doses. Thermal analysis and x-ray diffractometer (XRD) indicated that HCT remained crystalline in the polymeric matrix whilst EM appeared to be in an amorphous form. The interaction between anionic EM and cationic methacrylate polymer may have contributed to a drop in the glass transition temperature (Tg) of the filament and obviated the need for a plasticiser. Across all tablet sets, the methacrylate polymeric matrix provided immediate drug release profiles. This dynamic dosing system maintained the advantages of FDCs while providing a superior flexibility of dosing range, hence offering an optimal clinical solution to hypertension therapy in a patient-centric healthcare service.