1
|
Junnila A, Mortier L, Arbiol A, Harju E, Tomberg T, Hirvonen J, Viitala T, Karttunen AP, Peltonen L. Rheological insights into 3D printing of drug products: Drug nanocrystal-poloxamer gels for semisolid extrusion. Int J Pharm 2024; 655:124070. [PMID: 38554740 DOI: 10.1016/j.ijpharm.2024.124070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 03/27/2024] [Accepted: 03/27/2024] [Indexed: 04/02/2024]
Abstract
The importance of ink rheology to the outcome of 3D printing is well recognized. However, rheological properties of printing inks containing drug nanocrystals have not been widely investigated. Therefore, the objective of this study was to establish a correlation between the composition of nanocrystal printing ink, the ink rheology, and the entire printing process. Indomethacin was used as a model poorly soluble drug to produce nanosuspensions with improved solubility properties through particle size reduction. The nanosuspensions were further developed into semisolid extrusion 3D printing inks with varying nanocrystal and poloxamer 407 concentrations. Nanocrystals were found to affect the rheological properties of the printing inks both by being less self-supporting and having higher yielding resistances. During printing, nozzle blockages occurred. Nevertheless, all inks were found to be printable. Finally, the rheological properties of the inks were successfully correlated with various printing and product properties. Overall, these experiments shed new light on the rheological properties of printing inks containing nanocrystals.
Collapse
Affiliation(s)
- Atte Junnila
- Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, § ,University of Helsinki, Helsinki, Finland.
| | - Laurence Mortier
- Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, § ,University of Helsinki, Helsinki, Finland; Laboratory of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
| | - Alba Arbiol
- Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, § ,University of Helsinki, Helsinki, Finland
| | - Elina Harju
- Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, § ,University of Helsinki, Helsinki, Finland
| | - Teemu Tomberg
- Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, § ,University of Helsinki, Helsinki, Finland
| | - Jouni Hirvonen
- Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, § ,University of Helsinki, Helsinki, Finland
| | - Tapani Viitala
- Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, § ,University of Helsinki, Helsinki, Finland; Pharmaceutical Sciences Laboratory, Faculty of Science and Engineering, Åbo Akademi University, Turku, Finland
| | - Anssi-Pekka Karttunen
- Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, § ,University of Helsinki, Helsinki, Finland
| | - Leena Peltonen
- Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, § ,University of Helsinki, Helsinki, Finland
| |
Collapse
|
2
|
Camacho Vieira C, Peltonen L, Karttunen AP, Ribeiro AJ. Is it advantageous to use quality by design (QbD) to develop nanoparticle-based dosage forms for parenteral drug administration? Int J Pharm 2024:124163. [PMID: 38670473 DOI: 10.1016/j.ijpharm.2024.124163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 04/07/2024] [Accepted: 04/22/2024] [Indexed: 04/28/2024]
Abstract
Parenteral administration is one of the most commonly used drug delivery routes for nanoparticle-based dosage forms, such as lipid-based and polymeric nanoparticles. For the treatment of various diseases, parenteral administration include intravenous, subcutaneous, and intramuscular route. In drug development phase, multiparameter strategy with a focus on drug physicochemical properties and the specificity of the administration route is required. Nanoparticle properties in terms of size and targeted delivery, among others, are able to surpass many drawbacks of conventional dosage forms, but these unique properties can be a bottleneck for approval by regulatory authorities. Quality by Design (QbD) approach has been widely utilized in development of parenteral nanoparticle-based dosage forms. It fosters knowledge of product and process quality by involving sound scientific data and risk assessment strategies. A full and comprehensive investigation into the state of implementation and applications of the QbD approach in these complex drug products can highlight the gaps and challenges. In this review, the analysis of critical attributes and Design of Experiment (DoE) approach in different nanoparticulate systems, together with the proper utilization of Process Analytical Technology (PAT) applications are described. The essential of QbD approach for the design and development of nanoparticle-based dosage forms for delivery via parenteral routes is discussed thoroughly.
Collapse
Affiliation(s)
- C Camacho Vieira
- Universidade de Coimbra, Faculdade de Farmácia, 3000-148 Coimbra, Portugal
| | - L Peltonen
- Drug Research Program, Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
| | - A P Karttunen
- Drug Research Program, Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
| | - A J Ribeiro
- Universidade de Coimbra, Faculdade de Farmácia, 3000-148 Coimbra, Portugal; i(3)S, IBMC, Rua Alfredo Allen, 4200-135 Porto, Portugal.
| |
Collapse
|
3
|
Pedersen T, Karttunen AP, Korhonen O, Wu JX, Naelapää K, Skibsted E, Rantanen J. Determination of Residence Time Distribution in a Continuous Powder Mixing Process With Supervised and Unsupervised Modeling of In-line Near Infrared (NIR) Spectroscopic Data. J Pharm Sci 2020; 110:1259-1269. [PMID: 33217424 DOI: 10.1016/j.xphs.2020.10.067] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 10/12/2020] [Accepted: 10/30/2020] [Indexed: 11/25/2022]
Abstract
Successful implementation of continuous manufacturing processes requires robust methods to assess and control product quality in a real-time mode. In this study, the residence time distribution of a continuous powder mixing process was investigated via pulse tracer experiments using near infrared spectroscopy for tracer detection in an in-line mode. The residence time distribution was modeled by applying the continuous stirred tank reactor in series model for achieving the tracer (paracetamol) concentration profiles. Partial least squares discriminant analysis and principal component analysis of the near infrared spectroscopy data were applied to investigate both supervised and unsupervised chemometric modeling approaches. Additionally, the mean residence time for three powder systems was measured with different process settings. It was found that a significant change in the mean residence time occurred when comparing powder systems with different flowability and mixing process settings. This study also confirmed that the partial least squares discriminant analysis applied as a supervised chemometric model enabled an efficient and fast estimate of the mean residence time based on pulse tracer experiments.
Collapse
Affiliation(s)
- Troels Pedersen
- University of Copenhagen, Copenhagen, Denmark; Novo Nordisk A/S, Måløv, Denmark
| | | | | | | | | | | | | |
Collapse
|
4
|
Al-Sharabi M, Markl D, Mudley T, Bawuah P, Karttunen AP, Ridgway C, Gane P, Ketolainen J, Peiponen KE, Rades T, Zeitler JA. Simultaneous investigation of the liquid transport and swelling performance during tablet disintegration. Int J Pharm 2020; 584:119380. [PMID: 32407939 DOI: 10.1016/j.ijpharm.2020.119380] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 04/23/2020] [Accepted: 04/24/2020] [Indexed: 11/17/2022]
Abstract
Fast disintegrating tablets have commonly been used for fast oral drug delivery to patients with swallowing difficulties. The different characteristics of the pore structure of such formulations influence the liquid transport through the tablet and hence affect the disintegration time and the release of the drug in the body. In this work, terahertz time-domain spectroscopy and terahertz pulsed imaging were used as promising analytical techniques to quantitatively analyse the impact of the structural properties on the liquid uptake and swelling rates upon contact with the dissolution medium. Both the impact of porosity and formulation were investigated for theophylline and paracetamol based tablets. The drug substances were either formulated with functionalised calcium carbonate (FCC) with porosities of 45% and 60% or with microcrystalline cellulose (MCC) with porosities of 10% and 25%. The terahertz results reveal that the rate of liquid uptake is clearly influenced by the porosity of the tablets with a faster liquid transport observed for tablets with higher porosity, indicating that the samples exhibit structural similarity in respect to pore connectivity and pore size distribution characteristics in respect to permeability. The swelling of the FCC based tablets is fully controlled by the amount of disintegrant, whereas the liquid uptake is driven by the FCC material and the interparticle pores created during compaction. The MCC based formulations are more complex as the MCC significantly contributes to the overall tablet swelling. An increase in swelling with increasing porosity is observed in these tablets, which indicates that such formulations are performance-limited by their ability to take up liquid. Investigating the effect of the microstructure characteristics on the liquid transport and swelling kinetics is of great importance for reaching the next level of understanding of the drug delivery, and, depending on the surface nature of the pore carrier function, in turn controlling the performance of the drug mainly in respect to dissolution in the body.
Collapse
Affiliation(s)
- Mohammed Al-Sharabi
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 0AS, UK
| | - Daniel Markl
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, G4 0RE Glasgow, UK; EPSRC Centre for Innovative Manufacturing in Continuous Manufacturing and Crystallisation, University of Strathclyde, 99 George Street, G1 1RD Glasgow, UK
| | - Theona Mudley
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 0AS, UK
| | - Prince Bawuah
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 0AS, UK
| | - Anssi-Pekka Karttunen
- School of Pharmacy, Promis Centre, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland
| | - Cathy Ridgway
- Omya International AG, Forschackerstrasse 6, CH 4622 Egerkingen, Switzerland
| | - Patrick Gane
- Aalto University, School of Chemical Engineering, Department of Bioproducts and Biosystems, FI-00076 Aalto, Finland
| | - Jarkko Ketolainen
- School of Pharmacy, Promis Centre, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland
| | - Kai-Erik Peiponen
- Institute of Photonics, University of Eastern Finland, P.O. Box 111, FI-80101 Joensuu, Finland
| | - Thomas Rades
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - J Axel Zeitler
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 0AS, UK.
| |
Collapse
|
5
|
Karttunen AP, Hörmann TR, De Leersnyder F, Ketolainen J, De Beer T, Hsiao WK, Korhonen O. Measurement of residence time distributions and material tracking on three continuous manufacturing lines. Int J Pharm 2019; 563:184-197. [DOI: 10.1016/j.ijpharm.2019.03.058] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Revised: 03/21/2019] [Accepted: 03/27/2019] [Indexed: 10/27/2022]
|
6
|
Karttunen AP, Wikström H, Tajarobi P, Fransson M, Sparén A, Marucci M, Ketolainen J, Folestad S, Korhonen O, Abrahmsén-Alami S. Comparison between integrated continuous direct compression line and batch processing - The effect of raw material properties. Eur J Pharm Sci 2019; 133:40-53. [PMID: 30862514 DOI: 10.1016/j.ejps.2019.03.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 02/27/2019] [Accepted: 03/02/2019] [Indexed: 11/26/2022]
Abstract
There is a current trend in pharmaceutical manufacturing to shift from traditional batch manufacture to continuous manufacturing. The purpose of this study was to test the ability of an integrated continuous direct compression (CDC) line, in relation to batch processing, to achieve consistent tablet quality over long processing periods for formulations with poor flow properties or with a tendency to segregate. The study design included four industrially relevant formulations with different segregation indices and flow properties induced through different grades of the Active Pharmaceutical Ingredient (API), paracetamol, and major filler as well as varying the amount of API. The performance metrics investigated were content, uniformity of content, tablet weight, and tablet strength. The overall process stability over time was significantly improved with the CDC line as compared to the batch process. For all the formulations with a high API content, the CDC line provided better or equal uniformity of content and tablet weight as compared to batch. The CDC line was especially efficient in providing a stable content and tablet weight for poorly flowing formulations containing the standard, cohesive, grade of API. The only formulation that performed better in the batch process was the formulation with a low API content. Thus, for this formulation, the batch process achieved lower variation in tablet content since maintaining a low feed rate for the API proved challenging in the CDC line. In addition, some of the API became stuck in the CDC line between feeding and tableting, most likely at the funnel in the mixer inlet, highlighting the need for properly designed interfaces between units. The insensitivity of the CDC line towards poor flow indicates that one could use direct compression at high drug load compositions of poorly flowing powder blends that could not be processed via batch manufacturing.
Collapse
Affiliation(s)
- Anssi-Pekka Karttunen
- University of Eastern Finland, School of Pharmacy, PROMIS-Centre, FI-70211 Kuopio, Finland
| | | | | | | | | | | | - Jarkko Ketolainen
- University of Eastern Finland, School of Pharmacy, PROMIS-Centre, FI-70211 Kuopio, Finland
| | | | - Ossi Korhonen
- University of Eastern Finland, School of Pharmacy, PROMIS-Centre, FI-70211 Kuopio, Finland.
| | | |
Collapse
|
7
|
Taipale-Kovalainen K, Karttunen AP, Niinikoski H, Ketolainen J, Korhonen O. The effects of unintentional and intentional process disturbances on tablet quality during long continuous manufacturing runs. Eur J Pharm Sci 2019; 129:10-20. [PMID: 30550973 DOI: 10.1016/j.ejps.2018.11.030] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 11/13/2018] [Accepted: 11/26/2018] [Indexed: 11/24/2022]
|
8
|
Rehrl J, Karttunen AP, Nicolaï N, Hörmann T, Horn M, Korhonen O, Nopens I, De Beer T, Khinast JG. Control of three different continuous pharmaceutical manufacturing processes: Use of soft sensors. Int J Pharm 2018; 543:60-72. [DOI: 10.1016/j.ijpharm.2018.03.027] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 02/26/2018] [Accepted: 03/14/2018] [Indexed: 11/30/2022]
|
9
|
Bawuah P, Karttunen AP, Markl D, Ridgway C, Korhonen O, Gane P, Zeitler JA, Ketolainen J, Peiponen KE. Investigating elastic relaxation effects on the optical properties of functionalised calcium carbonate compacts using optics-based Heckel analysis. Int J Pharm 2018; 544:278-284. [PMID: 29689369 DOI: 10.1016/j.ijpharm.2018.04.043] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 04/09/2018] [Accepted: 04/20/2018] [Indexed: 10/17/2022]
Abstract
Heckel analysis is a widely used method for the characterisation of the compression behaviour of pharmaceutical samples during the preparation of solid dosage formulations. The present study introduces an optical version of the Heckel equation that is based on a combination of the conventional Heckel equation together with the linear relationship defined between the effective terahertz (THz) refractive index and the porosity of pharmaceutical tablets. The proposed optical Heckel equation allows us to, firstly, calculate the zero-porosity refractive index, and, secondly, predict the in-die development of the effective refractive index as a function of the compressive pressure during tablet compression. This was demonstrated for five batches of highly porous functionalised calcium carbonate (FCC) excipient compacts. The close match observed between the estimated in-die effective refractive index and the measured/out-of-die effective THz refractive index supports the validity of the proposed form of the equation. By comparing the measured and estimated in-die tablet properties, a clear change in the porosity and hence, the effective refractive index, due to post-compression elastic relaxation of the FCC compacts, has been observed. We have, therefore, proposed a THz-based compaction setup that will permit in-line monitoring of processes during tablet compression. We envisage that this new approach in tracking powder properties introduced in this preliminary study will lead to the onset of further extensive and detailed future studies.
Collapse
Affiliation(s)
- Prince Bawuah
- School of Pharmacy, Promis Centre, University of Eastern Finland, P.O. Box 1617, FI-70211 Kuopio, Finland.
| | - Anssi-Pekka Karttunen
- School of Pharmacy, Promis Centre, University of Eastern Finland, P.O. Box 1617, FI-70211 Kuopio, Finland
| | - Daniel Markl
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, G4 0RE Glasgow, United Kingdom
| | - Cathy Ridgway
- Omya International AG, CH-4665 Oftringen, Switzerland
| | - Ossi Korhonen
- School of Pharmacy, Promis Centre, University of Eastern Finland, P.O. Box 1617, FI-70211 Kuopio, Finland
| | - Patrick Gane
- Omya International AG, CH-4665 Oftringen, Switzerland; Aalto University, Chemical Engineering, Bioproducts and Biosystems, FI-00076 Aalto, Helsinki, Finland
| | - J Axel Zeitler
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, CB3 0AS Cambridge, United Kingdom
| | - Jarkko Ketolainen
- School of Pharmacy, Promis Centre, University of Eastern Finland, P.O. Box 1617, FI-70211 Kuopio, Finland
| | - Kai-Erik Peiponen
- Institute of Photonics, University of Eastern Finland, P.O. Box 111, FI-80101 Joensuu, Finland
| |
Collapse
|
10
|
Markl D, Wang P, Ridgway C, Karttunen AP, Bawuah P, Ketolainen J, Gane P, Peiponen KE, Zeitler JA. Resolving the rapid water absorption of porous functionalised calcium carbonate powder compacts by terahertz pulsed imaging. Chem Eng Res Des 2018. [DOI: 10.1016/j.cherd.2017.12.048] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
11
|
Taipale-Kovalainen K, Karttunen AP, Ketolainen J, Korhonen O. Lubricant based determination of design space for continuously manufactured high dose paracetamol tablets. Eur J Pharm Sci 2017; 115:1-10. [PMID: 29277668 DOI: 10.1016/j.ejps.2017.12.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 12/21/2017] [Accepted: 12/22/2017] [Indexed: 11/25/2022]
Abstract
The objective of this study was to devise robust and stable continuous manufacturing process settings, by exploring the design space after an investigation of the lubrication-based parameters influencing the continuous direct compression tableting of high dose paracetamol tablets. Experimental design was used to generate a structured study plan which involved 19 runs. The formulation variables studied were the type of lubricant (magnesium stearate or stearic acid) and its concentration (0.5, 1.0 and 1.5%). Process variables were total production feed rate (5, 10.5 and 16kg/h), mixer speed rpm (500, 850 and 1200rpm), and mixer inlet port for lubricant (A or B). The continuous direct compression tableting line consisted of loss-in-weight feeders, a continuous mixer and a tablet press. The Quality Target Product Profile (QTPP) was defined for the final product, as the flowability of powder blends (2.5s), tablet strength (147N), dissolution in 2.5min (90%) and ejection force (425N). A design space was identified which fulfilled all the requirements of QTPP. The type and concentration of lubricant exerted the greatest influence on the design space. For example, stearic acid increased the tablet strength. Interestingly, the studied process parameters had only a very minor effect on the quality of the final product and the design space. It is concluded that the continuous direct compression tableting process itself is insensitive and can cope with changes in lubrication, whereas formulation parameters exert a major influence on the end product quality.
Collapse
Affiliation(s)
| | | | - Jarkko Ketolainen
- University of Eastern Finland, School of Pharmacy, Promis Centre, Kuopio, Finland
| | - Ossi Korhonen
- University of Eastern Finland, School of Pharmacy, Promis Centre, Kuopio, Finland.
| |
Collapse
|
12
|
Lakio S, Ervasti T, Tajarobi P, Wikström H, Fransson M, Karttunen AP, Ketolainen J, Folestad S, Abrahmsén-Alami S, Korhonen O. Provoking an end-to-end continuous direct compression line with raw materials prone to segregation. Eur J Pharm Sci 2017; 109:514-524. [DOI: 10.1016/j.ejps.2017.09.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 07/23/2017] [Accepted: 09/08/2017] [Indexed: 10/18/2022]
|
13
|
Markl D, Wang P, Ridgway C, Karttunen AP, Chakraborty M, Bawuah P, Pääkkönen P, Gane P, Ketolainen J, Peiponen KE, Zeitler JA. Characterization of the Pore Structure of Functionalized Calcium Carbonate Tablets by Terahertz Time-Domain Spectroscopy and X-Ray Computed Microtomography. J Pharm Sci 2017; 106:1586-1595. [PMID: 28267446 DOI: 10.1016/j.xphs.2017.02.028] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 02/23/2017] [Accepted: 02/24/2017] [Indexed: 11/15/2022]
Abstract
Novel excipients are entering the market to enhance the bioavailability of drug particles by having a high porosity and, thus, providing a rapid liquid uptake and disintegration to accelerate subsequent drug dissolution. One example of such a novel excipient is functionalized calcium carbonate, which enables the manufacture of compacts with a bimodal pore size distribution consisting of larger interparticle and fine intraparticle pores. Five sets of functionalized calcium carbonate tablets with a target porosity of 45%-65% were prepared in 5% steps and characterized using terahertz time-domain spectroscopy and X-ray computed microtomography. Terahertz time-domain spectroscopy was used to derive the porosity using effective medium approximations, that is, the traditional and an anisotropic Bruggeman model. The anisotropic Bruggeman model yields the better correlation with the nominal porosity (R2 = 0.995) and it provided additional information about the shape and orientation of the pores within the powder compact. The spheroidal (ellipsoids of revolution) shaped pores have a preferred orientation perpendicular to the compaction direction causing an anisotropic behavior of the dielectric porous medium. The results from X-ray computed microtomography confirmed the nonspherical shape and the orientation of the pores, and it further revealed that the anisotropic behavior is mainly caused by the interparticle pores. The information from both techniques provides a detailed insight into the pore structure of pharmaceutical tablets. This is of great interest to study the impact of tablet microstructure on the disintegration and dissolution performance.
Collapse
Affiliation(s)
- Daniel Markl
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK
| | - Parry Wang
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK
| | | | | | | | - Prince Bawuah
- Institute of Photonics, University of Eastern Finland, Joensuu, Finland
| | - Pertti Pääkkönen
- Institute of Photonics, University of Eastern Finland, Joensuu, Finland
| | - Patrick Gane
- Omya International AG, Oftringen, Switzerland; Department of Bioproducts and Biosystems, School of Chemical Engineering, Aalto University, Aalto, Helsinki, Finland
| | - Jarkko Ketolainen
- School of Pharmacy, Promis Centre, University of Eastern Finland, Kuopio, Finland
| | - Kai-Erik Peiponen
- Institute of Photonics, University of Eastern Finland, Joensuu, Finland
| | - J Axel Zeitler
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK.
| |
Collapse
|