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Puckhaber D, Kwade A, Finke JH. Investigation of Dispersion Kinetics of Particulate Lubricants and their Effect on the Mechanical Strength of MCC Tablets. Pharm Res 2023; 40:2479-2492. [PMID: 37752367 PMCID: PMC10661788 DOI: 10.1007/s11095-023-03602-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 09/01/2023] [Indexed: 09/28/2023]
Abstract
INTRODUCTION Tablets are commonly produced by internally adding particulate lubricants, which are known to possibly lower the mechanical strength of tablets. This reduction is caused by the coverage of matrix forming components by lubricant particles, resulting in decreased interparticulate interactions. The known incompatibilities with some active compounds of the predominantly used lubricant, magnesium stearate, call for the in-depth characterization of alternative lubricants. PURPOSE Investigation of the dispersion behavior of five commonly applied pharmaceutical lubricants by mathematically modeling the dispersion kinetics for short and extended mixing times. METHODS The dispersion behavior of five different pharmaceutical lubricants were examined by systematically varying lubricant concentration and mixing time of binary formulations and evaluating the kinetic of tensile strength reduction by theoretically estimating the surface coverage based on particle sizes. RESULTS For short mixing times, a unifying relationship between compactibility reduction and theoretical surface coverage was identified. Subsequently, for extended mixing times, distinct differences in the shear strength and dispersion kinetics of the investigated lubricants were found. CONCLUSIONS The lubricant particle size controls the tensile strength reduction if short mixing times are applied. For extended mixing times, the investigated lubricants can be divided into two groups in terms of dispersion kinetics. Possible underlying reasons are discussed in detail in order to enhance the general understanding of lubricant dispersions in tablet formulations.
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Affiliation(s)
- Daniel Puckhaber
- Institute for Particle Technology, Technische Universität Braunschweig, Braunschweig, Germany.
- Center of Pharmaceutical Engineering (PVZ), Technische Universität Braunschweig, Braunschweig, Germany.
| | - Arno Kwade
- Institute for Particle Technology, Technische Universität Braunschweig, Braunschweig, Germany
- Center of Pharmaceutical Engineering (PVZ), Technische Universität Braunschweig, Braunschweig, Germany
| | - Jan Henrik Finke
- Institute for Particle Technology, Technische Universität Braunschweig, Braunschweig, Germany
- Center of Pharmaceutical Engineering (PVZ), Technische Universität Braunschweig, Braunschweig, Germany
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Chaves MK, Kelly RC, Milne JE, Burke SE. Data-driven approach to mitigate quality impact of hygroscopic pharmaceutical raw materials throughout the supply chain. Pharm Dev Technol 2022; 27:511-524. [PMID: 35702831 DOI: 10.1080/10837450.2022.2084105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The challenges of working with hygroscopic pharmaceutical raw materials can have a significant impact on the industry's ability to make high-quality medicines. In order to mitigate the impact to the manufacturing process or product quality it is critical to understand the hygroscopicity of the raw materials across the entire supply chain so that the proper management strategies can be implemented, from the raw material manufacturing to the use of the raw material in the drug manufacturing process. Employing suitable controls protects these materials from physical and chemical changes due to moisture uptake such as caking or hydrolysis. We have developed a fit for purpose and data-driven approach to hygroscopicity classifications of over 200 commonly used chemicals, excipients, media and resins in drug manufacturing processes. Dynamic vapor sorption data is presented with supporting thermal gravimetric analysis and X-ray powder diffraction data where pertinent. Approximately 60% of all raw materials tested were determined to be hygroscopic. Strategies for applying this data to reduce the potential impact of hygroscopic materials on the manufacturing of pharmaceuticals are discussed with examples.
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Affiliation(s)
| | - Ron C Kelly
- Amgen, Inc. One Amgen Center Drive, Thousand Oaks, CA, USA
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A Razak NF, Abd Karim RH, Jamal JA, Said MM. Rapid Discrimination of Halal and Non-halal Pharmaceutical Excipients by Fourier Transform Infrared Spectroscopy and Chemometrics. J Pharm Bioallied Sci 2021; 12:S752-S757. [PMID: 33828373 PMCID: PMC8021044 DOI: 10.4103/jpbs.jpbs_364_19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 03/09/2020] [Accepted: 04/13/2020] [Indexed: 11/06/2022] Open
Abstract
Introduction: The appendage of “halal” to a product is not just a guarantee that the product is permitted for Muslims, but it has also become favorable lifestyle choice globally. However, the expansion of halal pharmaceutical market was hindered by lack of global halal standards for pharmaceutical ingredients and product integrity analytical methodology. Objective: This work aimed to explore the possibility of using Fourier-transform infrared (FTIR) spectroscopy and chemometrics to develop multivariate models to authenticate the “halal-ity” of pharmaceutical excipients with controversial halal status (e.g., magnesium stearate). Materials and Methods: The FTIR spectral fingerprints of the substance were used to build principal component analysis (PCA) models. The effects of different spectral pretreatment processes such as auto-scaling, baseline correction, standard normal variate (SNV), first, and second derivatives were evaluated. The optimization of the model performance was established to ensure the sensitivity, specificity, and accuracy of the predicted models. Results: Significant peaks corresponding to the properties of the compound were identified. For both bovine and plant-derived magnesium stearate, the peaks associated can be seen within the regions 2900cm-1 (C–H), 2800cm-1 (CH3), 1700cm-1 (C=O), and 1000–1300cm-1 (C–O). There was not much difference observed in the FTIR raw spectra of the samples from both sources. The quality and accuracy of the classification models by PCA and soft independent modeling classification analogy (SIMCA) have shown to improve using spectra optimized by first derivative followed by SNV smoothing. Conclusion: This rapid and cost-effective technique has the potential to be expanded as an authentication strategy for halal pharmaceuticals.
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Affiliation(s)
- Nurul F A Razak
- Faculty of Pharmacy, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | | | - Jamia A Jamal
- Drug and Herbal Research Center, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Mazlina M Said
- Drug and Herbal Research Center, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
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4
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Lapham DP, Lapham JL. BET surface area measurement of commercial magnesium stearate by krypton adsorption in preference to nitrogen adsorption. Int J Pharm 2019; 568:118522. [PMID: 31319149 DOI: 10.1016/j.ijpharm.2019.118522] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 06/18/2019] [Accepted: 07/13/2019] [Indexed: 11/28/2022]
Affiliation(s)
- Darren P Lapham
- MCA Services, Unit 1A Long Barn, North End, Meldreth, Cambridgeshire, UK.
| | - Julie L Lapham
- MCA Services, Unit 1A Long Barn, North End, Meldreth, Cambridgeshire, UK
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Lapham DP, Lapham JL. Gas adsorption on commercial magnesium stearate: The origin of atypical isotherms and BET transform data. POWDER TECHNOL 2019. [DOI: 10.1016/j.powtec.2018.10.035] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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6
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Wang T, Potts AR, Hoag SW. Elucidating the Variability of Magnesium Stearate and the Correlations With Its Spectroscopic Features. J Pharm Sci 2018; 108:1569-1580. [PMID: 30528196 DOI: 10.1016/j.xphs.2018.11.041] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 11/21/2018] [Accepted: 11/27/2018] [Indexed: 11/15/2022]
Abstract
The objective of this study is to investigate the variability in physiochemical and spectral properties of commercially available vegetable-grade magnesium stearate (MgSt) samples and to assess the correlation between physiochemical properties and near-infrared and Raman spectroscopic features to determine if fast spectral measurements could be used for physical and chemical evaluation. Thirteen MgSt samples of 9 manufacturer grades were obtained from 3 suppliers. The chemical composition was examined using gas chromatography and loss on drying. The physical characteristics were examined on 3 levels: solid state, particle, and bulk level. Comparing the largest to the smallest test values of 13 samples, the variation of the properties ranged from 7% to 335%, with majority of them varying by more than 100% of the smallest value. The samples could be categorized into 4 groups based on solid state properties (1) monohydrate, (2) dihydrate, (3) mixture of monohydrate and dihydrate, and (4) anhydrous form. Scanning electron microscopy images revealed 2 morphological types: thin, flat, and plate-like crystal habit versus irregular crystal habit. The overall variability was mapped using Principal Component Analysis. The greatest variation was due to different manufacturers and perhaps manufacturing methods and starting materials. Based on correlations to physiochemical properties of MgSt, near-infrared and Raman spectra showed potential as a rapid technique for evaluating the differences in excipient properties.
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Affiliation(s)
- Ting Wang
- Department of Pharmaceutical Sciences, University of Maryland, Baltimore, Baltimore, Maryland 21201
| | - Alan R Potts
- Department of Chemical Medicines, United States Pharmacopeial Convention, Rockville, Maryland 20852
| | - Stephen W Hoag
- Department of Pharmaceutical Sciences, University of Maryland, Baltimore, Baltimore, Maryland 21201.
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Lapham DP, Lapham JL. Gas adsorption on commercial magnesium stearate: Effects of degassing conditions on nitrogen BET surface area and isotherm characteristics. Int J Pharm 2017; 530:364-376. [DOI: 10.1016/j.ijpharm.2017.08.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 07/25/2017] [Accepted: 08/01/2017] [Indexed: 10/19/2022]
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8
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Zarmpi P, Flanagan T, Meehan E, Mann J, Fotaki N. Biopharmaceutical aspects and implications of excipient variability in drug product performance. Eur J Pharm Biopharm 2017; 111:1-15. [DOI: 10.1016/j.ejpb.2016.11.004] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 11/02/2016] [Accepted: 11/07/2016] [Indexed: 12/29/2022]
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Characterization of Synthesized and Commercial Forms of Magnesium Stearate Using Differential Scanning Calorimetry, Thermogravimetric Analysis, Powder X-Ray Diffraction, and Solid-State NMR Spectroscopy. J Pharm Sci 2016; 106:338-347. [PMID: 27836109 DOI: 10.1016/j.xphs.2016.10.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 09/11/2016] [Accepted: 10/11/2016] [Indexed: 11/21/2022]
Abstract
Magnesium stearate is the salt of a complex mixture of fatty acids, with the majority being stearate and palmitate. It has multiple crystalline forms and, potentially, an amorphous form. Magnesium stearate is used in the pharmaceutical manufacturing industry as a powder lubricant, and typically is added at low levels (∼1%) during the manufacturing process and blended for a relatively short time (∼5 min). Proper levels and mixing times are needed, as too short a mixing time or too small a quantity will result in improper lubrication, and too much can negatively impact dissolution rates. The complex mixture of multiple fatty acids and crystalline forms in magnesium stearate leads to variability between commercial sources, and switching between sources can impact both the amount of lubricant and mixing time needed for proper lubrication. In order to better understand the complex nature of magnesium stearate, a variety of analytical techniques were used to characterize both synthesized and commercial magnesium stearate samples. The results show that correlation among differential scanning calorimetry, thermogravimetric analysis, solid-state NMR spectroscopy, and other techniques provides a unique insight into the forms of magnesium stearate. Finally, the ability to monitor form changes of magnesium stearate in an intact tablet using solid-state NMR spectroscopy is shown.
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Delay effect of magnesium stearate on tablet dissolution in acidic medium. Int J Pharm 2016; 511:757-64. [DOI: 10.1016/j.ijpharm.2016.07.034] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 07/09/2016] [Accepted: 07/16/2016] [Indexed: 11/21/2022]
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11
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Galenic approaches in troubleshooting of glibenclamide tablet adhesion in compression machine punches. Saudi Pharm J 2014; 22:445-53. [PMID: 25473333 DOI: 10.1016/j.jsps.2013.08.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Accepted: 08/31/2013] [Indexed: 11/21/2022] Open
Abstract
This study aimed to examine the adhesion of glibenclamide 5 mg tablets to the tools of compression machines. This problem is not commonly reported in the literature, since it is considered as tacit knowledge. The starting point was the implementation of three technical alternatives: changing the parameters of compression, evaluating the humidity of the powder blend and the manufacturer of the lubricant magnesium stearate. The adhesion was directly related to the characteristics of magnesium stearate from different manufacturers, and the feasibility of evaluating powder flow characteristics by different techniques that are not routinely followed in various pharmaceutical companies. In vitro dissolution tests showed that the magnesium stearate manufacturer can influence on the dissolution profile of glibenclamide tablets. This study presented various aspects of tablet adhesion to compression machine punches. Troubleshooting approaches can be, most of times, conducted based on previous experience, or an experimental research needs to be implemented in order to have confident results.
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13
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Use of surface energy distributions by inverse gas chromatography to understand mechanofusion processing and functionality of lactose coated with magnesium stearate. Eur J Pharm Sci 2011; 43:325-33. [DOI: 10.1016/j.ejps.2011.05.012] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Revised: 05/02/2011] [Accepted: 05/14/2011] [Indexed: 11/22/2022]
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Influence of hydration state and homologue composition of magnesium stearate on the physical chemical properties of liquid paraffin lipogels. Int J Pharm 2011; 411:121-7. [PMID: 21457766 DOI: 10.1016/j.ijpharm.2011.03.052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Revised: 03/21/2011] [Accepted: 03/22/2011] [Indexed: 11/23/2022]
Abstract
Lipogels were prepared by dispersing mixed (60:40 C(16)-C(18)) and pure (C(18)) homologue magnesium stearate (MgSt) in liquid paraffin, using three methods of preparation, i.e. addition of water at 95 °C during cooling cycle (method 1), homogenisation upon cooling (method 2) or cooling without addition of water or homogenisation (method 3). The systems were characterised by physical inspection, polarised, hot stage and scanning electron microscopy (SEM), differential scanning calorimetry (DSC), rheology, and X-ray diffraction (XRD). Systems formed stable semisolid lipogels (no syneresis), unstable solids showing syneresis or structured fluids, depending on the type of magnesium stearate used and the preparation technique. The stable semisolid lipogels containing mixed homologue MgSt (commercial-as received, anhydrous or dihydrate) prepared by methods 1 (∼ 1-2% water) and 2 contained α-crystalline lamellar structure. These were not present in the unstable solids formed with method 3 or in systems prepared from pure homologue MgSt which were generally structured fluids rather than semisolids. In addition, semisolid lipogels of pure homologue trihydrate MgSt prepared by method 3 showed plate-like crystals, implying pressure sensitivity. There is significantly more amorphous MgSt in the unstable solids compared to the stable semisolid lipogels, which are mainly crystalline (confirmed by XRD).
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15
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Wakabayashi K, Register RA. Phase Behavior of Magnesium Stearate Blended with Polyethylene Ionomers. Ind Eng Chem Res 2010. [DOI: 10.1021/ie100109e] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Katsuyuki Wakabayashi
- Department of Chemical Engineering Princeton University, Princeton, New Jersey 08544-5263
| | - Richard A. Register
- Department of Chemical Engineering Princeton University, Princeton, New Jersey 08544-5263
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16
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Phadke DS, Collier JL. Effect of Degassing Temperature on the Specific Surface Area and Other Physical Properties of Magnesium Stearate. Drug Dev Ind Pharm 2008. [DOI: 10.3109/03639049409038335] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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18
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Barra J, Somma R. Influence of the Physicochemical Variability of Magnesium Stearate on Its Lubricant Properties: Possible Solutions. Drug Dev Ind Pharm 2008. [DOI: 10.3109/03639049609065947] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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20
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Compatibility studies between piroxicam and pharmaceutical excipients used in solid dosage forms. Pharm Chem J 2008. [DOI: 10.1007/s11094-008-0091-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Harding L, Qi S, Hill G, Reading M, Craig D. The development of microthermal analysis and photothermal microspectroscopy as novel approaches to drug–excipient compatibility studies. Int J Pharm 2008; 354:149-57. [DOI: 10.1016/j.ijpharm.2007.11.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2007] [Revised: 10/29/2007] [Accepted: 11/05/2007] [Indexed: 10/22/2022]
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Rao KP, Chawla G, Kaushal AM, Bansal AK. Impact of solid-state properties on lubrication efficacy of magnesium stearate. Pharm Dev Technol 2005; 10:423-37. [PMID: 16176023 DOI: 10.1081/pdt-54462] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The advent of high-speed tableting and slug capsule-filling machines has ushered in an increasingly important role for the lubricants to enact during manufacturing of dosage forms. Although lubricants help in processing, they can also adversely affect the flow properties and dissolution profile of the drug. It is thus critical to maintain a balance between these two behaviors, by understanding the underlying mechanisms and using their optimum concentration in the formulation. The source and manufacturing process inculcate different solid-state properties to magnesium stearate, the most commonly used lubricant, leading to variations in its lubrication efficacy. However, there has been no complete study relating the lubrication efficacy of magnesium stearate to various levels of solid state. Hence, this study was aimed at comprehensively scrutinizing the role of molecular, particle, and bulk level properties of solid state on the lubrication efficacy of magnesium stearate. A method based on net work done during compression using texture analyzer, was developed and validated to analyze its performance. Particle and bulk-level properties were studied using microscopy, particle size analysis, and particle surface area determination, and molecular level was characterized using thermal, spectroscopic, and crystallographic methods. Interplay of solid-state characteristics such as particle size, degree of agglomeration, and crystal habit were found to markedly influence the lubrication potential of magnesium stearate.
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Affiliation(s)
- K Phanidhara Rao
- Department of Pharmaceutical Technology (Formulations), National Institute of Pharmaceutical Education and Research, Punjab, India
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23
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Koivisto M, Jalonen H, Lehto VP. Effect of temperature and humidity on vegetable grade magnesium stearate. POWDER TECHNOL 2004. [DOI: 10.1016/j.powtec.2004.09.041] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Roy S, Alexander KS, Riga AT, Chatterjee K. Characterization of physical mixtures and directly compressed tablets of sulfamerazine polymorphs: implications on in vitro release characteristics. J Pharm Sci 2003; 92:747-59. [PMID: 12661061 DOI: 10.1002/jps.10322] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The present study evaluates the effects of excipients, compression pressure, and relative humidity (RH) on the stability of sulfamerazine polymorphs (referred here as SMZ I and SMZ II) and their release from directly compressed tablets using differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), and dissolution analysis. SMZ I and SMZ II tablets were compressed with magnesium stearate (MGST), and microcrystalline cellulose (MCC) at 5000, 7500, and 10,000 lbs. pressures and stored at 40, 75, 95, and 100% RH conditions for 5 weeks. There were indications of possible drug-excipient interaction in the binary mixtures under different relative humidity conditions from the DSC data, but they could not be confirmed by PXRD because the crystal structures of the drug and excipients remained unaltered. The crystal structures of the polymorphs in the tablet also remained unaltered under the above conditions. There were, however, significant differences observed in the drug release properties of the two polymorphs. SMZ II was found in general to have a higher rate of drug release than SMZ I. Extensive gelation of MCC under higher moisture conditions, compression pressure during tableting, and inherent tabletability of the sulfamerazine crystals were factors that affected drug release. All these factors contributed towards prolonging the disintegration and deaggregation of the tablet particles and were therefore concluded to be the rate limiting steps for the dissolution process.
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Affiliation(s)
- Shouvik Roy
- Department of Pharmacy Practice, University of Toledo, Toledo, Ohio 43606, USA.
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25
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Physical characterization of the polymorphic variations of magnesium stearate and magnesium palmitate hydrate species. Struct Chem 1997. [DOI: 10.1007/bf02272348] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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26
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Adeyeye CM, Rowley J, Madu D, Javadi M, Sabnis SS. Evaluation of crystallinity and drug release stability of directly compressed theophylline hydrophilic matrix tablets stored under varied moisture conditions. Int J Pharm 1995. [DOI: 10.1016/0378-5173(94)00273-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
Three batches of commercial magnesium stearate were characterized in terms of their fatty acid composition, moisture content, and specific surface area. None of these variables appeared to have any effect on the lubricant activity of the samples. The lubricant properties of the compound were further examined using three hydrates of laboratory-prepared (pure) magnesium stearate. Based on the results obtained from the pure samples, it appears that differences in the lubricant properties of magnesium stearate are correlated with differences in moisture content and crystalline structure.
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Affiliation(s)
- K D Ertel
- University of Wisconsin School of Pharmacy, Madison 53706
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