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Mahboobian MM, Dadashzadeh S, Rezaei M, Mohammadi M, Bolourchian N. Simvastatin in ternary solid dispersion formulations: Improved In vitro dissolution and anti-hyperlipidemia efficiency. J Drug Deliv Sci Technol 2022. [DOI: 10.1016/j.jddst.2022.103571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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2
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The Study of the Influence of Formulation and Process Variables on the Functional Attributes of Simvastatin–Phospholipid Complex. J Pharm Innov 2016. [DOI: 10.1007/s12247-016-9256-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Singh M, Kanoujia J, Singh P, Parashar P, Arya M, Tripathi CB, Sinha VR, Saraf SA. Development of an α-linolenic acid containing a soft nanocarrier for oral delivery-part II: buccoadhesive gel. RSC Adv 2016. [DOI: 10.1039/c6ra20896g] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Development and evaluation of a novel buccoadhesive gel containing microemulsion to enhance the permeation and bioavailability of simvastatin.
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Affiliation(s)
- Mahendra Singh
- Department of Pharmaceutical Sciences
- Babasaheb Bhimrao Ambedkar University (A Central University) Vidya Vihar
- Lucknow-226025
- India
| | - Jovita Kanoujia
- Department of Pharmaceutical Sciences
- Babasaheb Bhimrao Ambedkar University (A Central University) Vidya Vihar
- Lucknow-226025
- India
| | - Pooja Singh
- Department of Pharmaceutical Sciences
- Babasaheb Bhimrao Ambedkar University (A Central University) Vidya Vihar
- Lucknow-226025
- India
| | - Poonam Parashar
- Department of Pharmaceutical Sciences
- Babasaheb Bhimrao Ambedkar University (A Central University) Vidya Vihar
- Lucknow-226025
- India
| | - Malti Arya
- Department of Pharmaceutical Sciences
- Babasaheb Bhimrao Ambedkar University (A Central University) Vidya Vihar
- Lucknow-226025
- India
| | - Chandra Bhushan Tripathi
- Department of Pharmaceutical Sciences
- Babasaheb Bhimrao Ambedkar University (A Central University) Vidya Vihar
- Lucknow-226025
- India
| | - Vivek R. Sinha
- University Institute of Pharmaceutical Sciences
- Panjab University
- Chandigarh-160014 (UT)
- India
| | - Shubhini A. Saraf
- Department of Pharmaceutical Sciences
- Babasaheb Bhimrao Ambedkar University (A Central University) Vidya Vihar
- Lucknow-226025
- India
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Singh M, Kanoujia J, Singh P, Tripathi CB, Arya M, Parashar P, Sinha VR, Saraf SA. Development of an α-linolenic acid containing soft nanocarrier for oral delivery: in vitro and in vivo evaluation. RSC Adv 2016. [DOI: 10.1039/c6ra15166c] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Use of α-linolenic acid as an oil phase for microemulsion preparation with synergistic effect of oil in lowering of lipid levels in combination with simvastatin.
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Affiliation(s)
- Mahendra Singh
- Department of Pharmaceutical Sciences
- Babasaheb Bhimrao Ambedkar University (A Central University)
- Lucknow-226025
- India
| | - Jovita Kanoujia
- Department of Pharmaceutical Sciences
- Babasaheb Bhimrao Ambedkar University (A Central University)
- Lucknow-226025
- India
| | - Pooja Singh
- Department of Pharmaceutical Sciences
- Babasaheb Bhimrao Ambedkar University (A Central University)
- Lucknow-226025
- India
| | - Chandra B. Tripathi
- Department of Pharmaceutical Sciences
- Babasaheb Bhimrao Ambedkar University (A Central University)
- Lucknow-226025
- India
| | - Malti Arya
- Department of Pharmaceutical Sciences
- Babasaheb Bhimrao Ambedkar University (A Central University)
- Lucknow-226025
- India
| | - Poonam Parashar
- Department of Pharmaceutical Sciences
- Babasaheb Bhimrao Ambedkar University (A Central University)
- Lucknow-226025
- India
| | - Vivek R. Sinha
- University Institute of Pharmaceutical Sciences
- Panjab University
- Chandigarh-160014 (UT)
- India
| | - Shubhini A. Saraf
- Department of Pharmaceutical Sciences
- Babasaheb Bhimrao Ambedkar University (A Central University)
- Lucknow-226025
- India
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Bhalekar MR, Bargaje RV, Upadhaya PG, Madgulkar AR, Kshirsagar SJ. Formulation of mucoadhesive gastric retentive drug delivery using thiolated xyloglucan. Carbohydr Polym 2016; 136:537-42. [DOI: 10.1016/j.carbpol.2015.09.064] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 09/11/2015] [Accepted: 09/21/2015] [Indexed: 12/01/2022]
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Patel JK, Sutariya VB. Micronisation of simvastatin by the supercritical antisolvent technique:in vitro–in vivoevaluation. J Microencapsul 2014; 32:193-200. [PMID: 25535989 DOI: 10.3109/02652048.2014.995726] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Jayvadan K Patel
- Department of Pharmceutics, Nootan Pharmacy College , Visnagar , India and
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Karim FT, Kalam A, Anwar R, Miah MM, Rahman MS, Islam SMA. Preparation and evaluation of SEDDS of simvastatin byin vivo, in vitroandex vivotechnique. Drug Dev Ind Pharm 2014; 41:1338-42. [DOI: 10.3109/03639045.2014.950271] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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El-Say KM, Ahmed TA, Badr-Eldin SM, Fahmy U, Aldawsari H, Ahmed OAA. Enhanced permeation parameters of optimized nanostructured simvastatin transdermal films:ex vivoandin vivoevaluation. Pharm Dev Technol 2014; 20:919-926. [PMID: 25019166 DOI: 10.3109/10837450.2014.938859] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Khalid M El-Say
- a Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy , King Abdulaziz University , Jeddah , Saudi Arabia
- b Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy , Al-Azhar University , Cairo , Egypt
| | - Tarek A Ahmed
- a Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy , King Abdulaziz University , Jeddah , Saudi Arabia
- b Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy , Al-Azhar University , Cairo , Egypt
| | - Shaimaa M Badr-Eldin
- a Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy , King Abdulaziz University , Jeddah , Saudi Arabia
- c Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy , Cairo University , Cairo , Egypt , and
| | - Usama Fahmy
- a Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy , King Abdulaziz University , Jeddah , Saudi Arabia
| | - Hibah Aldawsari
- a Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy , King Abdulaziz University , Jeddah , Saudi Arabia
| | - Osama A A Ahmed
- a Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy , King Abdulaziz University , Jeddah , Saudi Arabia
- d Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy , Minia University , Minia , Egypt
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9
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In vitro assessment of the anticancer activity of simvastatin-loaded microemulsion in liver and colon cancer cells. J Drug Deliv Sci Technol 2014. [DOI: 10.1016/s1773-2247(14)50076-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Enhanced bioavailability and hypolipidemic activity of Simvastatin formulations by particle size engineering: Physicochemical aspects and in vivo investigations. Biochem Eng J 2013. [DOI: 10.1016/j.bej.2013.08.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Sav AK, Ali MT, Fule RA, Amin PD. Formulation of highly purified fenugreek gum based silica lipid drug delivery system for simvastatin with enhanced dissolution rate and in vitro characterization. JOURNAL OF PHARMACEUTICAL INVESTIGATION 2013. [DOI: 10.1007/s40005-013-0081-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Taupitz T, Dressman JB, Klein S. New formulation approaches to improve solubility and drug release from fixed dose combinations: case examples pioglitazone/glimepiride and ezetimibe/simvastatin. Eur J Pharm Biopharm 2012; 84:208-18. [PMID: 23246797 DOI: 10.1016/j.ejpb.2012.11.027] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2012] [Revised: 11/16/2012] [Accepted: 11/19/2012] [Indexed: 11/17/2022]
Abstract
Low aqueous solubility is often a limiting aspect to the bioavailability of poorly soluble, but highly permeable drugs (class II compounds according to the Biopharmaceutics Classification System - BCS) administered in single drug products or as fixed dose combinations. The aim of the present series of experiments was to improve the solubility and dissolution of two fixed dose combination formulations (FDC), each consisting of two BCS class II drugs. The first FDC contained a weak acid (glimepiride) and a weak base (pioglitazone), while the second FDC contained two compounds (simvastatin and ezetimibe) that are essentially non-ionised over the physiological pH range. The formulation approaches used were as follows: (a) an inclusion complex with hydroxypropyl-β-cyclodextrin (HP-β-CD), (b) a solid dispersion with Soluplus, a new highly water soluble polyvinyl caprolactam - polyvinyl acetate - polyethylene glycol graft copolymer and (c) a ternary inclusion complex with both HP-β-CD and Soluplus. Solid state analysis was performed for the pure drugs, and all formulations using powder X-ray diffraction (PXRD). The in vitro performance of the different formulation approaches, as gauged by solubility and dissolution experiments, was compared with that of the marketed products containing the respective fixed dose combinations, Tandemact 30 mg/4 mg tablets and Inegy 10 mg/40 mg tablets. The FDCs of the pure drugs and the marketed products showed very poor (and especially for pioglitazone, strongly pH-dependent) dissolution. By contrast, all binary and ternary inclusion complexes showed enhanced release for both drugs in the FDC. The ternary inclusion complex generated synergistic improvement in solubility and dissolution results for both FDCs. For example, in pH conditions of the fasted small intestine after a test duration of 240 min, we observed 100% dissolution of both drugs from the ternary pioglitazone/glimepiride (30 mg/4 mg) complex formulation, whereas from the marketed formulation less than 5% pioglitazone, and only 25% glimepiride dissolved. Using the same conditions, 60% ezetimibe and 85% simvastatin dissolved from the ternary ezetimibe/simvastatin (10 mg/40 mg) complex formulation, whereas with less than 5% ezetimibe and 10% simvastatin dissolved after 240 min, the marketed FDC formulation showed poor dissolution. Based on the results of the present study, the bioavailability of both drugs in the fixed dose combination is likely to be increased after oral administration of the new formulations, especially when the fixed dose combination is formulated as a ternary complex consisting of HP-β-CD and Soluplus.
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Affiliation(s)
- Thomas Taupitz
- Institute of Pharmaceutical Technology, Goethe University, Frankfurt, Germany
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Luo Y, Xu L, Tao X, Xu M, Feng J, Tang X. Preparation, characterization, stability andin vitro-in vivoevaluation of pellet-layered Simvastatin nanosuspensions. Drug Dev Ind Pharm 2012; 39:936-46. [DOI: 10.3109/03639045.2012.699067] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Abdelbary G, Amin M, Salah S. Self nano-emulsifying simvastatin based tablets: design andin vitro/in vivoevaluation. Pharm Dev Technol 2012; 18:1294-304. [DOI: 10.3109/10837450.2012.672989] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Shanmugam S, Ryu JK, Yoo SD, Choi HG, Woo JS. Evaluation of Pharmacokinetics of Simvastatin and Its Pharmacologically Active Metabolite from Controlled-Release Tablets of Simvastatin in Rodent and Canine Animal Models. Biomol Ther (Seoul) 2011. [DOI: 10.4062/biomolther.2011.19.2.248] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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Jun SW, Kim MS, Kim JS, Park HJ, Lee S, Woo JS, Hwang SJ. Preparation and characterization of simvastatin/hydroxypropyl-β-cyclodextrin inclusion complex using supercritical antisolvent (SAS) process. Eur J Pharm Biopharm 2007; 66:413-21. [PMID: 17240129 DOI: 10.1016/j.ejpb.2006.11.013] [Citation(s) in RCA: 153] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2006] [Revised: 11/04/2006] [Accepted: 11/22/2006] [Indexed: 11/16/2022]
Abstract
In the present study, the practically insoluble drug, simvastatin (SV), and its inclusion complex with hydroxypropyl beta-cyclodextrin (HP-beta-CD) prepared using supercritical antisolvent (SAS) process were investigated to improve the aqueous solubility and the dissolution rate of drug, thus enhancing its bioavailability. Inclusion complexation in aqueous solution and solid state was evaluated by the phase solubility diagram, differential scanning calorimetry (DSC), powder X-ray diffractometry (PXRD), Fourier-transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The phase solubility diagram with HP-beta-CD was classified as A(L)-type at all temperatures investigated, indicating the formation of 1:1 stoichiometric inclusion complex. The apparent complexation constants (K(1:1)) calculated from phase solubility diagram were 774, 846 and 924 M(-1) at 25, 37 and 45+/-0.5 degrees C, respectively. No endothermic and characteristic diffraction peaks corresponding to SV was observed for the inclusion complex in DSC and PXRD. FT-IR study demonstrated the presence of intermolecular hydrogen bonds between SV and HP-beta-CD in inclusion complex, resulting in the formation of amorphous form. Aqueous solubility and dissolution studies indicated that the dissolution rates were remarkably increased in inclusion complex, compared with the physical mixture and drug alone. Moreover, SV/HP-beta-CD inclusion complex performed better than SV in reducing total cholesterol and triglyceride levels. This could be primarily attributed to the improved solubility and dissolution associated with inclusion complex between drug and HP-beta-CD. In conclusion, SAS process could be a useful method for the preparation of the inclusion complex of drug with HP-beta-CD and its solubility, dissolution rate and hypolipidemic activity were significantly increased by complexation between SV and HP-beta-CD.
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Affiliation(s)
- Seoung Wook Jun
- College of Pharmacy, Chungnam National University, Daejeon, Republic of Korea
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Ambike AA, Mahadik KR, Paradkar A. Spray-dried amorphous solid dispersions of simvastatin, a low tg drug: in vitro and in vivo evaluations. Pharm Res 2005; 22:990-8. [PMID: 15948043 DOI: 10.1007/s11095-005-4594-z] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2005] [Accepted: 03/09/2005] [Indexed: 10/25/2022]
Abstract
PURPOSE To obtain free flowing, stable, amorphous solid dispersions (SDs) of simvastatin (SIM), a drug with relatively lower glass transition temperature (T(g)) by spray drying technique, and to perform comparative in vivo study in rats, which could justify the improvement in rate and extent of in vitro drug release. METHODS Dichloromethane suspensions of SIM either alone or in combination with PVP (1:1 or 1:2 parts by weight) were spray dried with proposed quantity of Aerosil 200 (1:1, 1:1:1, 1:2:2 parts by weight of SIM, Aerosil 200 and PVP, respectively). SDs were characterized initially in comparison with pure drug and corresponding physical mixtures in same ratios by drug content, saturation solubility, SEM, DSC, XRPD, IR, and in vitro drug release. SD 1:2:2 was further subjected to accelerated stability testing and checked for in vitro drug release and presence of crystallinity using DSC and XRPD. In addition, improvement in rate and extent of in vitro drug release from SD 1:2:2 was justified by in vivo study in rats. RESULTS Combination of SD and surface adsorption techniques has been attempted to overcome the limitations of spray drying technique for amorphization of low T(g) drugs. Based on powder characteristics, drug content, saturation solubility, and feasibility of processing into tablets; SD 1:2:2 was selected as the optimized formulation. During initial characterization, SEM, DSC, and XRPD analyses confirmed the presence of amorphous form in SD 1:2:2. IR spectroscopy revealed possibility of hydrogen bonding interaction between SIM and PVP in SDs. Also, there was dramatical improvement in rate and extent of in vitro drug release of SD 1:2:2. Insignificant decrease in dissolution was observed with no evidence of crystallinity during accelerated stability studies of SD 1:2:2. Moreover in vivo study in rats also justified the improvement in therapeutic efficacy of SD 1:2:2 over pure SIM. CONCLUSIONS Thus, present study demonstrates high potential of spray drying technique for obtaining stable amorphous SDs of low T(g) drugs.
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Affiliation(s)
- Anshuman A Ambike
- Department of Pharmaceutics, Poona College of Pharmacy, Bharati Vidyapeeth Deemed University, Erandwane, Pune, 411 038, Maharashtra, India
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Kang BK, Lee JS, Chon SK, Jeong SY, Yuk SH, Khang G, Lee HB, Cho SH. Development of self-microemulsifying drug delivery systems (SMEDDS) for oral bioavailability enhancement of simvastatin in beagle dogs. Int J Pharm 2004; 274:65-73. [PMID: 15072783 DOI: 10.1016/j.ijpharm.2003.12.028] [Citation(s) in RCA: 354] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2003] [Revised: 12/09/2003] [Accepted: 12/20/2003] [Indexed: 10/26/2022]
Abstract
The main purpose of this work is to prepare self-microemulsifying drug delivery system (SMEDDS) for oral bioavailability enhancement of a poorly water soluble drug, simvastatin. Solubility of simvastatin was determined in various vehicles. SMEDDS is mixture of oils, surfactants, and cosurfactants, which are emulsified in aqueous media under conditions of gentle agitation and digestive motility that would be encountered in the gastro-intestinal (GI) tract. Pseudo-ternary phase diagrams were constructed to identify the efficient self-emulsification region and particle size distributions of the resultant microemulsions were determined using a laser diffraction sizer. Optimized formulations for in vitro dissolution and bioavailability assessment were Carpryol 90 (37%), Cremophor EL (28%), and Carbitol (28%). The release rate of simvastatin from SMEDDS was significantly higher than the conventional tablet. The prepared SMEDDS was compared with the conventional tablet (Zocor) by administering the prefilled hard capsules to fasted beagle dogs. The absorption of simvastatin acid from SMEDDS form resulted in about 1.5-fold increase in bioavailability compared with the conventional tablet. Our studies illustrated the potential use of SMEDDS for the delivery of hydrophobic compounds, such as simvastatin by the oral route.
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Affiliation(s)
- Bok Ki Kang
- Department of Polymer Science and Engineering, Chonbuk National University, Duckjin Dong, Jeonju 561-756, South Korea
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Lennernäs H, Fager G. Pharmacodynamics and pharmacokinetics of the HMG-CoA reductase inhibitors. Similarities and differences. Clin Pharmacokinet 1997; 32:403-25. [PMID: 9160173 DOI: 10.2165/00003088-199732050-00005] [Citation(s) in RCA: 376] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Hypercholesterolaemia plays a crucial role in the development of atherosclerotic diseases in general and coronary heart disease in particular. The risk of progression of the atherosclerotic process to coronary heart disease increases progressively with increasing levels of total serum cholesterol or low density lipoprotein (LDL) cholesterol at both the individual and the population level. The statins are reversible inhibitors of the microsomal enzyme HMG-CoA reductase, which converts HMG-CoA to mevalonate. This is an early rate-limiting step in cholesterol biosynthesis. Inhibition of HMG-CoA reductase by statins decreases intracellular cholesterol biosynthesis, which then leads to transcriptionally upregulated production of microsomal HMG-CoA reductase and cell surface LDL receptors. Subsequently, additional cholesterol is provided to the cell by de novo synthesis and by receptor-mediated uptake of LDL-cholesterol from the blood. This resets intracellular cholesterol homeostasis in extrahepatic tissues, but has little effect on the overall cholesterol balance. There are no simple methods to investigate the concentration-dependent inhibition of HMG-CoA reductase in human pharmacodynamic studies. The main clinical variable is plasma LDL-cholesterol, which takes 4 to 6 weeks to show a reduction after the start of statin treatment. Consequently, a dose-effect rather than a concentration-effect relationship is more appropriate to use in describing the pharmacodynamics. Fluvastatin, lovastatin, pravastatin and simvastatin have similar pharmacodynamic properties; all can reduce LDL-cholesterol by 20 to 35%, a reduction which has been shown to achieve decreases of 30 to 35% in major cardiovascular outcomes. Simvastatin has this effect at doses of about half those of the other 3 statins. The liver is the target organ for the statins, since it is the major site of cholesterol biosynthesis, lipoprotein production and LDL catabolism. However, cholesterol biosynthesis in extrahepatic tissues is necessary for normal cell function. The adverse effects of HMG-reductase inhibitors during long term treatment may depend in part upon the degree to which they act in extrahepatic tissues. Therefore, pharmacokinetic factors such as hepatic extraction and systemic exposure to active compound(s) may be clinically important when comparing the statins. Different degrees of liver selectivity have been claimed for the HMG-CoA reductase inhibitors. However, the literature contains confusing data concerning the degree of liver versus tissue selectivity. Human pharmacokinetic data are poor and incomplete, especially for lovastatin and simvastatin, and it is clear that any conclusion on tissue selectivity is dependent upon the choice of experimental model. However, the drugs do differ in some important aspects concerning the degree of metabolism and the number of active and inactive metabolites. The rather extensive metabolism by different cytochrome P450 isoforms also makes it difficult to characterise these drugs regarding tissue selectivity unless all metabolites are well characterised. The effective elimination half-lives of the hydroxy acid forms of the 4 statins are 0.7 to 3.0 hours. Protein binding is similar (> 90%) for fluvastatin, lovastatin and simvastatin, but it is only 50% for pravastatin. The best characterised statins from a clinical pharmacokinetic standpoint are fluvastatin and pravastatin. The major difference between these 2 compounds is the higher liver extraction of fluvastatin during the absorption phase compared with pravastatin (67 versus 45%, respectively, in the same dose range). Estimates of liver extraction in humans for lovastatin and simvastatin are poorly reported, which makes a direct comparison difficult.
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Affiliation(s)
- H Lennernäs
- Department of Pharmacy, Uppsala University, Sweden.
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Desager JP, Horsmans Y. Clinical pharmacokinetics of 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors. Clin Pharmacokinet 1996; 31:348-71. [PMID: 9118584 DOI: 10.2165/00003088-199631050-00003] [Citation(s) in RCA: 135] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
3-Hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase is the key enzyme of cholesterol synthesis. HMG-CoA reductase inhibitors are potent reversible inhibitors of this enzyme, which act by competing for the substrate HMG-CoA. This review is mainly devoted to the 4 main HMG-CoA reductase inhibitors used today: lovastatin, simvastatin, pravastatin and fluvastatin. Depending upon the dosage, these drugs are able to reduce plasma cholesterol levels by more than 40%. After absorption, each undergoes extensive hepatic first-pass metabolism. Up to 5 primary metabolites are formed, some of which are active inhibitors. The elimination half-lives vary from 0.5 to 3.5 hours and excretion is mainly via the faeces. A limited number of drug interactions has been reported. Increases in liver enzymes and muscle creatine kinase activity are among the most severe adverse effects. These powerful drugs should be reserved for patients with high plasma cholesterol levels and/or those with cardiovascular disease. New therapeutic approaches to atherosclerosis are currently under investigation. HMG-CoA reductase inhibitors are the cornerstone of this research.
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Affiliation(s)
- J P Desager
- Departement de Médecine Interne, Université Catholique de Louvain, Brussels, Belgium
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