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Maghsoodi M, Mollaie Astemal S, Nokhodchi A, Kiaie H, Talebi F. The effect of anionic Eudragit polymers on drug supersaturation and in vitro permeation improvement. Drug Dev Ind Pharm 2023:1-10. [PMID: 37096982 DOI: 10.1080/03639045.2023.2206495] [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: 04/26/2023]
Abstract
OBJECTIVES In the present study, Cinnarizine was selected as a weakly basic drug with poor aqueous solubility to investigate the supersaturation maintaining the ability of different types of anionic Eudragit polymers (Eudragits L100-55, L100 and S100). Furthermore, the interplay between polymer-mediated supersaturation maintenance and in vitro permeation enhancement was studied. METHODS The effect of Eudragit polymers on the pH-induced supersaturation of Cinnarizine was examined under different pHs (6.4, 6.8 and 7.8). Moreover, the effect of Eudragit polymers on the permeation of Cinnarizine through the Caco-2 membrane was investigated. RESULTS The aggregate size of Eudragit polymers in solution was determined and it was found that the size of polymer aggregate was bigger when lower pH or more hydrophobic polymer was used, which corresponded strongly with improved drug supersaturation. Based on the findings, hydrophobic Cinnarizine-polymer interactions seemed to be essential in determining the impact of Eudragit polymers on maintaining the Cinnarizine supersaturation. The permeation study demonstrated that the rate of drug permeation through the Caco-2 membrane increased in the presence of Eudragit polymers, but their effect on maintaining supersaturation was more significant than their effect on the drug permeation rate. Moreover, the highest level of Cinnarizine supersaturation observed in a non-permeation condition did not correlate with the optimal absorption in a permeation condition. CONCLUSION This study revealed that the integration of permeation and supersaturation assays is needed to reliably predict the impact of supersaturation maintenance by polymers on the absorption of poorly soluble drugs.
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Affiliation(s)
- Maryam Maghsoodi
- Faculty of Pharmacy and Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | | | - Ali Nokhodchi
- Lupin Pharmaceutical Research Center, Coral Springs, Florida, USA
- Pharmaceutics Research Laboratory, School of Life Sciences, University of Sussex, Brighton, UK
| | - Hossein Kiaie
- Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
- Nano Drug Delivery Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran
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An Artificial Gut/Absorption Simulator: Simultaneous Evaluation of Desupersaturation and Absorption from Ketoconazole Supersaturated Solutions. J Pharm Sci 2022:S0022-3549(22)00418-X. [PMID: 36162494 DOI: 10.1016/j.xphs.2022.09.017] [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: 07/07/2022] [Revised: 09/15/2022] [Accepted: 09/15/2022] [Indexed: 10/14/2022]
Abstract
For supersaturating formulations of BCS-II compounds, which by definition have high intestinal permeability, a closed USP apparatus does not provide the necessary absorptive conditions during dissolution. To address this, an artificial gut simulator (AGS) has been constructed consisting of a 2.5 mL donor compartment in which a hollow fiber-based absorption module is suspended. Drug from donor diffuses across the hollow fiber membrane to be absorbed by the continuously flowing intraluminal receiver fluid. The membrane surface area and intraluminal fluid flow rate are tuned to obtain the physiologically observed absorption rate constant for a weakly basic, poorly water-soluble model compound, ketoconazole (KTZ). Supersaturated solutions of KTZ were generated in the donor in pH 6.5 phosphate buffer by the pH-shift method in the absence (closed system, control) and presence (open system, biorelevant) of an optimally or suboptimally tuned absorption module. Drug concentrations in the donor and intraluminal fluids were determined by in-line UV spectroscopy. The presence of an absorptive sink reduced the supersaturated solution's crystallization propensity, more so in the case of the optimally tuned AGS. This study demonstrates the significance of simulating absorption of drug at a physiological rate during dissolution studies, especially to predict the performance of formulations of BCS-II drugs.
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3
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A Physiologically Based Pharmacokinetic Model for Predicting Diazepam Pharmacokinetics after Intravenous, Oral, Intranasal, and Rectal Applications. Pharmaceutics 2021; 13:pharmaceutics13091480. [PMID: 34575556 PMCID: PMC8465253 DOI: 10.3390/pharmaceutics13091480] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 09/07/2021] [Accepted: 09/13/2021] [Indexed: 12/17/2022] Open
Abstract
Diazepam is one of the most prescribed anxiolytic and anticonvulsant that is administered through intravenous (IV), oral, intramuscular, intranasal, and rectal routes. To facilitate the clinical use of diazepam, there is a need to develop formulations that are convenient to administer in ambulatory settings. The present study aimed to develop and evaluate a physiologically based pharmacokinetic (PBPK) model for diazepam that is capable of predicting its pharmacokinetics (PK) after IV, oral, intranasal, and rectal applications using a whole-body population-based PBPK simulator, Simcyp®. The model evaluation was carried out using visual predictive checks, observed/predicted ratios (Robs/pred), and the average fold error (AFE) of PK parameters. The Diazepam PBPK model successfully predicted diazepam PK in an adult population after doses were administered through IV, oral, intranasal, and rectal routes, as the Robs/pred of all PK parameters were within a two-fold error range. The developed model can be used for the development and optimization of novel diazepam dosage forms, and it can be extended to simulate drug response in situations where no clinical data are available (healthy and disease).
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Elkhabaz A, Sarkar S, Simpson GJ, Taylor LS. Characterization of Phase Transformations for Amorphous Solid Dispersions of a Weakly Basic Drug upon Dissolution in Biorelevant Media. Pharm Res 2019; 36:174. [DOI: 10.1007/s11095-019-2718-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 10/06/2019] [Indexed: 12/18/2022]
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5
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Conversion of a soluble diazepam prodrug to supersaturated diazepam for rapid intranasal delivery: Kinetics and stability. J Control Release 2018; 289:1-9. [DOI: 10.1016/j.jconrel.2018.09.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 08/08/2018] [Accepted: 09/14/2018] [Indexed: 01/21/2023]
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6
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Investigation of supersaturation and in vitro permeation of the poorly water soluble drug ezetimibe. Eur J Pharm Sci 2018; 117:147-153. [DOI: 10.1016/j.ejps.2018.01.047] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 01/30/2018] [Accepted: 01/31/2018] [Indexed: 11/19/2022]
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7
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Indulkar AS, Waters JE, Mo H, Gao Y, Raina SA, Zhang GG, Taylor LS. Origin of Nanodroplet Formation Upon Dissolution of an Amorphous Solid Dispersion: A Mechanistic Isotope Scrambling Study. J Pharm Sci 2017; 106:1998-2008. [DOI: 10.1016/j.xphs.2017.04.015] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 03/30/2017] [Accepted: 04/10/2017] [Indexed: 11/28/2022]
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8
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Impact of Micellar Surfactant on Supersaturation and Insight into Solubilization Mechanisms in Supersaturated Solutions of Atazanavir. Pharm Res 2017; 34:1276-1295. [DOI: 10.1007/s11095-017-2144-0] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 03/15/2017] [Indexed: 02/04/2023]
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9
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Kapoor M, Cloyd JC, Siegel RA. A review of intranasal formulations for the treatment of seizure emergencies. J Control Release 2016; 237:147-59. [PMID: 27397490 DOI: 10.1016/j.jconrel.2016.07.001] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Revised: 06/30/2016] [Accepted: 07/01/2016] [Indexed: 12/20/2022]
Abstract
Epileptic seizure emergencies are life-threatening conditions, which in their most severe form, status epilepticus, have a high mortality rate if not quickly terminated. Treatment requires rapid delivery of anti-epileptics such as benzodiazepines to the brain. The nasal route is attractive due to its non-invasiveness, potential for direct nose to brain delivery, high vascularity, relatively large absorptive surface area, and avoidance of intestinal/liver metabolism. However, the limited volume of the nasal cavity and poor water solubility of anti-epileptics restrict absorption, leading to insufficient therapeutic brain levels. This review covers various formulation approaches adopted to improve nasal delivery of drugs, especially benzodiazepines, used to treat seizure emergencies. Other general topics such as nasal anatomy, challenges to nasal delivery, and drug/formulation considerations for nose to brain delivery are also discussed.
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Affiliation(s)
- Mamta Kapoor
- Department of Pharmaceutics, University of Minnesota, Minneapolis, MN, USA
| | - James C Cloyd
- Department of Experimental and Clinical Pharmacology, University of Minnesota, Minneapolis, MN, USA; Department of Neurology, University of Minnesota, Minneapolis, MN, USA
| | - Ronald A Siegel
- Department of Pharmaceutics, University of Minnesota, Minneapolis, MN, USA; Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA.
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Kapoor M, Cheryala N, Rautiola D, Georg GI, Cloyd JC, Siegel RA. Chirally Pure Prodrugs and Their Converting Enzymes Lead to High Supersaturation and Rapid Transcellular Permeation of Benzodiazepines. J Pharm Sci 2016; 105:2365-71. [PMID: 27342435 DOI: 10.1016/j.xphs.2016.05.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Revised: 05/05/2016] [Accepted: 05/09/2016] [Indexed: 11/29/2022]
Abstract
Water-soluble prodrugs can be rapidly converted by enzymes to hydrophobic drugs, whose aqueous thermodynamic solubilities are low, but are maintained in aqueous solution at supersaturated concentrations due to slow precipitation kinetics. Recently, we investigated avizafone (AVF) in combination with Aspergillus oryzae protease as a prodrug/enzyme system intended to produce supersaturated diazepam (DZP). Several fold enhancement of permeation of supersaturated DZP across Madin-Darby canine kidney II-wild type (MDCKII-wt) monolayers was observed, compared to saturated DZP solutions. However, prodrug conversion was incomplete, putatively due to partial racemization of AVF and stereoselectivity of A oryzae protease. Here we report synthesis of chirally pure AVF, and demonstrate complete conversion to supersaturated DZP followed by complete DZP permeation at enhanced rates across MDCKII-wt cell monolayers. We also synthesized, for the first time, a chirally pure prodrug of midazolam (MDZ-pro) and carried out the same sequence of studies. A oryzae protease was identified as a benign and efficient activating enzyme for MDZ-pro. The MDZ-pro/A oryzae protease system showed greater than 25-fold increase in absorption rate of MDZ across MDCKII-wt monolayers, compared to saturated MDZ. Such chirally pure prodrug/enzyme systems are promising candidates for efficient intranasal delivery of benzodiazepine drugs used in the treatment of seizure emergencies.
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Affiliation(s)
- Mamta Kapoor
- Department of Pharmaceutics, University of Minnesota, Minneapolis, Minnesota 55414
| | - Narsihmulu Cheryala
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55414; Institute for Therapeutics Discovery and Development, University of Minnesota, Minneapolis, Minnesota 55414
| | - Davin Rautiola
- Department of Pharmaceutics, University of Minnesota, Minneapolis, Minnesota 55414
| | - Gunda I Georg
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55414; Institute for Therapeutics Discovery and Development, University of Minnesota, Minneapolis, Minnesota 55414
| | - James C Cloyd
- Department of Experimental and Clinical Pharmacology, University of Minnesota, Minneapolis, Minnesota 55414; Center for Orphan Drug Research, University of Minnesota, Minneapolis, Minnesota 55414
| | - Ronald A Siegel
- Department of Pharmaceutics, University of Minnesota, Minneapolis, Minnesota 55414; Department of Biomedical Engineering, University of Minnesota, Minneapolis, Minnesota 55414.
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11
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Siegel RA, Kapoor M, Cheryala N, Georg GI, Cloyd JC. Water-soluble benzodiazepine prodrug/enzyme combinations for intranasal rescue therapies. Epilepsy Behav 2015; 49:347-50. [PMID: 26115606 DOI: 10.1016/j.yebeh.2015.05.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2015] [Accepted: 05/01/2015] [Indexed: 10/23/2022]
Abstract
Benzodiazepines (BZDs), including diazepam (DZP) and midazolam (MDZ), are drugs of choice for rapid treatment of seizure emergencies. Current approved use of these drugs involves administration via either intravenous or rectal routes. The former requires trained medical personnel, while the latter is socially unacceptable for many patients and caregivers. In recent years, efforts have been made to formulate BZDs for nasal administration. Because of the low solubility of these molecules, organic vehicles have been used to solubilize the drugs in the nasal products under development. However, organic solvents are irritating, potentially resulting in injury to nasal tissue. Here we report preliminary studies supporting a strategy in which water-soluble BZD prodrugs and a suitable converting enzyme are coadministered in an aqueous vehicle. Diazepam and midazolam prodrugs were synthesized and were readily converted to their active forms by a protease from Aspergillus oryzae. Using a permeation assay based on monolayers of Madin-Darby canine kidney II-wild type cells, we found that enzymatically produced BZDs could be maintained at high degrees of supersaturation, enabling faster transport across the membrane than can be achieved using saturated solutions. This strategy not only obviates the need for organic solvents, but it also suggests more rapid absorption and earlier peak concentrations than can be otherwise achieved. This article is part of a Special Issue entitled "Status Epilepticus".
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Affiliation(s)
- Ronald A Siegel
- Department of Pharmaceutics, University of Minnesota, Minneapolis, MN 55455, USA; Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455, USA
| | - Mamta Kapoor
- Department of Pharmaceutics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Narsihmulu Cheryala
- Department of Medicinal Chemistry and Institute for Therapeutics Discovery and Development, University of Minnesota, Minneapolis, MN 55414, USA; Institute for Therapeutics Discovery and Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Gunda I Georg
- Department of Medicinal Chemistry and Institute for Therapeutics Discovery and Development, University of Minnesota, Minneapolis, MN 55414, USA; Institute for Therapeutics Discovery and Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - James C Cloyd
- Department of Experimental and Clinical Pharmacology, University of Minnesota, Minneapolis, MN 55455, USA; Center for Orphan Drug Research, University of Minnesota, Minneapolis, MN 55455, USA.
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12
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Kapoor M, Winter T, Lis L, Georg GI, Siegel RA. Rapid delivery of diazepam from supersaturated solutions prepared using prodrug/enzyme mixtures: toward intranasal treatment of seizure emergencies. AAPS JOURNAL 2014; 16:577-85. [PMID: 24700272 DOI: 10.1208/s12248-014-9596-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 03/20/2014] [Indexed: 11/30/2022]
Abstract
Current treatments for seizure emergencies, such as status epilepticus, include intravenous or rectal administration of benzodiazepines. While intranasal delivery of these drugs is desirable, the small volume of the nasal cavity and low drug solubility pose significant difficulties. Here, we prepared supersaturated diazepam solutions under physiological conditions and without precipitation, using a prodrug/enzyme system. Avizafone, a peptide prodrug of diazepam, was delivered with--Aspergillus oryzae (A.O.) protease, an enzyme identified from a pool of hydrolytic enzymes in assay buffer, pH 7.4 at 32°C. This enzyme converted avizafone to diazepam at supersaturated concentrations. In vitro permeability studies were performed at various prodrug/enzyme ratios using Madin-Darby canine kidney II-wild type (MDCKII-wt) monolayers, a representative model of the nasal epithelium. Monolayer integrity was examined using TEER measurement and the lucifer yellow permeability assay. Prodrug/drug concentrations were measured using HPLC. Enzyme kinetics with avizafone-protease mixtures revealed K(M) = 1,501 ± 232 μM and V(max) = 1,369 ± 94 μM/s. Prodrug-protease mixtures, when co-delivered apically onto MDCKII-wt monolayers, showed 2-17.6-fold greater diazepam flux (S = 1.3-15.3) compared to near-saturated diazepam (S = 0.7). Data for prodrug conversion upstream (apical side) and drug permeability downstream (basolateral side) fitted reasonably well to a previously developed in vitro two compartment pharmacokinetic model. Avizafone-protease mixtures resulted in supersaturated diazepam in less than 5 min, with the rate and extent of supersaturation determined by the prodrug/enzyme ratio. Together, these results suggest that an intranasal avizafone-protease system may provide a rapid and alternative means of diazepam delivery.
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Affiliation(s)
- Mamta Kapoor
- Department of Pharmaceutics, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota, 55455, USA
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13
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Nuxoll E. BioMEMS in drug delivery. Adv Drug Deliv Rev 2013; 65:1611-25. [PMID: 23856413 DOI: 10.1016/j.addr.2013.07.003] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2013] [Revised: 05/31/2013] [Accepted: 07/05/2013] [Indexed: 12/25/2022]
Abstract
The drive to design micro-scale medical devices which can be reliably and uniformly mass produced has prompted many researchers to adapt processing technologies from the semiconductor industry. By operating at a much smaller length scale, the resulting biologically-oriented microelectromechanical systems (BioMEMS) provide many opportunities for improved drug delivery: Low-dose vaccinations and painless transdermal drug delivery are possible through precisely engineered microneedles which pierce the skin's barrier layer without reaching the nerves. Low-power, low-volume BioMEMS pumps and reservoirs can be implanted where conventional pumping systems cannot. Drug formulations with geometrically complex, extremely uniform micro- and nano-particles are formed through micromolding or with microfluidic devices. This review describes these BioMEMS technologies and discusses their current state of implementation. As these technologies continue to develop and capitalize on their simpler integration with other MEMS-based systems such as computer controls and telemetry, BioMEMS' impact on the field of drug delivery will continue to increase.
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Affiliation(s)
- Eric Nuxoll
- Department of Chemical and Biochemical Engineering, Seamans Center for the Engineering Arts & Sciences, University of Iowa, Iowa City, IA 52245, USA.
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14
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Kapoor M, Siegel RA. Prodrug/Enzyme Based Acceleration of Absorption of Hydrophobic Drugs: An in Vitro Study. Mol Pharm 2013; 10:3519-24. [DOI: 10.1021/mp400272m] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Mamta Kapoor
- Departments
of Pharmaceutics and ‡Biomedical Engineering, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Ronald A Siegel
- Departments
of Pharmaceutics and ‡Biomedical Engineering, University of Minnesota, Minneapolis, Minnesota 55455, United States
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15
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Zhang J, Sun M, Fan A, Wang Z, Zhao Y. The effect of solute-membrane interaction on solute permeation under supersaturated conditions. Int J Pharm 2012. [PMID: 23178214 DOI: 10.1016/j.ijpharm.2012.11.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The purpose of this work was to investigate the effect of solute-membrane interaction under supersaturated conditions on the transport of model solute (salicylic acid) across poly(dimethylsiloxane) (PDMS) membrane. Supersaturated systems with a degree of saturation (DS) up to 8 were prepared using a molecular form technique with water as the vehicle to minimize the vehicle-membrane interaction. The spectroscopic and thermal analysis revealed the presence of both hydrogen bonding and nonpolar interaction between the solute and PDMS. Upon treatment by supersaturated solutions the degree of solute-membrane interaction increased with increasing DS. This enhanced the barrier property of PDMS and thus led to the flux attenuation compared to that calculated by Higuchi equation. This work highlighted the importance of solute-membrane interaction under supersaturation in the flux reduction, which should be considered when designing, and optimizing supersaturated topical and transdermal drug delivery systems.
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Affiliation(s)
- Jingsi Zhang
- Tianjin Key Laboratory for Modern Drug Delivery & High Efficiency, School of Pharmaceutical Science & Technology, Tianjin University, 92 Weijin Road, Tianjin 300072, China
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16
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Manaspon C, Hongeng S, Boongird A, Nasongkla N. Preparation and in vitro characterization of SN-38-loaded, self-forming polymeric depots as an injectable drug delivery system. J Pharm Sci 2012; 101:3708-17. [PMID: 22778058 DOI: 10.1002/jps.23238] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2012] [Revised: 05/23/2012] [Accepted: 05/31/2012] [Indexed: 11/07/2022]
Abstract
This work describes the preparation and characterization of anticancer-loaded injectable polymeric depots that consisted of D,L-lactide (LA), ε-caprolactone (CL), and poly(ethylene glycol) (PEG) or [poly(ε-caprolactone)-random-poly(D,L-lactide)]-block-poly(ethylene glycol)-block-[poly(ε-caprolactone)-random-poly(D,L-lactide)] (PLEC) copolymers for malignant gliomas treatment. PLECs were polymerized with different percentages of LA to deliver 7-ethyl-10-hydroxycamptothecin (SN-38), a highly potent anticancer drug. SN-38-loaded depots could form directly in phosphate buffer saline with more than 98% encapsulation efficiency. The release rate of SN-38 from depots was found to depend on the amount of LA in PLECs, loading content of SN-38 in the depots, and depot weight. Encapsulation of SN-38 inside depots could enhance the stability of SN-38 where all of SN-38 released after 60 days was in an active form. Depots without SN-38 were evaluated as noncytotoxic against U-87MG, whereas SN-38-loaded depots showed cytotoxic effect as a function of concentration.
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Affiliation(s)
- Chawan Manaspon
- Department of Biomedical Engineering, Faculty of Engineering, Mahidol University, Nakorn Pathom 73170, Thailand
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Xia X, Zhou C, Ballell L, Garcia-Bennett AE. In vivo Enhancement in Bioavailability of Atazanavir in the Presence of Proton-Pump Inhibitors using Mesoporous Materials. ChemMedChem 2011; 7:43-8. [DOI: 10.1002/cmdc.201100500] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2011] [Indexed: 11/11/2022]
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18
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Santos P, Watkinson AC, Hadgraft J, Lane ME. Formulation issues associated with transdermal fentanyl delivery. Int J Pharm 2011; 416:155-9. [PMID: 21723931 DOI: 10.1016/j.ijpharm.2011.06.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Revised: 06/11/2011] [Accepted: 06/16/2011] [Indexed: 10/18/2022]
Abstract
Supersaturation has previously been studied as a mechanism to enhance membrane transport of fentanyl from propylene glycol:water formulations (PG:H(2)O) across silicone. In this study these supersaturated fentanyl formulations were evaluated in human skin. A number of polymers were also screened for their ability to stabilise the supersaturated formulations and permeation was evaluated for both infinite and finite doses. For infinite dose studies, permeation in skin increased linearly with increasing degree of drug saturation (DS) for formulations containing 0.5, 1, 2 DS of fentanyl and a 3 DS formulation stabilised with 1% (w/v) hydroxypropylcellulose (HPC). An excellent correlation was obtained for flux values in silicone compared with flux values in skin, for infinite dose studies for formulations containing 0.5, 1, 2 DS of fentanyl and the 3 DS formulation stabilised HPC. The concentration of the fentanyl in the stratum corneum also increased in proportion to the DS. However the same trend was not observed for finite dose studies. This is because the depletion of the solvent carrier promotes drug crystallisation with consequent implications for membrane transport. Tape-stripping experiments indicated that supersaturation of the drug is maintained in the outer layers of the stratum corneum. The ideal vehicle must, therefore, maintain the drug in solution on and in the skin in a sustained manner for effective transdermal delivery.
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Affiliation(s)
- P Santos
- Department of Pharmaceutics, University of London, London, UK
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Santos P, Watkinson AC, Hadgraft J, Lane ME. Enhanced permeation of fentanyl from supersaturated solutions in a model membrane. Int J Pharm 2011; 407:72-7. [PMID: 21256946 DOI: 10.1016/j.ijpharm.2011.01.025] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2010] [Revised: 01/10/2011] [Accepted: 01/13/2011] [Indexed: 10/18/2022]
Abstract
The aim of the present study was to investigate the permeation of fentanyl from supersaturated formulations when applied to silicone membrane. Silicone was chosen in order to separate the effects of supersaturation from other possible influences of volatile formulation components on biological membranes. Supersaturated formulations containing either propylene glycol/water (PG/H(2)O) or propylene glycol/ethanol (PG/Et) were prepared containing varying degrees of saturation (DS) of fentanyl. Permeation of finite and infinite doses of the PG/H(2)O formulations, and finite doses of the PG/Et formulations was investigated using Franz-type diffusion cells. For the PG/H(2)O formulations a good correlation between the flux and the DS of the formulation up to 5 DS for infinite dose studies (r(2)=0.99), and up to 7 DS for finite dose studies (r(2)=0.98), was evident. Similarly, for the PG/Et formulations there is a good correlation between the mean flux and the theoretical DS of the formulation (r(2)=0.95). Except for the 2 DS formulations, no significant differences were seen in the mean flux between PG/H(2)O and PG/Et finite dose studies. The larger fluxes observed for infinite doses of the PG/H(2)O formulations versus finite doses reflect changes in the effective area of diffusion over the time of the experiment for the latter set of experiments. The permeation enhancement observed for PG/Et formulations confirms that enhanced drug thermodynamic activity was induced by ethanol evaporation.
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Affiliation(s)
- P Santos
- Department of Pharmaceutics, The School of Pharmacy, University of London, 29-39 Brunswick Square, London WC1N 1AX, United Kingdom
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Fiala S, Brown MB, Jones SA. An investigation into the influence of binary drug solutions upon diffusion and partition processes in model membranes. J Pharm Pharmacol 2010. [DOI: 10.1211/jpp.60.12.0007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Abstract
Few studies have assessed the impact of binary systems on the fundamental mathematical models that describe drug permeation. The aim of this work was to determine the influence of varying the proportions of prilocaine and lidocaine in a binary saturated solution on mass transfer across synthetic membranes. Infinite-dose permeation studies were performed using Franz diffusion cells with either regenerated cellulose or silicone membranes, and partition coefficients were determined by drug loss over 24 h. There was a linear relationship between the flux of prilocaine and lidocaine through regenerated cellulose membrane (R2 ≥ 0.985, n = 5) and their normalised ratio in solution. This linear model was also applicable for the permeation of prilocaine through silicone membrane (R2 = 0.991, n = 5), as its partition coefficient was independent of the drug ratio (15.84 ± 1.41). However, the partition coefficient of lidocaine increased from 27.22 ± 1.68 to 47.03 ± 3.32 as the ratio of prilocaine increased and this resulted in a non-linear relationship between permeation and drug ratio. Irrespective of the membrane used, the permeation of one drug from a binary system was hindered by the presence of the second, which could be attributed to a reduction in available membrane diffusion volume.
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Affiliation(s)
- Sarah Fiala
- Pharmaceutical Science Division, King's College London, 150 Stamford Street, London SE1 9NH, UK
| | - Marc B Brown
- School of Pharmacy, University of Hertfordshire, College Lane, Hatfield, Herts. AL10 9AB, UK
- MedPharm Ltd, Unit 3/Chancellor Court, 50 Occam Road, Surrey Research Park, Guildford GU2 7YN, UK
| | - Stuart A Jones
- Pharmaceutical Science Division, King's College London, 150 Stamford Street, London SE1 9NH, UK
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21
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Brouwers J, Brewster ME, Augustijns P. Supersaturating Drug Delivery Systems: The Answer to Solubility-Limited Oral Bioavailability? J Pharm Sci 2009; 98:2549-72. [PMID: 19373886 DOI: 10.1002/jps.21650] [Citation(s) in RCA: 690] [Impact Index Per Article: 46.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Joachim Brouwers
- Laboratory for Pharmacotechnology and Biopharmacy, Katholieke Universiteit Leuven, Gasthuisberg O/N 2 - Herestraat 49, Box 921, BE-3000 Leuven, Belgium
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Affiliation(s)
- Eric E Nuxoll
- University of Minnesota Department of Pharmaceutics, 9-177 Weaver- Densford Hall, 308 Harvard St. SE, Minneapolis, MN 55455, USA
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23
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Reid ML, Jones SA, Brown MB. Transient drug supersaturation kinetics of beclomethasone dipropionate in rapidly drying films. Int J Pharm 2009; 371:114-9. [DOI: 10.1016/j.ijpharm.2008.12.025] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2008] [Accepted: 12/18/2008] [Indexed: 10/21/2022]
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Ivaturi VD, Riss JR, Kriel RL, Siegel RA, Cloyd JC. Bioavailability and tolerability of intranasal diazepam in healthy adult volunteers. Epilepsy Res 2009; 84:120-6. [DOI: 10.1016/j.eplepsyres.2009.01.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2008] [Revised: 12/02/2008] [Accepted: 01/11/2009] [Indexed: 11/17/2022]
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