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Zhang Y, Ma M, Yang J, Qiu X, Xin L, Lu Y, Huang H, Zeng Z, Zeng D. Preparation, Characterization, and Oral Bioavailability of Solid Dispersions of Cryptosporidium parvum Alternative Oxidase Inhibitors. Int J Mol Sci 2024; 25:7025. [PMID: 39000132 PMCID: PMC11241238 DOI: 10.3390/ijms25137025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2024] [Revised: 06/12/2024] [Accepted: 06/24/2024] [Indexed: 07/16/2024] Open
Abstract
The phenylpyrazole derivative 5-amino-3-[1-cyano-2-(3-phenyl-1H-pyrazol-4-yl) vinyl]-1-phenyl-1H-pyrazole-4-carbonitrile (LN002), which was screened out through high-throughput molecular docking for the AOX target, exhibits promising efficacy against Cryptosporidium. However, its poor water solubility limits its oral bioavailability and therapeutic utility. In this study, solid dispersion agents were prepared by using HP-β-CD and Soluplus® and characterized through differential scanning calorimetry, Fourier transform infrared, powder X-ray diffraction, and scanning electron microscopy. Physical and chemical characterization showed that the crystal morphology of LN002 transformed into an amorphous state, thus forming a solid dispersion of LN002. The solid dispersion prepared with an LN002/HP-β-CD/Soluplus® mass ratio of 1:3:9 (w/w/w) exhibited significantly increased solubility and cumulative dissolution. Meanwhile, LN002 SDs showed good preservation stability under accelerated conditions of 25 °C and 75% relative humidity. The complexation of LN002 with HP-β-CD and Soluplus® significantly improved water solubility, pharmacological properties, absorption, and bioavailability.
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Affiliation(s)
- Yongxiang Zhang
- Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, Guangzhou 510642, China
| | - Minglang Ma
- Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, Guangzhou 510642, China
| | - Jinyu Yang
- Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, Guangzhou 510642, China
| | - Xiaotong Qiu
- Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, Guangzhou 510642, China
| | - Lin Xin
- Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, Guangzhou 510642, China
| | - Yixing Lu
- Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, Guangzhou 510642, China
| | - Huiguo Huang
- Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, Guangzhou 510642, China
| | - Zhenling Zeng
- Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, Guangzhou 510642, China
| | - Dongping Zeng
- Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, Guangzhou 510642, China
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Pisay M, Padya S, Mutalik S, Koteshwara KB. Stability Challenges of Amorphous Solid Dispersions of Drugs: A Critical Review on Mechanistic Aspects. Crit Rev Ther Drug Carrier Syst 2024; 41:45-94. [PMID: 38037820 DOI: 10.1615/critrevtherdrugcarriersyst.2023039877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2023]
Abstract
The most common drawback of the existing and novel drug molecules is their low bioavailability because of their low solubility. One of the most important approaches to enhance the bioavailability in the enteral route for poorly hydrophilic molecules is amorphous solid dispersion (ASD). The solubility of compounds in amorphous form is comparatively high because of the availability of free energy produced during formulation. This free energy results in the change of crystalline nature of the prepared ASD to the stable crystalline form leading to the reduced solubility of the product. Due to the intrinsic chemical and physical uncertainty and the restricted knowledge about the interactions of active molecules with the carriers making, this ASD is a challenging task. This review focused on strategies to stabilize ASD by considering the various theories explaining the free-energy concept, physical interactions, and thermal properties. This review also highlighted molecular modeling and machine learning computational advancement to stabilize ASD.
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Affiliation(s)
- Muralidhar Pisay
- Department of Pharmaceutics, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal 576104, Karnataka State, India
| | - Singh Padya
- Department of Pharmaceutics, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal 576104, Karnataka State, India
| | - Srinivas Mutalik
- Department of Pharmaceutics, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal 576104, Karnataka State, India
| | - Kunnatur B Koteshwara
- Department of Pharmaceutics, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal 576104, Karnataka State, India
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Sun W, Wang B, Wang P, Liu B, Pan B. Microenvironment pH modified solid dispersion of Toltrazuril as a new strategy to improve the treatment of experimental Apicomplexan infection. Acta Trop 2023; 238:106797. [PMID: 36528088 DOI: 10.1016/j.actatropica.2022.106797] [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: 09/20/2022] [Revised: 11/27/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022]
Abstract
The phylum Apicomplexa contains some of the most serious human and veterinary parasites, including Eimeria magna, Toxoplasma gondii, and many others. Toltrazuril (TOL) has activity against multiple stages of Apicomplexan parasites, but its clinical use is limited by low bioavailability. In present study, we prepared one new formulation named the microenvironment pH modified solid dispersion (pHM-SD), which was composed of three components including Ca(OH)2, TOL, and PVPk30 with the weight ratio of 1:8:8. In vivo evaluation for bioavailability and efficacy of the pHM-SD was conducted following oral administration and hypodermic injection. The performance of the pHM-SD was also contrast to corresponding results of raw material drug and commercial Baycox® to evaluate the advantages for clinical application. The results showed that the bioavailability of prototype TOL and its active metabolites toltrazuril sulfoxide (TOLSO), toltrazuril sulfone (TOLSO2) in rabbits were improved remarkably after oral administration of the pHM-SD. The safety of the pHM-SD via oral administration was adequately verified via the histopathological examination. We subsequently evaluated effects of the pHM-SD on Eimeria magna oocysts and Toxoplasma gondii tachyzoites. In vivo anti-coccidia efficacy further confirmed that the pHM-SD could be used as a strategy to minimize the oocyst exposure. In vitro cytotoxicity and anti-Toxoplasma tests showed that the pHM-SD had little damage to host cells within the concentration of 100 μg/ mL, and the anti-Toxoplasma efficacy was significantly improved compared with TOL. Combined with the above-mentioned experimental results, we conclude that the pHM-SD maybe a promising candidate for providing better clinical outcomes.
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Affiliation(s)
- Weiwei Sun
- College of Veterinary Medicine, China Agricultural University, No. 2 Yuan Ming Yuan West Road, Hai Dian District, Beijing 100193, China
| | - Bohan Wang
- College of Veterinary Medicine, China Agricultural University, No. 2 Yuan Ming Yuan West Road, Hai Dian District, Beijing 100193, China
| | - Penglong Wang
- College of Veterinary Medicine, China Agricultural University, No. 2 Yuan Ming Yuan West Road, Hai Dian District, Beijing 100193, China
| | - Boxing Liu
- College of Veterinary Medicine, China Agricultural University, No. 2 Yuan Ming Yuan West Road, Hai Dian District, Beijing 100193, China
| | - Baoliang Pan
- College of Veterinary Medicine, China Agricultural University, No. 2 Yuan Ming Yuan West Road, Hai Dian District, Beijing 100193, China.
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Li B, Wang Y, Feng Y, Yuan D, Xu R, Jiang C, Xiao X, Lu S. Design and molecular insights of drug-active metabolite based co-amorphous formulation: A case study of toltrazuril-ponazuril co-amorphous. Int J Pharm 2022; 615:121475. [PMID: 35041914 DOI: 10.1016/j.ijpharm.2022.121475] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 12/21/2021] [Accepted: 01/11/2022] [Indexed: 12/15/2022]
Abstract
Co-amorphous supersaturated drug delivery systems are emerging as an alternative strategy to improve the water solubility of BCS II drugs. Typically, the supersaturation and stability of co-amorphous systems largely depend on the type of employed co-former. This study aims to assess the potential for active metabolites of drugs as co-former in drug-drug co-amorphous formulations. Toltrazuril (Tol) was chosen as the model drug, to which ponazuril (Pon) was added as co-former. Considering the importance of intermolecular interactions in co-amorphous systems, we performed highlighted investigations including molecular dynamics simulation and quantum mechanics calculations. The results indicated that Tol and Pon molecules were connected by N-H···O = C hydrogen bonds in the form of a complementary pairing of amide groups. Further, the solubility/dissolution and solid-state stability of the co-amorphous system were investigated. We found that co-amorphous Tol-Pon was stable for at least one month at 40 °C/75% RH, while amorphous materials underwent recrystallization within 10 days. Moreover, both drugs in the co-amorphous system exhibited enhanced "spring parachute effect" during the dissolution process. This could be attributed to the noticeably increased solid-state stabilization as well as inhibition of Pon on the crystallization of Tol from a supersaturated state. In general, our study provides some useful information and molecular insights to guide the development of drug-active metabolite-based co-amorphous formulations.
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Affiliation(s)
- Bin Li
- School of Pharmacy, Hubei University of Chinese Medicine, Wuhan 430065, China
| | - Yingyun Wang
- School of Pharmacy, Hubei University of Chinese Medicine, Wuhan 430065, China
| | - Ying Feng
- School of Pharmacy, Hubei University of Chinese Medicine, Wuhan 430065, China
| | - Dan Yuan
- School of Pharmacy, Hubei University of Chinese Medicine, Wuhan 430065, China
| | - Renjie Xu
- School of Pharmacy, Hubei University of Chinese Medicine, Wuhan 430065, China
| | - Cuiping Jiang
- Guangdong Provincial Key Laboratory of Chinese Medicine Pharmaceutics, School of Traditional Chinese Medicine, Southern Medical University, Guangzhou 510515, China.
| | - Xuecheng Xiao
- School of Pharmacy, Hubei University of Chinese Medicine, Wuhan 430065, China.
| | - Shan Lu
- School of Pharmacy, Hubei University of Chinese Medicine, Wuhan 430065, China.
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Zhang S, Xu X, Sun W, Zhang Z, Pan B, Hu Q. Enteric and hydrophilic polymers enhance dissolution and absorption of poorly soluble acidic drugs based on micro-environmental pH-modifying solid dispersion. Eur J Pharm Sci 2022; 168:106074. [PMID: 34798261 DOI: 10.1016/j.ejps.2021.106074] [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: 05/05/2021] [Revised: 11/09/2021] [Accepted: 11/09/2021] [Indexed: 11/16/2022]
Abstract
The oral bioavailability of poorly water-soluble active pharmaceutical ingredient (API) is often inadequate for the desired therapeutic effect. Micro-environmental pH-modifying solid dispersion (micro pHm SD) is an effective method for enhancing the dissolution of pH-dependent soluble APIs. However, erratic bioavailability of these drugs was often found when the micro pHm SD of the drugs was orally administrated and passed through the gastrointestinal tract. Because the added alkalizer in micro pHm SD could be neutralized by the acid in the stomach, as a result not enough alkalizer is left to form alkaline micro-environment around the drug in the intestine, leading to poor dissolution and bioavailability of API. Enteric polymers are applicable materials for site-specific drug delivery that are insoluble in gastric tract but soluble in the intestine targeted for drug release. In this study, a poorly water-soluble model drug, toltrazuril (TOL), was prepared as enteric micro pHm SD with enteric, hydrophilic polymers and alkalizer. The surface of enteric micro pHm SD tablets staining and alkalizer protection test in the acid dissolution medium qualitatively and quantitatively confirmed the protective effects of the enteric polymer on the alkalizer. Dissolution studies revealed that the drug release from the enteric micro pHm SDs was improved significantly compared with micro pHm SD with no enteric polymer. The pH-dependent solubility of enteric polymer had effects on the dissolution of APIs from the SDs in neutral medium. Enteric micro pHm SDs with higher proportion of enteric polymer showed higher Cmax and dissolution rate of TOL. The physicochemical characterization and the molecular interaction between drug and matrix were analyzed by electron microscopy (SEM), differential scanning calorimetry (DSC), and fourier transform infrared spectroscopy (FTIR), finding that the formation of hydrogen bonds between TOL and matrix was helpful to promote dissolution of TOL. Ca(OH)2-TOL-PVPk30-HPMCAS 8: 8: 18: 6 was determined as the most optimal enteric micro pHm SD, which significantly improved the bioavailability of TOL and its active metabolism (TOLSO, TOLSO2) in pharmacokinetic study and could effectively reduce the irritation of the gastrointestinal mucosa caused by the alkalizer Ca(OH)2 when the SD was orally administrated to rabbits. The present study demonstrates that formulating APIs with poor water solubility as enteric micro pHm SD is an effective method for protecting the alkalizer in SD and improving the dissolution of APIs and the bioavailability following oral administration.
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Affiliation(s)
- Shudong Zhang
- The Department of Veterinary Parasitology, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China; NMPA Key Laboratory for Research and Evaluation of Generic Drugs, Beijing Key Laboratory of Analysis and Evaluation on Chinese Medicine, Beijing Institute for Drug Control, Beijing 102206, China
| | - Xiaolin Xu
- The Department of Veterinary Parasitology, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China; Institute of Animal Quarantine, Chinese Academy of Inspection and Quarantine, Beijing 100176, China
| | - Weiwei Sun
- The Department of Veterinary Parasitology, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Zhe Zhang
- NMPA Key Laboratory for Research and Evaluation of Generic Drugs, Beijing Key Laboratory of Analysis and Evaluation on Chinese Medicine, Beijing Institute for Drug Control, Beijing 102206, China
| | - Baoliang Pan
- The Department of Veterinary Parasitology, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
| | - Qin Hu
- NMPA Key Laboratory for Research and Evaluation of Generic Drugs, Beijing Key Laboratory of Analysis and Evaluation on Chinese Medicine, Beijing Institute for Drug Control, Beijing 102206, China
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Zhang Z, Li L, Dong L, Tian J, Meng T, Zhao Q, Yang J. Molecular mechanisms involved in supersaturation of Emodin ternary solid dispersions based on bonding agents. J Pharm Sci 2022; 111:2000-2010. [DOI: 10.1016/j.xphs.2022.01.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 01/24/2022] [Accepted: 01/24/2022] [Indexed: 11/24/2022]
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Pharmacokinetics of toltrazuril and its metabolites after oral and parenteral administration of novel oil-based suspension based on micro-environmental pH-modifying solid dispersion in rabbits. Vet Parasitol 2021; 299:109580. [PMID: 34597913 DOI: 10.1016/j.vetpar.2021.109580] [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: 04/15/2021] [Revised: 09/16/2021] [Accepted: 09/17/2021] [Indexed: 11/22/2022]
Abstract
Toltrazuril (TOL) is a broad-spectrum anticoccidial drug which is widely used in poultry and livestock. A novel oral suspension based on soybean oil-based TOL micro-environmental pH-modifying solid dispersion (micro pHm SD) and a novel injectable suspension based on white oil-based TOL micro pHm SD were developed, showing high physicochemical stability and high drug release in vitro with good histocompatibility. The present study is to evaluate the pharmacokinetic profiles of TOL and its major metabolites, e.g. toltrazuril sulfoxide (TOLSO) and toltrazuril sulfone (TOLSO2) in rabbits following oral or subcutaneous administration with these two TOL SD suspensions. The plasma concentrations of TOL, TOLSO and TOLSO2 were determined by high performance liquid chromatography (HPLC). Plasma concentration-time data were analyzed by a non-compartmental model analysis. The soybean oil-based TOL suspension after single oral administration at 20 mg/kg body weight (bw) significantly increased the plasma concentrations of TOL, TOLSO and TOLSO2 compared with Baycox® 5 % suspension. Following subcutaneous administration of the white oil-based TOL suspension (20 mg/kg bw), TOL was well absorbed and metabolized more slowly to TOLSO and TOLSO2, compared with oral administration, resulting in the significantly prolonged residence time in rabbits. The two suspensions significantly improved the relative bioavailability of TOL and its two metabolites, showing their potential usage in the control of coccidian in poultry and livestock.
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Zhang Z, Dong L, Guo J, Li L, Tian B, Zhao Q, Yang J. Prediction of the physical stability of amorphous solid dispersions: relationship of aging and phase separation with the thermodynamic and kinetic models along with characterization techniques. Expert Opin Drug Deliv 2020; 18:249-264. [PMID: 33112679 DOI: 10.1080/17425247.2021.1844181] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Introduction: Solid dispersion has been considered to be one of the most promising methods for improving the solubility and bioavailability of insoluble drugs. However, the physical stability of solid dispersions (SDs), including its aging and recrystallization, or phase separation, has always been one of the most challenging problems in the process of formulation development and storage.Areas covered: The high energy state of SDs is one of the primary reasons for the poor physical stability. The factors affecting the physical stability of SDs have been described from the perspective of thermodynamics and kinetics, and the corresponding theoretical model is put forward. We briefly summarize several commonly used techniques to characterize the thermodynamic and kinetic properties of SDs. Specific measures to improve the physical stability of SDs have been proposed from the perspective of prescription screening, process parameters, and storage conditions.Expert opinion: The separation of the drug from the polymer, the formation, and migration of drug crystals will cause the SDs to shift toward the direction of energy reduction, which is the intrinsic cause of instability. Furthermore, computational simulation can be used for efficient and rapid screening suitable for the excipients to improve the physical stability of SDs.
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Affiliation(s)
- Zhaoyang Zhang
- Department of Pharmaceutics, School of Pharmacy, Ningxia Medical University, Yinchuan, People's Republic of China
| | - Luning Dong
- Department of Pharmaceutics, School of Pharmacy, Ningxia Medical University, Yinchuan, People's Republic of China
| | - Jueshuo Guo
- Department of Pharmaceutics, School of Pharmacy, Ningxia Medical University, Yinchuan, People's Republic of China
| | - Li Li
- Department of Pharmaceutics, School of Pharmacy, Ningxia Medical University, Yinchuan, People's Republic of China
| | - Bin Tian
- Department of Pharmaceutical Sciences, School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an, People's Republic of China
| | - Qipeng Zhao
- Department of Pharmacology, School of Pharmacy, Ningxia Medical University, Yinchuan, People's Republic of China
| | - Jianhong Yang
- Department of Pharmaceutics, School of Pharmacy, Ningxia Medical University, Yinchuan, People's Republic of China
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Mechanism and Improved Dissolution of Glycyrrhetinic Acid Solid Dispersion by Alkalizers. Pharmaceutics 2020; 12:pharmaceutics12010082. [PMID: 31968604 PMCID: PMC7022421 DOI: 10.3390/pharmaceutics12010082] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 01/06/2020] [Accepted: 01/15/2020] [Indexed: 12/22/2022] Open
Abstract
The purpose of this study was to increase the dissolution of glycyrrhetinic acid (GA) by preparing ternary solid dispersion (TSD) systems containing alkalizers, and to explore the modulating mechanism of alkalizers in solid dispersion systems. GA TSDs were prepared by hot melt extrusion (HME) with Kollidon® VA64 as the carrier and L-arginine/meglumine as the alkalizers. The in vitro release of the TSD was investigated with a dissolution test, and the dissociation constant (pKa) was used to describe the ionization degree of the drug in different pH buffers. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD), Fourier Transform Infrared Spectroscopy (FTIR), Raman spectra, X-ray photoelectron spectroscopy (XPS), and a molecular model were used for solid-state characterizations and to study the dissolution mechanism of the TSDs. It was evident that the dissolution of GA significantly increased as a result of the TSD compared to the pure drug and binary solid dispersion. SEM, DSC, and XPRD data showed that GA transformed into an amorphous form in TSD. As illustrated by FTIR, Raman, XPS, and molecular docking, high binding energy ion-pair complexes formed between GA and the alkalizers during the process of HME. These can destroy the H-bond between GA molecules. Further, intermolecular H-bonds formed between the alkalizers and Kollidon® VA64, which can increase the wettability of the drug. Our results will significantly improve the solubility and dissolution of GA. In addition, the lower pKa value of TSD indicates that higher ionization is beneficial to the dissolution of the drug. This study should facilitate further developments of TSDs containing alkalizers to improve the dissolution of weakly acidic drugs and gain a richer understanding of the mechanism of dissolution.
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Zhang S, Wan Q, Xu X, Xing Y, Ding J, Yang S, Sun W, Lu M, Pan B. A novel oil-based suspension of a micro-environmental, pH-modifying solid dispersion for parenteral delivery: Formulation and stability evaluation. Colloids Surf B Biointerfaces 2019; 179:382-392. [PMID: 30999117 DOI: 10.1016/j.colsurfb.2019.04.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 03/12/2019] [Accepted: 04/01/2019] [Indexed: 01/23/2023]
Abstract
The objective of this study was to evaluate a novel oil-based suspension as a potential parenteral drug delivery system for drugs with poor water solubility. Most of the new active pharmaceutical ingredients are weak acid or basic drugs with pH-dependent solubility. To limit this dependence, use of micro-environmental pH-modifying solid dispersions (micro pHm SD) has been proved to increase the bioavailability of these drugs. Toltrazuril (TOL), a weakly acidic drug with poor aqueous and pH-dependent solubility, was studied as a model drug. Recently, studies on TOL with focus on the parenteral injection are rarely to find in the literature. A novel parenteral oil-based TOL suspension was prepared containing TOL micro pHm SD (TSD) powders suspended in oil-based vehicles and the optimal formulation was screened. The stability of this formulation was assessed considering particle size distribution, settling volume ratio, redispersibility, thermal stability, and drug content. The optimized white oil-based TOL pHm SD suspension (W-TSDS) showed significant improved stability and shear-thinning behavior. In particular, fumed silica as suspending agent positively influenced the physical stability of the formulation. Furthermore, W-TSDS showed good injectability using 21 G needles and more rapid and sustained drug release compared to TSD powders in vitro. In the in vivo safety evaluation, W-TSDS showed good histocompatibility in rabbits injected subcutaneously or intramuscularly. We believe these findings provide an alternative choice of dosage form for the delivery of new active pharmaceutical ingredients.
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Affiliation(s)
- Shudong Zhang
- The Department of Veterinary Parasitology, College of Veterinary Medicine, China Agricultural University, Hai Dian District, Beijing, 100193, China
| | - Qiang Wan
- The Department of Veterinary Parasitology, College of Veterinary Medicine, China Agricultural University, Hai Dian District, Beijing, 100193, China
| | - Xiaolin Xu
- The Department of Veterinary Parasitology, College of Veterinary Medicine, China Agricultural University, Hai Dian District, Beijing, 100193, China
| | - Yidan Xing
- The Department of Veterinary Parasitology, College of Veterinary Medicine, China Agricultural University, Hai Dian District, Beijing, 100193, China
| | - Jiafeng Ding
- The Department of Veterinary Parasitology, College of Veterinary Medicine, China Agricultural University, Hai Dian District, Beijing, 100193, China
| | - Shizhuang Yang
- The Department of Veterinary Parasitology, College of Veterinary Medicine, China Agricultural University, Hai Dian District, Beijing, 100193, China
| | - Weiwei Sun
- The Department of Veterinary Parasitology, College of Veterinary Medicine, China Agricultural University, Hai Dian District, Beijing, 100193, China
| | - Mengmeng Lu
- The Department of Veterinary Parasitology, College of Veterinary Medicine, China Agricultural University, Hai Dian District, Beijing, 100193, China
| | - Baoliang Pan
- The Department of Veterinary Parasitology, College of Veterinary Medicine, China Agricultural University, Hai Dian District, Beijing, 100193, China.
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Zhang S, Wan Q, Xing Y, Ding J, Yang S, Sun W, Lu M, Pan B. Formulation and Evaluation of a Novel Oral Oil-Based Suspension Using Micro-environmental pH-Modifying Solid Dispersion. AAPS PharmSciTech 2019; 20:75. [PMID: 30631975 DOI: 10.1208/s12249-018-1222-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 10/16/2018] [Indexed: 01/28/2023] Open
Abstract
Drugs with pH-dependent solubility that have poor water solubility can be identified in the drug discovery pipeline. Some of them have poor oral absorption, which can result in insufficient efficacy. Micro-environmental pH-modifying solid dispersion (micro pHm SD) is a promising approach to overcome the poor oral absorption of these drugs. In the present study, toltrazuril (TOL), a weakly acidic drug with poor aqueous and pH-dependent solubility, was used as a model drug. Using micro pHm SD, a novel oral oil-based suspension of TOL SD (TSDS) was developed, and the stability of this formulation was evaluated based on particle size, settling volume ratio, redispersibility, thermal stability, and drug content. The optimized soybean oil-based TSDS (S-TSDS) had high physicochemical stability and good histocompatibility with common inflammatory reactions. The results of the in vitro dissolution analysis showed that S-TSDS rapidly and markedly released the drug and provided higher efficacy and longer persistence against coccidiosis (above 90.9%) in rabbits. This technique could increase the oral absorption and bioavailability of new drug candidates.
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