ABSTRACT
Since the introduction of combinatorial chemistry, compound libraries have undergone a significant increase in size and diversity. The ensuing expansion and diversification of compound libraries have resulted in increased demand for analytical throughput. Following the evolution of new technologies for generating lead compounds and targets and the desire to increase research and development productivity, analytical chemistry is now gaining attention as a bottleneck that would benefit from advances in instrumentation for increased analytical throughput. The commercial introduction of the Veloce trade mark micro parallel liquid chromatography system from Nanostream offers discovery analytical chemists the capability to analyze 24 samples in parallel with as little as 0.5 microl of sample. The system offers a scalable analytical approach to address bottlenecks in historically underserved areas, such as compound library purity screening, as well as higher value-added applications, such as log P determination and aqueous solubility assessment. This article describes the Veloce system and presents representative data from several discovery analytical applications.
Subject(s)
Chemistry Techniques, Analytical/instrumentation , Chemistry Techniques, Analytical/methods , Chromatography, Liquid/methodsABSTRACT
The concepts of high-throughput (HT) screening and combinatorial synthesis have been integrated into the pharmaceutical discovery process, but are not yet commonplace in the pharmaceutical development arena. Emerging strategies to speed pharmaceutical development and capture solid form diversity of pharmaceutical substances have resulted in the emergence of HT crystallization technologies. The primary type of diversity often refers to polymorphs, which are different crystal forms of the same chemical composition. However, diverse salt forms, co-crystals, hydrates and solvates are also amenable to study in HT crystallization systems. The impact of form diversity encompasses issues of stability and bioavailability, as well as development considerations such as process definition, formulation design, patent protection and regulatory control. This review highlights the opportunities and challenges of HT crystallization technologies as they apply to pharmaceutical research and development.
Subject(s)
Chemistry, Pharmaceutical/methods , Pharmaceutical Preparations/chemistry , Phase Transition , Technology, Pharmaceutical/methods , Chemistry, Pharmaceutical/instrumentation , Crystallization/instrumentation , Crystallization/methods , Crystallography , Databases, Factual , Drug Stability , Excipients/chemistry , Humans , Models, Molecular , Molecular Conformation , Molecular Structure , Powder Diffraction , Salts/chemistry , Solubility , Solvents/chemistry , Spectrum Analysis, Raman , Technology, Pharmaceutical/instrumentationABSTRACT
PURPOSE: The purpose of this work was to replace Cremophor-EL in the commercial paclitaxel intravenous formulation, Taxol, using a novel high-throughput combinatorial formulation approach. METHODS: Full factorial combinations of 12 generally regarded as safe excipients at three different concentrations were screened using an automated liquid dispenser. The hit formulations were further optimized to give the final optimized formulation TPI-1. TPI-1 was then tested in rats to compare its pharmacokinetic profile to Taxol. RESULTS: Of the 9,880 combinations tested in the initial screen, 19 were identified as hit combinations. These were further optimized to give the final formulation TPI-1. When tested in rats, TPI-1 was well tolerated at both the low and high doses of 5 mg/kg and 10 mg/kg, whereas Taxol killed all the rats at the high dose. TPI-1 experienced slower elimination compared to Taxol. Similar to Taxol, TPI-1 also exhibited nonlinear pharmacokinetics. CONCLUSIONS: This study demonstrated the power of a high-throughput combinatorial approach for alternative paclitaxel formulations. We believe that this approach can be applied to drug formulation in general and it can improve the speed and efficiency of drug formulation design.
Subject(s)
Combinatorial Chemistry Techniques , Drug Compounding , Excipients/chemistry , Glycerol/analogs & derivatives , Paclitaxel/chemistry , Animals , Chemistry, Pharmaceutical , Dose-Response Relationship, Drug , Glycerol/chemistry , Male , Paclitaxel/administration & dosage , Paclitaxel/pharmacokinetics , Rats , Rats, Sprague-Dawley , Time FactorsABSTRACT
Three crystal forms of acetaminophen were prepared and characterized using a newly developed high-throughput crystallization platform, CrystalMax. The platform consists of design software, robotic sample dispensing and handling, and high-throughput microanalytics and is capable of running thousands of crystallizations in parallel using several different methods to drive supersaturation and subsequent crystallization. Additionally, structural models of the elusive third form of acetaminophen will be discussed on the basis of powder X-ray diffraction data. One structure suggested has a bilayer motif, held together by O-H...O(H) hydrogen bonds, and helps explain the difficulty associated with preparing this form from solution.
