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1.
Diabetes Ther ; 15(4): 819-832, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38402332

ABSTRACT

INTRODUCTION: We assessed the effect of the prandial state on the pharmacokinetics, safety, and tolerability of single and multiple doses of orforglipron (LY3502970), an oral, non-peptide glucagon-like peptide 1 receptor agonist (GLP-1 RA), in two studies (A and B). METHODS: Study A and study B were phase 1, randomized, crossover studies in healthy adults aged 18-65 years and 21-70 years, respectively. Participants received single (3 mg, study A) or multiple (16 mg, study B) oral doses of orforglipron under fasted and fed conditions. Blood samples were collected pre- and postdose to assess area under the concentration-time curve (AUC), maximum observed drug concentration (Cmax), time of Cmax (tmax), and half-life (t1/2) associated with terminal rate constant. AUC and Cmax were analyzed using a linear mixed-effects model. Treatment differences were presented as ratios of geometric least squares means (GLSM). Treatment-emergent adverse events (TEAEs), adverse events of special interest, and serious adverse events were assessed. RESULTS: Study A included 12 participants (mean age 45.0 years; male 66.7%); study B included 34 participants (mean age 42.8 years; male 88.2%). GLSM AUC and Cmax were lower by 23.7% and 23.2% in study A, and 17.6% and 20.9% in study B, in the fed versus fasted states, respectively. In both studies, t1/2 and median tmax were comparable between fed and fasted states. The majority of TEAEs in both studies were gastrointestinal tract-related conditions. No serious adverse events or deaths were reported in either study. CONCLUSION: The observed pharmacokinetic differences due to the prandial state are unlikely to contribute to clinically meaningful differences in the efficacy of orforglipron. The safety profile was consistent with the known profiles of other GLP-1 RAs. Given the absence of prandial restrictions, orforglipron may emerge as a convenient oral treatment option for patients with type 2 diabetes or obesity. TRIAL REGISTRATION: ClinicalTrials.gov identifiers, NCT03929744 and NCT05110794.

2.
Drug Discov Today ; 26(3): 713-723, 2021 03.
Article in English | MEDLINE | ID: mdl-33333320

ABSTRACT

Drug-delivery technologies for modified drug release have been in existence for decades, but their utilization has been largely limited to post-launch efforts improving therapeutic outcomes. Recently, they have gained renewed importance because the pharmaceutical industry is steadily shifting to a more integrated discovery-development approach. In discovery, modulating target engagement via drug-delivery technologies can enable crucial pharmacological studies for building well-defined criteria for molecular design. In development, earlier implementation of delivery technologies can enhance the value of drug products through reduced dosing frequency and improved tolerability and/or safety profile, thereby leading to better adherence and therapeutic effectiveness.


Subject(s)
Drug Delivery Systems , Drug Development/methods , Drug Discovery/methods , Animals , Drug Design , Drug Development/trends , Drug Discovery/trends , Drug Industry/methods , Drug Industry/trends , Drug Liberation , Humans , Technology, Pharmaceutical/methods , Technology, Pharmaceutical/trends
3.
Mol Cancer Ther ; 18(12): 2207-2219, 2019 12.
Article in English | MEDLINE | ID: mdl-31530649

ABSTRACT

Although Aurora A, B, and C kinases share high sequence similarity, especially within the kinase domain, they function distinctly in cell-cycle progression. Aurora A depletion primarily leads to mitotic spindle formation defects and consequently prometaphase arrest, whereas Aurora B/C inactivation primarily induces polyploidy from cytokinesis failure. Aurora B/C inactivation phenotypes are also epistatic to those of Aurora A, such that the concomitant inactivation of Aurora A and B, or all Aurora isoforms by nonisoform-selective Aurora inhibitors, demonstrates the Aurora B/C-dominant cytokinesis failure and polyploidy phenotypes. Several Aurora inhibitors are in clinical trials for T/B-cell lymphoma, multiple myeloma, leukemia, lung, and breast cancers. Here, we describe an Aurora A-selective inhibitor, LY3295668, which potently inhibits Aurora autophosphorylation and its kinase activity in vitro and in vivo, persistently arrests cancer cells in mitosis, and induces more profound apoptosis than Aurora B or Aurora A/B dual inhibitors without Aurora B inhibition-associated cytokinesis failure and aneuploidy. LY3295668 inhibits the growth of a broad panel of cancer cell lines, including small-cell lung and breast cancer cells. It demonstrates significant efficacy in small-cell lung cancer xenograft and patient-derived tumor preclinical models as a single agent and in combination with standard-of-care agents. LY3295668, as a highly Aurora A-selective inhibitor, may represent a preferred approach to the current pan-Aurora inhibitors as a cancer therapeutic agent.


Subject(s)
Antineoplastic Agents/therapeutic use , Aurora Kinase A/antagonists & inhibitors , Mitosis/drug effects , Antineoplastic Agents/pharmacology , Apoptosis , Cell Line, Tumor , Cell Proliferation , Female , HeLa Cells , Humans , Male
4.
J Pharm Sci ; 108(1): 8-17, 2019 Jan.
Article in English | MEDLINE | ID: mdl-30053554

ABSTRACT

Relative bioavailability (RBA) studies are often carried out to bridge changes made between drug products used for clinical studies. In this work, we describe the development of a risk assessment (RA) tool that comprehensively and objectively assesses the risk of noncomparable in vivo performance associated with Chemistry, Manufacturing, and Controls (CM&C)-related changes. The RA tool is based on a risk grid that provides a quantitative context to facilitate discussions to determine the need for an in vivo RBA study. Relevant regulatory guidances and the required in vitro and in silico absorption modeling data, on which the RA is based, are discussed. In addition, an analysis of previously executed RBA studies at Eli Lilly and Company over a period of several years is presented. The risk grid incorporates individual risk factors for a given study and provides a recommendation on the risk associated with bypassing an RBA study. The outcome of an RA results in 1 of 3 possible risk zones; lower tier risk, intermediate tier risk, and upper tier risk. In cases where the outcome from the RA falls into the intermediate tier risk zone, further in depth data analysis is required.


Subject(s)
Pharmaceutical Preparations/metabolism , Biological Availability , Biopharmaceutics/methods , Chemistry, Pharmaceutical/methods , Humans , Risk Assessment/methods , Risk Factors
5.
AAPS PharmSciTech ; 19(1): 1-10, 2018 Jan.
Article in English | MEDLINE | ID: mdl-28755053

ABSTRACT

This commentary reflects the collective view of pharmaceutical scientists from four different organizations with extensive experience in the field of drug discovery support. Herein, engaging discussion is presented on the current and future approaches for the selection of the most optimal and developable drug candidates. Over the past two decades, developability assessment programs have been implemented with the intention of improving physicochemical and metabolic properties. However, the complexity of both new drug targets and non-traditional drug candidates provides continuing challenges for developing formulations for optimal drug delivery. The need for more enabled technologies to deliver drug candidates has necessitated an even more active role for pharmaceutical scientists to influence many key molecular parameters during compound optimization and selection. This enhanced role begins at the early in vitro screening stages, where key learnings regarding the interplay of molecular structure and pharmaceutical property relationships can be derived. Performance of the drug candidates in formulations intended to support key in vivo studies provides important information on chemotype-formulation compatibility relationships. Structure modifications to support the selection of the solid form are also important to consider, and predictive in silico models are being rapidly developed in this area. Ultimately, the role of pharmaceutical scientists in drug discovery now extends beyond rapid solubility screening, early form assessment, and data delivery. This multidisciplinary role has evolved to include the practice of proactively taking part in the molecular design to better align solid form and formulation requirements to enhance developability potential.


Subject(s)
Drug Compounding , Drug Design , Drug Discovery , Laboratory Personnel , Pharmaceutical Preparations/administration & dosage , Pharmaceutical Preparations/chemistry , Solubility
6.
Mol Cancer Ther ; 16(12): 2677-2688, 2017 Dec.
Article in English | MEDLINE | ID: mdl-29054982

ABSTRACT

NAMPT, an enzyme essential for NAD+ biosynthesis, has been extensively studied as an anticancer target for developing potential novel therapeutics. Several NAMPT inhibitors have been discovered, some of which have been subjected to clinical investigations. Yet, the on-target hematological and retinal toxicities have hampered their clinical development. In this study, we report the discovery of a unique NAMPT inhibitor, LSN3154567. This molecule is highly selective and has a potent and broad spectrum of anticancer activity. Its inhibitory activity can be rescued with nicotinic acid (NA) against the cell lines proficient, but not those deficient in NAPRT1, essential for converting NA to NAD+ LSN3154567 also exhibits robust efficacy in multiple tumor models deficient in NAPRT1. Importantly, this molecule when coadministered with NA does not cause observable retinal and hematological toxicities in the rodents, yet still retains robust efficacy. Thus, LSN3154567 has the potential to be further developed clinically into a novel cancer therapeutic. Mol Cancer Ther; 16(12); 2677-88. ©2017 AACR.


Subject(s)
Cytokines/antagonists & inhibitors , Niacin/therapeutic use , Nicotinamide Phosphoribosyltransferase/antagonists & inhibitors , Retinal Pigment Epithelium/drug effects , Animals , Humans , Mice , Niacin/pharmacology , Retinal Pigment Epithelium/pathology
7.
Bioorg Med Chem Lett ; 27(6): 1478-1483, 2017 03 15.
Article in English | MEDLINE | ID: mdl-28190634

ABSTRACT

We describe a novel class of acidic mPGES-1 inhibitors with nanomolar enzymatic and human whole blood (HWB) potency. Rational design in conjunction with structure-based design led initially to the identification of anthranilic acid 5, an mPGES-1 inhibitor with micromolar HWB potency. Structural modifications of 5 improved HWB potency by over 1000×, reduced CYP2C9 single point inhibition, and improved rat clearance, which led to the selection of [(cyclopentyl)ethyl]benzoic acid compound 16 for clinical studies. Compound 16 showed an IC80 of 24nM for inhibition of PGE2 formation in vitro in LPS-stimulated HWB. A single oral dose resulted in plasma concentrations of 16 that exceeded its HWB IC80 in both rat (5mg/kg) and dog (3mg/kg) for over twelve hours.


Subject(s)
Benzoates/chemistry , Benzoates/pharmacology , Drug Discovery , Microsomes/drug effects , Prostaglandin-E Synthases/antagonists & inhibitors , Animals , Crystallography, X-Ray , Dogs , Microsomes/enzymology , Prostaglandin-E Synthases/chemistry , Rats
8.
Bioorg Med Chem Lett ; 26(19): 4824-4828, 2016 10 01.
Article in English | MEDLINE | ID: mdl-27554445

ABSTRACT

Here we report on novel, potent 3,3-dimethyl substituted N-aryl piperidine inhibitors of microsomal prostaglandin E synthases-1(mPGES-1). Example 14 potently inhibited PGE2 synthesis in an ex vivo human whole blood (HWB) assay with an IC50 of 7nM. In addition, 14 had no activity in human COX-1 or COX-2 assays at 30µM, and failed to inhibit human mPGES-2 at 62.5µM in a microsomal prep assay. These data are consistent with selective mPGES-1-mediated reduction of PGE2. In dog, 14 had oral bioavailability (74%), clearance (3.62mL/(min*kg)) and volume of distribution (Vd,ss=1.6L/kg) values within our target ranges. For these reasons, 14 was selected for further study.


Subject(s)
Piperidines/chemistry , Piperidines/pharmacology , Prostaglandin-E Synthases/antagonists & inhibitors , A549 Cells , Animals , Crystallography, X-Ray , Dogs , Humans , Piperidines/pharmacokinetics , Rats , Species Specificity , Structure-Activity Relationship
9.
J Med Chem ; 59(1): 194-205, 2016 Jan 14.
Article in English | MEDLINE | ID: mdl-26653180

ABSTRACT

As part of a program aimed at the discovery of antinociceptive therapy for inflammatory conditions, a screening hit was found to inhibit microsomal prostaglandin E synthase-1 (mPGES-1) with an IC50 of 17.4 µM. Structural information was used to improve enzyme potency by over 1000-fold. Addition of an appropriate substituent alleviated time-dependent cytochrome P450 3A4 (CYP3A4) inhibition. Further structure-activity relationship (SAR) studies led to 8, which had desirable potency (IC50 = 12 nM in an ex vivo human whole blood (HWB) assay) and absorption, distribution, metabolism, and excretion (ADME) properties. Studies on the formulation of 8 identified 8·H3PO4 as suitable for clinical development. Omission of a lipophilic portion of the compound led to 26, a readily orally bioavailable inhibitor with potency in HWB comparable to celecoxib. Furthermore, 26 was selective for mPGES-1 inhibition versus other mechanisms in the prostanoid pathway. These factors led to the selection of 26 as a second clinical candidate.


Subject(s)
Analgesics/chemical synthesis , Analgesics/pharmacology , Cyclooxygenase Inhibitors/chemical synthesis , Cyclooxygenase Inhibitors/pharmacology , Imidazoles/chemical synthesis , Imidazoles/pharmacology , Intramolecular Oxidoreductases/antagonists & inhibitors , Microsomes/enzymology , Animals , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Biological Availability , Celecoxib/pharmacology , Cyclooxygenase Inhibitors/pharmacokinetics , Cytochrome P-450 CYP3A , Cytochrome P-450 Enzyme Inhibitors/chemical synthesis , Cytochrome P-450 Enzyme Inhibitors/pharmacology , Dogs , Drug Discovery , Humans , Microsomes/drug effects , Models, Molecular , Prostaglandin-E Synthases , Rats , Structure-Activity Relationship
10.
J Pharm Sci ; 100(11): 4756-65, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21681753

ABSTRACT

Dogs are one of the most commonly used non-rodent species in toxicology studies and are known to have basal stomach pH ranging from 2 to 7 in the fasted state. Thus absorption and resulting plasma exposure of weakly basic compounds administered as crystalline suspensions to dogs are often variable. LY2157299 is a potent and selective transforming growth factor (TGF)-beta receptor type 1 kinase (TGF-ßRI) inhibitor that displayed variable absorption in early dog studies. This molecule is a weakly basic Biopharmaceutics Classification System (BCS)Class II compound, and depends on the rate and extent of dissolution to drive oral absorption. An artificial stomach and duodenum (ASD) dissolution model was utilized to evaluate potential effect of gastric pH on the absorption of suspension and buffered solution formulations. GastroPlus™ was also employed to predict the magnitude of gastric pH changes on LY2157299 absorption. The ASD experiments demonstrated that administration of a buffered acidic solution could improve the potential for absorption by normalizing gastric pH and enabling supersaturation in the duodenum. GastroPlus™ modeling suggested that direct modulation of gastric pH could lead to marked changes in bioavailability. Pharmacokinetic experiments were conducted in dogs to evaluate the effect of gastric pH modification on plasma exposure. The data were qualitatively consistent with the predictions.


Subject(s)
Artificial Organs , Duodenum/metabolism , Gastric Juice/metabolism , Gastric Mucosa/metabolism , Hydrogen-Ion Concentration , Pyrazoles/pharmacokinetics , Quinolines/pharmacokinetics , Animals , Biological Availability , Dogs , Male , Protein Serine-Threonine Kinases/antagonists & inhibitors , Receptor, Transforming Growth Factor-beta Type I , Receptors, Transforming Growth Factor beta/antagonists & inhibitors , Solubility
11.
ACS Med Chem Lett ; 2(2): 91-96, 2011 Feb 10.
Article in English | MEDLINE | ID: mdl-21666860

ABSTRACT

Fatty acid amide hydrolase (FAAH) is an integral membrane serine hydrolase that degrades the fatty acid amide family of signaling lipids, including the endocannabinoid anandamide. Genetic or pharmacological inactivation of FAAH leads to analgesic and anti-inflammatory phenotypes in rodents without showing the undesirable side effects observed with direct cannabinoid receptor agonists, indicating that FAAH may represent an attractive therapeutic target for the treatment of inflammatory pain and other nervous system disorders. Herein, we report the discovery and characterization of a highly efficacious and selective FAAH inhibitor PF-04457845 (23). Compound 23 inhibits FAAH by a covalent, irreversible mechanism involving carbamylation of the active-site serine nucleophile of FAAH with high in vitro potency (k(inact)/K(i) and IC(50) values of 40300 M(-1) s(-1) and 7.2 nM, respectively, for human FAAH). Compound 23 has exquisite selectivity for FAAH relative to other members of the serine hydrolase superfamily as demonstrated by competitive activity-based protein profiling. Oral administration of 23 at 0.1 mg/kg results in efficacy comparable to that of naproxen at 10 mg/kg in a rat model of inflammatory pain. Compound 23 is being evaluated in human clinical trials.

12.
Int J Pharm ; 412(1-2): 95-8, 2011 Jun 30.
Article in English | MEDLINE | ID: mdl-21527324

ABSTRACT

This work reports on the solubility of two weakly basic model compounds in media containing sodium lauryl sulfate (SLS). Results clearly show that the presence of SLS in the media (e.g. simulated gastric fluid or dissolution media) can result in an underestimation of solubility of some weak bases. We systematically study this phenomenon and provide evidence (chromatography and pXRD) for the first time that the decrease in solubility is likely due to formation of a less soluble salt/complex between the protonated form of the weak base and lauryl sulfate anion.


Subject(s)
Antimalarials/pharmacokinetics , Gastric Juice/metabolism , Pharmaceutic Aids/chemistry , Sodium Dodecyl Sulfate/chemistry , Surface-Active Agents/chemistry , Trimethoprim/pharmacokinetics , Antimalarials/analysis , Antimalarials/chemistry , Chemical Precipitation , Chromatography, High Pressure Liquid , Diffusion , Gastric Juice/chemistry , Gastric Mucosa/metabolism , Hydrogen-Ion Concentration , Intestinal Absorption , Pharmaceutic Aids/analysis , Powder Diffraction , Reproducibility of Results , Sodium Dodecyl Sulfate/analysis , Solubility , Surface-Active Agents/analysis , Trimethoprim/analysis , Trimethoprim/chemistry
13.
J Pharmacol Exp Ther ; 338(1): 114-24, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21505060

ABSTRACT

The endogenous cannabinoid (endocannabinoid) anandamide is principally degraded by the integral membrane enzyme fatty acid amide hydrolase (FAAH). Pharmacological blockade of FAAH has emerged as a potentially attractive strategy for augmenting endocannabinoid signaling and retaining the beneficial effects of cannabinoid receptor activation, while avoiding the undesirable side effects, such as weight gain and impairments in cognition and motor control, observed with direct cannabinoid receptor 1 agonists. Here, we report the detailed mechanistic and pharmacological characterization of N-pyridazin-3-yl-4-(3-{[5-(trifluoromethyl)pyridin-2-yl]oxy}benzylidene)piperidine-1-carboxamide (PF-04457845), a highly efficacious and selective FAAH inhibitor. Mechanistic studies confirm that PF-04457845 is a time-dependent, covalent FAAH inhibitor that carbamylates FAAH's catalytic serine nucleophile. PF-04457845 inhibits human FAAH with high potency (k(inact)/K(i) = 40,300 M(-1)s(-1); IC(50) = 7.2 nM) and is exquisitely selective in vivo as determined by activity-based protein profiling. Oral administration of PF-04457845 produced potent antinociceptive effects in both inflammatory [complete Freund's adjuvant (CFA)] and noninflammatory (monosodium iodoacetate) pain models in rats, with a minimum effective dose of 0.1 mg/kg (CFA model). PF-04457845 displayed a long duration of action as a single oral administration at 1 mg/kg showed in vivo efficacy for 24 h with a concomitant near-complete inhibition of FAAH activity and maximal sustained elevation of anandamide in brain. Significantly, PF-04457845-treated mice at 10 mg/kg elicited no effect in motility, catalepsy, and body temperature. Based on its exceptional selectivity and in vivo efficacy, combined with long duration of action and optimal pharmacokinetic properties, PF-04457845 is a clinical candidate for the treatment of pain and other nervous system disorders.


Subject(s)
Amidohydrolases/antagonists & inhibitors , Enzyme Inhibitors/pharmacology , Enzyme Inhibitors/therapeutic use , Pain/drug therapy , Pain/enzymology , Pyridazines/pharmacology , Pyridazines/therapeutic use , Urea/analogs & derivatives , Amidohydrolases/metabolism , Animals , Enzyme Inhibitors/chemistry , Humans , Inflammation/drug therapy , Inflammation/enzymology , Inflammation/pathology , Male , Mice , Mice, Inbred C57BL , Piperidines/chemistry , Piperidines/pharmacology , Piperidines/therapeutic use , Pyridazines/chemistry , Rats , Rats, Sprague-Dawley , Urea/chemistry , Urea/pharmacology , Urea/therapeutic use
14.
Mol Pharm ; 4(4): 498-512, 2007.
Article in English | MEDLINE | ID: mdl-17629304

ABSTRACT

Most pharmacologically active molecules contain one or more ionizing groups, and it is well-known that knowledge of the ionization state of a drug, indicated by the pKa value, is critical for understanding many properties important to the drug discovery and development process. The ionization state of a compound directly influences such important pharmaceutical characteristics as aqueous solubility, permeability, crystal structure, etc. Tremendous advances have been made in the field of experimental determination of pKa, in terms of both quantity/speed and quality/accuracy. However, there still remains a need for accurate in silico predictions of pKa both to estimate this parameter for virtual compounds and to focus screening efforts of real compounds. The computer program SPARC (SPARC Performs Automated Reasoning in Chemistry) was used to predict the ionization state of a drug. This program has been developed based on the solid physical chemistry of reactivity models and applied to successfully predict numerous physical properties as well as chemical reactivity parameters. SPARC predicts both macroscopic and microscopic pKa values strictly from molecular structure. In this paper, we describe the details of the SPARC reactivity computational methods and its performance on predicting the pKa values of known drugs as well as Pfizer internal discovery/development compounds. A high correlation (r2=0.92) between experimental and the SPARC calculated pKa values was obtained with root-mean-square error (RMSE) of 0.78 log unit for a set of 123 compounds including many known drugs. For a set of 537 compounds from the Pfizer internal dataset, correlation coefficient r2=0.80 and RMSE=1.05 were obtained.


Subject(s)
Computer Simulation , Ions/chemistry , Pharmaceutical Preparations/chemistry , Software , Electrophoresis, Capillary , Hydrogen Bonding , Models, Chemical , Molecular Structure , Static Electricity , Stereoisomerism , Thermodynamics
15.
J Pharm Biomed Anal ; 43(5): 1660-6, 2007 Apr 11.
Article in English | MEDLINE | ID: mdl-17270379

ABSTRACT

The design and validation of a novel high-throughput system for thermodynamic solubility determination requiring only 5 mg of sample is described. The system uses a sintered nickel filter assembly to recover excess solids from saturated solutions for rapid crystallinity assessment via powder X-ray diffraction (PXRD). Moreover, the system measures the pH of filtrates to provide a final pH value with the solubility measurement. The limit of detection for the UV-vis plate reader used on this system is approximately 0.001 mg/ml, while the practical upper limit is approximately 3 mg/mL. The solubility measurements of 60 proprietary Pfizer compounds were used to validate the nickel filter assembly against a more conventional polyvinylidenedifluoride (PVDF) filter. Additionally, a comparison was made between a subset of 10 compounds run on the automated system and a more traditional shake-flask method employing HPLC analysis. In both cases, a favorable comparison was obtained.


Subject(s)
Drug Design , Pharmaceutical Preparations/chemistry , Autoanalysis , Automation , Buffers , Chemistry, Pharmaceutical/methods , Chromatography, High Pressure Liquid , Crystallization , Filtration , Hydrogen-Ion Concentration , Nickel/chemistry , Powders , Reference Standards , Solubility , Spectrophotometry, Ultraviolet , Thermodynamics , X-Ray Diffraction
16.
Int J Pharm ; 330(1-2): 105-13, 2007 Feb 07.
Article in English | MEDLINE | ID: mdl-17049191

ABSTRACT

In drug development, the thermodynamically most stable form of a compound is preferred because metastable forms are prone to transform to the stable form during processing, formulation, or storage [Guillory, J.K., 1999. Generation of polymorphs, hydrates, solvates, and amorphous solids. In: Brittain, H.G. (Ed.), Polymorphism in Pharmaceutical Solids. Marcel Dekker, New York, pp. 183-226]. It is therefore important to discover and characterize the stable form as early as possible. One of the most important properties to determine is thermodynamic solubility. However, due to compound and time constraints this solubility value is usually not determined until late in discovery. This report explores the ability of the pH-metric titration method to measure intrinsic solubility of the stable form of compounds that exist in one or more polymorphic forms. One metastable form and the stable form of eight compounds were examined. Intrinsic solubility was measured via pH-metric titration. The technique was performed on a larger scale in order to monitor polymorphic form changes by powder X-ray diffraction. Shake-flask solubility and corresponding X-ray diffraction data of each form was also determined. The results of this study indicate that, in general, when starting with a metastable polymorph, the pH-metric titration method is able to achieve the solubility of the stable form by the third titration, while the traditional shake-flask solubility method is unable to consistently determine the stable form solubility.


Subject(s)
Pharmaceutical Preparations/chemistry , Potentiometry/methods , Acetaminophen/chemistry , Acetazolamide/chemistry , Chlorpropamide/chemistry , Crystallography, X-Ray , Fluoroquinolones/chemistry , Furosemide/chemistry , Hydrogen-Ion Concentration , Pyrroles/chemistry , Quinolones/chemistry , Solubility , Sulfamethoxazole/chemistry , Sulfathiazole , Sulfathiazoles/chemistry , Thermodynamics , Titrimetry/methods
17.
Drug Discov Today ; 11(21-22): 1012-8, 2006 Nov.
Article in English | MEDLINE | ID: mdl-17055411

ABSTRACT

Solubility data are used to make crucial decisions from the earliest stages of drug discovery throughout the development process, but often the decision-maker is far removed, in terms of both organization and scientific background, from the scientist who generates the data. Here we provide a reference point for consumers of solubility who are presented with increasingly sophisticated strategies to measure sooner, faster or more accurately. We discuss the fundamental forces that govern solubility, the role of physical-chemical parameters such as pH and pK(a), and the principles involved in different solubility measurements. Our ultimate goal is to enable a decision-maker, when presented with solubility data, to have in hand the tools to evaluate not just the magnitude but also the context and appropriateness of those measurements to the drug in question.


Subject(s)
Chemistry, Pharmaceutical , Pharmaceutical Preparations/chemistry , Hydrogen-Ion Concentration , Models, Chemical , Molecular Structure , Solubility , Technology, Pharmaceutical , Thermodynamics
18.
Expert Opin Drug Metab Toxicol ; 2(4): 591-608, 2006 Aug.
Article in English | MEDLINE | ID: mdl-16859407

ABSTRACT

Optimisation of oral bioavailability is a continuing challenge for the pharmaceutical and biotechnology industries. The number of potential drug candidates requiring in vivo evaluation has significantly increased with the advent of combinatorial chemistry. In addition, drug discovery programmes are increasingly forced into more lipophilic and lower solubility chemical space. To aid in the use of in vitro and in silico tools as well as reduce the number of in vivo studies required, a team-based discussion tool is proposed that provides a 'road map' to guide the selection of profiling assays that should be considered when optimising oral bioavailability. This road map divides the factors that contribute to poor oral bioavailability into two interrelated categories: absorption and metabolism. This road map provides an interface for cross discipline discussions and a systematic approach to the experimentation that drives the drug discovery process towards a common goal - acceptable oral bioavailability using minimal resources in an acceptable time frame.


Subject(s)
Biological Availability , Drug Industry , Pharmaceutical Preparations/metabolism , Chemistry, Pharmaceutical , Hepatocytes/metabolism , Humans , Intestinal Absorption , Permeability , Pharmaceutical Preparations/administration & dosage , Solubility
19.
J Pharm Biomed Anal ; 41(1): 152-7, 2006 Apr 11.
Article in English | MEDLINE | ID: mdl-16364585

ABSTRACT

Solubility measurements using chemiluminescent nitrogen detection (CLND) has advantages of reduced compound requirement and increased throughput compared to UV-spectrophotometric and HPLC-based measurements. CLND with direct flow injection was evaluated for the measurement of thermodynamic solubility to support drug discovery. The limit of quantitation (LOQ), accuracy, and day-to-day reproducibility of the detector were measured. Measurements made on CLND were compared to those obtained from UV spectrophotometry and HPLC. Based on the results obtained, it was concluded that the CLND performs satisfactorily for discovery stage thermodynamic solubility measurements.


Subject(s)
Chemistry, Pharmaceutical/methods , Drug Design , Luminescence , Nitrogen/analysis , Technology, Pharmaceutical/methods , Calibration , Chromatography, High Pressure Liquid , Dose-Response Relationship, Drug , Evaluation Studies as Topic , Hydrogen-Ion Concentration , Solubility , Spectrophotometry, Ultraviolet , Thermodynamics , Ultraviolet Rays
20.
Pharm Dev Technol ; 10(4): 451-60, 2005.
Article in English | MEDLINE | ID: mdl-16370174

ABSTRACT

Micronization is a commonly used enabling technology to improve the bioavailability of compounds where absorption is dissolution rate limited. However, decreasing particle size often results in increased Van der Waals' interactions and electrostatic attraction between particles. This causes agglomeration of particles, thereby compromising the increase in surface area gained by micronization. Comicronization with excipients has been reported to offer significant advantages over neat micronization. The present work describes the comicronization of a model compound CI-1040 at a high drug load that shows an increase in the dissolution rate and bioavailability in male Wistar rats. Physicochemical characterization of the comicronized and neat micronized material is presented to help explain the in-vitro and in-vivo data.


Subject(s)
Benzamides/chemistry , Benzamides/pharmacokinetics , Cellulose/chemistry , Excipients/chemistry , Technology, Pharmaceutical/methods , Animals , Biological Availability , Male , Microscopy, Electron, Scanning , Particle Size , Rats , Rats, Wistar , Solubility , Surface Properties , X-Ray Diffraction
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