Publications by authors named "Lawrence Block"

Introduction: Previous studies on the outcomes of asthma and COVID-19 have shown inconsistent results. This study aimed to elucidate the association between asthma and COVID-19 outcomes.

Methods: We conducted a prospective study with a large health plan to compare the incidence of COVID-19 infection, hospitalization and ICU admission in a cohort of 41,282 patients with asthma and a 1:1 age-, sex-, and race-ethnicity-matched cohort without asthma across the following pandemic periods: pre-Delta (03/01/2020 to 05/31/2021), Delta (06/01/2021 to 12/31/2021), and Omicron (01/01/2022 to 08/13/2022).

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Background: Epidemiological studies of interstitial lung disease (ILD) are limited by small numbers and tertiary care bias. Investigators have leveraged the widespread use of electronic health records (EHRs) to overcome these limitations, but struggle to extract patient-level, longitudinal clinical data needed to address many important research questions. We hypothesized that we could automate longitudinal ILD cohort development using the EHR of a large, community-based healthcare system.

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Objective: To develop and evaluate a program to presvent hospital-acquired pneumonia (HAP).

Design: Prospective, observational, surveillance program to identify HAP before and after 7 interventions. An order set automatically triggered in programmatically identified high-risk patients.

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The purpose of this study is to characterize the inter-grade and inter-batch variability of sodium alginate used in the formulation of matrix tablets. Four different grades and three batches of one grade of sodium alginate were used to prepare matrix tablets. Swelling, erosion, and drug release tests of sodium alginate matrix tablets were conducted in a USP dissolution apparatus.

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In this whitepaper, the Manufacturing Technical Committee (MTC) of the Product Quality Research Institute has updated the 1997 Transdermal Drug Delivery Systems Scale-Up and Post Approval Change workshop report findings to add important new product development and control principles. Important topics reviewed include ICH harmonization, quality by design, process analytical technologies, product and process validation, improvements to control of critical excipients, and discussion of Food and Drug Administration's Guidance on Residual Drug in Transdermal and Related Drug Delivery Systems as well as current thinking and trends on in vitro-in vivo correlation considerations for transdermal systems.

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Solid-state nuclear magnetic resonance (SSNMR) spectroscopy has become more prevalent in the pharmaceutical industry due to its nondestructive nature and the wealth of information it can provide on a wide variety of solid samples. In this study, SSNMR spectra and relaxation times were used to analyze differences in monomer composition, molecular weight (MW), and water content among various sodium alginate samples. Differences in structure could be determined via spectral deconvolution of SSNMR spectra, and differences in intrinsic viscosity, MW, and water content were found to correlate to SSNMR relaxation times.

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The purpose of this study is to determine whether sodium alginate solutions' rheological parameters are meaningful relative to sodium alginate's use in the formulation of calcium alginate gels. Calcium alginate gels were prepared from six different grades of sodium alginate (FMC Biopolymer), one of which was available in ten batches. Cylindrical gel samples were prepared from each of the gels and subjected to compression to fracture on an Instron Universal Testing Machine, equipped with a 1-kN load cell, at a cross-head speed of 120 mm/min.

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Polymeric excipients are often the least well-characterized components of pharmaceutical formulations. The aim of this study was to facilitate the QbD approach to pharmaceutical manufacturing by evaluating the inter-grade and inter-batch variability of pharmaceutical-grade polymeric excipients. Sodium alginate, a widely used polymeric excipient, was selected for evaluation using appropriate rheological methods and test conditions.

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A pharmaceutical formulation typically contains one or more excipients in addition to the active pharmaceutical ingredient(s). Though excipients have been considered inert components of a formulation, variability in their properties has been shown to affect the performance of drug dosage forms and delivery systems. This study investigates the inter- and intra-manufacturer variability among different NF grades and lots of xanthan gum made by two manufacturers.

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Purpose: Application of spray-dried chitinosans as excipients for use in drug delivery systems was explored.

Methods: Spray- and tray-dried chitinosans previously N-deacetylated and depolymerized were used. Directly compressed tablets (200mg) containing tetracycline, chitinosan, and magnesium stearate were prepared.

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Purpose: Physicochemical and micromeritic characterization of chitinosans.

Methods: Chitinosans subjected to N-deacetylation and depolymerization were characterized for degree of N-deacetylation (DD), molecular weight (MW), pK(a), particle size determination and morphology, tap/bulk density measurements, surface area determinations, and determination of flow properties.

Results: The chitinosan DDs and MWs were dependent on the processing conditions and ranged from 66 to 89% and 2-522 kDa, respectively.

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The purpose of this study was to examine the potential use of electrolytes to control naproxen sodium (I) release from chitinosan (II) tablets. An ANOVA was employed to evaluate the effects of molecular weight (MW) of II, electrolyte valence (EV), and pH of the dissolution medium on I's release. The intrinsic dissolution rates and saturation solubilities of I were determined at each of the pHs used.

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Alkyl 2-imidazolyl disulfide compounds are novel antitumor agents, one of which is currently being evaluated in Phase I clinical trials. These molecules contain an unsymmetrical disulfide fragment, the lipophilic and electronic contributions of which are still not defined in the literature. Lipophilicity, ionization, and solubility of a number of alkyl 2-imidazolyl disulfides were studied.

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1-Methylpropyl-2-imidazolyl disulfide (MID) is a novel antitumor agent currently in Phase I clinical trials. The chromatographic behavior of MID and its potential impurity, degradation product, and metabolite 2-mercaptoimidazole (2MI) was studied under reversed-phase (RP) and normal-phase (NP) conditions. Both RP- and NP-HPLC separation methods were developed.

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