Inter-grade and inter-batch variability of sodium alginate used in alginate-based matrix tablets.

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.

Analysis of composition, molecular weight, and water content variations in sodium alginate using solid-state NMR spectroscopy.

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.

Relevance of rheological properties of sodium alginate in solution to calcium alginate gel properties.

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.

Rheological evaluation of inter-grade and inter-batch variability of sodium alginate.

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.

Inter- and intra-manufacturer variability in pharmaceutical grades and lots of xanthan gum.

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.

Spray-dried chitinosans. Part II: in vitro drug release from tablets made from spray-dried chitinosans.

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.

Spray-dried chitinosans. Part I: preparation and characterization.

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.

Chitinosan-drug complexes: effect of electrolyte on naproxen release in vitro.

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.

Solubility, ionization, and partitioning behavior of unsymmetrical disulfide compounds: alkyl 2-imidazolyl disulfides.

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.

Normal-phase and stability-indicating reversed-phase high-performance liquid chromatographic methods for the determination of the novel antitumor agent: 1-methylpropyl-2-imidazolyldisulfide.

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.