Analysis

The purpose of the present study was to investigate incorporation of hydrophobic (ie, waxy) material into pellets using a thermal sintering technique and to evaluate the pellets in vitro for controlled release. Pellets prepared by extrusion-spheronization technology were formulated with a water-soluble drug, microcrystalline cellulose, and carnauba wax. Powdered carnauba wax (4%-20%) prepared by grinding or by emulsification was studied with an attempt to retard the drug release. The inclusion of ground or emulsified carnauba wax did not sustain the release of theophylline for more than 3 hours. Matrix pellets of theophylline prepared with various concentrations of carnauba wax were sintered thermally at various times and temperatures. In vitro drug release profiles indicated an increase in drug release retardation with increasing carnauba wax concentration.

The purpose of this article is 2-fold: (1) to document in the public domain the considerations that led to the development of a regulatory statistical test for comparison of aerodynamic particle size distribution (APSD) of aerosolized drug formulations, which was proposed in a US Food and Drug Administration (FDA) draft guidance for industry; and (2) to explain the background and process for evaluation of that test through a working group involving scientists from the FDA, industry, academia, and the US Pharmacopeia, under the umbrella of the Product Quality Research Institute (PQRI).

View Full Article

A serum biomarker for monitoring myocardial dysfunction could potentially serve as a valuable adjunct to risk assessment and management when the biomarker is applied during the clinical development of cancer treatments. We explored the potential utility of serum brain natriuretic peptide (BNP), a hormone secreted predominantly by the ventricles in response to increased intracardiac pressure. In diverse clinical settings, elevated BNP has been reported to be a sensitive biomarker for the early (subclinical) diagnosis of congestive heart failure (CHF).1 In the setting of a phase 1 study of an experimental agent for patients with advanced malignancies, we describe 3 cases in which serum BNP presented reliable information about left ventricular (LV) function, independent from or complementary to the results of conventional echocardiography (echo) or radionuclide multigated acquisition scan (MuGA).

This latest textbook in the “Drugs and the Pharmaceutical
Sciences”series aims at providing in-depth information
on injectable suspensions and emulsions,
delivery systems which are becoming more common,in
particular, for biologics,gene therapy,and some small-molecule
low-solubility drugs. Indeed,this 644-page book,
which encompasses all dispersed systems from simple suspensions
and emulsions to more complex systems such as
liposomes and microspheres,includes a wide range of information
related to formulation,scale up,characterization,
testing,and regulatory registration.

View Full Article

This paper reports on studies of the geometric dimensions and irregularities in the surface of standard 1-L glass dissolution
vessels. Eleven sets of six dissolution vessels from 10 commercial sources were selected for study. A three-dimensional
coordinate measuring machine (CMM) was used to obtain results. The geometric dimensions studied were height,inner
diameter of the cylindrical portion of the vessel,and radius of the hemispheric region. The following irregularities of the
flange and of the internal surface of dissolution vessels were quantified: (1) flatness of the vessel flange,(2) roundness of
the hemisphere at the base of the vessel, required to ensure smooth,unperturbed media flow, (

View Full Article

The specifications and acceptable ranges for nine critical dissolution apparatus variables were examined during a perturbation
study of USP dissolution Apparatus 2 using USP Prednisone Reference Standard (RS) Tablets. A Design of Experiment
(1) approach was used to screen the nine variables to determine the contribution of each, alone and in combination,
to mean percent dissolved and standard deviation results.We observed a wide range of dissolution results,including several
values that fell outside of current acceptance limits,even though the variables were kept within currently acceptable
ranges.When we analyzed mean percent dissolved results,we found three variables that were statistically significant: level
of deaeration,vessel type,and rotation speed.When we examined standard deviation results,we found that five variables
or combinations of variables were statistically significant:vessel type, level of deaeration,paddle height,paddle

Introduction
Correlations between in vitro and in vivo data (IVIVC)
are often used during pharmaceutical development in
order to reduce development time and optimize the
formulation. A good correlation is a tool for predicting in
vivo results based on in vitro data. IVIVC allows dosage form
optimization with the fewest possible trials in man, fixes
dissolution acceptance criteria,and can be used as a surrogate
for further bioequivalence studies; it is also recommended
by regulatory authorities (1–5).

View Full Article

In the electronics industry, the main application of silicon dioxide (SiO2) is used as the gate oxide in the manufacture of semiconductor devices (MOSFETs) and as an insulation layer. With fast progress in integration density, the importance of thin-gate oxides with thicknesses less than 7 nm increases (1). Moreover, transistors are expected to use a gate dielectric with capacitance equivalent to 2–3 nm of SiO2. These trends require thickness and optical constants measurement techniques for such thin SiO2 films.

While perhaps the most extensive such timeline to date, it is surely not complete. Sources for further information have been provided.

Figure 1: Sir Lsaac Newton.
1666: Isaac Newton (1642–1727) (Figure 1) shows that the white light from the sun could be dispersed into a continuous series of colors. He coined the word "spectrum." His apparatus, an aperture to define a light beam, a lens, a prism, and a screen, was the first spectroscope. He suggested that light was composed of minute corpuscles (particles) moving at high speed.

1678: Dutch mathematician and physicist Christian Huygens (1629–1695) proposes the wave theory of light.

1729: French mathematician and scientist Pierre Bougeur (1698–1758) notes that the amount of light passing through a liquid sample decreases with increasing sample thickness.

The term spectral engine is not new and is normally intended to indicate the integration of optics and electronics to form a single measurement package. In the system described in this column, the term is extended to include the close-coupling of the measurement system to the sample via nonimaging optics.

Emil W. Ciurczak