Application of surface area measurement for identifying the source of batch-to-batch variation in processability.

The primary goal of this study was to evaluate the use of specific surface area as a measurable physical property of materials for understanding the batch-to-batch variation in the flow behavior. The specific surface area measurements provide information about the nature of the surface making up the solid, which may include defects or void space on the surface. These void spaces are often present in the crystalline material due to varying degrees of disorderness and can be considered as amorphous regions.

Comprehensive validation scheme for in situ fiber optics dissolution method for pharmaceutical drug product testing.

There has been a growing interest during the past decade in the use of fiber optics dissolution testing. Use of this novel technology is mainly confined to research and development laboratories. It has not yet emerged as a tool for end product release testing despite its ability to generate in situ results and efficiency improvement.

Content uniformity determination of pharmaceutical tablets using five near-infrared reflectance spectrometers: a process analytical technology (PAT) approach using robust multivariate calibration transfer algorithms.

Near-infrared calibration models were developed for the determination of content uniformity of pharmaceutical tablets containing 29.4% drug load for two dosage strengths (X and Y). Both dosage strengths have a circular geometry and the only difference is the size and weight.

Strategy for identification of leachables in packaged pharmaceutical liquid formulations.

Drug stability is one of the key properties to be monitored in pharmaceutical drug development. Drug degradation products, impurities and/or leachables from the drug product and packages may have significant impacts on drug efficacy, safety profile and storage conditions. In the registration stability samples of an ophthalmic pharmaceutical drug product, an unknown compound was found at a level of 0.

Elimination of metformin-croscarmellose sodium interaction by competition.

During analytical method development and validation, a strong charge interaction between metformin and croscarmellose sodium was observed when the aqueous solution containing metformin was spiked with croscarmellose sodium. The charge interaction resulted in the retention of metformin in croscarmellose sodium and caused a serious drug recovery problem. The percent recovery of metformin in the solution was much lower than its theoretical values, especially in the low metformin concentration range.

The use of LC/MS, GC/MS, and LC/NMR hyphenated techniques to identify a drug degradation product in pharmaceutical development.

Understanding drug degradation in the formulated product is critical in pharmaceutical development as it has significant impacts on drug efficacy, safety profile and storage conditions. As a result, identification of degradation compounds has taken an important role in the drug development process. In this study, various hyphenated analytical techniques, such as liquid chromatography mass spectrometry (LC/MS), gas chromatography mass spectrometry (GC/MS), and liquid chromatography nuclear magnetic resonance with a solid phase extraction interface (LC/SPE/NMR), have been applied to the identification of a drug degradation product which grew over time in the stability study of the drug product.

Reversed-phase high-performance liquid chromatography behavior of chaotropic counteranions.

The retention behavior of inorganic liophilic anions in reversed-phase HPLC columns was studied. Usually, the addition of these ions to the mobile phase influences the retention of protonated basic analytes similar to the effect of amphiphilic ions (ion-pairing agents). The nature of this influence is the subject of this paper.

Separation of ritalin racemate and its by-product racemates by capillary electrophoresis.

Ritalin, [(+)-threo]methylphenidate hydrochloride, is a chiral drug substance with two chiral centers. The drug substance may contain three pairs of enantiomers, [(+)-threo], [(-)-threo], [(+)-erythro] and [(-)-erythro] isomers, and its degradation products, threoritalinic acid racemate. Determination of the optical purity of ritalin drug substance and the amount of its by-product isomers is a critical step in the single-isomer drug development.

Enhancement of chiral recognition by formation of a sandwiched complex in capillary electrophoresis.

For chiral primary amino compounds not separable by cyclodextrins alone, chiral recognition was successfully achieved by the formation of a sandwiched complex of the non-chiral 18-crown-6, the chiral amine and cyclodextrin (CD) [18-crown-6+amino compound+CD]. The separation of 1-methyl-3-phenylpropylamine and 1,2,3,4-tetrahydro-1-naphthylamine racemates showed the special function of the non-chiral 18-crown-6 on chiral recognition. By formation of the sandwiched complex, the chiral center of 1-methyl-3-phenylpropylamine was successfully recognized, and resolution of 1,2,3,4-tetrahydro-1-naphthylamine dramatically increased.

Effect of skin pigmentation on pulse oximetry accuracy in the emergency department.

Objective: To determine whether pulse oximeter (PO) accuracy and signal quality are affected by level of skin pigmentation.

Methods: Observational study in a community hospital ED. Consecutive adult patients undergoing arterial blood gas determination were enrolled into the study.

Chiral separation of primary amino compounds using a non-chiral crown ether with beta-cyclodextrin by capillary electrophoresis.

A non-chiral crown ether (18-crown-6) along with beta-cyclodextrin (beta-CD) was used to achieve enantioselective separations of primary amino compounds in capillary electrophoresis. In this new method, the amino group of these compounds is protonated in a low pH separation buffer and forms a selective host-guest complex with the crown ether (amino compound+18-crown-6). The hydrophobic portion of the host-guest complex is then incorporated into the cavity of the beta-cyclodextrin.