Enantiomeric purity analysis of synthetic peptide therapeutics by direct chiral high-performance liquid chromatography-electrospray ionization tandem mass spectrometry.

The determination of chiral purity is critical to the evaluation of the quality of peptide pharmaceutical products. For synthetic peptides, the undesirable d-isomers can be introduced as impurities in amino acid starting materials and can also be formed during peptide synthesis and in some cases during product shelf life. A chiral high-performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) method is described that facilitates rapid and accurate determination of amino acid chiral purity of a peptide.

Characterization of a novel cross-linked lipase: impact of cross-linking on solubility and release from drug product.

Liprotamase is a novel non-porcine pancreatic enzyme replacement therapy containing purified biotechnology-derived lipase, protease, and amylase together with excipients in a capsule formulation. To preserve the structural integrity and biological activity of lipase (the primary drug substance) through exposure of the drug product to the low-pH gastric environment, the enzyme was processed through the use of cross-linked enzyme crystal (CLEC) technology, making the lipase-CLEC drug substance insoluble under acidic conditions but fully soluble at neutral pH and in alkaline environments. In this report we characterize the degree of cross-linking for lipase-CLEC and demonstrate its impact on lipase-CLEC solubility and release from the drug product under relevant physiological pH conditions.

Total residue analysis of swabs by ion mobility spectrometry.

Ion mobility spectrometry (IMS) is a technique attractive for use within the pharmaceutical industry for at-line determination of residues on swabs taken from the surfaces of manufacturing equipment for the purposes of cleaning validation or verification. In this study, the development of a novel IMS method to provide a measurement of total residue present on a swab is described. The technique is based upon quantitation of charged atmospheric gas reactant ion consumption (RIC) within the instrument as a direct measure of the mass of total ionizable residue.

At-line quantitative ion mobility spectrometry for direct analysis of swabs for pharmaceutical manufacturing equipment cleaning verification.

The potential for ion mobility spectrometry (IMS) to provide rapid at-line quantitation of residues on surfaces via direct analysis of swabs is attractive for pharmaceutical manufacturing equipment cleaning verification. In this study, the development of an IMS method to provide acceptable quantitation of active pharmaceutical ingredients and cleaning agents is described. Key modifications to commercially available instrumentation were made to achieve a dynamic range of 5-100 microg per 25 cm2 surface area and acceptable analyte recovery in the presence of ionizable matrix components.

Discovery of cercosporamide, a known antifungal natural product, as a selective Pkc1 kinase inhibitor through high-throughput screening.

The Pkc1-mediated cell wall integrity-signaling pathway is highly conserved in fungi and is essential for fungal growth. We thus explored the potential of targeting the Pkc1 protein kinase for developing broad-spectrum fungicidal antifungal drugs through a Candida albicans Pkc1-based high-throughput screening. We discovered that cercosporamide, a broad-spectrum natural antifungal compound, but previously with an unknown mode of action, is actually a selective and highly potent fungal Pkc1 kinase inhibitor.

Novel lipoglycopeptides as inhibitors of bacterial signal peptidase I.

Signal peptidase (SPase) I is responsible for the cleavage of signal peptides of many secreted proteins in bacteria. Because of its unique physiological and biochemical properties, it serves as a potential target for development of novel antibacterial agents. In this study, we report the production, isolation, and structure determination of a family of structurally related novel lipoglycopeptides from a Streptomyces sp.