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B Skagerberg

Publications and source records attributed to B Skagerberg.

7 recordsLinked to original sources

Accelerated dissolution rate analysis (ACDRA) for controlled release drugs. Application to Roxiam.

Accelerated dissolution rate analysis by elevated temperature has been applied to the release of remoxipride from a controlled release drug. Roxiam, and compared to the standard USP method. A PLS model has been used in evaluating the factors of importance of the release as well as for the comparison to the standard USP method. Accelerated Dissolution Rate Analysis (ACDRA) offers the possibility of substantial reduction of analysis time. The time needed for one analysis with ACDRA is less than 5% of the USP-method. The automated analytical procedure is well suited for use in process control as well as in the early stages of the formulation development.

Capsules↗

Minimum analogue peptide sets (MAPS) for quantitative structure-activity relationships.

The information contents in previously published peptide sets was compared with smaller sets of peptides selected according to statistical designs. It was found that minimum analogue peptide sets (MAPS) constructed by factorial or fractional factorial designs in physiochemical properties contained substantial structure-activity information. Although five to six times smaller than the originally published peptide sets the MAPS resulted in QSAR models able to predict biological activity. The QSARs derived from a MAPS of nine dipeptides, and from a set of 58 dipeptides inhibiting angiotensin converting enzyme were compared and found to be of equal strength. Furthermore, for a set of bitter tasting dipeptides it was found that an incomplete MAPS of 10 dipeptides gave just as good a model as the model based on a set of 48 dipeptides. By comparison other non-designed sets of peptides gave QSARs with poor predictive power. It was also demonstrated how MAPS centered on a lead peptide can be constructed as to specifically explore the physiochemical and biological properties in the vicinity of the lead. It was concluded that small information-rich peptide sets MAPS can be constructed on the basis of statistical designs with principal properties of amino acids as design variables.

Amino Acid Sequence↗

Peptide QSAR on substance P analogues, enkephalins and bradykinins containing L- and D-amino acids.

Peptide QSARs are constructed for substance P analogues, enkephalins (two examples) and bradykinins containing both L- and D-amino acids. As descriptors in the QSARs, the previously developed descriptors z1 (hydrophobicity), z2 (bulk) and z3 (electronic effect) are used together with a qualitative variable coding for variation in chirality. Two parametrizations of the peptide sequences are tested. In the first no chiral description is used at all, and in the second chirality is described by the qualitative variable. It is concluded that for the current series of peptides, the biological response to variation in amino acid sequence and chirality can be modelled.

Amino Acid Sequence↗

Peptide quantitative structure-activity relationships, a multivariate approach.

The variation in amino acid sequence within sets of peptides is described by three principal properties, z1, z2, and z3, per varied amino acid position. These principal properties are derived from a principal components analysis of a matrix of 29 physicochemical variables for the 20 coded (in mRNA) amino acids. The scales z1, z2, and z3 are used to construct informative sets of analogues for exploring and developing quantitative structure-activity relationships (QSAR) of peptides. For the QSARs, the multivariate partial least squares (PLS) method is used. Multivariate QSARs are developed for four families of peptides, and it is shown how these QSARs can predict the activity of new peptide analogues.

Bradykinin↗