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α-Lactalbumin (α-la) provides essential amino acids to the diet and is therefore of nutritional importance. Bovine α-la is routinely supplemented to infant formulas, which makes it essential to obtain quantitative data of its content. In this study a quantitative, internally standardised Liquid Chromatography-Mass Spectrometry (LC-MS) method for bovine α-la in infant formula was validated, with good accuracy (90–110%) and precision (RSDRint < 7%). The specificity was high because the bovine α-la calibration samples were prepared with goat milk-based infant formula to avoid background of the endogenous bovine target peptide (CEVFR). Additionally, the method includes the qualitative monitoring of (i) a second confirmative tryptic peptide from the bovine α-la sequence (VGINYWLAHK), (ii) glycation of adjacent lysine residues and (iii) the presence of goat α-la adulteration in bovine infant milk formula. The methodology will be of importance to the dairy and infant formula industry in supporting bovine α-la label claims.

Fine excipient particles or 'fines' have been shown to improve the dispersion performance of carrier-based formulations for dry powder inhalation. Mechanistic formulation studies have focussed mainly on explaining this positive effect. Previous studies have shown that higher drug contents may cause a decrease in dispersion performance, and there is no reason why this should not be true for fines with a similar shape, size and cohesiveness as drug particles. Therefore, the effects on drug detachment of 'fine lactose fines' (FLF, X50= 1.95 mm) with a similar size and shape as micronised budesonide were studied and compared to those of 'coarse lactose fines' (CLF, X50= 3.94 mm). Furthermore, interactions with the inhalation flow rate, the drug content and the mixing order were taken into account. The observed effects of FLF are comparable to drug content effects in that the detached drug fraction was decreased at low drug content and low flow rates but increased at higher flow rates. At high drug content the effects of added FLF were negligible. In contrast, CLF resulted in higher detached drug fractions at all flow rates and drug contents. The results from this study suggest that the effects of fines may be explained by two new mechanisms in addition to those previously proposed. Firstly, fines below a certain size may increase the effectiveness of press-on forces or cause the formation of strongly coherent fine particle networks on the carrier surface containing the drug particles. Secondly, when coarse enough, fines may prevent the formation of, or disrupt such fine particle networks, possibly through a lowering of their tensile strength. It is recommended that future mechanistic studies are based on the recognition that added fines may have any effect on dispersion performance, which is determined by the formulation and dispersion conditions. © 2014 Grasmeijer et al.