The effects of ultrasound, assisting the compaction of pharmaceutical mixtures, were examined in a variety of systems, coupling indomethacin, theophylline and ketoprofen with beta-cyclodextrin, Eudragit, PVP and PEG. In most cases the main effect observed was the amorphisaztion of the drug, which, under thermal side effects generated by US discharge, undergo a softening or a melting covering the surface of the excipient surface. This thin amorphous film covering a highly hydrophilic carrier resulted into a notable increase of the dissolution rate with respect to the pure drug or its physical mixture with the selected excipient, as a further demonstration of the important physical modification of the compacted solids under US. As a continuation of this research line in this paper we examined the effects of ultrasound on the compaction of indomethacin with three lactose based excipients containing anhydrous beta-Lactose. Physical mixtures were prepared containing Indomethacin and beta-Lactose, Ludipress and Cellactose, widely used in pharmaceutical technology and containing alfa-Lactose monohydrate. The mixtures were compacted under ultrasound (20,000 Hz), obtaining tablets, which were milled and sieved. Powders thus obtained were examined by optical microscopy, IR spectrometry and differential scanning calorimetry. The intense yellow colour of the final powders and the absence of indomethacin peak in thermograms suggest important modifications of indomethacin physical state; the drug thus modified appears to cover the excipient particles surface as a thin film, giving them a lustrous appearance. No influence of ultrasound was observed on phase transition concerning lactose. Dissolution profiles suggest an increased release of the drug from the formulation treated under ultrasound at high energy, with respect to a traditional compaction; while no difference could be evidenced among the three excipients, that however appear all suitable for this direct compression process under ultrasound.
Effect of ultrasound on the compaction of Indomethacin with lactose-containing excipients.
FINI, ADAMO;CAVALLARI, CRISTINA;ALBERTINI, BEATRICE;PASSERINI, NADIA;RODRIGUEZ, LORENZO
2004
Abstract
The effects of ultrasound, assisting the compaction of pharmaceutical mixtures, were examined in a variety of systems, coupling indomethacin, theophylline and ketoprofen with beta-cyclodextrin, Eudragit, PVP and PEG. In most cases the main effect observed was the amorphisaztion of the drug, which, under thermal side effects generated by US discharge, undergo a softening or a melting covering the surface of the excipient surface. This thin amorphous film covering a highly hydrophilic carrier resulted into a notable increase of the dissolution rate with respect to the pure drug or its physical mixture with the selected excipient, as a further demonstration of the important physical modification of the compacted solids under US. As a continuation of this research line in this paper we examined the effects of ultrasound on the compaction of indomethacin with three lactose based excipients containing anhydrous beta-Lactose. Physical mixtures were prepared containing Indomethacin and beta-Lactose, Ludipress and Cellactose, widely used in pharmaceutical technology and containing alfa-Lactose monohydrate. The mixtures were compacted under ultrasound (20,000 Hz), obtaining tablets, which were milled and sieved. Powders thus obtained were examined by optical microscopy, IR spectrometry and differential scanning calorimetry. The intense yellow colour of the final powders and the absence of indomethacin peak in thermograms suggest important modifications of indomethacin physical state; the drug thus modified appears to cover the excipient particles surface as a thin film, giving them a lustrous appearance. No influence of ultrasound was observed on phase transition concerning lactose. Dissolution profiles suggest an increased release of the drug from the formulation treated under ultrasound at high energy, with respect to a traditional compaction; while no difference could be evidenced among the three excipients, that however appear all suitable for this direct compression process under ultrasound.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.