Marcel Hoppentocht | University of Groningen (original) (raw)
Papers by Marcel Hoppentocht
European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft für Pharmazeutische Verfahrenstechnik e.V, 2014
Dry powder formulations for inhalation have to be screened in animal studies for therapeutic effi... more Dry powder formulations for inhalation have to be screened in animal studies for therapeutic efficacy and safety aspects and both are significantly affected by the dose and the particle size distribution (PSD) of the aerosol that is given. One of the most frequently used apparatus for pulmonary delivery of dry powder formulations in mice studies is the PennCentury DP-4M Dry Powder Insufflator. To make researchers of future preclinical animal studies with the DP-4M insufflator aware of the pitfalls regarding the conclusions to be drawn from their data, we investigated the dispersion behaviour by the DP-4M insufflator using two to three different powder preparation techniques for four different compounds. The primary PSDs of the different formulations were determined in duplicate by laser diffraction analysis. To measure the PSDs of the aerosols obtained with the DP-4M insufflator, the same diffractometer was used in combination with an in-house constructed adapter for the insufflator...
European Journal of Pharmaceutics and Biopharmaceutics, 2014
Inhaled antibiotics have been a valuable tool in treating pulmonary infections in cystic fibrosis... more Inhaled antibiotics have been a valuable tool in treating pulmonary infections in cystic fibrosis patients for decades, and the pulmonary route is now becoming increasingly interesting for other infectious diseases like tuberculosis too. Especially with multidrug and extensively drug-resistant tuberculosis emerging, great effort is put into the improvement of pulmonary antibiotic administration to fight this global threat. Several reviews have been written on inhalable antibiotics, giving clear overviews of the compounds of interest. Furthermore, various formulation studies and administration strategies are on-going with these compounds. What is often missing is a critical evaluation of these developments. Several risks may be involved varying from obtaining insufficient local drug concentrations to adverse side effects and unwanted changes in physiological processes from the excipients used. In this manuscript, the pros and cons and feasibility of recent advances in pulmonary antibiotic tuberculosis therapy are presented and critically evaluated. Furthermore, the advantages of dry powder inhalation over wet nebulisation for inhaled antibiotics in developing countries where prevalence of tuberculosis is highest are discussed. It has to be concluded that a greater effort in good inhaler development and more research in the physicochemical properties of the compounds of interest are needed.
Advanced Drug Delivery Reviews, 2014
a b s t r a c t a r t i c l e i n f o
European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft für Pharmazeutische Verfahrenstechnik e.V, 2015
Patients infected with pathogenic bacteria have to be treated with antibiotics. When the infectio... more Patients infected with pathogenic bacteria have to be treated with antibiotics. When the infection is in the lungs, as for instance in cystic fibrosis, bronchiectasis and tuberculosis, inhaled antibiotics have certain advantages over systemically administered antibiotics. In this study, it is shown that re-designing the Twincer™ high dose disposable inhaler into a device named Cyclops enables effective dispersion of up to 50mg of pure spray dried tobramycin. This proves that spray dried tobramycin powders in the preferred size range for inhalation can be administered without applying complex particle engineering techniques and/or using excipients. Only some coarse sweeper crystals added separately are desired to minimise the inhaler losses to less than 20% at 4kPa. The fine particle fractions <5μm of the aerosol obtained from the Cyclops closely resemble the primary particle size distribution of the spray dried tobramycin powder. Moreover, without any further optimisation the Cyc...
European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft für Pharmazeutische Verfahrenstechnik e.V, 2014
Dry powder formulations for inhalation have to be screened in animal studies for therapeutic effi... more Dry powder formulations for inhalation have to be screened in animal studies for therapeutic efficacy and safety aspects and both are significantly affected by the dose and the particle size distribution (PSD) of the aerosol that is given. One of the most frequently used apparatus for pulmonary delivery of dry powder formulations in mice studies is the PennCentury DP-4M Dry Powder Insufflator. To make researchers of future preclinical animal studies with the DP-4M insufflator aware of the pitfalls regarding the conclusions to be drawn from their data, we investigated the dispersion behaviour by the DP-4M insufflator using two to three different powder preparation techniques for four different compounds. The primary PSDs of the different formulations were determined in duplicate by laser diffraction analysis. To measure the PSDs of the aerosols obtained with the DP-4M insufflator, the same diffractometer was used in combination with an in-house constructed adapter for the insufflator...
European Journal of Pharmaceutics and Biopharmaceutics, 2014
Inhaled antibiotics have been a valuable tool in treating pulmonary infections in cystic fibrosis... more Inhaled antibiotics have been a valuable tool in treating pulmonary infections in cystic fibrosis patients for decades, and the pulmonary route is now becoming increasingly interesting for other infectious diseases like tuberculosis too. Especially with multidrug and extensively drug-resistant tuberculosis emerging, great effort is put into the improvement of pulmonary antibiotic administration to fight this global threat. Several reviews have been written on inhalable antibiotics, giving clear overviews of the compounds of interest. Furthermore, various formulation studies and administration strategies are on-going with these compounds. What is often missing is a critical evaluation of these developments. Several risks may be involved varying from obtaining insufficient local drug concentrations to adverse side effects and unwanted changes in physiological processes from the excipients used. In this manuscript, the pros and cons and feasibility of recent advances in pulmonary antibiotic tuberculosis therapy are presented and critically evaluated. Furthermore, the advantages of dry powder inhalation over wet nebulisation for inhaled antibiotics in developing countries where prevalence of tuberculosis is highest are discussed. It has to be concluded that a greater effort in good inhaler development and more research in the physicochemical properties of the compounds of interest are needed.
Advanced Drug Delivery Reviews, 2014
a b s t r a c t a r t i c l e i n f o
European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft für Pharmazeutische Verfahrenstechnik e.V, 2015
Patients infected with pathogenic bacteria have to be treated with antibiotics. When the infectio... more Patients infected with pathogenic bacteria have to be treated with antibiotics. When the infection is in the lungs, as for instance in cystic fibrosis, bronchiectasis and tuberculosis, inhaled antibiotics have certain advantages over systemically administered antibiotics. In this study, it is shown that re-designing the Twincer™ high dose disposable inhaler into a device named Cyclops enables effective dispersion of up to 50mg of pure spray dried tobramycin. This proves that spray dried tobramycin powders in the preferred size range for inhalation can be administered without applying complex particle engineering techniques and/or using excipients. Only some coarse sweeper crystals added separately are desired to minimise the inhaler losses to less than 20% at 4kPa. The fine particle fractions <5μm of the aerosol obtained from the Cyclops closely resemble the primary particle size distribution of the spray dried tobramycin powder. Moreover, without any further optimisation the Cyc...