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  • 1.
    Alhalaweh, Amjad
    et al.
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Kaialy, Waseem
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Buckton, Graham
    Department of Pharmaceutics, School of Pharmacy, University College London.
    Gill, Hardyal
    Chemistry and Drug Delivery Group, Medway School of Pharmacy, University of Kent.
    Nokhodchi, Ali
    Chemistry and Drug Delivery Group, Medway School of Pharmacy, University of Kent.
    Velaga, Sitaram
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Theophylline cocrystals prepared by spray drying: physicochemical properties and aerosolization performance2013Ingår i: AAPS PharmSciTech, ISSN 1530-9932, E-ISSN 1530-9932, Vol. 14, nr 1, s. 265-276Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The purpose of this work was to characterize theophylline (THF) cocrystals prepared by spray drying in terms of the physicochemical properties and inhalation performance when aerosolized from a dry powder inhaler. Cocrystals of theophylline with urea (THF-URE), saccharin (THF-SAC) and nicotinamide (THF-NIC) were prepared by spray drying. Milled THF and THF-SAC cocrystals were also used for comparison. The physical purity, particle size, particle morphology and surface energy of the materials were determined. The in vitro aerosol performance of the spray-dried cocrystals, drug-alone and a drug-carrier aerosol, was assessed. The spray-dried particles had different size distributions, morphologies and surface energies. The milled samples had higher surface energy than those prepared by spray drying. Good agreement was observed between multi-stage liquid impinger and next-generation impactor in terms of assessing spray-dried THF particles. The fine particle fractions of both formulations were similar for THF, but drug-alone formulations outperformed drug-carrier formulations for the THF cocrystals. The aerosolization performance of different THF cocrystals was within the following rank order as obtained from both drug-alone and drug-carrier formulations: THF-NIC > THF-URE > THF-SAC. It was proposed that micromeritic properties dominate over particle surface energy in terms of determining the aerosol performance of THF cocrystals. Spray drying could be a potential technique for preparing cocrystals with modified physical properties.

  • 2.
    Kaialy, Waseem
    et al.
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Alhalaweh, Amjad
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Velaga, Sitaram
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Nokhodchi, Ali
    University of Kent.
    Effect of carrier particle shape on dry powder inhaler performance2011Ingår i: International Journal of Pharmaceutics, ISSN 0378-5173, E-ISSN 1873-3476, Vol. 421, nr 1, s. 12-23Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    he aim of this study was to characterise the aerosolisation properties of salbutamol sulphate (SS) from dry powder inhaler (DPI) formulations containing different carrier products. The difference in the elongation ratio (ER) of the different carriers was highlighted. Different set of carriers, namely commercial mannitol (CM), commercial lactose (CL), cooling crystallised mannitol (CCM), acetone crystallised mannitol (ACM) and ethanol crystallised mannitol (ECM) were used and inspected in terms of size, shape, density, crystal form, flowability, and in vitro aerosolisation performance using Multi Stage Liquid Impinger (MSLI) and Aerolizer® inhaler device. Solid-state and morphological characterization showed that CM product was in pure β-form having particles with smaller ER (CM: ER = 1.62 ± 0.04) whereas ACM and ECM mannitol particles were in pure α form with higher ER (ACM: ER = 4.83 ± 0.18, ECM: ER = 5.89 ± 0.19). CCM product crystallised as mixtures of β-form and δ-form and showed the largest variability in terms of particle shape, size, and DPI performance. Linear relationships were established showing that carrier products with higher ER have smaller bulk density (Db), smaller tap density (Dt), higher porosity (P), and poorer flow properties. In vitro aerosolisation assessments showed that the higher the ER of the carrier particles the greater the amounts of SS delivered to lower airway regions indicating enhanced DPI performance. Yet, DPI performance enhancement by increasing carrier ER reached a “limit” as increasing carrier ER from 4.83 ± 0.18 (ACM) to 5.89 ± 0.19 (ECM) did not significantly alter fine particle fraction (FPF) of SS. Also, carrier particles with higher ER were disadvantageous in terms of higher amounts of SS remained in inhaler device (drug loss) and deposited on throat. Linear relationship was established (r2 = 0.87) showing that the higher the carrier ER the lower the drug emission (EM) upon inhalation. Moreover, poorer flowability for carrier products with higher ER is disadvantageous in terms of DPI formulation dose metering and processing on handling scale. In conclusion, despite that using carrier particles with higher ER can considerably increase the amounts of drug delivered to lower airway regions; this enhancement is restricted to certain point. Also, other limitations should be taken into account including higher drug loss and poorer flowability.

  • 3.
    Kaialy, Waseem
    et al.
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Alhalaweh, Amjad
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Velaga, Sitaram
    Luleå tekniska universitet, Institutionen för hälsovetenskap, Medicinsk vetenskap.
    Nokhodchi, Ali
    Chemistry and Drug Delivery Group, Medway School of Pharmacy, University of Kent.
    Influence of lactose carrier particle size on the aerosol performance of budesonide from a dry powder inhaler2012Ingår i: Powder Technology, ISSN 0032-5910, E-ISSN 1873-328X, Vol. 227, s. 74-85Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The purpose of this study was to evaluate the effect of carrier particle size on properties of dry powder and its effect on dry powder inhaler (DPI) performance. Commercial α-lactose-monohydrate, a commonly used carrier in DPI formulations, was carefully sieved to obtain different lactose size fractions, namely Lac A (90–125 μm), Lac B (63–90 μm), Lac C (45–63 μm), Lac D (20–45 μm), and Lac E (< 20 μm). The lactose samples were analysed in terms of size, shape, solid state, density, and flowability. Lactose particles were blended with budesonide (< 5 μm) powder to generate five different formulations. These formulations were then evaluated in terms of budesonide-lactose adhesion properties, drug content homogeneity, and in vitro aerosolisation performance. The results demonstrated that lactose samples with smaller particle volume mean diameter have higher amorphous lactose content, higher true density (linear, r2 = 0.9932), higher surface smoothness (linear, r2 = 0.8752), smaller angularity (linear, r2 = 0.921), smaller bulk density, higher porosity (linear, r2 = 0.914), poorer flowability, and higher specific surface area. In general, the smaller the lactose particles the smaller are the budesonide-lactose adhesion properties. Budesonide formulated with smaller lactose particles exhibited smaller aerodynamic diameter and higher amounts of budesonide were delivered to lower stages of the impactor indicating improved DPI aerosolisation performance. However, the use of lactose particles with smaller volume mean diameter had a detrimental effect on budesonide content homogeneity and caused an increase in the amounts of budesonide deposited on oropharyngeal region. Therefore, particle size of the lactose within dry powder inhaler formulations should be selected carefully. Accordingly, higher drug aerosolisation efficiency of lactose particles with smaller size may have to be balanced due to considerations of other disadvantages including poorer flowability, reduced formulation stability, higher potential side effects, and higher dose variability.

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