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Theophylline Cocrystals Prepared by Spray Drying: Physicochemical Properties and Aerosolization Performance 总被引:1,自引:0,他引:1
Amjad Alhalaweh Waseem Kaialy Graham Buckton Hardyal Gill Ali Nokhodchi Sitaram P. Velaga 《AAPS PharmSciTech》2013,14(1):265-276
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.
Electronic supplementary material
The online version of this article (doi:10.1208/s12249-012-9883-3) contains supplementary material, which is available to authorized users.Key words: aerodynamic diameter, cocrystal, spray drying, surface energy, theophylline 相似文献3.
BACKGROUND: Morbidity management is a core component of the global programme for the elimination of lymphatic filariasis. In a double-blind clinical trial, the tolerability and efficacy of Daflon (500 mg) + DEC (25 mg) or DEC (25 mg) alone, twice daily for 90 days, was studied in 26 patients with bancroftian filarial lymphoedema. RESULTS: None of the patients in either drug group reported any adverse reaction throughout the treatment period (90 days). Haematological and biochemical parameters were within normal limits and there was no significant difference between the pre-treatment (day 0) and post-treatment (day 90) values. The group receiving Daflon showed significant reduction in oedema volume from day 90 (140.6 PlusMinus; 18.8 ml) to day 360 (71.8 PlusMinus; 20.7 ml) compared to the pre-treatment (day 0, 198.4 PlusMinus; 16.5 ml) value. This accounted for a 63.8% reduction in oedema volume by day 360 (considering the pre-treatment (day 0) as 100%). In the DEC group, the changes in oedema volume (between day 1 and day 360) were not significant when compared to the pre-treatment (day 0) value. The percentage reduction at day 360 was only 9%, which was not significant (P > 0.05). CONCLUSION: This study has shown that Daflon (500 mg, twice a day for 90 days) is both safe and efficacious in reducing oedema volume in bancroftian filarial lymphoedema. Further clinical trials are essential for strengthening the evidence base on the role of this drug in the morbidity management of lymphatic filariasis. 相似文献
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BACKGROUND: Macroorchidism in prepuberty is an uncommon condition which we hypothesised might reflect constitutive activation of the FSH receptor (FSHR). PATIENTS AND METHODS: Patient 1 was found to have macroorchidism (15 ml testicular volume) at the time of orchidopexy when 3.7 years of age. A gonadal biopsy was obtained at the time of surgery. Patient 2 developed macroorchidism (5 ml) when 8.8 years old. Despite a testicular volume >4 ml, morning testosterone levels were unrecordable with no measurable gonadotrophin production in either patient. Patient 2 had prepubertal gonadotrophin levels 3 years later despite a testicular volume that was 8 ml bilaterally. Inhibin B was measured and the FSHR sequenced in both patients. RESULTS: Inhibin B levels were age and pubertal stage appropriate. Gonadal biopsy (patient 1) demonstrated areas of Sertoli cell hyperplasia. Sequence analysis of all 10 exons of the FSHR was normal. There was significant, presumed gonadotrophin-dependent testosterone production in both boys by 15 years of age. CONCLUSIONS: The cause of prepubertal macroorchidism in our patients is unclear but the pronounced difference in phenotype suggests that there may be more than one underlying mechanism. This mechanism was not constitutive activation of a mutated FSHR. 相似文献
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Sampling properties of DNA sequence data in phylogenetic analysis 总被引:20,自引:6,他引:20
We inferred phylogenetic trees from individual genes and random samples of
nucleotides from the mitochondrial genomes of 10 vertebrates and compared
the results to those obtained by analyzing the whole genomes. Individual
genes are poor samples in that they infrequently lead to the whole-genome
tree. A large number of nucleotide sites is needed to exactly determine the
whole-genome tree. A relatively small number of sites, however, often
results in a tree close to the whole-genome tree. We found that blocks of
contiguous sites were less likely to lead to the whole-genome tree than
samples composed of sites drawn individually from throughout the genome.
Samples of contiguous sites are not representative of the entire genome, a
condition that violates a basic assumption of the bootstrap method as it is
applied in phylogenetic studies.
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Miguel Montenegro-Nicolini Patricio E. Reyes Miguel O. Jara Parameswara R. Vuddanda Andrónico Neira-Carrillo Nicole Butto Sitaram Velaga Javier O. Morales 《AAPS PharmSciTech》2018,19(8):3376-3387
The buccal mucosa appears as a promissory route for biologic drug administration, and pharmaceutical films are flexible dosage forms that can be used in the buccal mucosa as drug delivery systems for either a local or systemic effect. Recently, thin films have been used as printing substrates to manufacture these dosage forms by inkjet printing. As such, it is necessary to investigate the effects of printing biologics on films as substrates in terms of their physical and mucoadhesive properties. Here, we explored solvent casting as a conventional method with two biocompatible polymers, hydroxypropyl methylcellulose, and chitosan, and we used electrospinning process as an electrospun film fabrication of polycaprolactone fibers due to its potential to elicit mucoadhesion. Lysozyme was used as biologic drug model and was formulated as a solution for printing by thermal inkjet printing. Films were characterized before and after printing by mechanical and mucoadhesive properties, surface, and ultrastructure morphology through scanning electron microscopy and solid state properties by thermal analysis. Although minor differences were detected in micrographs and thermograms in all polymeric films tested, neither mechanical nor mucoadhesive properties were affected by these differences. Thus, biologic drug printing on films was successful without affecting their mechanical or mucoadhesive properties. These results open way to explore biologics loading on buccal films by inkjet printing, and future efforts will include further in vitro and in vivo evaluations. 相似文献
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The Kosi coastal lake system, a chain of four interconnected basins, is located in the subtropical north-eastern corner of South Africa. Little information is available on zooplankton of the system and the main aim of this study is to report on zooplankton samples collected during 2002 and 2003. The set of samples consists of seasonal, subsurface mesozooplankton samples that were collected during nighttime in each of the lakes. A well-developed salinity gradient was evident along the interconnected lakes in the subsurface water during all seasons, ranging from freshwater in the upper lake Amanzamnyama to a maximum of 22 recorded in Lake Makhawulani. The zooplankton community structures of the lakes reflected the salinity gradient of the system, with some coastal marine taxa recorded in the lakes closer to the mouth and only freshwater taxa recorded in Lake Amanzamnyama. Mesozooplankton diversity and abundance were relatively low compared to other estuarine systems along the eastern coast of South Africa. The dominant taxa were calanoid copepods Acartiella natalensis and Pseudodiaptomus stuhlmanni and the mysid Mesopodopsis africana in the lower lakes, whereas cyclopoids Mesocyclops sp. and Thermocyclops sp. dominated the freshwater lake Amanzamnyama. 相似文献
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Type IX collagen is a key component of the extracellular matrix of
cartilage where it occurs at the surfaces of type II collagen fibrils as a
glycanated molecule. The function of the glycosaminoglycan (GAG) side chain
of the molecule is, however, unknown. We have shown that type IX collagen
in chicken sternal cartilage is synthesized with a unimodal distribution of
GAG chain size, but at post 17 days of development three predominant
glycanforms of type IX collagen accumulate. Such accumulation did not occur
in sterna from day 15 embryos. In day 17 embryos predominant glycanforms
were found in the caudal region of the sternum. By day 19 of development
the three predominant glycanforms are widespread throughout the caudal and
cephalic regions. The results indicate that developmental and anatomical
changes occur to type IX collagen that depend on the size of the GAG chain
attached to the alpha2(IX) chain of the molecule.
相似文献