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J Van der Veen

Publications and source records attributed to J Van der Veen.

9 recordsLinked to original sources
PubMed1994

Controlled release of theophylline monohydrate from amylodextrin tablets: in vitro observations.

Amylodextrin is a linear dextrin and can be produced by enzymatic hydrolysis of the alpha-1,6 glycosidic bonds of amylopectin. Tablets compacted from pure amylodextrin showed good binding properties and did not disintegrate in aqueous media. Extended and decreasing drug release rates were found for tablets of 300 mg with a diameter of 9 mm containing 70% amylodextrin and 30% theophylline monohydrate, when compacted at 5 kN. Almost-constant drug release rates were obtained for these tablets when compacted at 10 or 15 kN. Nearly constant drug release rates were also shown for amylodextrin tablets with a drug load up to 75% compacted at 10 kN. Both release rate and release profile could be adjusted by selecting tablet thickness and incorporation of either lactose as a highly soluble excipient or talc as a hydrophobic excipient.

Chemical Phenomena↗
PubMed1976

Comparison of replication of adenovirus type 2 and type 4 in human lymphocyte cultures.

Adenovirus type 2 was capable of replicating in purified lymphocyte cultures from human adenoid specimens. Phytohemagglutinin stimulation enhanced the replication of virus. Viral titers of 103 to 104 50% tissue culture infective doses per ml were reached after 4 to 8 days. Only 1 to 3 per 106 cells were found to produce virus. In contrast, there was no evidence that lymphocyte cultures could support the replication of adenovirus type 4. The life span of cultures infected with type 2 or 4 was not reduced. The possibility that lymphocytes infected with virus play a role in initiating natural, persisting adenovirus infections of human adenoids is discussed.

Adenoids↗
PubMedDate not supplied

Particulate matter determination in LVPs produced in Dutch hospital pharmacies. Part 2: Overview of the results.

The Laboratory of Dutch Pharmacists determines LVP particulate matter contamination of LVPs produced in Dutch hospital pharmacies. The investigated LVPs must conform to the NVZA/LNA criteria, which prescribes eight samples and sets limits for particles > or = 2 microns, > or = 5 microns, > or = 10 microns, and > or = 25 microns for both mean and mean + 2x standard deviation. LVPs produced in 500 mL glass containers or plastic containers mostly met the NVZA/LNA criteria, but LVPs produced in 100 mL glass containers showed higher levels of particulate matter contamination. The composition of the LVP significantly affected the extent of particulate matter contamination, but the effect was relatively small when compared to the influence of the type of container. LVPs produced in Dutch hospital pharmacies and LVPs obtained from pharmaceutical industries showed comparable amounts of particulate matter contamination.

Drug Contamination↗
PubMedDate not supplied

Role of mycoplasmas in chronic prostatitis.

In 17 out of 102 patients with clinically diagnosed chronic prostatitis the disease could be attributed to known urogenital tract pathogens. Of the remaining 85 patients, Ureaplasma urealyticum was isolated from 38, Chlamydia trachomatis from five, and both organisms together from two. The results of antimicrobial treatment of the patients suggest an etiological relationship between Ureaplasma urealyticum and certain cases of chronic prostatitis. In these cases urethritis seems to be an accompanying symptom (urethro-prostatitis). No relation could be demonstrated between a favorable outcome of therapy and particular serotypes of ureaplasma. Our study could not establish any pathogenic role for Mycoplasma hominis.

Adolescent↗
PubMedDate not supplied

Particulate matter determination in LVPs produced in Dutch hospital pharmacies, Part 1: Particle-counting accuracy.

Reproducible particle counting using the light-obscuration technique is often troublesome because no absolute standard is available. Therefore, at the Laboratory of Dutch Pharmacists the "calibration-in-time" method was developed. This method enables checking of the amount of particles counted from a diluted latex suspension as a function of time. A particularity of the method is the one-step dilution procedure. The calibration-in-time method is compared with the particle-counting accuracy test according to the USP < 788 >. Advantages and disadvantages of both methods are discussed.

Calibration↗