In vitro uptake and release studies of ocular pharmaceutical agents by silicon-containing and p-HEMA hydrogel contact lens materials

In vitro uptake of 67Ga-citrate and 59Fe-citrate by DS sarcoma cells in the presence of tumor-bearing animal blood plasma showed a dramatic inhibition of both 67Ga and 59Fe uptakes: about ii/io of 67Ga and 1/5o of the 59Fe are taken up by the cells. Subcellular fractionation appears to indicate no specific binding to cell structures, and the difference of binding seems to be related to the transferrin chelation and transmembrane transport differences

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IN VITRO UPTAKE OF TRITIATED OESTRADIOL BY THE ANTERIOR HYPOTHALAMUS AND HYPOPHYSIS OF THE RAT

Acta Endocrinologica ◽

10.1530/acta.0.0640687 ◽

1970 ◽

Vol 64 (4) ◽

pp. 687-695 ◽

Cited By ~ 10

Author(s):

Junzo Kato

Keyword(s):

Incubation Medium ◽

Posterior Hypothalamus ◽

Anterior Hypothalamus ◽

Ovariectomized Rats ◽

Free Medium ◽

Cortex Cerebri ◽

Anterior Hypophysis ◽

In Vitro Uptake

ABSTRACT The anterior, middle, and posterior hypothalamus, the cortex cerebri, the anterior hypophysis as well as the diaphragm of adult ovariectomized rats were incubated in vitro with tritiated 17β-oestradiol. The uptake of tritiated oestradiol was differentially distributed intracerebrally with higher accumulation in the anterior hypothalamus and the hypophysis. Lowering the temperature of the incubation medium caused a reduction in the uptake of radioactivity by the anterior hypothalamus as compared to that found in other brain tissues. Tritiated oestradiol taken up in vitro by the anterior hypothalamus and the hypophysis tended to be retained after further incubation in a steroid-free medium. The addition of non-radioactive 17β-oestradiol to the medium inhibited the uptake of tritiated oestradiol by these tissues. Moreover, pretreatment with non-radioactive 17β-oestradiol in vivo prevented the preferential accumulation of tritiated oestradiol in vitro in the anterior hypothalamus and the hypophysis. These results indicate that oestradiol is preferentially taken up in vitro by the anterior hypothalamus and the hypophysis of the rat.

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IN VITRO UPTAKE OF RADIOACTIVE 131I LABELLED L-TRIIODOTHYRONINE BY HUMAN ERYTHROCYTES AS AN INDEX OF THYROID FUNCTION

Acta Endocrinologica ◽

10.1530/acta.0.xxxiv0305 ◽

1960 ◽

Vol XXXIV (II) ◽

pp. 305-311 ◽

Cited By ~ 3

Author(s):

M. G. Woldring ◽

A. Bakker ◽

H. Doorenbos

Keyword(s):

Thyroid Function ◽

Incubation Time ◽

Clinical Results ◽

Human Erythrocytes ◽

Red Cell ◽

Clinical Value ◽

Blood Samples ◽

In Vitro Uptake

ABSTRACT The red cell triiodothyronine uptake technique as used in our hospital is described. Incubation time is of almost no importance. The temperature during incubation should be 37° C. Further improvement of the technique is obtained when all blood samples are brought up to 40 % haematocrit prior to incubation. Clinical results are discussed. It is yet too early to give a definite assessment of its clinical value, but it is definitely superior to the measurement of the BMR.

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Synthesis, Characterization and in-vitro drug release studies of a macromolecular prodrug of Didanosine.

International Journal of Drug Delivery Technology ◽

10.25258/ijddt.v2i2.8845 ◽

2010 ◽

Vol 2 (2) ◽

Author(s):

Neeraj Agrawal ◽

M.J. Chandrasekar ◽

U.V. Sara ◽

Rohini A.

Keyword(s):

Drug Release ◽

Drug Level ◽

Drug Release Profile ◽

Sustained Drug Release ◽

In Vitro Drug Release ◽

Alkaline Environment ◽

Stomach Acid ◽

Release Studies ◽

Macromolecular Prodrug

A macromolecular prodrug of didanosine (ddI) for oral administration was synthesized and evaluated for in-vitro drug release profile. Didanosine was first coupled to 2-hydroxy ethyl methacrylate (HEMA) through a succinic spacer to form HEMA-Suc-ddI monomeric conjugate which was subsequently polymerized to yield Poly(HEMA-Suc-ddI) conjugate. The structures of the synthesized compounds were characterized by FT-IR, Mass and 1H-NMR spectroscopy. The prodrug was subjected for in-vitro drug release studies in buffers of pH 1.2 and 7.4 mimicking the upper and lower GIT. The results showed that the drug release from the polymeric backbone takes place in a sustained manner over a period of 24 h and the amount of drug released was comparatively higher at pH 7.4 indicating that the drug release takes place predominantly at the alkaline environment of the lower GIT rather than at the acidic environment of the upper GIT. This pH dependent sustained drug release behavior of the prodrug may be capable of reducing the dose limiting toxicities by maintaining the plasma drug level within the therapeutic range and increasing t1/2 of ddI. Moreover, the bioavailability of the drug should be improved as the prodrug releases ddI predominantly in the alkaline environment which will reduce the degradation of ddI in the stomach acid.

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Ophthalmic optics. Contact lenses and contact lens care products. Guidelines for the determination of preservative uptake and release

10.3403/02381043u ◽

2015 ◽

Keyword(s):

Contact Lens ◽

Contact Lenses ◽

Uptake And Release

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Preparation and in vitro Evaluation of Bioadhesive Microparticulate System

International Journal of Pharmaceutical Sciences and Nanotechnology ◽

10.37285/ijpsn.2008.1.3.9 ◽

1970 ◽

Vol 1 (3) ◽

pp. 257-266

Author(s):

Nagda C. D. ◽

Chotai N. P. ◽

Patel S. B. ◽

Soni T. J ◽

Patel U. L

Keyword(s):

Drug Loading ◽

In Vitro Release ◽

Phenyl Acetic Acid ◽

Solvent Evaporation Method ◽

Elimination Half ◽

Release Studies ◽

Differential Scanning Colorimetry ◽

Polymer Interactions ◽

Vitro Release

Aceclofenac (ACE) is NSAIDs of a phenyl acetic acid class. It is indicated in arthritis and osteoarthritis, rheumatoid arthritis, ankylosing spondylitis. It has short elimination half life of 4 hours. The objective of the study is to design, characterize and evaluate bioadhesive microspheres of ACE employing carbopol (CP) as bioadhesive polymer. Bioadhesive microspheres of ACE were prepared by solvent evaporation method. The prepared microspheres were free flowing and spherical in shape and characterized for drug loading, mucoadhesion test, infrared spectroscopy (IR), differential scanning colorimetry (DSC) and scanning electron microscopy (SEM). The in-vitro release studies were performed using pH 6.8 phosphate buffer. The drug loaded microspheres in a ratio of 1:5 showed 47% of drug entrapment; percentage mucoadhesion was 81% and 89% release in 10 h. The infrared spectra and DSC showed stable character of aceclofenac in the drug loaded microspheres and revealed the absence of drug-polymer interactions. SEM studies showed that the microspheres are spherical and porous in nature. The in vitro release profiles from microspheres of different polymer-drug ratios followed Higuchi model.

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