Biomedical subjects

T Govender

Publications and source records attributed to T Govender.

24 records · Page 2Linked to original sources

PubMed1987

A study of erythrocyte insulin receptors in normal Indian and African volunteers.

125I-insulin binding to erythrocytes were compared between 19 Indian and African healthy volunteers matched for age, sex and body mass index. There were no significant differences in 125I-insulin binding between Indians and Africans (maximum specific binding 9.13 +/- 0.52% and 8.74 +/- 0.51% respectively, p = 0.29). However, when 125I-insulin binding was compared between 16 males and females matched for age and body mass index, the males had significantly higher specific binding than the females (maximum specific binding 9.8 +/- 0.6% and 7.9 +/- 0.4% respectively, p less than 0.01). This difference in binding was due to a lower receptor number in females as evidence by Scatchard analysis; ID50 values revealed similar receptor affinities. In conclusion, while there is no difference in receptor binding between Indians and Africans, males have significantly higher specific binding than females.

Adult↗

PubMed1986

The insulin and glucose response to an oral glucose load in non-insulin-dependent diabetes in the young. A study of 4 families.

Four Indian families with three-generation transmission of non-insulin-dependent diabetes were studied. Only 30% of the siblings were diabetic. The mean age of onset of diabetes was 20,1 years; 25% of the diabetics were obese, while all non-diabetic family members were of normal weight. All consenting living family members (12 diabetics and 16 non-diabetics) were subjected to an oral glucose tolerance test. After glucose administration, the 12 diabetics displayed a delayed and attenuated insulinaemic response. The area under the insulin curve and the insulin-glucose ratio were lower in the diabetics.

Adolescent↗

PubMedDate not supplied

In vitro characterization of a controlled-release chlorpheniramine maleate delivery system prepared by the air-suspension technique.

Non-pareil cores were spray-coated with a chlorpheniramine maleate (an alkylamine antihistamine) layer and a Eudragit NE30D overcoat in a Wurster air-suspension apparatus. In vitro dissolution studies demonstrated that drug release was a function of polymer membrane thickness. Polyethylene glycol 6000, as a hydrophillic additive, increased the in vitro release of chlorpheniramine maleate from the pellets. Pellets coated with 8.30% Eudragit NE30D, 0.50% talc and 1.00% polyethylene glycol 6000 were found to display desirable controlled release characteristics for chlorpheniramine maleate over the 8-h testing period, which were also comparable with that of Dykatuss capsules. The controlled release pellets exhibited first-order release characteristics for chlorpheniramine maleate. Reproducibility of the manufacturing conditions employed in the study were confirmed thus ensuring reproducibility of drug release characteristics between batches of chlorpheniramine maleate pellets. Drug release from the pellets was shown to be independent of the dissolution method and medium used. Pellets displayed no significant change in drug release characteristics relative to the initial drug release data when stored for 12 weeks at room temperature (20 +/- 2 degrees C) and for 8 weeks at a low temperature (5 +/- 1 degrees C). However, pellets stored at 37 degrees C with 80% relative humidity and at 40 +/- 2 degrees C showed a slower in vitro drug release after 8-week storage and therefore failed to maintain their initial drug release profile.

Capsules↗

PubMedDate not supplied

Formulation and preparation of controlled release pellets of salbutamol by the air suspension technique.

A controlled release preparation of salbutamol may improve patient compliance, minimise side effects and be valuable in the treatment of nocturnal asthma by extending drug action throughout the night. The aim of the study was therefore to formulate a controlled release pellet preparation of salbutamol via the air suspension technique. The study established that curing for 24 h at 38 +/- 0.5 degrees C was necessary for homogeneous film coats of Eudragit RS30D and hence stable drug release characteristics. Pellets coated with 6% Eudragit RS30D (polymer), 12.5% triethyl citrate (plasticiser) and 0.5% magnesium stearate (antitackiness agent) displayed desirable controlled drug release characteristics over the 8 h testing period. The manufacturing conditions employed in the study were shown to be reproducible thus ensuring reproducibility of drug release characteristics between batches of salbutamol controlled release pellets. Short term stability testing on the newly formulated pellets indicated no significant change in drug release characteristics relative to the initial drug release data when stored for 8 weeks at room temperature 20 +/- 2 degrees C or 37 degrees C with 80% Relative Humidity or at low temperature (5 +/- 1 degrees C). However, pellets stored at 40 degrees C showed a slower in-vitro drug release after 8 weeks of storage and therefore failed to maintain their initial drug release profile.

Adrenergic beta-Agonists↗

PubMedDate not supplied

Microencapsulated Eudragit RS30D-coated controlled-release pellets: the influence of dissolution variables and topographical evaluation.

The air suspension technique was employed to prepare Eudragit RS30D-coated controlled-release pellets of salbutamol. Drug release in dissolution studies can be dependent on the dissolution method and medium used. Thus, the aim of this study was to investigate the influence of various dissolution methods and dissolution medium pH values on drug release from a batch of pellets which displayed controlled drug-release characteristics over an 8-h period in deionized water using the rotating basket method. In vitro testing using the official USP XXII (rotating basket and rotating paddle) and non-official (rotating bottle) methods showed drug release to be independent of the method used. The prepared pellets displayed pH-dependent drug-release characteristics when tested in hydrochloric acid (pH 1.5), phosphate buffer (pH 6.8) and deionized water (pH 7.2). Also, in vitro testing, which exposed the pellets to a changing pH gradient that simulated the gastrointestinal pH conditions following oral administration, was used to confirm the drug-release characteristics. The results showed controlled-release characteristics to be maintained, with the drug being released over an 8-h period. Scanning electron microscopic evaluation proved useful in the elucidation of the physical characteristics of the controlled-release pellets as well as in the identification of a possible mode of drug transfer into the dissolution medium.

Acrylic Resins↗

PubMedDate not supplied

Ionotropic gelation: encapsulation of indomethacin in calcium alginate gel discs.

Ionotropic gelation by divalent metal interaction was employed as an approach to design a modified release multiple-unit oral drug-delivery system. This process was achieved by crosslinking an indomethacin-sodium alginate dispersion with calcium ions to induce the spontaneous formation of indomethacin-calcium alginate gel discs. A significant part in the validation of the integrity of the system, involved a preformulatory stage for the optimization of the curing conditions and potency determination of the gel discs. A three-phase approach was developed to establish the critical curing parameters. Since curing involved crosslinking of the sodium alginate with calcium ions, an optimal concentration of calcium chloride (phase one) and crosslinking reaction-time (phase two) had to be determined. Furthermore, the third phase involved the optimization of the air-drying time of the gel discs. In phases one and two, stabilization of in vitro drug-release characteristics was used as the marker of optimal crosslinking efficiency. Phase three was based on achieving fully dried gel discs by drying to constant weight at 21 degrees C under an extractor. The study revealed that optimal crosslinking efficiency was achieved in 1%w/v calcium chloride solution for 24 h and air-dried at 21 degrees C under an extractor for 48 h. The three solvent/solution systems investigated for their ability to liberate completely the drug from the matrix system were methanol, sodium citrate (1%w/v) and phosphate buffer pH 6.2. Phosphate buffer provided optimal drug removal, in addition to its ability to induce swelling of the calcium alginate gel discs. Furthermore, drug loading also increased with the use of increasing concentrations of sodium alginate in the formulations.

Administration, Oral↗