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Biomedical subjects

L Nikolić

Publications and source records attributed to L Nikolić.

At least 19 recordsLinked to original sources
PubMed1997

The influence of Eudragit type on the dissolution rate of acetylsalicylic acid from matrix tablets.

The effect of four Eudragits used as matrix substances on the physical characteristics of tablets and on the dissolution rate of acetylsalicylic acid has been investigated. The concentration of matrix substance necessary for achieving the appropriate effect of sustained release of acetylsalicylic acid (ASA) depends on the type of Eudragit used. For tablets prepared using Eudragit RS-100, Eudragit L-100-55 and Eudragit S-100, the acceptable dissolution rate of ASA was obtained with only 3% of polymer. In the case of Eudragit RL-100, to obtain the same effect, 10% of polymer was required. The dissolution data were evaluated on the basis of theoretical dissolution equations and by linear transformation of dissolution curves. The following mathematical models were employed: zero order equation, first order kinetics, Hixon-Crowell's cube root kinetics and diffusion model. The results indicated that the fitness of the kinetic model was dependent on the type of Eudragit used.

Acrylic Resins↗
PubMed1993

[Induction of labor using endocervical administration of dinoprost in post-term pregnancy].

The authors analyzed results of 295 labors induced with endocervical application of dinoprostin (152 term- and 143 postterm labors) in relation to 242 (125 term- and 117 postterm-) spontaneous labors. Delayed labor increases the occurrence of meconial amniotic fluid (21.96%:9.03% p < 0.01), and pathological and prepathological CTG records (23.85%: 11.97% p < 0.005). In addition, children show lower Apgar score (p < 0.001), and among them there are more hypertrophic (6.54%:2.53% p < 0.05), postterm (6.92%:0.0% p < 0.005), and dysmature children (11.92%:3.12% p < 0.01) when compared to children born between the days 274 and 287 of the gestational age. Perinatal morbidity of children born after 287 gestational days in rather high-32.31%. Induction of labor with endocervical application of prostine shortens the duration of the labor (p < 0.001). Large numbers of labors are finished with vacuum extraction-3.73% (3.29% of term- and 4.19% of postterm labors) and cesarear section-12.88% (10.53% of term- and 15.38% of postterm labors) usually due to dystocia of the uterus and hypoxion of the neonate. Labor trauma is the most usual trauma among perinatal problems of new born infants delivered by the induction with prostaglandins and high perinatal morbidity rate is due not only to the induction method but also to the incorrect assessment of the gestational age.

Adolescent↗
PubMed1992

Influence of in vitro test conditions on release of aspirin from commercial tablets.

The influence of in vitro test conditions on the release of aspirin from commercial tablets was assessed with a USP rotating-basket dissolution apparatus. Three types of aspirin tablets were evaluated: plain, buffered, and microencapsulated. The variables investigated were stirring speed, pH, and volume and temperature of the dissolution medium. Plain tablets gave the best dissolution profiles under all experimental conditions, except at pH 3. Microencapsulated tablets showed sustained release. For all three types of tablets, faster dissolution was observed at pH 4.5 compared with that in artificial gastric juices. Increasing the stirring rate increased the dissolution rate, an effect most pronounced for plain tablets. Very similar dissolution curves were obtained when the dissolution test was conducted in 500 and 900 mL of dissolution media regardless of the pH of the media. No significant difference in dissolution profiles was observed when the effect of temperature was investigated. The dissolution data were evaluated on the basis of theoretical dissolution equations and by linear transformation of dissolution curves. Highly significant linear correlation coefficients revealed that the cube root equation could be used to describe drug release in artificial gastric juices, regardless of tablet type. When pH 4.5 buffer solution was used as the dissolution medium, different kinetic models were applicable.

Aspirin↗
PubMed1992

[Breech presentation terminated by cesarean section].

The prospective study was carried out in 86 mothers and their newborns born in breech presentation; 41 were delivered by cesarean section, 45 vaginally. The incidence of prepathologic and pathologic CTGs was rather high in both groups (34.14% and 24.34%) as well as the presence of meconium in the amniotic fluid (34.15% and 22.22%). The infants delivered by cesarean section have significantly (p < 0.05) higher pH levels (7.28 +/- 0.068) than those delivered vaginally (7.25 +/- 0.093). The acidosis incidence (pH +/- 7.20) is significantly (p < 0.01) lower in the first (9.76%) than in the second (26.66%) group. In the early neonatal period 24.35% of the children in the first group and 35.55% of the children in the second group developed a disease (p < 0.05). The difference in the morbidity rate can also be found in the fact that in the studied group no intracranial hemorrhage was diagnosed while in the control group it was found in 17.77% of the children. Manifest cerebral disfunction syndrome was detected in 2.44% of the children delivered by cesarean section and in 8.88% of the children delivered vaginally. One child (2.22%) delivered with manual help has died. The morbidity of the mothers was significantly (p < 0.05) higher in women who gave birth abdominally (17.68%) than in those who gave birth vaginally (8.88%).

Apgar Score↗
PubMed1992

[Risks for neonates born in the breech presentation].

A prospective study included 106 females and their newborns, 45 of them born in breech presentation and 61 delivered normally. The incidence of prepathologic and pathologic CTG records and meconial amniotic fluid is significant (0.01), more frequent in breech presentation (24.44% and 22.2%) than in normal deliveries (8.20% and 9.84%). Children born in breech presentation have significantly (p < 0.005) lower Apgar score values after the 1st and 5th minute than the control children. Infants born in breech presentation have significantly (p < 0.01) lower pH values (7.25 +/- 0.093) than those delivered normally (7.30 +/- 0.056). The acidosis incidence (pH < 7.20) in the studied group was 26.66% and 3.38% in the control group. In early neonatal period the disease occurred in 35.55% of the breech presentation group and 9.83% of the normal group (p < 0.01). In the control group there was no intracranial hemorrhages and manifest cerebral disfunction--complications most frequently involved in perinatal morbidity of children born in breech presentation (17.77% and 8.88%). One (2.22%) child born in breech presentation died in the early neonatal period.

Breech Presentation↗
PubMed1984

Ocular cicatricial pemphigoid associated with hyperproliferation of the conjunctival epithelium.

We determined the mitotic rate, measured by evaluating uptake of tritiated thymidine autoradiographically, and the frequency of goblet cells in conjunctival epithelial biopsy specimens from nine normal subjects and from 11 patients (seven women and four men ranging in age from 50 to 80 years) with ocular cicatricial pemphigoid. The mitotic rate of patients with the disease was significantly higher than that of normal subjects, 7.2 +/- 2.2 vs 1.6 +/- 0.2 labeled cells per 100 basal epithelial cells (P less than .01). The goblet cell frequency, however, was significantly less in patients than in normal subjects. This suggests that ocular cicatricial pemphigoid is associated with hyperproliferation of the conjunctival epithelium, with a concurrent failure of normal conjunctival differentiation.

Aged↗