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Biomedical subjects

S Galal

Publications and source records attributed to S Galal.

10 recordsLinked to original sources
PubMed2006

Towards a universal dissolution medium for carbamazepine.

The aim of this study was to develop a dissolution medium for assessment of various carbamazepine (CBZ) formulations with different strengths. The design of a system inhibiting transformation of the anhydrous CBZ (CBZ A) to the dihydrate form (CBZ D), with minimum surface-active properties and suitable sink was investigated. The effect of pH, different concentrations of sodium lauryl sulphate (SLS), polyvinylpyrrolidone (PVP), and methyl cellulose (MC) on dissolution rate, solubility, dissolution solubility, and polymorphic transformation of CBZ was assessed. Solution-mediated transformation of CBZ A into CBZ D was monitored using optical microscopy, Fourier transform infrared spectroscopy and differential scanning calorimetry. Results showed that different strengths (100, 200, 400 mg) of the same CBZ tablet formulation exhibited different dissolution patterns, in 1% SLS (USP system). Such differences were reduced in 0.5% SLS solution which provided sufficient sink for up to 200 mg CBZ. It was also shown that solubility of CBZ A could not be detected in the media under study (water, SGF, SIF, and SLS solutions) due to its rapid transformation into CBZ D. The use of 3% PVP solution protected CBZ A from conversion for 75 min, while 0.01% MC completely inhibited the transformation up to 24 h. Therefore, a medium consisting of 0.5% SLS and 0.01% MC was selected. The medium provided: a) protection against transformation of CBZ A to CBZ D, b) increased solubility of CBZ A (204 mg % compared to 128 mg % of CBZ D in 0.5% SLS), c) suitable sink for up to 400 mg CBZ and d) overlapping dissolution profiles of various strengths of the same CBZ formulation. The suggested system may be a step in the way of solving CBZ dissolution problems that forced the USP to specify two similar dissolution tests with two different limits for conventional 200 mg CBZ tablets.

Carbamazepine↗
PubMed2004

Study of in-vitro release characteristics of carbamazepine extended release semisolid matrix filled capsules based on Gelucires.

Various extended release carbamazepine (CBZ) formulations have been developed previously, in order to reduce the frequency of dosing in chronic therapy and to decrease the variability in drug plasma concentration. In the present study, the suitability of different grades of Gelucires (G, glyceride based excipients) to formulate CBZ extended release capsules by the application of semisolid matrix (SSM) filling capsule technology was investigated. The possible modification of CBZ release kinetics by using Gelucire blends or inclusion of hydrophilic additives in the SSM was studied. The effect of ageing on some selected formulations was also evaluated, using scanning electron microscopy and differential thermal analysis. Twenty-one capsule formulations were prepared and assessed for their release characteristics. The mechanism of drug release from the test formulations was studied. The following results were obtained: a) Release data could not be correlated to the melting point (mp) of Gelucires used, pointing to relative lipophilicity of the base as a more important determinant of drug release. Among Gelucire grades having melting points higher than 37 degrees C, the release rate proved to be highly dependent on the HLB value and matrix composition. b) CBZ release occurred by different mechanisms, including matrix disintegration, diffusion and or erosion depending on the vehicle employed. c) Zero order release profiles of CBZ were obtained from SSM-based on G50/13, G53/10 and their blends in ratios higher than 1:1 and G53/10 containing croscarmellose sodium. d) The ageing study revealed that these latter formulations, except those based on G50/13, also showed high dissolution stability during one year of shelf ageing. e) PVP, as a polymorphic transformation inhibitor, can be used to reduce the storage-induced changes of some grades of Gelucires. From the above data, it can be concluded that different grades of Gelucires and their blends as well as hydrophilic additives could be successfully used to formulate CBZ extended release SSM filled capsules with various release kinetics.

Capsules↗
PubMed2003

Semisolid matrix filled capsules: an approach to improve dissolution stability of phenytoin sodium formulation.

Seven semisolid fill bases were selected for the formulation of 24 capsule formulations, each containing 100 mg of phenytoin sodium. The fill materials were selected based on the water absorption capacity of their mixtures with phenytoin sodium. The fill matrices included lipophilic bases (castor oil, soya oil, and Gelucire (G) 33/01), amphiphilic bases (G 44/14 and Suppocire BP), and water-soluble bases (PEG 4000 and PEG 6000). The drug:base ratio was 1:2. Excipients such as lecithin, docusate sodium, and poloxamer 188 were added to some formulations. The dissolution rate study indicated that formulations containing lipophilic and amphiphilic bases showed the best release profiles. These are F4 (castor oil-1% docusate sodium); F10 (castor oil-3% poloxamer 188); F14 (G33/01-10% lecithin); F17 (G33/01-1% docusate sodium), and F20 (Suppocire BP). Further, the dissolution stability of the five formulations above was assessed by an accelerated stability study at 30 degrees C and 75% RH using standard Epanutin capsules for comparison. The study included the test and standard capsules either packed in the container of marketed Epanutin capsules (packed) or removed from their outer pack (unpacked). Release data indicated superior release rates of castor oil based formulations (F4 and F10) relative to standard capsules in both the unpacked and packed forms. For instance, the extent of drug release at 30 min after 1 month was 91% for F4 and F10 and 20% for standard capsules. Drug release from packed capsules after 6 months storage was 88% for both formulations F4 and F10 and 35% for standard capsules. In conclusion, the pharmaceutical quality of phenytoin sodium capsules can be improved by using a semisolid lipophilic matrix filled in hard gelatin capsules.

Alkalies↗
PubMed2001

Infections in children under 5 years old and latrine cleanliness.

The aim of this study is to assess the cleanliness of the latrine and its relation to occurrence of disease in children under 5 years old. A stratified random sample of 1327 households was conducted in 11 villages in Upper Egypt. It included a sub-sample of 541 children under 5 years living in households with latrines. The latrine cleanliness was assessed and its relationship to disease occurrence within a period of 2 weeks. Thirty-three percent (33.1%) of children under 5 years old with latrines in their household had infections, compared to 28.3% of those without latrines in the house. Infection with diarrhoea was found most in houses with latrine and water tap. A relation was found between latrine cleanliness score and presence of flies, house building material and maternal education, but none with occurrence of infection in children under 5 years old within a period of 2 weeks.

Child Welfare↗
PubMed1990

Specialization preference and attitude of medical students in Cairo within the primary health care context.

This cross-sectional study investigates specialization preference of medical students in Cairo, Ain Shams and El-Azhar Medical Schools using a stratified systematic random sample of 428 students and house officers (199 females and 229 males). They represent 5% of all second, fifth year students and house officers from all three universities. In addition 31 female students of El-Azhar were followed up to the final year and house officer year. The aim of the study is to compare students specialization preference with PHC needs. The questionnaire used comprised besides demographic data like age, sex, origin, maternal and paternal education and occupation also factors influencing the specialization preference like motive for choosing medical education, lecturer's personality, subject content, future location and setting intention. The distribution of specialization preference was found significantly different with educational year, sex, maternal education and occupation, father's occupation, socioeconomic standard, reason for choosing medical study and content attraction of the subject. Major subjects like surgery, medicine and gynaecology and obstetric were preferred significantly more by males, students with non-medical fathers, of lower SES, those who choose medicine for prestige and help of people, and who were attracted by the content of subject, while vis versa for pediatric and other specializations like cardiology, ophthalmology, clinical pathology and psychiatry among others. The follow-up study indicated that female students of El-Azhar tended to gynaecology and obstetric (from 32.3% to 42.1%) orienting themselves toward community needs being themselves to 34.1% from rural areas. The multiple regression analysis indicated that the best subset of variables influencing specialization preference are SES, maternal education, study reason, father occupation, sex, future setting and location. Students preferences are far from the PHC needs.

Adolescent↗
PubMed1989

Study of serum copper and zinc in cases of hyperemesis gravidarum.

The dehydration, electrolyte and metabolic changes which occur in hyperemesis gravidarum are well recognized. The aim of this paper was to study the changes in serum copper and zinc and their correlation with the changes in serum electrolytes that occur in patients with hyperemesis gravidarum. Serum copper, zinc, sodium and potassium and urinary chloride were measured in 30 patients suffering from hyperemesis gravidarum and compared to the levels in 10 normal pregnant women in their first trimester. There was no significant change in serum copper or zinc in patients with hyperemesis compared to normal pregnant women. Also, there was no significant correlation between the changes in the level of these trace elements and the decrease which occurred in serum sodium and potassium and urinary chloride.

Chlorides↗
PubMed1980

Effect of aspirin on gastric acid secretion in the rat.

The effects of aspirin on gastric acid and sodium have been studied in a perfused rat stomach preparation. In the pentagastrin-stimulated stomach, as intraluminal aspirin concentration increased, there was a significant fall in acid output together with a significant decrease in the loss of sodium from the gastric lumen. It was concluded that these observations were due to a back-diffusion effect resulting from disruption of the gastric mucosal barrier rather than parietal cell inhibition

Animals↗