Synthesis, characterization, release kinetics and toxicity profile of drug-loaded starch nanoparticles.

The current research work focuses on the medical application of the cost-effective cross-linked starch nanoparticles, for the transdermal delivery using Diclofenac sodium (DS) as a model drug. The prepared DS-cross-linked starch nanoparticles were synthesized using nanoprecipitation technique at different concentrations of sodium tripolyphosphate (STPP) in the presence of Tween 80 as a surfactant. The resultant cross-linked starch nanoparticles loaded with DS were characterized using world-class facilities such as TEM, DLS, FT-IR, XRD, and DSc. The efficiency of DS loading was also evaluated via entrapment efficiency as well as in vitro release and histopathological study on rat skin. The optimum nanoparticles formulation selected by the JMP(®) software was the formula that composed of 5% maize starch, 57.7mg DS and 0.5% STPP and 0.4% Tween 80, with particle diameter of about 21.04nm, polydispersity index of 0.2 and zeta potential of -35.3mV. It is also worth noting that this selected formula shows an average entrapment efficiency of 95.01 and sustained DS release up to 6h. The histophathological studies using the best formula on rat skin advocate the use of designed transdermal DS loaded cross-linked starch nanoparticles as it is safe and non-irritant to rat skin. The overall results indicate that, the starch nanoparticles could be considered as a good carrier for DS drug regarding the enhancement in its controlled release and successful permeation, thus, offering a promising nanoparticulate system for the transdermal delivery non-steroidal anti-inflammatory drug (NSAID).

A novel photosynthesis of carboxymethyl starch-stabilized silver nanoparticles.

The water soluble photoinitiator (PI) 4-(trimethyl ammonium methyl) benzophenone chloride is used for the first time in the synthesis of silver nanoparticles (AgNPs). A new green synthesis method involves using PI/UV system, carboxymethyl starch (CMS), silver nitrate, and water. A mechanism of the reduction of silver ions to AgNPs by PI/UV system as well as by the newly born aldehydic groups was proposed. The synthesis process was assessed by UV-vis spectra and TEM of AgNPs colloidal solution. The highest absorbance was obtained using CMS, PI and AgNO3 concentrations of 10 g/L, 1 g/L, and 1 g/L, respectively; 40 °C; 60 min; pH 7; and a material : liquor ratio 1 : 20. AgNPs so-obtained were stable in aqueous solution over a period of three weeks at room temperature (~25 °C) and have round shape morphology. The sizes of synthesized AgNPs were in the range of 1-21 nm and the highest counts % of these particles were for particles of 6-10 and 1-3 nm, respectively.

Antimicrobial wound dressing and anti-inflammatory efficacy of silver nanoparticles.

Powdered silver nanoparticles (AgNPs) were successfully prepared through addition of AgNO3 to alkali dissolved starch followed by precipitation with ethanol. AgNPs aqueous suspensions were prepared from powder AgNPs by dispersion and dilution with water. Wound dressings were obtained by treating cotton fabrics with different concentrations of AgNPs aqueous suspensions (60, 125 and 250 ppm). The as prepared AgNPs were characterized using UV-vis spectroscopy, transmission electron microscopy (TEM), particle size analyzer, polydispersity index (PdI), zeta potential. The prepared AgNPs powder had particle size value (22 nm), polydispersity index (0.163) and zeta potential (-28 mV) indicating the formed AgNPs had small and well stabilized particles. The treated cotton fabrics were characterized by making use of SEM-EDX. Cotton fabrics containing 250 ppm AgNPs were more effective against different species of organisms than those containing 60 and 125 ppm. The results of potent healing using fabrics treated with 250 ppm AgNPs indicate that it leads to similar results compared with that of the Dermazin cream. Moreover, the anti-inflammatory effect AgNPs is nearly similar to 20 ml dose of the reference indomethacin drug.

Intercanthal Distance of a Sudanese Population Sample as a Reference for Selection of Maxillary Anterior Teeth Size

Background: The choice of the size of artificial teeth takes an important place in the removable prosthodontic treatment. However; the standards or proportions commonly used as a guide have been developed mainly on Caucasian populations. Objectives: to investigate the relationship between intercanthal distance and the anterior maxillary teeth size in Sudanese population. Methods: This is a descriptive cross sectional study conducted in 114 subjects; (45 males - 69 females); from Khartoum and Juba Universities. The age range was from 18-46 years. The intercanthal distance (I.C.D) was the measurement taken between the median angles of the palpabral fissure. Maxillary intercanine distance was obtained by measuring a line from the tip of the canine on one side; to the canine on the other side. An electronic digital caliper (Narex - Czechoslovakia) was used for all measurements. Data were analyzed using Person chi-square test. Results: a significant correlation is found between intercanthal distance and maxillary intercanine distance in all subjects (P-value 0.015); and in females who had a (P-value of 0.006).Maxillary intercanine distance may be estimated by dividing I.C.D by factor 0.9. Conclusion: These results could be used as a helpful guide for selection of anterior teeth width in the Sudanese population

Treatment of chronic hepatitis C genotype 4 with alpha-interferon in Saudi Arabia: a multicenter study.

BACKGROUND/AIM: Several studies have indicated that there are certain predictive factors (gender, duration of infection with HCV, cirrhosis and genotype of HCV) of a better response with alpha-interferon treatment in patients with chronic hepatitis C. The aim of this study was to evaluate these factors in Saudis and other Arab nationals with chronic hepatitis C-genotype 4-undergoing alpha-interferon treatment. METHODOLOGY: A multicenter study was conducted between 1992 and 1994 on 80 consecutive patients who were prospectively recruited and randomized in treatment and control groups. RESULTS: The results of this multicenter study indicated a low response rate to alpha-interferon with an overall response rate of 43%, of which 28% was complete. The sustained response was only 16%. Among the reasons for this low response in our study are the high percentage of patients with cirrhosis and the long infection interval, as about 80% of our HCV cases were community-acquired. CONCLUSION: Liver cirrhosis was found to be the main predetermining factor for response to interferon treatment. Genotype 4 was not a contributing factor to the difference in response rate.

Reproductive hormone profiles in regularly menstruating Sudanese women.

Venous blood samples were taken daily from 21 regularly menstruating Sudanese women throughout one complete menstrual cycle. FSH, LH, estradiol-17 beta and progesterone were assayed in all plasma samples and normal reference ranges were thus established. Fifteen subjects had a luteal phase of more than 12 days whilst in 3 subjects it was shorter. Two subjects were found to be hyperprolactinemic and one had an anovulatory cycle with an elevated LH. The plasma concentrations of estradiol-17 beta in the follicular phase and progesterone in the luteal phase were significantly lower in subjects with short luteal phase than in those with a luteal phase of more than 12 days. The hormonal profile of FSH, LH, estradiol-17 beta and progesterone throughout a normal menstrual cycle in regularly menstruating Sudanese women was similar to what has been reported in the literature for other ethnic groups.

Pathological mechanisms in polycystic ovary syndrome: modulation of LH pulsatility by progesterone.

The pulsatile discharge of luteinizing hormone (LH) in nine patients with polycystic ovary syndrome (PCO) and nine patients with amenorrhoea but without PCO, who exhibited LH discharge in response to oestrogen provocation, were studied by 4-h measurement of gonadotrophin pulsatility before and after a course of progesterone injections. No significant differences were found in the gonadotrophin pulsatility patterns of the two groups, although the LH/FSH ratio rose significantly in the patients without PCO after progesterone but not in the patients with PCO, suggesting an abnormality of FSH storage. The ability to discharge gonadotrophins in response to oestrogen provocation has been reported to be present in patients with greater than or equal to 3 LH pulses in a 4-h study period. This, however, was not demonstrated in five of the nine PCO patients despite the presence of 'normal' gonadotrophin pulsatility patterns.

Cycle initiation in amenorrhoea; the effect of progesterone and oestrogen administration on the pulsatile release of gonadotrophins.

The modulation of pulsatile gonadotrophin release by endogenous ovarian steroids during the normal menstrual cycle may be involved in the initiation of the following menstrual cycle. The absence of this cyclical variation may, in some cases, be the cause of, or contribute to the cause of, amenorrhoea. To assess this the modulatory effect of gonadal steroid administration on the pulsatile release of gonadotrophins was studied in fourteen amenorrhoeic and four oligomenorrhoeic women. Pulsatility was assessed by samples collected at 10 min intervals during a 4 h morning period before and after treatment with either progesterone or micronized oestradiol or a sequential combination of both. Ten patients with intact positive oestrogen-gonadotrophin feedback responded to progesterone treatment by both a significant reduction in LH pulse frequency, from a mean of 4.1 to a mean of 2.1 pulses within the 4 h study period and an increase in pulse amplitude. Progesterone therapy did not affect mean LH concentrations but there was a significant reduction in mean FSH concentrations. In the eight patients with absence of positive feedback, none of the treatment regimes elicited significant changes in LH release. No definable FSH pulses were detected before or after treatment in either group. Both the changes in LH and FSH concentrations and their release observed in this study, support the concept that cycle initiation may be related to a reduced pituitary exposure to LHRH associated with elevated progesterone concentration in the luteal phase of the cycle. This selectively induces FSH synthesis and storage. Release of this stored FSH may occur as a result of failure of the corpus luteum and falling progesterone concentrations.

Dydrogesterone increases serum lactalbumin concentration in the puerperium.

Eight women taking oral dydrogesterone 10 mg twice daily for the first 10 d of the puerperium, had significantly (P less than 0.01) greater levels of serum lactalbumin than controls (n = 9), from day 4. No difference was observed in prolactin concentrations between groups.

LH pulse frequency in relation to positive oestrogen-gonadotrophin feedback in amenorrhoea.

The relationship between the pattern of pulsatile LH release and the response to oestrogen provocation was studied in twenty amenorrhoeic or oligomenorrhoeic subjects. In 12 subjects with positive oestrogen-gonadotrophin feedback a definite pulsatile pattern of LH release was demonstrated with a pulse frequency of 60--80 min and an increase from nadir to peak ranging between 30 and 58%. The mean basal LH concentration was significantly higher in this group (P less than 0.001). Of eight subjects who had absence of positive feedback, five showed infrequent pulses, 1--2 during the four-hour period. These were of low amplitude and with a percentage increase of 45--70 from nadir to peak. The remaining three did not have a pulsatile pattern of LH release. Positive feedback, as demonstrated by an oestrogen provocation test was thus found only in patient having 3 or more LH pulses in the 4 h study period; an LH pulse frequency similar to that in the early follicular phase in regularly menstruating women.