Browsing by Author "Sakr, Tamer"

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    Adaptation of Hard Gelatin Capsules for Aqueous Solution Delivery Using Gamma Radiation
    (JAPR, 2017-10) Sakr, Tamer; Assaly, Mohamed K.; AbdelRashid, Rania S; Omar, Samia
    Objective: Directly incorporating aqueous solutions into hard gelatin capsules (HGCs) without dispersing them in an oily medium is considered a challenge for most researchers and manufacturers. The aim of the study is to evaluate the effect of gamma radiation (ɣ-radiation) on the adaptation of HGCs for aqueous solution delivery. Methods: Empty HGC shells were exposed to four of ɣ-radiation doses (1, 3, 5, 10 kGy). Then, the physicochemical properties of irradiated capsules were evaluation and compared with those of non-irradiated capsules. Fourier-transform infrared spectroscopy (FT-IR), capsule hardness, and water incorporation tests were performed. In-vitro disintegration/dissolution behavior determined as (rupture time) in different dissolution media was evaluated. Results: The results showed direct proportionality between the ɣ-radiation dose and HGC crosslinking degree up to 3 kGy, while at doses >3 kGy, degradation rather than crosslinking occurred. The results were clearly demonstrated by FTIR as peptide linkages between gelatin molecules. All the ɣ-irradiated HGCs submitted to hardness test were completely deformed without rupture with increasing capsule deformation work (J) for γ-radiation doses up to 3 kGy; the deformation work declined at doses >3 kGy. The water incorporation study revealed that capsules exposed to 3 kGy could hold up to 100 ml of methylene blue solution without deformation or leakage for 45 minutes compared with non-irradiated HGCs, which showed a significantly lower tolerance of only 2 minutes (p<0.001). The crosslinking of HGCs had a minor significant effect on in-vitro rupture time, especially at gastric pH. Conclusion: The irradiation technique may be used not only for sterilizing HGCs but also for adapting HGCs for aqueous solutions delivery, as it showed a significant positive effect, which was optimal at a dose of 3 kGy. However, these results are not sufficient for scaled-up manufacturing; thus, further investigations are strongly recommended.
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    Labeling of ceftriaxone for infective inflammation imaging using 99mTc eluted from 99Mo/99mTc generator based on zirconium molybdate
    (PERGAMON-ELSEVIER SCIENCE LTD, 2010) Mostafa, M; Motaleb, MA; Sakr, Tamer
    Zirconium molybdate gel was prepared by mixing 99Mo, produced from 98Mo(n,γ) reaction and Zr solutions in nitrate media with excess H2O2, and used as the base material for 99Mo/99mTc generator. The prepared generator showed a good performance. 99mTc eluted from the prepared generator passed the quality control tests with specifications meeting the requirements of European and US Pharmacopeias. The 99mTc eluate was used for labeling of cephalosporin analogue, ceftriaxone, which was then assessed for infection imaging in a mouse model. 99mTc-ceftriaxone was prepared at pH 9 with a radiochemical yield of 95±2% by adding 99mTc to 30 mg ceftriaxone in the presence of 50 μg SnCl2·2H2O. Biodistribution studies in mice were carried out using experimentally induced infection in the left thigh using E. coli. Both thighs of the mice were dissected and counted to evaluate the ratio of bacterial infected thigh/contralateral thigh. 99mTc-ceftriaxone showed high uptake in the infectious lesion (T/NT =5.6±0.6 at 4 h post injection). The abscess to normal muscle ratio indicated that 99mTc-ceftriaxone could be used for infection imaging. Besides, in vitro studies showed that 99mTc-ceftriaxone can differentiate between bacterial infection and sterile inflammation