In Vitro and In Vivo evaluation of hydroxypropylmethyl cellulose phthalate capsules

The aim of this study was to develop a novel HPMCP capsule. The HPMCP capsule containing99mTc-DTPA and lactose was evaluated in in vitro and in vivo studies. First of all, the HPMCP capsules were prepared and characterized with lenght and diameter size, brittleness facility, moisture content and microbiological test. In vitro resistance and solubility studies of prepared capsules were tested at pH 1.2 and pH 7.4 buffers. The radiolabeled HPMCP capsules were administrated to fasted volunteers. The disintegration times and positions of capsules were recorded by using gamma scintigraphy. In vitro studies showed that HPMCP capsules were gastro resistant for 2 h at pH 1.2 and dissolved at pH 7.4 in 20-25 minutes. The radiolabeled capsules did not disintegrate in stomach whereas disintegrated in intestines. In conclusion, it was found that, the prepared HPMCP capsules can be an alternative to the hard gelatine capsules and used for intestinal targeting.Keywords: Capsule, hydroxypropylmethylcellulose phthalate (HPMCP), gamma scintigraphy, radiolabelling, technetium-99m

Raman and fluorescence contributions to resonant inelastic soft x-ray scattering on LaAlO3_3/SrTiO3_3 heterostructures

We present a detailed study of the Ti 3$d$ carriers at the interface of LaAlO$_3$/SrTiO$_3$ heterostructures by high-resolution resonant inelastic soft x-ray scattering (RIXS), with special focus on the roles of overlayer thickness and oxygen vacancies. Our measurements show the existence of interfacial Ti 3$d$ electrons already below the critical thickness for conductivity and an increase of the total interface charge up to a LaAlO$_3$ overlayer thickness of 6 unit cells before it levels out. By comparing stoichiometric and oxygen deficient samples we observe strong Ti 3$d$ charge carrier doping by oxygen vacancies. The RIXS data combined with photoelectron spectroscopy and transport measurements indicate the simultaneous presence of localized and itinerant charge carriers. However, it is demonstrated that the relative amount of localized and itinerant Ti $3d$ electrons in the ground state cannot be deduced from the relative intensities of the Raman and fluorescence peaks in excitation energy dependent RIXS measurements, in contrast to previous interpretations. Rather, we attribute the observation of either the Raman or the fluorescence signal to the spatial extension of the intermediate state reached in the RIXS excitation process.Comment: 9 pages, 6 figure

In vitro and in vivo evaluation of hydroxypropylmethyl cellulose phthalate capsules

The aim of this study was to develop a novel HPMCP capsule. The HPMCP capsule containing 99mTc-DTPA and lactose was evaluated in in vitro and in vivo studies. First of all, the HPMCP capsules were prepared and characterized with lenght and diameter size, brittleness facility, moisture content and microbiological test. In vitro resistance and solubility studies of prepared capsules were tested at pH 1.2 and pH 7.4 buffers. The radiolabeled HPMCP capsules were administrated to fasted volunteers. The disintegration times and positions of capsules were recorded by using gamma scintigraphy. In vitro studies showed that HPMCP capsules were gastro resistant for 2 h at pH 1.2 and dissolved at pH 7.4 in 20-25 minutes. The radiolabeled capsules did not disintegrate in stomach whereas disintegrated in intestines. In conclusion, it was found that, the prepared HPMCP capsules can be an alternative to the hard gelatine capsules and used for intestinal targeting

Is Ethylcellulose capsule appropriate for colonic transit study?

WOS: 00020296740133

Evaluation of in vitro release and skin irritation of benzoyl peroxide-containing products

Benzoyl peroxide (BPO) has been known as a highly effective topical agent in acne vulgaris therapy for a long time. It induces an irritant dermatitis with erythema and scaling. Therefore, the aim of this study was to formulate BPO containing w/o/w multiple emulsion and gel formulations with and without chitosan microparticles to decrease skin irritation and to compare the release profiles through cellulose acetate, cellophane membranes and excised rat skin. A commercial preparation was also used and the similarities between commercial and experimental formulations were assessed by difference factor (f(1)). The release results indicated that gel base exhibited a higher drug release than the other experimental formulations (p <= 0.05). The release rate of BPO from different membranes was found to be statistically different (p < 0.05). Histological examinations realized by light microscopy on wistar rat skin indicated no observable damage to whole experimental formulations. The results described in this study pointed out that w/o/w multiple emulsion system containing chitosan microparticles has shown the lowest release rate and could be suggested as an effective carrier for BPO to achieve sustained release, to prevent skin irritation and to protect the drug from environmental factors. Moreover, this system could present additional therapeutic benefits due to the wound healing effects of chitosan