Nasal Inserts for Drug Delivery: An Overview

Nasal mucosa, owing to its high vascularity and thin epithelial membrane, has been widely explored for drug administration in the last two decades. Within that period various nasal dosage forms have been researched and developed. Among them, nasal inserts are easily prepared by lyophilization or gelsification, allow easy dosing with a high potential for systemic  administration, enable avoidance of hepatic first pass metabolism, and make possible the release of active ingredient in a controlled manner. In this review, the benefits, limitations and absorption mechanisms of the nasal route, as well as findings from nasal insert-related studies are addressed.Keywords: Nasal drug delivery, Insert, Mucoadhesion, Absorption, Lyophilization, Gelsificatio

Transdermal Spray in Hormone Delivery

This review examines advances in hormone delivery, particularly using transdermal spray. Transdermal gels, emulsions, patches, subcutaneous implants and sprays have been developed for transdermal hormone therapy in recent years. Transdermal sprays, in their general form of metered-dose transdermal spray, possess major advantages such as enhanced passive transdermal drug delivery with little or no skin irritations, improved cosmetic acceptability, dose flexibility, uniform distribution on the application site and ease of manufacture, and have thus assumed significant importance in hormone delivery. Estradiol, nestrone, testosterone and hydrocortisone aceponate are some of the drugs prepared as metered-dose transdermal spray. Results from recent surveys indicate that there is a market for the delivery system and ongoing development of transdermal sprays for hormone delivery.Keywords: Transdermal, Delivery systems, Metered dose, Spray, Hormon

Iatrogenic superficial external pudendal artery pseudoaneurysm: Treatment with doppler us-guided compression

Pseudoaneurysms rarely occur as a serious complication following incomplete hemostasis of an arterial puncture site. As a result of the increase in diagnostic and therapeutic angiography, the frequency of iatrogenic pseudoaneurysm has increased as well. Iatrogenic pseudoaneurysms associated with angiographic catheterization occur most commonly in the common femoral artery. Here we report a case of iatrogenic superficial external pudendal artery (SEPA) pseudoaneurysm following cardiac catheterization, which was diagnosed with Doppler ultrasound (US) and multidetector computed tomographic angiography (MDCTA) before Doppler US-guided compression therapy. To the best of our knowledge, iatrogenic SEPA pseudoaneurysm, which is an unusual vessel location for pseudoaneurysm occurrence, has not been reported in the literature. In patients in whom anticoagulant-thrombolytic therapy or therapeutic catheterization with larger sized sheath is planned, determination of the precise localization of arterial puncture site is important for the prevention of iatrogenic pseudoaneurysm development. Arterial puncture guided with Doppler US might reduce complications. When suspected, MDCTA is useful in the diagnosis and demonstration of iatrogenic pseudoaneurysms. Treatment of US-guided compression should be the first choice for iatrogenic pseudoaneurysms. Interventional radiologists and cardiologists should have enough experience about the catheterization complications and their treatment in order to decrease the morbidity and mortality related to the intervention

Evaluation of In vitro and In vivo Performance of Granisetron In situ Forming Implants: Effect of Sterilization, Storage Condition and Degradation

Purpose: To investigate the effect of various solvent systems and gamma irradiation on the in vitro and in vivo performance of granisetron HCl injectable phase-sensitive in situ forming implants (ISFIs).Methods: ISFIs were prepared by mixing and sterilized by gamma  irradiation. Effect of solvent system was studied. Injectability, polymer degradation and stability studies (4 and 25 oC for 4 months), viscositymeasurements, as well as in vitro and in vivo (in rabbits) drug release, and also histological examinations for biocompatibility studies (in rabbits and rats) were carried out.Results: ISFIs showed good injectability from 20-gauge needle and their in vitro drug release increased in the following rank order of solvent/solvent combinations: dimethylsulphoxide (DMSO) > DMSO:prophylenecarbonate (PC) > DMSO:triacetin(TA) > DMSO:benzylbenzoate (BB). DMSO:PC incorporating ISFI gave zero order (r2 = 0.9503) drug release for 21 days; application of gamma irradiation accelerated drug release with a difference factor (f1) of 53 but zero order release (r2 = 9690) was maintained. Following test results for DMSO:PC including ISFI as decrease in molecular weight of polymer was descriptive for drug release behavior and  sterilization effect, additionally dynamic viscosities decreased in line with polymer degradation and all forms of this ISFI showed plastic flow(fresh, irradiated, aged at 4 and 25 oC for 4 months). In vivo performance showed steady state plasma drug concentrations between 2 to 21 days with value of 0.55 ± 0.03 ìg/ml and biocompatibility was confirmed by  histological results obtained at specific stages of tissue reactions, and also by lack of fibrous capsule formation.Conclusion: An ISFI for long-term antiemetic therapy achieved in this  preliminary study is promising and, therefore, further investigations are required.Keywords: Implant, Poly(DL-lactide-co-glycolide), Granisetron, Gamma irradiation, Sterilization, Degradation, Viscosity, Stability, Pharmacokinetic, Biocompatibility

Reduction of the Radiofrequency Heating of Metallic Devices Using a Dual-Drive Birdcage Coil

Cataloged from PDF version of article.In this work, it is demonstrated that a dual-drive birdcage coil can be used to reduce the radiofrequency heating of metallic devices during magnetic resonance imaging. By controlling the excitation currents of the two channels of a birdcage coil, the radiofrequency current that is induced near the lead tip could be set to zero. To monitor the current, the image artifacts near the lead tips were measured. The electric field distribution was controlled using a dual-drive birdcage coil. With this method, the lead currents and the lead tip temperatures were reduced substantially [<0.3 C for an applied 4.4 W/kg SAR compared to >4.9 C using quadrature excitation], as demonstrated by phantom and animal experiments. The homogeneity of the flip angle distribution was preserved, as shown by volunteer experiments. The normalized root-mean-square error of the flip angle distribution was less than 10% for all excitations. The average specific absorption rate increased as a trade-off for using different excitation patterns. Magn Reson Med 69:845–852, 2013. VC 2012 Wiley Periodicals, In

Comparison between Capsule Endoscopy and Magnetic Resonance Enterography for the Detection of Polyps of the Small Intestine in Patients with Familial Adenomatous Polyposis

Objective. The objective of this study was to assess the utility of magnetic resonance enterography (MRE) compared with capsule endoscopy (CE) for the detection of small-bowel polyps in patients with familial adenomatous polyposis (FAP). Methods. Patients underwent MRE and CE. The polyps were classified according to size of polyp: <5 mm (small size), 5–10 mm (medium size), or >10 mm (large size). The location (jejunum or ileum) and the number of polyps (1–5, 6–20, >20) detected by CE were also assessed. MRE findings were compared with the results of CE. Results. Small-bowel polyps, were detected by CE in 4 of the 6 (66%) patients. Three patients had small-sized polyps and one patient had medium-sized polyps. CE detected polyps in four patients that, were not shown on MRE. Desmoid tumors were detected on anterior abdominal wall by MRE. Conclusion. In patients with FAP, CE can detect small-sized polyps in the small intestine not seen with MRE whereas MRE yields additional extraintestinal information

Reduction of the radiofrequency heating of metallic devices using a dual-drive birdcage coil

In this work, it is demonstrated that a dual-drive birdcage coil can be used to reduce the radiofrequency heating of metallic devices during magnetic resonance imaging. By controlling the excitation currents of the two channels of a birdcage coil, the radiofrequency current that is induced near the lead tip could be set to zero. To monitor the current, the image artifacts near the lead tips were measured. The electric field distribution was controlled using a dual-drive birdcage coil. With this method, the lead currents and the lead tip temperatures were reduced substantially [4.9°C using quadrature excitation], as demonstrated by phantom and animal experiments. The homogeneity of the flip angle distribution was preserved, as shown by volunteer experiments. The normalized root-mean-square error of the flip angle distribution was less than 10% for all excitations. The average specific absorption rate increased as a trade-off for using different excitation patterns. Copyright © 2012 Wiley Periodicals, Inc

Level density of 56^{56}Fe and low-energy enhancement of γ\gamma-strength function

The $^{55}$Mn$(d,n)^{56}$Fe differential cross section is measured at $E_d=7$ MeV\@. The $^{56}$Fe level density obtained from neutron evaporation spectra is compared to the level density extracted from the $^{57}$Fe$(^3$He,$\alpha\gamma)^{56}$Fe reaction by the Oslo-type technique. Good agreement is found between the level densities determined by the two methods. With the level density function obtained from the neutron evaporation spectra, the $^{56}$Fe $\gamma$-strength function is also determined from the first-generation $\gamma$ matrix of the Oslo experiment. The good agreement between the past and present results for the $\gamma$-strength function supports the validity of both methods and is consistent with the low-energy enhancement of the $\gamma$ strength below $\sim 4$ MeV first discovered by the Oslo method in iron and molybdenum isotopes.Comment: 7 pages, 5 figure