Nanostructured Lipid Carrier for Topical Application of N-Acetyl Glucosamine

Purpose: Hyperpigmentation occurs when melanin is overproduced in certain spots on the skin and is one of the most challenging skin conditions to treat. Although it is usually harmless, for cosmetic reasons, it is dreadfully bothersome to those who undergo it. It was reported that N-acetyl-glucosamine (NAGA) prevents melanin synthesis and alters the expression of numerous genes related to pigmentation. In spite of these advantages, NAGA cannot be employed in topical formulations due to its extremely polar characteristics. Nanoparticles, especially lipid-based ones, have been introduced as an efficient carrier for dermal drug delivery. Methods: The aim of the present study was to load adequate hydrophilic NAGA to the lipophilic nanostructured lipid carriers (NLCs) for potential dermal application. Methods: NAGA-loaded NLCs were formulated, using hot homogenization technique, and the characteristics of the optimized formulation were analyzed by laser light scattering, X-ray diffraction, and scanning electron microscopy methods. Loading capacity percentage and in vitro release study were carried out by applying a validated HPLC method. The optimum formulation was utilized for the in vivo skin lightening evaluations in healthy volunteers. Results: NAGA-loaded NLCs demonstrated promising results (the size of 190 nm, narrow size distribution, loading capacity of 9%, and appropriate NAGA release profile) suitable for dermal delivery. XRD results exhibited a dramatic reduction in the crystalline structure of encapsulated NAGA. Dermoscopy images indicated a considerable decline in melanin distribution pattern in the majority of the cases treated with NAGA-loaded NLCs. Conclusion: Thus, this study has opened new horizons for the potential use of lipid based nanoparticles in the managing of hyperpigmentation

Diagnostic validity of ultrasonography in evaluation of pulmonary thromboembolism

Background: Diagnosis of pulmonary embolism (PE) remains difficult due to its nonspecific symptoms and signs. Therefore, many patients die undiagnosed or untreated. We decided to study the sensitivity, specificity, and accuracy of ultrasonography in the diagnosis of pulmonary thromboembolism. Materials and Methods: In this prospective study, 77 patients with clinically suspected PE in the emergency department of Isfahan Al-Zahra Hospital were enrolled from September 2011 to September 2012. At first, they were evaluated by thoracic ultrasonography (TUS) and then divided into four groups based on their TUS findings. Multi-slice computed tomography (MSCT) was the reference method in this study performed within 24 h from admission. MSCT scans were interpreted by a radiologist who was unaware of the TUS results. Sensitivity, specificity, positive predictive value (PPV), and negative predictive values (NPVs) of thoracic ultrasonography were determined. Results: PE diagnosis was confirmed by MSCT in 25 patients and 54 hypoechoic lesions were detected by TUS with the average size of 16.4 mm × 11.1 mm. In our study, sensitivity, specificity, PPV, NPV, and accuracy of TUS for PE diagnosis were 84%, 94.2%, 87.5%, and 92.5%, respectively. Conclusion: TUS is an inexpensive, safe and easily available method for timely diagnosis and treatment of PE in emergency department and its NPV is high for cases with low scores for Wells criteria who had a normal or possible TUS findings. It is also specific in the diagnosis of PE in cases with high scores Wells criteria who have confirmed or probable TUS findings