Učinak topljivosti na kinetiku oslobađanja vodotopljivih i vodonetopljivih lijekova iz matriksnog sustava na bazi HPMC

The purpose of the present research work was to observe the effects of drug solubility on the release kinetics of water soluble verapamil hydrochloride and insoluble aceclofenac from polymer based matrix formulations. Matrix formulations were prepared by the direct compression method. The formulations were evaluated for various physical parameters. Along with the dynamics of water uptake and erosion, SEM and in vitro drug release of tablets were studied. Applying an exponential equation, it was found that the kinetics of soluble drug release followed anomalous non-Fickian diffusion transport whereas insoluble drug showed zero-order release. SEM study showed pore formation on the tablet surface that differed depending on drug solubility. t-Test pointed to a significant difference in the amount of both drugs released due to their difference in solubility. Solubility of the drug affects the kinetics and the mechanism of drug release.Cilj rada bio je praćenje učinka topljivosti na kinetiku oslobađanja vodotopljivog verapamil hidroklorida i netopljivog lijeka aceklofenaka iz matriksnih sustava na bazi hidrofilnog polimera. Matriksni sustavi pripravljeni su izravnom metodom kompresije. Uz ispitivanje uobičajenih fizikalnih svojstava, ispitivana je i dinamika primanja vode, te erozija, SEM i in vitro oslobađanje ljekovite tvari iz tableta. Primjenom eksponencijalne jednadžbe utvrđeno je da mehanizam oslobađanja topljivih lijekova slijedi anomalni ne-Fickov difuzijski transport, dok netopljivi lijekovi slijede kinetiku nultog reda. SEM ispitivanja pokazala su pore na površini matriksa ovisne o topljivosti ljekovite tvari. T-test ukazuje da količina oslobođenog lijeka značajno ovisi o njegovoj topljivosti. Topljivost lijeka ima značajan učinak na kinetiku i mehanizam oslobađanja

Oral Drug Delivery Systems Comprising Altered Geometric Configurations for Controlled Drug Delivery

Recent pharmaceutical research has focused on controlled drug delivery having an advantage over conventional methods. Adequate controlled plasma drug levels, reduced side effects as well as improved patient compliance are some of the benefits that these systems may offer. Controlled delivery systems that can provide zero-order drug delivery have the potential for maximizing efficacy while minimizing dose frequency and toxicity. Thus, zero-order drug release is ideal in a large area of drug delivery which has therefore led to the development of various technologies with such drug release patterns. Systems such as multilayered tablets and other geometrically altered devices have been created to perform this function. One of the principles of multilayered tablets involves creating a constant surface area for release. Polymeric materials play an important role in the functioning of these systems. Technologies developed to date include among others: Geomatrix® multilayered tablets, which utilizes specific polymers that may act as barriers to control drug release; Procise®, which has a core with an aperture that can be modified to achieve various types of drug release; core-in-cup tablets, where the core matrix is coated on one surface while the circumference forms a cup around it; donut-shaped devices, which possess a centrally-placed aperture hole and Dome Matrix® as well as “release modules assemblage”, which can offer alternating drug release patterns. This review discusses the novel altered geometric system technologies that have been developed to provide controlled drug release, also focusing on polymers that have been employed in such developments

Evaluation of sesamum gum as an excipient in matrix tablets

In developing countries modern medicines are often beyond the affordability of the majority of the population. This is due to the reliance on expensive imported raw materials despite the abundance of natural resources which could provide an equivalent or even an improved function. The aim of this study was to investigate the potential of sesamum gum (SG) extracted from the leaves of Sesamum radiatum (readily cultivated in sub-Saharan Africa) as a matrix former. Directly compressed matrix tablets were prepared from the extract and compared with similar matrices of HPMC (K4M) using theophylline as a model water soluble drug. The compaction, swelling, erosion and drug release from the matrices were studied in deionized water, 0.1 N HCl (pH 1.2) and phosphate buffer (pH 6.8) using USP apparatus II. The data from the swelling, erosion and drug release studies were also fitted into the respective mathematical models. Results showed that the matrices underwent a combination of swelling and erosion, with the swelling action being controlled by the rate of hydration in the medium. SG also controlled the release of theophylline similar to the HPMC and therefore may have use as an alternative excipient in regions where Sesamum radiatum can be easily cultivated

Factors affecting the morphology of benzoyl peroxide microsponges

Benzoyl peroxide (BPO) is primarily used in the treatment of mild to moderate acne. However, its application is associated with skin irritation. It has been shown that encapsulation and controlled release of BPO could reduce the side effect while also reducing percutaneous absorption when administered to the skin. The aim of the present investigation was to design and formulate an appropriate encapsulated form of BPO, using microsponge technology, and explore the parameters affecting the morphology and other characteristics of the resultant products employing scanning electron microscopy (SEM). Benzoyl peroxide particles were prepared using an emulsion solvent diffusion method by adding an organic internal phase containing benzoyl peroxide, ethyl cellulose and dichloromethane into a stirred aqueous phase containing polyvinyl alcohol (PVA). Different concentrations of BPO microsponges were incorporated in lotion formulations and the drug release from these formulations were studied. The SEM micrographs of the BPO microsponges enabled measurement of their size and showed that they were spherical and porous. Results showed that the morphology and particle size of microsponges were affected by drug:polymer ratio, stirring rate and the amount of emulsifier used. The results obtained also showed that an increase in the ratio of drug:polymer resulted in a reduction in the release rate of BPO from the microsponges. The release data showed that the highest and the lowest release rates were obtained from lotions containing plain BPO particles and BPO microsponges with the drug:polymer ratio of 13:1, respectively. The kinetics of release study showed that the release data followed Peppas model and the main mechanism of drug release from BPO microsponges was diffusion

The relationship between serum ferritin levels and metabolic syndrome in postmenopausal women, a cross-sectional study

مقدمه: یائسگی، بحرانی‌ترین دوره تغییرات نامطلوب آنتروپومتریک و پارامترهای متابولیک بوده که با خطر بیماری‌های قلبی - عروقی همراه است. سندرم متابولیک، نقش کلیدی در ایجاد بیماری قلبی- عروقی دارد و به‌عنوان یک مشکل عمده در بسیاری از کشورها درآمده است. بر اساس مطالعات مختلف، افزایش فریتین با سندرم متابولیک در ارتباط است و افراد با سطح فریتین بالاتر، خطر ابتلاء به سندرم متابولیک در آنها بیشتر است. بنابراین با توجه به بالا بودن شیوع سندرم متابولیک در ایران، مطالعه حاضر با هدف بررسی ارتباط بین سطح فریتین سرم با سندرم متابولیک انجام شد. روش‌کار: این مطالعه مقطعی در سال 1392 بر روی 165 زن یائسه واجد شرایط مراجعه کننده به مرکز بهداشت 17 شهریور و بهداشت شماره 8 اهواز انجام شد. پرسشنامه اطلاعات فردی برای نمونه­ها تکمیل و جهت بررسی اجزای سندرم متابولیک، فشارخون 2 بار به فاصله 10 دقیقه و بعد از استراحت اندازه‌گیری شد و میانگین آنها در نظر گرفته شد. دور کمر افراد اندازه‌گیری و آزمایشات HDL، تری‌گلیسیرید، کلسترول، فریتین و FBS بعد از 12 ساعت ناشتایی شبانه بر روی سرم افراد انجام شد. تجزیه و تحلیل داده‌ها با استفاده از نرم‌افزار آماری SPSS (نسخه 19) و آزمون‌های کای‌دو، آنالیز واریانس یک‌طرفه، ضریب همبستگی پیرسون و اسپیرمن انجام گرفت. میزان p‌ کمتر از 05/0 معنی‌دار در نظر گرفته شد. یافته‌ها: در این مطالعه 58 نفر (2/35%) به سندرم متابولیک مبتلا بودند. میانگین سطح سرم فریتین در زنان مبتلا به سندرم متابولیک 45/25±53/34 و در زنان غیر مبتلا 12/23±56/33 بود. بین شاخص توده بدنی، دور کمر، قندخون، سطح تری‌گلیسیرید پلاسما، چربی خون و ابتلاء به سندرم متابولیک ارتباط معناداری مشاهده شد (05/0>p)، اما بین سندرم متابولیک و سن، سندرم متابولیک و فریتین سرم ارتباط معنی‌داری وجود نداشت (05/

The role of various surfactants and fillers in controlling the release rate of theophylline from HPMC matrices

The effect of lactose, NaCMC and various surfactants, i.e. sodium lauryl sulfate, cetyltriammonium bromide, Arlacel 60 and Tween 80 on the release rate of theophylline from HPMC matrices was evaluated. The results showed that an increase in the concentration of lactose or NaCMC resulted in an increase in the release rate. Results concerning the effect of surfactants on the release rate showed that incorporating sodium lauryl sulfate into HPMC matrices increased the release rate. Different results were obtained for the other surfactants. The effects of filler and surfactants on the release kinetics were also investigated. The results showed that a reduction in the ratio of HPMC to NaCMC resulted in a reduction in the n value (indicative of the mechanism of release in Higuchi's equations). The presence of sodium lauryl sulfate caused a reduction in the n values from 0.75 (without surfactant) to 0.591 (10 w/w sodium lauryl sulfate), indicating that the contribution of erosion fell as the concentration of sodium lauryl sulfate rose

Factors affecting the morphology of benzoyl peroxide microsponges

Benzoyl peroxide (BPO) is primarily used in the treatment of mild to moderate acne. However, its application is associated with skin irritation. It has been shown that encapsulation and controlled release of BPO could reduce the side effect while also reducing percutaneous absorption when administered to the skin. The aim of the present investigation was to design and formulate an appropriate encapsulated form of BPO, using microsponge technology, and explore the parameters affecting the morphology and other characteristics of the resultant products employing scanning electron microscopy (SEM). Benzoyl peroxide particles were prepared using an emulsion solvent diffusion method by adding an organic internal phase containing benzoyl peroxide, ethyl cellulose and dichloromethane into a stirred aqueous phase containing polyvinyl alcohol (PVA). Different concentrations of BPO microsponges were incorporated in lotion formulations and the drug release from these formulations were studied. The SEM micrographs of the BPO microsponges enabled measurement of their size and showed that they were spherical and porous. Results showed that the morphology and particle size of microsponges were affected by drug:polymer ratio, stirring rate and the amount of emulsifier used. The results obtained also showed that an increase in the ratio of drug:polymer resulted in a reduction in the release rate of BPO from the microsponges. The release data showed that the highest and the lowest release rates were obtained from lotions containing plain BPO particles and BPO microsponges with the drug:polymer ratio of 13:1, respectively. The kinetics of release study showed that the release data followed Peppas model and the main mechanism of drug release from BPO microsponges was diffusion

A review on the methods of preparation of pharmaceutical nanoparticles

Objectives: Nanotechnology will affect human being life impressively over the next decade in different fields, including medicine and pharmacy. Polymeric nanoparticles have been far and wide studied as particulate carriers in the pharmaceutical and medical fields since they show promise as drug delivery systems on account of their controlled and sustained- release properties, sub cellular size, biocompatibility with tissue and cells and enhancing the effectiveness of the loaded drugs. Methods: Numerous methods have been developed during the last two decades to formulate the pharmaceutical nanoparticles. These methods have been classified according to whether the particle formation implies a polymerization reaction or arises from a macromolecule or preformed polymer. Results: In the current review the most important methods of preparation are explicated, more than ever those that make use of preformed synthetic polymers. Furthermore, the methods which can be commercialized as well as pharmaceutical aspects are discussed briefly. Conclusion: Pharmaceutical nanoparticles can be prepared using different methods depending on the physicochemical properties of the drug and polymers