Nidal A. Qinna

Formulation and characterization of an oily-based system for oral delivery of insulin

The present work explored the possibility of formulating an oral insulin delivery system by combining the advantages of nanoencapsulation and the use of oily vehicle. The parameters affecting formulation such as association efficiency were characterized. The preparation was evaluated for its chemical, physical and biological stability. The preparation has unimodal particle size distribution with a mean diameter of 108+/-9 nm. Insulin was protected from gastric enzymes by incorporation into lipid-based formulation. The results of RP HPLC and ELISA indicated that insulin was able to withstand the preparation procedure. Insulin in the preparations was stable for a period of one month at storage temperatures of 4 and 25 degrees C. It was also biologically active and stable as demonstrated by the remarkable reduction of blood glucose levels of the STZ-diabetic rats after oral administration of the preparation. Moreover, hypoglycemic effect of nanoparticles administered orally was sustained for a longer period of time compared to the subcutaneous injection. These results clearly evidenced the ability of the nanoparticles to enhance the pharmacological response of insulin when given orally and could be used to deliver other peptides.

Chitosan–Sodium Lauryl Sulfate Nanoparticles as a Carrier System for the In Vivo Delivery of Oral Insulin

The present work explores the possibility of formulating an oral insulin delivery system using nanoparticulate complexes made from the interaction between biodegradable, natural polymer called chitosan and anionic surfactant called sodium lauryl sulfate (SLS). The interaction between chitosan and SLS was confirmed by Fourier transform infrared spectroscopy. The nanoparticles were prepared by simple gelation method under aqueous-based conditions. The nanoparticles were stable in simulated gastric fluids and could protect the encapsulated insulin from the GIT enzymes. Additionally, the in vivo results clearly indicated that the insulin-loaded nanoparticles could effectively reduce the blood glucose level in a diabetic rat model. However, additional formulation modifications are required to improve insulin oral bioavailability.

Plasma concentrations of 25-hydroxyvitamin D among Jordanians: Effect of biological and habitual factors on vitamin D status

BackgroundVitamin D is cutaneously synthesized following sun exposure (vitamin D3) as well as it is derived from dietary intake (vitamin D3 and D2). Vitamin D2 and D3 are metabolized in the liver to 25-hydroxyvitamin D (25(OH)D). This metabolite is considered the functional indicator of vitamin D stores in humans. Since Jordan latitude is 31°N, cutaneous synthesis of vitamin D3 should be sufficient all year round. However, many indications reveal that it is not the case. Thus, this study was conducted to determine the 25(OH)D status among Jordanians.MethodsThree hundred healthy volunteers were enrolled in a cross sectional study; 201 females and 99 males. 25(OH)D and calcium concentrations were measured by enzyme linked immunosorbent assay and spectroscopy techniques, respectively. All participants filled a study questionnaire that covered age, sex, height, weight, diet, and dress style for females. Females were divided according to their dress style: Western style, Hijab (all body parts are covered except the face and hands), and Niqab (all body parts are covered including face and hands).ResultsThe average plasma 25(OH)D levels in males and females were 44.5 ± 10.0 nmol/l and 31.1 ± 12.0 nmol/l, respectively. However, when female 25(OH)D levels were categorized according to dress styles, the averages became 40.3, 31.3 and 28.5 nmol/l for the Western style, Hijab and Niqab groups, respectively. These 25(OH)D levels were significantly less than those of males (p < 0.05, 0.001, 0.001, respectively). In addition, the plasma 25(OH)D levels of the Western style group was significantly higher than those of Hijab and Niqab groups (p < 0.001). Furthermore, dairy consumption in males was a positive significant factor in vitamin D status. Even though calcium concentrations were within the reference range, the Hijab and Niqab-dressed females have significantly less plasma calcium levels than males (p < 0.01).ConclusionsVery low plasma 25(OH)D levels in females wearing Hijab or Niqab are highly attributed to low sunlight or UVB exposure. In addition, most of males (76%) and Western style dressed females (90%) have 25(OH)D concentrations below the international recommended values (50 nmol/l), suggesting that although sun exposure should be enough, other factors do play a role in these low concentrations. These findings emphasize the importance of vitamin D supplementation especially among conservatively dressed females, and determining if single nucleotide polymorphisms of the genes involved in vitamin D metabolism do exist among Jordanians.

Impact of streptozotocin on altering normal glucose homeostasis during insulin testing in diabetic rats compared to normoglycemic rats

Streptozotocin (STZ) is currently the most used diabetogenic agent in testing insulin and new antidiabetic drugs in animals. Due to the toxic and disruptive nature of STZ on organs, apart from pancreas, involved in preserving the body’s normal glucose homeostasis, this study aims to reassess the action of STZ in inducing different glucose response states in diabetic rats while testing insulin. Diabetic Sprague-Dawley rats induced with STZ were classified according to their initial blood glucose levels into stages. The effect of randomizing rats in such a manner was investigated for the severity of interrupting normal liver, pancreas, and kidney functions. Pharmacokinetic and pharmacodynamic actions of subcutaneously injected insulin in diabetic and nondiabetic rats were compared. Interruption of glucose homeostasis by STZ was challenged by single and repeated administrations of injected insulin and oral glucose to diabetic rats. In diabetic rats with high glucose (451–750 mg/dL), noticeable changes were seen in the liver and kidney functions compared to rats with lower basal glucose levels. Increased serum levels of recombinant human insulin were clearly indicated by a significant increase in the calculated maximum serum concentration and area under the concentration–time curve. Reversion of serum glucose levels to normal levels pre- and postinsulin and oral glucose administrations to STZ diabetic rats were found to be variable. In conclusion, diabetic animals were more responsive to insulin than nondiabetic animals. STZ was capable of inducing different levels of normal glucose homeostasis disruption in rats. Both pharmacokinetic and pharmacodynamic actions of insulin were altered when different initial blood glucose levels of STZ diabetic rats were selected for testing. Such findings emphasize the importance of selecting predefined and unified glucose levels when using STZ as a diabetogenic agent in experimental protocols evaluating new antidiabetic agents and insulin delivery systems.

Bioadhesive Controlled Metronidazole Release Matrix Based on Chitosan and Xanthan Gum

Metronidazole, a common antibacterial drug, was incorporated into a hydrophilic polymer matrix composed of chitosan xanthan gum mixture. Hydrogel formation of this binary chitosan-xanthan gum combination was tested for its ability to control the release of metronidazole as a drug model. This preparation (MZ-CR) was characterized by in vitro, ex vivo bioadhesion and in vivo bioavailability study. For comparison purposes a commercial extended release formulation of metronidazole (CMZ) was used as a reference. The in vitro drug-release profiles of metronidazole preparation and CMZ were similar in 0.1 M HCl and phosphate buffer pH 6.8. Moreover, metronidazole preparation and CMZ showed a similar detachment force to sheep stomach mucosa, while the bioadhesion of the metronidazole preparation was higher three times than CMZ to sheep duodenum. The results of in vivo study indicated that the absorption of metronidazole from the preparation was faster than that of CMZ. Also, MZ-CR leads to higher metronidazole Cmax and AUC relative to that of the CMZ. This increase in bioavailability might be explained by the bioadhesion of the preparation at the upper part of the small intestine that could result in an increase in the overall intestinal transit time. As a conclusion, formulating chitosan-xanthan gum mixture as a hydrophilic polymer matrix resulted in a superior pharmacokinetic parameters translated by better rate and extent of absorption of metronidazole.

Influence of Molecular Weight and Degree of Deacetylation of Low Molecular Weight Chitosan on the Bioactivity of Oral Insulin Preparations

The objective of the present study was to prepare and characterize low molecular weight chitosan (LMWC) with different molecular weight and degrees of deacetylation (DDA) and to optimize their use in oral insulin nano delivery systems. Water in oil nanosized systems containing LMWC-insulin polyelectrolyte complexes were constructed and their ability to reduce blood glucose was assessed in vivo on diabetic rats. Upon acid depolymerization and testing by viscosity method, three molecular weights of LMWC namely, 1.3, 13 and 18 kDa were obtained. As for the DDA, three LMWCs of 55%, 80% and 100% DDA were prepared and characterized by spectroscopic methods for each molecular weight. The obtained LMWCs showed different morphological and in silico patterns. Following complexation of LMWCs with insulin, different aggregation sizes were obtained. Moreover, the in vivo tested formulations showed different activities of blood glucose reduction. The highest glucose reduction was achieved with 1.3 kDa LMWC of 55% DDA. The current study emphasizes the importance of optimizing the molecular weight along with the DDA of the incorporated LMWC in oral insulin delivery preparations in order to ensure the highest performance of such delivery systems.

Effects of Prickly Pear Dried Leaves, Artichoke Leaves, Turmeric and Garlic Extracts, and Their Combinations on Preventing Dyslipidemia in Rats

The successful use of herbal combinations in managing diseases or conditions over a single herb has lead us to evaluate the anti-dyslipidemic properties of the combination of the artichoke leaves extract, turmeric extract, prickly pear dried leaves (PPL) and garlic extract versus each one alone in two different hyperlipidemic animal models. A two-week treatment of each of the natural extracts, combination 1 (artichoke, turmeric and PPL) or combination 2 (artichoke, turmeric, PPL and garlic) prior to a single intraperitoneal injection of Pluronic F-127 resulted in decreasing significantly serum LDL levels by garlic and PPL extracts and serum LDL/HDL ratios by turmeric, PPL, combination 1 and 2. In a 10-day high fat diet model, only the combination 1 and 2 lowered serum cholesterol, LDL by 8–12%, decreased significantly triglycerides, LDL/HDL ratio; and increased significantly HDL (P < 0.0001). However, a long term treatment of each natural product for 7 weeks resulted in decreasing significantly serum LDL levels and LDL/HDL ratio (P < 0.05–0.0001). Furthermore, only artichoke and PPL inhibited significantly HMG-CoA reductase activity (P < 0.05). In conclusion, short term, as well as long term, treatment using the combination of artichoke, turmeric, PPL and garlic extract prevents dyslipidemia; partially through inhibiting HMG-CoA reductase.

Pioglitazone Hcl Levels and Its Pharmacokinetic Application in Presence of Sucralose in Animals Serum by HPLC Method

Purpose: to develop a simple, valid and rapid chromatographic method for quantifying pioglitazone HCl in rats serum in order to study the pharmacokinetic parameters of pioglitazone HCl in rats serum fed with sucralose simultaneously for examination of interaction possibility between pioglitazone HCl and sucralose in rats. Methods: In our developed method of analysis, mobile phase was consisted of [51.50%] acetonitrile and [48.50%] 0.025 mM ammonium acetate with pH of 8, column of separation was C8 at temperature of 40°C using injection volume of 90 μl, mobile phase flow rate was 1 ml/min and samples run time was 10 min, the signals were monitored and analyzed at λ=269 nm and sildenafil citrate was used as internal standard. Pioglitazone was given to rats orally of [10mg/kg] dose while sucralose was given with [11 mg/kg/day] dose. Results: A successful HPLC method was validated and developed to quantify pioglitazone HCl in rats serum, overall intra-day precision and accuracy were reasonable with CV % values range [0.16-3.54] and accuracy % range [ 98.4-107.9], while inter-day precision and accuracy showed accepted precision with CV% range [ 0.15- 4.13] and accuracy % range [99.35-103.99]. The coefficient of correlation was 0.9991 with reasonable sensitivity and selectivity. Combination effect of pioglitazone with sucralose on pioglitazone serum profile was demonstrated as strong statistical effect according to Cohen’s d and significant P values too. Conclusion: A successful HPLC method was validated and developed to quantify pioglitazone HCl in rats serum, combination effect of pioglitazone with sucralose over all time intervals of pioglitazone serum profile was demonstrated as strong statistical effect.

Anti-inflammatory aminoacetylenic isoindoline-1,3-dione derivatives modulate cytokines production from different spleen cell populations.

We recently designed a series of N-[4-(t-amino-yl)-but-2-yn-1-yl] isoindoline-1,3-diones as anti-inflammatory compounds, called ZM compounds. These ZM compounds were categorized according to the nature of the cyclic amino groups into ZM2, ZM3, ZM4, and ZM5 and were shown to reduce carrageenan-induced inflammation, inhibit cyclooxygenase (1 and 2) and have less adverse effects than the common non-steroidal anti-inflammatory drugs. In the present study, we are examining the potential effects of ZM compounds in modulating cytokines production in vivo and in vitro from stimulated spleen cells, CD4+ CD25+ve T regulatory cells and CD4+CD25-ve T helper cells. Six hours following oral administration of 20mg/kg of ZM4 and ZM5 compounds reversed LPS-induced TGF-β suppression whereas ZM2, ZM3, ZM4, and ZM5 reversed LPS-induced TNF-α and IL-12 increase in mice spleen. In addition, increasing concentrations of ZM2, ZM4 and ZM5 increased significantly TGF-β1 production, whereas ZM3, ZM4 and ZM5 suppressed only TNF-α production in LPS and LPS+PMA stimulated spleen cells. Furthermore, only ZM5, enhanced significantly TGF-β1 production from LPS and LPS+PMA stimulated CD4+CD25+ve cells (p<0.001), whereas none of the ZM compounds modulated TNF-α from CD4+CD25-ve T helper cells. These results indicate that ZM5 (N-{4-(2-Azepan-1-yl)-but-2-yn-1-yl}isoindoline-1,3-dione) enhances TGF-β production from CD4+CD25+ve cells independent of protein kinase C activation and suggest that all ZM compounds suppress TNF-α from monocytes/macrophage cells. In conclusion, these ZM compounds have potential to be used use as anti-inflammatory agents and further studies to show the possibility of utilizing these basic aminoacetylenic isoindolines in autoimmune mediated inflammatory diseases are warranted.

Factors Involved in Formulation of Oily Delivery System for Proteins Based on PEG-8 Caprylic/Capric Glycerides and Polyglyceryl-6 Dioleate in a Mixture of Oleic Acid with Chitosan

Systematic experimental work is required to improve knowledge related to the use of oily delivery systems. This work aimed to examine the influence of different molecular weights chitosan on formation and solubilization ability of w/o system of Labrasol, Plurol Oleique, water and oleic acid. Phase diagrams were constructed. Size measurements were performed for each surfactant in oleic acid. Interfacial tension of chitosan was measured between oleic acid and water at pH 1.5 and 6.25. Effect of chitosan on microemulsion size was studied. When used to deliver rh-insulin to diabetic rats, the mixture showed reduction in blood glucose compared to control.