Bioadhesive drug delivery system of diltiazem hydrochloride for improved bioavailability in cardiac therapy

Purpose: To prepare and evaluate bioadhesive buccal films of diltiazem hydrochloride (a L-type calcium channel blocker) for overcoming the limitations of frequent dosing, low bioavailability and gastrointestinal discomfort of oral delivery. Methods: Buccal films were prepared by solvent casting technique using sodium carboxymethylcellulose, polyvinyl pyrrolidone K-30 and polyvinyl alcohol. The films were evaluated for weight, thickness, surface pH, swelling index, in vitro residence time, folding endurance, in vitro release, ex-vivo permeation (across porcine buccal mucosa) and drug content uniformity. Results: The drug content of the formulations was uniform with a range of 18.94 ± 0.066 (F2) to 20.08 ± 0.07 mg per unit film (F1). The films exhibited controlled release ranging from 58.76 ± 1.62 to 91.45 ± 1.02 % over a period > 6 h. The films containing 20 mg diltiazem hydrochloride, polyvinyl alcohol (10 %) and polyvinyl pyrrolidone (1 % w/v) i.e. formulation F5, showed moderate swelling, convenient residence time and promising drug release, and thus can be selected for further development of a buccal film for potential therapeutic uses. Conclusion: The developed formulation is a potential bioadhesive buccal system for delivering diltiazem directly to systemic circulation, circumventing first-pass metabolism, avoiding gastric discomfort and improving bioavailability at a minimal dose.

Thyroid function in multidrug-resistant tuberculosis patients with or without human immunodeficiency virus (HIV) infection before commencement of MDR-TB drug regimen.

Background: Mycobacterium tuberculosis and human immunodeficiency virus (HIV) are known to cause abnormal thyroid function. There is little information on whether HIV infection aggravates alteration of thyroid function in patients with MDRTB. Objectives: This study was carried out to determine if HIV co-infection alters serum levels of thyroid hormones (T3, T4) and thyroid stimulating hormone (TSH) in patients with MDR-TB patients and to find out the frequency of subclinical thyroid dysfunction before the commencement of MDR-TB therapy. Methods: This observational and cross-sectional study involved all the newly admitted patients in MDR-TB Referral Centre, University College Hospital, Ibadan, Nigeria between July 2010 and December 2014. Serum levels of thyroid stimulating hormone (TSH), free thyroxine (fT4) and free triiodothyronine (fT3) were determined using ELISA. Results: Enrolled were 115 patients with MDR-TB, out of which 22 (19.13%) had MDR-TB/HIV co-infection. Sick euthyroid syndrome (SES), subclinical hypothyroidism and subclinical hyperthyroidism were observed in 5 (4.35%), 9 (7.83%) and 2 (1.74%) patients respectively. The median level of TSH was insignificantly higher while the median levels of T3 and T4 were insignificantly lower in patients with MDR-TB/HIV co-infection compared with patients with MDRT-TB only. Conclusion: It could be concluded from this study that patients with MDR-TB/HIV co-infection have a similar thyroid function as patients having MDR-TB without HIV infection before commencement of MDR-TB drug regimen. Also, there is a possibility of subclinical thyroid dysfunction in patients with MDR-TB/HIV co-infection even, before the commencement of MDR-TB therapy.

Eradication of Helicobacter pylori in Children by Triple Therapy Regimens of Amoxicillin, Omeprazole, and Clarithromycin or Azithromycin

Background and Objectives: The present study aimed to evaluate the effect of classical and azithromycin-containing triple therapy eradication regimen against H. pylori in children, and to determine the level of patients’ tolerance. Patients and Methods: This single clinical trial was performed in 2014 on 2 to 15 years old children. All children, in whom H. Pylori infection was confirmed through multiple biopsies of the stomach and required treatment, were enrolled in the study. H. Pylori-positive patients were treated alternately with two different drug regimens; Group OCA received clarithromycin 7.5 mg/kg/day every 12 hours for 10 days, amoxicillin 50 mg/kg/day every 12 hours for 10 days, and omeprazole 1 mg/kg/day every 12 hours for two weeks, and Group OAA received azithromycin 10 mg/kg/day once a day (before meal) for 6 days along with amoxicillin and omeprazole. Four to six weeks after completion of treatment, patients’ stool was tested for H. Pylori through the monoclonal method using the Helicobacter antigen quick kit. Results: There were no significant differences between the two groups regarding gender and age of patients. Based on ITT analysis, the therapeutic response in the OAA and OCA groups were 56.2% and 62.5%, respectively (P = 0.40). Drug adverse effects were 15.6% in the OCA and 3.1% in the OAA group (P = 0.19). Conclusions: The therapeutic response was seen in more than half of the patients treated with triple therapy of H. Pylori eradication regimen including azithromycin or clarithromycin, and there was no significant difference between the two treatment groups. Keywords: Treatment,

Development of paclitaxel-loaded liposomal systems with anti-her2 antibody for targeted therapy

Purpose: To develop liposome formulations containing monoclonal antibody anti-HER2 (MabHer2), and Paclitaxel (PTX). Methods: Seven different liposomal systems containing PTX, or MabHer2 or a combination of PTX and MabHer2 were made using lipid film hydration technique and sonication. The effects of liposome preparation conditions and extraction methods on antibody structure were investigated by polyacrylamide gel electrophoresis and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The characteristics of the liposomes were determined by a zetasizer, while drug-loading efficiency was evaluated by high-performance liquid chromatography. The cytotoxic effect of the liposome formulations was evaluated on MDA-MB-453 (HER2+) and MCF-7 (HER2-) breast cancer cell lines by MTT assay. Results: The antibody was not significantly affected by the stress conditions and the method of extraction. The particle size of liposomes was < 200 nm while the amount of incorporated PTX was 97.6 % for liposome without cationic agent and 98.2 % for those with cationic agent. Recovery of MabHer2 was 94.38 % after extraction. Combined PTX/MabHer2 liposome was more toxic on HER2 overexpressing positive MDA-MB-453 cell line than PTX-loaded liposomes and MabHer2. MabHer2 and combined PTX/MabHer2 liposomes showed no toxic effects on HER2 overexpressing negative MCF-7 cells relative to cationic PTX-loaded liposomes. Conclusions: This results obtained show that PTX can be encapsulated successfully into liposoma systems and that owing to Her2 specific antibody, these systems can be delivered directly to the target cell.