Optimization of elastic transfersomes formulations for transdermal delivery of pentoxifylline.

Pentoxifylline (PTX) is a xanthine derivative indicated in treatment of intermittent claudication and chronic occlusive arterial diseases. It has low oral bioavailability and short half-life; thus, it was considered as a good candidate drug for the transdermal transfersomes formulation. In the present study, an attempt has been made for development, in-vitro and in-vivo evaluation of transdermal transfersomes using sodium cholate (SC) and non-ionic surfactants as edge activators. The optimal formulation, F4(Gcholate), exhibited drug entrapment efficiency of 74.9±1.6%, vesicles elasticity of 145±0.6 (mgs(-1)cm(-2)), zeta potential of -34.9±2.2mV, average vesicle diameter of 0.69±0.049µm with PDI of 0.11±0.037 and permeation flux of 56.28±0.19µgcm(-2)h(-1). It attained a prolonged drug release where 79.1±2.1% of PTX released after 10h of the run. The drug release kinetic obeys Higuchi model (R(2)=0.997) with Fickian diffusion mechanism. Moreover, the formula enhanced drug permeation through the excised rat's skin predominantly via the carrier-mediated mechanism by 9.1 folds in comparison with the control. Results of the in vivo pharmacokinetics study in male volunteers showed that F4(Gcholate) transfersomes formulation increased PTX absorption and prolonged its half-life comparing to the commercial oral SR tablets. Hence, the elastic transfersomes formulation of PTX possesses admirable potential to avoid drug metabolism, improve PTX bioavailability and sustain its release.

Development and Evaluation of Sustained Oral Ketorolac Tromethamine Particulate Matrix via Bioadhesive Chitosan Based Freeze-Dried Solid Dispersions.

OBJECTIVES: This study aimed to develop and evaluate chitosan (CTS) solid dispersion particulate matrix (SDPM) for sustained oral delivery of ketorolac tromethamine (KT). METHODS: SDPM formulations were prepared by freeze drying method and characterized for their effectiveness and biological activities via in vitro and in vivo assessment. KEY FINDINGS: Powder's flowability and bioadhesion of SDPM increased compared to KT-CTS physical mixtures and the raw materials. DSC analysis proved that the extent of drug crystallinity in matrix particles reduced as the amount of CTS content increased. FT-IR spectroscopy suggested drug-polymer interaction that was prominent in SDPM (1:7). In vitro drug release and simulated plasma profiles showed the superiority of SDPM (1:7) in sustaining drug release up to 12h. The optimized formula was stable during the storage time whereas the similarity factor (f2) for in vitro release data before and at the end of the study was 92%. Furthermore, in vivo bioactivity studies confirmed that the ulcerogenic property of SDPM (1:7) remarkably decreased compared to the standard drug while the analgesic and anti-inflammatory properties were maintained. CONCLUSION: Results suggested freeze-dried chitosan based SDPM (1:7) as a potential candidate for sustained oral administration of KT.

An investigation and characterization on alginate hydogel dressing loaded with metronidazole prepared by combined inotropic gelation and freeze-thawing cycles for controlled release.

The purpose of this study was to investigate the effect of combined Ca(2+) cross-linking and freeze-thawing cycle method on metronidazole (model drug) drug release and prepare a wound film dressing with improved swelling property. The hydrogel films were prepared with sodium alginate (SA) using the freeze-thawing method alone or in combination with ionotropic gelation with CaCl2. The gel properties such as morphology, swelling, film thickness, and content uniformity and in vitro dissolution profiles using Franz diffusion cell were investigated. The cross-linking process was confirmed by differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy. In vitro protein adsorption test, in vivo wound-healing test, and histopathology were also performed. The hydrogel (F2) composed of 6% sodium alginate and 1% metronidazole prepared by combined Ca(2+) cross-linking and freeze-thawing cycles showed good swelling. This will help to provide moist environment at the wound site. With the in vivo wound-healing and histological studies, F2 was found to improve the wound-healing effect compared with the hydrogel without the drug, and the conventional product.

Development of coated beads for oral controlled delivery of cefaclor: In vitro evaluation.

The aim of the present study was to develop and characterize coated chitosan-alginate beads containing cefaclor as a controlled release delivery system. Coated cefaclor beads were prepared by solvent evaporation techniques. Beads were found to be intact and spherical in shape. Their size range was 1.05 to 2.06. The loading efficiency showed maximum value when the concentration of cefaclor, chitosan and PEG 400 was 10 % (m/V), 0.5 % (m/V) and 2 % (V/V), respectively. Best retardation of cefaclor release from chitosan-alginate beads was achieved by coating with 15 % of shellac in formula F19. A significant antimicrobial activity (p < 0.05) against Staphylococcus aureus and Klebsiella pneumoniae was observed for formula F19 compared to the standard antibiotic disc. Furthermore, the simulated plasma profile showed the superiority of F19 in sustaining drug release for more than 12 h. Therefore, shellac coated chitosan-alginate beads could be considered a successful controlled release oral cefaclor dosage form.

Development and clinical evaluation of clotrimazole-ß-cyclodextrin eyedrops for the treatment of fungal keratitis.

Fungal keratitis is a serious corneal disease that may result in loss of vision. There are limited treatment options available in Iraqi eye hospitals which might be the main reason behind the poor prognosis of many cases. The purpose of this study was to prepare and pharmaceutically evaluate clotrimazole-ß-cyclodextrin (CTZ-ß-CD) eyedrops then clinically assess its therapeutic efficacy on fungal keratitis compared with extemporaneous amphotericin B eyedrops (0.5% w/v). A CTZ-ß-CD ophthalmic solution was prepared and evaluated by various physicochemical, microbiological, and biological tests. The prepared formula was stable in 0.05 M phosphate buffer pH 7.0 at 40 ± 2°C and 75 ± 5% RH for a period of 6 months. Light has no significant effect on the formula's stability. The CTZ-ß-CD eyedrops efficiently complied with the isotonicity, sterility, and antimicrobiological preservative effectiveness tests. Results of the clinical study revealed that 20 (80%) patients showed a favorable response to the CTZ-ß-CD eyedrops, while 16 patients (64%) exhibited a favorable response to amphotericin B (P > 0.05). The mean course of treatment was significantly (P < 0.05) less in the CTZ treatment group than in the amphotericin group (21.5 ± 5.2 vs. 28.3 ± 6.4 days, respectively). The CTZ formulation was significantly (P < 0.05) more effective in the management of severe cases and also against Candida sp. than amphotericin B. There was no significant difference (P < 0.05) between both therapies against filamentous fungi. The CTZ-ß-CD formulation can be used alternatively to other ophthalmic antimycotic treatment options in developing countries where stability, cost, or efficacy is a limiting factor.

Design and evaluation of a bioadhesive film for transdermal delivery of propranolol hydrochloride.

The objective of the study was to develop a suitable trans-dermal delivery system for propranolol hydrochloride (PPL) via employing chitosan as a film former. Drug concentration uniformity, thickness, moisture uptake capacity and skin bioadhesion of the films were characterized. The effects of chitosan and PPL concentration and different penetration enhancers on the release and permeation profiles from the films were investigated. Skin irritation of the candidate film was evaluated. Chitosan film (PPL 2 mg cm(-2), chitosan 2%, m/m, cineol 10%, m/m) was found nonirritant and achieved 88.2% release after 8 hours in phosphate buffer. Significant high (p < 0.001) permeation of PPL through rat skin was obtained using this film compared to the film without enhancer (about 8 times enhancement factor), making it a promising trans-dermal delivery system for PPL.

Development of an optimised application protocol for sonophoretic transdermal delivery of a model hydrophilic drug.

It has now been known for over a decade that low frequency ultrasound can be used to effectively enhance transdermal drug penetration - an approach termed sonophoresis. Mechanistically, acoustic cavitation results in the creation of defects in the stratum corneum that allow accelerated absorption of topically applied molecules. The aim of this study was to develop an optimised sonophoresis protocol for studying transdermal drug delivery in vitro. To this end, caffeine was selected as a model hydrophilic drug while porcine skin was used as a model barrier. Following acoustic validation, 20kHz ultrasound was applied for different durations (range: 5 s to 10 min) using three different modes (10%, 33% or 100% duty cycles) and two distinct sonication procedures (either before or concurrent with drug deposition). Each ultrasonic protocol was assessed in terms of its heating and caffeine flux-enhancing effects. It was found that the best regimen was a concurrent 5 min, pulsed (10% duty cycle) beam of SATA intensity 0.37 W/cm(2). A key insight was that in the case of pulsed beams of 10% duty cycle, sonication concurrent with drug deposition was superior to sonication prior to drug deposition and potential mechanisms for this are discussed.

Meloxicam ß-cyclodextrin transdermal gel: physicochemical characterization and in vitro dissolution and diffusion studies.

The aim of the study was to develop a Meloxicam (ME) transdermal gel formulations based on complexation with ß-cyclodextrin. ME ß-Cyclodextrin gel formulations were prepared using four different gel bases with different concentrations and different permeation enhancers. The developed formulations were examined for their in vitro characteristics and their diffusion through a mouse skin. The gel formulations were prepared successfully. Physicochemical characterization of ME ß-CD complex in solution state by phase solubility revealed 1:1 M complexation of ME with ß-Cyclodextrin. ME release profiles from the inclusion complex were superior over ME alone. Hydroxypropyl methyl cellulose 15% w/w gel base was proven to be a suitable base for ME inclusion complex formulation as it provides a high drug release than other studied bases. ME ß-CD complex gel formulations containing oleic acid (1% w/w) or (5% w/w) cineol used as permeation enhancers in (15% w/w) HPMC gel base were proven to provide a higher diffusion rate of the drug through the mouse skin. This is very promising in providing analgesic activity of meloxicam via topical route of administration.

Professional practices and perception towards rational use of medicines according to WHO methodology in United Arab Emirates.

UNLABELLED: Inappropriate prescribing reduces the quality of medical care and leads to a waste of resources. No study has been reported concerning rational drug use in United Arab Emirates, UAE, recently. OBJECTIVES: assessing patterns of use and defining problems regarding the rational drug use.Setting baseline situational analysis study for practices in the health care system relevant to drug use. METHOD: A descriptive pilot study, consisting of pharmacists, physicians and patients (100 of each of category) from four private hospitals, (12) medical clinics, (80) community pharmacies in addition to 150 prescriptions. A questionnaire of three sections was designed to include WHO indicators regarding patients, facility and prescribing patterns that are relevant to rational drug use was carried out in four emirates of the UAE in the period December 2008-Febreuary 2009. RESULTS: Consultation and dispensing times were 10 (SD=2.75) min and 68 (SD=9.7) seconds, respectively. Average no. of drugs per prescription was (2.9 + 0.97), % of prescriptions using generic name (7.35%), % of antibiotic containing prescriptions (31.1%), % of injection containing prescriptions (2.9%), adherence to Standard Treatment Protocols (46%), adherence to the essential drug list (64%), patient's knowledge of correct dosage (55%), adequately labeled drugs (45%), patient's information (65%). CONCLUSIONS: Several areas of deficiency in rational drug use had been defined in the private sector through UAE that can be remedied through adopting several strategies such as adherence to national standard treatment guidelines and essential drug list based on treatments of choice, interaction between health care system and providing drugs information to consumers.