Emulsions and rectal formulations containing myrrh essential oil for better patient compliance

Myrrh has long been used for its circulatory, disinfectant, analgesic, antirheumatic, antidiabetic, and schistosomicidal properties. Myrrh essential oil (MEO) was extracted from the oleo-gum resin of Commiphora molmol and formulated into emulsions and suppositories to mask/avoid its bitter taste. Three oil-in-water emulsions (E1-E3) were formulated and taste was evaluated by 10 volunteers. Particle size distribution was measured and correlated with excipients and the method of preparation. Physical and chemical stability testing was carried out for the optimum formulation (E2). Seven suppository formulations were investigated (F1-F7). Suppocire AML (F1) and Suppocire CM (F2) were chosen as fatty bases, and polyethylene glycol (PEG) 1500 (F3), PEG 4000 (F4), and a PEG blend (50% PEG 6000 + 30% PEG 1500 + 20% PEG 400) (F5) were chosen as water-soluble bases. A blend of PEG 1500 and Suppocire CM was also used (F7). Camphor (5%) was added to PEG 1500 (F6). Disintegration time, release rate, DSC, fracture points, and weight uniformity were evaluated. The overall average bitterness for formulations E1, E2, and E3 was 6.44, 4.15, and 3.45, respectively. Suppositories containing Suppocire AML had the fastest disintegration time (1.5 min) with dissolution efficiency (DE) of 56.8%. F3 containing PEG 1500 had a fast disintegration time of 2.5 min and maximum DE of 93.5%. The PEG blend had satisfactory release: (DE = 90.9%). A mixed fatty and water-soluble base (F7) had a disintegration time of 5 min and low DE (33.4%). A stable MEO emulsion with acceptable taste was formulated to improve patient acceptance and compliance. F3 suppositories yielded satisfactory results, while formulations containing fatsoluble bases exhibited poor release.

Using factorial design to improve the solubility and in-vitro dissolution of nimesulide hydrophilic polymer binary systems

The aim of the present study was to use factorial design to enhance the dissolution rate of nimesulide using solid binary systems with the hydrophilic carriers D-mannitol and polyethylene glycol (PEG 4000). Two-factor full factorial design was employed to investigate the effects of the drug/carrier ratio (X(1), 10 and 20%) and the method of　preparation (X(2), physical or co-melted mixture) on　the percent drug release after 60 min (Y(1)). Drugcarrier co-melted mixtures were prepared by melting the carriers D-mannitol or PEG with the drug. For physical mixtures, the drug and carrier were mixed thoroughly in a mortar until a homogeneous mixture was obtained. Drug-carrier interactions were investigated by differential scanning calorimetry (DSC). All prepared mixtures were filled in hard gelatin capsules, size 0, and then their dissolution rate was tested. The results showed an increase in the solubility of the drug with increasing polymer concentrations. Thermal analysis revealed no notable differences regarding thermal events of nimesulide, D-mannitol, PEG 4000, and their physical or comelted mixtures. The percent drug released after 60 min was 29.5% for nimesulide alone, 37.14 and 32.0% for a PEG/Physical mixture with a 10 or 20% drug/polymer ratio, and 69.7 and 53.1% for a PEG/Co-melted mixture with the same ratios. For nimesulide/D-mannitol, this percent drug released was 33.57 and 29.6% for a physical mixture and 63.13 and 48.04% for a co-melted mixture. Formulations with PEG showed an increase in solubility as well as dissolution in comparison to those prepared with D-mannitol. Factorial design was successfully used to optimize the dissolution rate of nimesulide. The chosen polymers caused a notable increase in drug solubility and co-melted formulations generally showed a higher dissolution than those prepared with physical mixtures.

Evaluation of Vitacel M80K as a new direct compressible vehicle

Vitacel M80K, a cellulose powder coated with 2% colloidal silica, is a recently developed direct compressible vehicle (DCV). The aim of this study is to investigate the performance of M80K, in comparison with: a laboratory prepared vehicle (ELC+) consisting of a mixture of Elcema P050 (ELC) and 2% Aerosil, and a microcrystalline cellulose (MCC), Avicel PH 101 (Avicel). Bulk density, flow and surface characteristics of the DCVs were determined. Tablets were prepared by direct compression using various drugs; ascorbic acid (fine and coarse crystals), cimetidine, and paracetamol. Tablets prepared with M80K showed less weight variation than those prepared with Avicel. Ascorbic acid-Avicel tablets were slightly harder than those with M80K. However, in the presence of either cimetidine or paracetamol, M80K resulted in the production of tablets with maximum hardness. In most cases, except with paracetamol, M80K produced tablets with slightly higher friability in comparison to Avicel, while ELC+ showed maximum friability. M80K-paracetamol tablets showed the minimum friability values and highest hardness sensitivity towards increase of the applied compression force between 5 and 35 kN. M80K-containing formulations showed better hardness tolerance upon the addition of magnesium stearate. Disintegration times for most tablets were relatively short (<5 min).

Preparation and evaluation of slow-release pan-coated indomethacin granules

Granules containing indomethacin crystals are coated with Eudragit solutions of different RL/RS ratios using a pan coating technique. The process is reproducible with regard to drug content, inexpensive and the formed granules were directly compressed into tablets. In vitro release of indomethacin from coated granules, tablets and capsules was studied as a function of different ratios of Eudragit RL/RS in the coating solution. The release of the drug was significantly reduced by the coating process in comparison with a formulation made from uncoated granules, prepared using 10 per cent gelatin solution as a binder. Release data were found to follow a diffusion-controlled model.

Preparation and in vitro evaluation of slow release ketoprofen microcapsules formulated into tablets and capsules

Ketoprofen powder was encapsulated with Eudragit RL/RS polymer solutions in isopropanol-acetone 1:1, using a simple and rapid method. Microcapsules were prepared using Eudragit solutions with different RL/RS ratios. The encapsulation process produces free-flowing microcapsules with good drug content and marked decrease in dissolution rate. The retardation in release profile of ketoprofen from microcapsules was a function of the polymer ratio employed in the encapsulation process. In vitro release of ketoprofen from microcapsules either filled in gelatin capsules or compressed into tablets, using calcium sulphate as diluent, confirmed the efficiency of the encapsulation process for preparing prolonged release medication. A capsule formulation with optimum sustained-release profile was suggested.