Abstract Liquisolid systems is an innovative technique for enhancing solubility, dissolution and bioavailability of poorly water soluble drugs. It involves changing of the drug in the liquid state into compressible and freely flowable dry powder throughout its absorption into appropriate porous carrier (e.g.microcrystalline cellulose), after that the powder coated with material has a highly adsorption capacity (known as colloidal silica). Orally disintegrating tablets represent a novel dosage form that overcomes the difficultiess of swallowing and provides a fast onset of action. Zolmitriptan is a slightly soluble drug used for treatment of acute headache of migraine; it's known to suffer from first pass effect with bioavailability of 40 %.
The solution homogeneity expelled, by centrifugation for 10 min. The sample was centrifuged and separated into two layers, and took the top of the sample is injected for HPLC (11,12). Measured concentration in total lipid: The total fats balanced concentration of the pesticide getting by dividing the measured pesticide residue concentration in the overalll tissue sample by the decimal fraction of the sample that consisted of ether-extractable lipid. The total lipid content of each specimen was estimated from its total cholesterol & triglycerides levels by using a summation method. Analytical results for organochlorine pesticides were reported on a lipid-adjusted basis (nanograms per gram or parts per billion) (14).
The terms “acceptable flow and compression properties” imply the desired and thus preselected flow and compaction properties which must be met by the final liquisolid formulation. Depending on the excipient ratio (R) of the powder substrate an acceptable flowing and compressible liquisolid system can be obtained only if a maximum liquid load on the carrier material is not exceeded. This liquid/carrier ratio is termed liquid load factor Lf [w/w] and is defined as the weight ratio of the liquid formulation (W) and the carrier material (Q) in the
Secondly, the obtained blend was uniformly spread as a homogeneous layer on the surface of the mortar and left standing for five minutes to allow the liquid medication to be absorbed inside powder particles. Thirdly, the powder was scraped from mortar surface by means of a spatula and blended with a calculated quantity of superdisintegrant 5% (w/w) for 10 minutes. Sodium starch glycolate (SSG) was used in the all liquisolid formulations, then the final mixture was lubricated with 1% magnesium stearate for two minutes. Lastly, the prepared formulations were compressed manually into cylindrical tablets by using a single punch tablet press machine of die sizes measuring 6 and 8 mm. The optimized formulation with optimal R value, drug concentration and loading factor was determined according to the flow properties and in-vitro dissolution studies.
pH, Percentage Drug Content and Content drug Uniformity Solution of 1g of gel dissolved in 30mL of distilled water was prepared and pH was determined by using digital pH meter (Systronics 361) and the results were summarized in the table 3. The drug Content Uniformity  was determined by the following method. 1g of gel was dissolved in a 100 mL of phosphate buffer pH 7.4 for 48 hrs with constant stirring using magnetic stirrer. Samples were taken from three different parts of the total ethosomal gel of 1g. Solution was then filtered and observed with UV-spectrophotometer at λmax 254nm.
• This evaporation was carried out slowly. • As a result of heating, vaporization or decomposition of some of the dissolved solids occurred but not completely. • Samples were heated in such a way that over heating may not occur. • After the samples got dry, weight of the solids present within the containers was again determined. These solids particles were dissolved in 1000 mL of
Surfactant, Cholesterol was dissolved in 8ml of diethyl ether and drug was dissolved in 2ml of ethanol. The mixture was then transferred to a round bottom flask, and the solvent was evaporated under reduced pressure at a temperature 20-25ºC, using a rotary flash evaporator until the formation of a thin lipid film. The formed film was hydrated with 10 ml of Phosphate buffer saline pH 7.4. The hydration was continued for 1 h, while the flask was kept rotating at 55-65°C. The hydrated niosomes were sonicated for 20 min using a bath sonicator to obtain niosomal dispersion containing both free and entrapped drugs of varying size.
The solution was shaken intermittently to assist the attainment of equilibrium with the undissolved drug particles. Then measured quantity of the filtered drug solution was withdrawn after 24 hrs and successively diluted with respective solvents and the concentration was measured spectrophotometrically. Average of triplicate readings was taken Analytical method A suitable method of estimation was developed for drugs namely diltiazem hydrochloride and nifedipine in methanol and phosphate buffer pH 6.8. Standard graph of Diltiazem hydrochloride in methanol and phosphate buffer pH7.4 Procedure Calibration curve for estimation of Diltiazem hydrochloride Spectrophotometric method is based on observed λ max of 238 nm in UV-region using phosphate buffer pH 7.4 and methanol was used for estimation of Diltiazem hydrochloride in the present study. Preparation of buffer Preparation of phosphate buffer pH 7.4: Potassium dihydrogen phosphate solution of 0.2 M was prepared and 250 ml of this solution was mixed with 195.5 ml of 0.2 M NaOH and volume was made up to 1000ml with distilled water.
STANDARD CURVE IN 0.1 N HCL Accurately weighed 10 mg of drug (hydrochlorthiazide) was first dissolved in10 mL of methonal in 100 mL of volumetric flask to make a concentration of 1000 μg/mL (primary stock solution). 1 mL of primary stock solution was pipetted out into 10 mL of volumetric flask and volume was adjusted with water to make a concentration of 100μg/mL (secondary stock solution).From the secondary stock solution various concentrations such as 1, 2, 3, 4, 5…..10 μg/mL were prepared for calibration curve. Standard curve was plotted by taking absorbance of secondary stock solutions in UV double beam spectrophotometer at 240 nm. Compatibility Studies Compatibility with excipients was conformed by carried out I R studies. The pure drug and its formulations along with excipients were subjected to IR studies.
Commonly the drugs may have dissolution conditions as in USP monograph. 0.1N HCl, pH 4.5 and pH 6.8 buffers should be used for evaluation of ODT in the same way as their ordinary tablet counterparts. USP 2 paddle apparatus is most suitable and common choice for dissolution test of FDT tablets as compared to USP1 (basket) apparatus due to specific physical properties of tablets. In paddle apparatus the paddle speed of 25-75 rpm is commonly used. Since the dissolution of ODTs is very fast when using USP monograph conditions hence slower paddle speeds may be utilized to obtain a comparative profile.