solubility

Murraya koenigi is a medium sized tree belonging to the family Rutaceae. The major constituents present in the Murraya koenigii leaves treat burns, bruises. Ayurveda is a traditional Indian medicinal system practiced for thousands of years. Natural remedies are more acceptable in the faith that they are safer with less side effects than the synthetic ones. The novel formulations are reported to have remarkable advantages over conventional formulations of plant actives and extracts which include enhancement of solubility, bioavailability, protection from toxicity, enhancement of pharmacological activity, enhancement of stability, improved tissue macrophages distribution, sustained delivery and protection from physical and chemical degradation. Our main purpose is to treat/heal wound at faster rate with minimum side effects. Nanosponges alone are difficult to use on local tissues because they diffuse away to other parts of the body very quickly so to overcome the drawback we combined nanosponges with the herbal extract of Murraya Koenigii. According to literature survey it was found that etanolic and aqueous extract shows good wound healing results. Research on curry leaves revealed that they are also effective in fighting bacterial and fungal infections. The leaf extracts from the plant have been comparable to popular main stream antibiotic drugs. During this research work, we prepared ethanolic extract of Murraya Koenigii leaves and prepared nanosponges from it for treating burn wound. The nanosponges are prepared by Quasi emulsion solvent diffusion method. The prepared nanosponges were evaluated for various in-vitro parameters and the results obtained were satisfactory.

Nateglinide is an anti-diabetic drug that lowers the blood glucose levels by stimulating insulin secretion from pancreas. Because of low solubility and bioavailability, its usage is limited. In the present study solid dispersions of Nateglinide were prepared by solvent evaporation method and evaluated through various steps for biological correlation. Nateglinide solid dispersions were prepared using PEG 6000, Pluronic F 127 and Labrafil M 1944. A 3-factor, 3-level Central composite design employed to study the effect of each independent variable on dependent variables. X-ray diffraction was used to analyze the crystallinity and FTIR was used to analyze the drug and excipient compatibility. Scanning electron microscopy was performed to analyze the surface of solid dispersion samples. The correlation coefficient showed that the release profile followed Higuchi model (R2= 0.95836). From Korsmeyer peppas model, the release exponent, n was found to be 0.80635 (0.43 < n < 0.85) and followed anomalous behaviour and hence release mechanism was indicative of diffusion. From in vitro dissolution studies it was proved that a Nateglinide solid dispersion may achieve good formulation capability for pharmaceutical manufacturer by increasing solubility and dissolution rate. Key words: Nateglinide, Diabetes mellitus, solid dispersions, solubility, Central composite  

The poor aqueous solubility and dissolution rate of API is one of the main challenge in pharmaceutical development. The improvement of solubility and dissolution profiles of these lipophilic drug molecules without altering the molecular structure is a particular challenge for the successful development of pharmaceutical products. Pharmaceutical cocrystals are molecular complexes of an API and one or more cocrystal formers, which are solids at room temperature, interacting through hydrogen bonding, π-stacking or van der Waals forces. A crystalline form of the API is strongly preferred because of their relative ease of isolation, and the physico-chemical stability that the crystalline solid state affords. The vast majority of APIs occur as solids; these include, salts, polymorphs, cocrystals and hydrates/solvates. Cocrystallization as a method of obtaining new forms of Active Pharmaceutical Ingredients (APIs) with improved physicochemical properties like solubility, stability, and melting point has gained much attention in recent years and is a promising alternative to so far employed preparation of salts, hydrates, solvates and other forms. Cocrystallization improves physicochemical properties of drug without affecting their pharmacological properties. There are various methods for preparation of cocrystals like solvent evaporation, solution crystallization, antisolvent addition, kneading etc. The characterization methods includes FTIR, DSC, PXRD, NMR, Raman spectroscopy etc.

The present investigation is mainly on the synthesis, characterization and determination of some properties of new compound cetylpyridinium hexafluorosilicate for his potential use as caries-preventive and antibacterial agent. Hexafluorosilicate of the composition (C21H38N)2SiF6 was separated as crystalline product of interaction of hexafluorosilicic acid with the methanol solution of cetylpyridinium chloride. This complex was characterized by elemental analysis, IR, 1H and 19F NMR, mass-spectrometry, differential thermal analysis, and solubility data. The IR spectral data indicates on absence of noticeable distortion of the symmetry of SiF62– anion with regard to Oh. The studied compound is characterized by the predicted tendency to hydrolyze in dilute aqueous solutions with the formation of silica and fluoride anions.

Aceclofenac is a non steroidal anti- inflammatory drug characterized by low solubility and high permeability which corresponds to BCS class II drug. The strategy of increasing the in vitro dissolution has the potential to enhance the oral bioavailability when using nanosized crystalline drugs. The purpose of this study was to evaluate a novel in situ micronization method avoiding any milling techniques to produce nano- or microsized drug particles by controlled crystallization to enhance the dissolution rate of poorly water-soluble drugs. Aceclofenac microcrystals were prepared by the association of the previously molecularly dispersed drug using a rapid solvent change process. The drug was precipitated in the presence of stabilizing agents, such as hydrocolloids. The obtained dispersion was spray-dried. Particle size, morphology, flow property, zeta potential and dissolution rate were analyzed. Physicochemical properties were characterized using differential scanning calorimetry and X-ray diffractometry. The obtained dispersions showed a homogeneous particle size distribution. Drugs are obtained in a mean particle size of approximately 3µm and below. A high specific surface area was created and in situ stabilized. The surface was hydrophilized because of the adsorbed stabilizer. The solubility of the drug was increased by 2 folds. Thus, a drug powder with markedly enhanced dissolution rate was obtained. In situ micronization is a suitable method for the production of micro-sized drugs. This technique can be performed continuously or discontinuously and uses only common technical equipment. Compared to milled products drug properties are optimized as all particle surfaces are naturally grown, the particle size is more uniformly distributed and the powder is less cohesive.

In the last decade, poorly soluble drugs have been an area of concern for all the researchers in the field of pharmacy. A number of researches have been carried out to enhance the solubility and dissolution properties of such drugs. This study deals with a comprehensive review of liquisolid technique carried out mainly for biopharmaceutical classification system (BCS) class II & IV drugs. These drugs are having problems of poor solubility, dissolution and thus poor bioavailability. Various studies conducted on a number of drugs so far, have been reviewed. A variety of techniques such as micronization, salt formation, complexation, solid solutions, and liquisolid technique etc. have been used to overcome such problems. It has been observed that liquisolid technique is the most promising way for solubility and dissolution enhancement of such drugs. It can be concluded that liquisolid technique results in increased solubility, dissolution and thus bioavailability.

A drug should be present in dissolved or solublized state before producing its therapeutic effect however in current market more than 40% drugs are poorly soluble in water. Such drugs exhibit poor dissolution rate and slow absorption throughout the gastrointestinal tract which leads to irregular bioavailability. Thus various techniques has been adopted for solubility and dissolution enhancement of poor water soluble drugs thereby bioavailability. Solubility plays an important role in achieving the desired plasma drug concentration. In this review article various techniques like solid dispersion, SLNs, SEDDS, dried emulsion were discussed for solubility and dissolution rate improvement of BCS class II anti hyperlipidemic drug Simvastatin. Amongst various method described in this review, solid dispersion was found to be most used technique by researcher as it provide ease in preparation and efficiency in terms of resolving the solubility and dissolution problems associated with Simvastatin.

Solubility plays a vital role in achieving the therapeutic efficacy of a drug from a dosage form. Advances in molecular screening techniques for identification of potential drug molecules investigated an increased number of new pharmacologically active lipophilic compounds that are poorly water soluble. About 40% of new chemical entities have been discovered as poorly water soluble. Numbers of technical strategies have been investigated for improving bioavailability like solid dispersions, cyclodextrins, micronization, surfactants, nanoparticles, lipids, permeation enhancers etc. It is a great task for pharmaceutical scientist to formulate oral dosage forms of these drug candidates with sufficient bioavailability. Among the various approaches to improve oral bioavailability of these drug candidates, Self- dispersing lipid formulations (SDLF’s) is one of the approaches used to improve the bioavailability of lipophilic drugs. SDLF’s is very broad area which covers Self-emulsifying drug delivery systems (SEDDS), Self-microemulsifying drug delivery systems (SMEDDS) and Self-nanoemulsifying drug delivery systems (SNEDDS) as carrier systems that have been developed. This review article covers basics of SDLF’s particularly SMEDDS and recent research updates in SDLF’s i.e. the research carried out and most recent solid SDLF’s.

The present study deals with the dissolution of an angiotensin II receptor antagonist drug, candesartan. Candesartan cilexetil is a poorly water-soluble prodrug. The in vitro dissolution testing of Candesartan cilexetil in water and buffer solutions is not possible. In the present study, an attempt was made to develop a dissolution medium for in vitro testing of the drug. A Kromacil C18, 5µm column having 150x4.6 mm internal diameter in isocratic mode with mobile phase containing mixture of buffer (pH 4.5) and acetonitrile in ratio of 45:55 was used. The flow rate was 1.5 mL/min and effluents were monitored by UV at 257 nm. The selection of the medium was made on the basis of solubility data of Candesartan cilexetil in different dissolution medium at 37 °C. Solubility data revealed that phosphate buffer (pH 6.5) consisting of 0.35% w/v tween 20 could be a suitable dissolution medium. Key words: Candesartan, solubility, buffer, dissolution.

This study evaluated the dissolution behaviour of a novel amorphous form (Form A) and the commercially preferred crystalline form (Form I) of efavirenz. Generally, amorphous forms tend to achieve a greater extent and rate of dissolution compared to their crystalline counterparts. The results showed that the dissolution of Form A to be significantly lower than that of Form I due to agglomeration. Factors which contributed to the agglomeration behaviour of Form A include: high surface free energy, a lower degree of wetting, and the low glass transition temperature of Form A which caused the sample to convert to the rubber phase which is stickier. The agglomeration increased the relative particle size thereby reducing the exposed surface area of Form A; ultimately reducing the rate and extent of dissolution. The dissolution behaviour of Form A was found to be dependent on sample size and surfactant (SLS) concentration. Scanning Electron Microscopy (SEM) was employed to investigate surface area properties which provided information supporting the powder dissolution results. The solubility and intrinsic behaviour of the two forms were found to be comparable. Upon further investigation it was found that Form A undergoes phase mediated transformation into Form I during the solubility and dissolution experiments and that this too contributed to the apparent dissolution and solubility behaviour of Form A.  It was found the nucleation rate of Form A was potentiated by higher SLS content in the dissolution medium. Keywords: polymorph, amorph, dissolution, solubility, efavirenz.