Preparation of Losartan Potassium Controlled Release Matrices and In-Vitro Investigation Using Rate Controlling Agents

Controlled release matrices have predictable drug release kinetics, provide drugs for an extended period of time, and reduce dosing frequency with improved patient compliance as compared with conventional tablet dosage forms. In the current research work, losartan potassium controlled release matrix tablets were fabricated and prepared with rate altering agents; that is, Ethocel grade 100 combined with Carbopol 934PNF. Various drug to polymer ratios were used. HPMC, CMC, and starch were incorporated in some of the matrices by replacing some amount of filler (5%). The direct compression method was adopted for the preparation of matrices. In phosphate buffer (pH 6.8), the dissolution study was conducted by adopting the USP method-I as the specified method. Drug release kinetics was determined and dissolution profiles were also compared with the reference standard. Prolonged release was observed for all matrices, but those with Ethocel 100FP Premium showed more extended release. The co-excipient (HPMC, CMC, and starch) exhibited enhancement in the drug release rates, while all controlled release matrices released the drug by anamolous non-Fickian diffusion mechanism. This combination of polymers (Ethocel grade 100 with Carbopol 934PNF) efficiently extended the drug release rates up to 24 h. It is suggested that these matrix tablets can be given in once a day dosage, which might improve patient compliance, and the polymeric blend of Ethocel grade 100 with Carbopol 934PNF might be used in the development of prolonged release matrices of other water-soluble drugs.     

Statistical optimization of tamsulosin hydrochloride controlled release pellets coated with the blend of HPMCP and HPMC

The objective of the present study was to evaluate three coating parameters for the application of a blend of HPMCP and HPMC in ethylcellulose aqueous dispersions (Surelease) in order to obtain controlled release of tamsulosin hydrochloride. The selected independent variables, HPMCP content (X1), HPMC content (X2) and coating level (X(3)), were optimized with a three-factor, three-level Box-Behnken design. The selected dependent variables were the cumulative percentage values of tamsulosin hydrochloride that had dissolved after 2, 3 and 5 h. Various dissolution profiles of the drug from controlled release pellets were obtained. Optimization was performed for X1, X2 and X3 using the following target ranges; 15% < or = Y1 < or= 30%; 50% < or = Y2 < or = 65%; 80% < or = Y3 < or = 95%. Results of the optimization procedure indicated that the optimized levels of HPMCP content (X1), HPMC content (X2) and coating level (X3) were 30%, 15% and 25%, respectively. Controlled release pellets coated with the optimized formulation provided a release profile that was close to predicted values. In addition, the dissolution profiles of the controlled release pellets coated with the optimized formulation were similar to those of the commercial product Harunal capsule (f1 = 4.6, f2 = 78.7).     

A controlled porosity osmotic pump system with biphasic release of theophylline

A controlled porosity osmotic pump system with biphasic release of theophylline was developed for the nocturnal therapy of asthma. The developed system was composed of a tablet-in-tablet (TNT) core and a controlled porosity coating membrane. Release pattern of the developed system was influenced by amount of pore former (18.2-45.5%, w/w of polymer), weight gain (16-26 mg per tablet) of the coating membrane and osmotic agents used in inner layer of the TNT core. When sodium phosphate and sodium chloride were selected as the osmotic agents in inner and outer layer of the TNT core respectively, target release profile was obtained with coating solution cellulose acetate-polyethylene glycol 400-diethyl phthalate (54.5-36.4-9.1%, w/w) at a weight gain of 16-22 mg per tablet. To examine the mechanism of drug release, release profiles of osmotic agents, micro-environmental osmotic pressure and micro-environmental pH of the formulation during dissolution were studied. Micro-environmental osmotic pressure decreased and micro-environmental pH increased continuously during the whole dissolution process, theophylline release was dominated by the successive dissolution of sodium chloride and sodium phosphate. Theophylline solubility increased as environmental pH exceeded 10.8. At the last stage of the biphasic release, micro-environmental pH in the developed formulation reached 10.9, and theophylline release was promoted by its elevated solubility despite of the decrease of micro-environmental osmotic pressure in the developed formulaiton.     

Formulation approach for nicorandil pulsatile release tablet

The purpose of this study was to obtain a nicorandil pulsatile release tablet that has a well-regulated release lag time. When nicorandil is used as an antiangina drug, administration time control is important. A pulsatile release tablet is one of the effective approaches to modified release to reduce daily administration frequency. In this study, a pulsatile release tablet of nicorandil was formulated by fumaric acid dry coating around the core tablet including nicorandil. The model tablets, which had different content ratios of excipients in the dry-coating layer, were characterized by a dissolution test. The results showed that the release lag time was generated with fast release profiles. Various lag time controls of tablets were achieved, from 60 to 310 min on average, by variation of outer layer composition. From an analysis of the relation between lag times and outer layer composition, the key ingredient for prolongation of lag time was found to be fumaric acid. To analyze the lag time generation mechanism, water penetration for tablet was measured. The results indicated that the penetration depth was proportionate to the square root of time and the lag time formation mechanism was simple water penetration through the matrix of fumaric acid to the tablet core. The results also showed that the Washburn equation could be used to design the lag time of the pulsatile release tablet in this study. In conclusion, novel release control technology using fumaric acid was appropriate to obtain a nicorandil pulsatile release tablet that has well regulated lag time.     

Formulation of Risperidone as Self-Nanoemulsifying Drug Delivery System in Form of Effervescent Tablets

Risperidone is an atypical antipsychotic drug used to treat schizophrenia. This study aims to formulate risperidone as effervescent tablets to improve patient compliance. Different nanoemulsion combinations were loaded with risperidone to improve its poor water solubility then adsorbed on Aeroperl. The formula showing highest drug dissolution was formulated as effervescent tablets. Factorial design was applied for different tablet formulation variables and the prepared formulae were tested for different criteria in comparison with their corresponding formulae containing drug without nanoemulsion formulation. Statistical analysis was used to determine the most desirable tablet formula considering its Carr index, effervescence time, and drug release.     

Optimization of metformin HCl 500 mg sustained release matrix tablets using Artificial Neural Network (ANN) based on Multilayer Perceptrons (MLP) model

The aim of the present study was to apply the simultaneous optimization method incorporating Artificial Neural Network (ANN) using Multi-layer Perceptron (MLP) model to the development of a metformin HCl 500 mg sustained release matrix tablets with an optimized in vitro release profile. The amounts of HPMC K15M and PVP K30 at three levels (-1, 0, +1) for each were selected as casual factors. In vitro dissolution time profiles at four different sampling times (1 h, 2 h, 4 h and 8 h) were chosen as output variables. 13 kinds of metformin matrix tablets were prepared according to a 2(3) factorial design (central composite) with five extra center points, and their dissolution tests were performed. Commercially available STATISTICA Neural Network software (Stat Soft, Inc., Tulsa, OK, U.S.A.) was used throughout the study. The training process of MLP was completed until a satisfactory value of root square mean (RSM) for the test data was obtained using feed forward back propagation method. The root mean square value for the trained network was 0.000097, which indicated that the optimal MLP model was reached. The optimal tablet formulation based on some predetermined release criteria predicted by MLP was 336 mg of HPMC K15M and 130 mg of PVP K30. Calculated difference (f(1) 2.19) and similarity (f(2) 89.79) factors indicated that there was no difference between predicted and experimentally observed drug release profiles for the optimal formulation. This work illustrates the potential for an artificial neural network with MLP, to assist in development of sustained release dosage forms.     

In vitro evaluation of mucoadhesive vaginal tablets of antifungal drugs prepared with thiolated polymer and development of a new dissolution technique for vaginal formulations

The main objective of this work was to develop antifungal matrix tablet for vaginal applications using mucoadhesive thiolated polymer. Econazole nitrate (EN) and miconazole nitrate (MN) were used as antifungal drugs to prepare the vaginal tablet formulations. Thiolated poly(acrylic acid)-cysteine (PAA-Cys) conjugate was synthesized by the covalent attachment of L-cysteine to PAA with the formation of amide bonds between the primary amino group of L-cysteine and the carboxylic acid group of the polymer. Vaginal mucoadhesive matrix tablets were prepared by direct compression technique. The investigation focused on the influence of modified polymer on water uptake behavior, mucoadhesive property and release rate of drug. Thiolated polymer increased the water uptake ratio and mucoadhesive property of the formulations. A new simple dissolution technique was developed to simulate the vaginal environment for the evaluation of release behavior of vaginal tablets. In this technique, daily production amount and rate of the vaginal fluid was used without any rotational movement. The drug release was found to be slower from PAA-Cys compared to that from PAA formulations. The similarity study results confirmed that the difference in particle size of EN and MN did not affect their release profile. The release process was described by plotting the fraction released drug versus time and n fitting data to the simple exponential model: M(t)/M(∞)=kt(n). The release kinetics were determined as Super Case II for all the formulations prepared with PAA or PAA-Cys. According to these results the mucoadhesive vaginal tablet formulations prepared with PAA-Cys represent good example for delivery systems which prolong the residence time of drugs at the vaginal mucosal surface.     

The effect of sodium alginate on physical and dissolution properties of Surelease-matrix pellets prepared by a novel pelletizer

The aim of this study was to investigate the effect of sodium alginate on the physical and dissolution properties of Surelease-matrix pellets prepared by a novel pelletizer-equipped piston extruder and double-arm counter-rotating rollers. The mean values of the shape factor (e(R)) and the aspect ratio of Surelease-matrix pellets were 0.615-0.625 and 1.06-1.070, respectively, indicating good sphericity of the pellets. The drug release rate increased as the amount of sodium alginate increased due to hydration, swelling, and erosion within the Surelease-matrix pellets. In addition, the porosity of pellets also increased with increasing sodium alginate content. The results of this study show that sodium alginate has a greater effect on the drug release rate than the drug release mechanism within the Surelease-matrix for sparingly water-soluble drug, such as tamsulosin hydrochloride.     

Application of polyglycolized glycerides in protection of amorphous form of etoricoxib during compression

Polymorphic transition and stability problems during amorphous drug formulation are the major limiting factors in pharmaceutical technology. The purpose of the study was to evaluate the ability of polyglycolized glycerides (Gelucire) in protection of amorphous form of drug during compression and shelf life with lower proportion. Amorphous etoricoxib (AET) was prepared by spray drying technique. Tablets of AET and melt granules of AET (MG-AET) with Gelucire 50/13 were prepared. Tablets parameters like hardness, disintegration and content uniformity were evaluated. Tablets were evaluated immediately after compression and on storage for 3 months at ambient conditions to determine degree of transformation using X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC) and dissolution profiles. Spray drying yielded the amorphous etoricoxib. Content uniformity in the tablet was in between 95 to 105%. Other parameters like disintegration and hardness were well within the limits. The results showed significant difference in the degree of crystallinity between AET tablet and MG-AET tablet. MG-AET tablet showed absence of crystallinity after 3 months storage. The reason could be formation of hydrogen bonding between the Gelucire and AET. Also Gelucire can be tableted very easily under low pressure and showed elastic recovery. Gelucire yielded a soft embedding during tableting, which prevented the polymorphic transformation. Polyglycolized glycerides (Gelucire 50/13) are able to protect amorphous etoricoxib during compression. As excipient required is low, it became possible to prepare tablet formulation as compared to other excipient like polyvinylpyrrolidon (PVP).     

Development and validation of HPLC method for simultaneous estimation of piperine and guggulsterones in compound Unani formulation (tablets) and a nanoreservoir system

An attempt has been made to develop and validate a simultaneous HPLC method for novel approach of drug release via oil‐in‐water (o/w) nanoemulsion formulation and Habb‐e‐Khardal Unani tablet containing piperine and guggul sterones E and Z as main ingredients. Nanoemulsion was prepared by titration method using sefsol‐218 as an oily phase, cremophor‐EL as a surfactant, transcutol as a co‐surfactant and distilled water as an aqueous phase. The formulation was optimized on the basis of thermodynamic stability and dispersibilty test. The nanoformulation was evaluated for particle size, surface morphology, electrical conductivity and viscosity determination. The in vitro dissolution was carried out by dialysis bag method. Drugs were quantified using an HPLC method developed in‐house with a C₁₈ column as stationary phase and acetonitrile and water as mobile phase at λ_max of 240 nm. The optimized formulation showed higher drug release, lower droplet size and less viscosity as compared with the conventional Habb‐e‐Khardal Unani tablet. The present study illustrated the potential of nanoemulsion dosage form in improving biopharmaceutic performance of piperine and guggul sterone. The HPLC method was also found to be quite sufficient for the routine quality control of formulations containing piperine and guggul sterone E and Z as ingredients and also for in vitro drug release studies. Copyright © 2011 John Wiley & Sons, Ltd.     

Effects of natural polysaccharide addition on drug release from calcium-induced alginate gel beads

Calcium-induced alginate gel beads (Alg-Ca) containing various polysaccharides, including an alginate hydrolysate, were prepared and the drug release profiles were investigated. Hydrocortisone (HC) was gradually released from Alg-Ca into the mimic gastric fluid, while in intestinal fluid, it was quickly released with the dissolution of Alg-Ca. However, with Alg-Ca containing 5% chitin (CT), dissolution of Alg-Ca was not observed, and release of HC showed apparent zero-order kinetics. Furthermore, addition of the alginate hydrolysate altered the HC-release profile for Alg-Ca.     

Formulation study for lansoprazole fast-disintegrating tablet. I. Effect of compression on dissolution behavior

Lansoprazole fast-disintegrating tablet (LFDT) is a new patient-friendly formulation of lansoprazole. Since lansoprazole is an antiulcer agent and is unstable under acidic conditions, we have developed LFDT as an orally disintegrating tablet containing enteric-coated microgranules. The effect of compression on dissolution behavior was investigated, as compression affected cleavage and crushing of the enteric layer. To decrease cleavage and crushing of the enteric layer, the effects of the combined ratio of methacrylic acid copolymer dispersion to ethyl acrylate-methyl methacrylate copolymer dispersion and the concentration of triethyl citrate on the dissolution in the acid stage and the dissolution in the buffer stage were evaluated. By adjusting the ratio of methacrylic acid copolymer dispersion to ethyl acrylate-methyl methacrylate copolymer dispersion to 9 : 1 and adding a 20% triethyl citrate concentration, sufficient flexibility of the enteric layer and sufficient stability against compression forces were achieved. Agglomeration of enteric-coated microgranules during the coating process was decreased at the optimized concentration of triethyl citrate and glyceryl monostearate. We compared the absorption properties of LFDT and lansoprazole capsules in dogs. The absorption profiles of LFDT were similar to those of lansoprazole capsules.     

A novel application of the T-cell for flow-through dissolution: The case of bioceramics used as ibuprofen carrier

This paper describes the use of a novel flow cell, the T-cell, adapted to the flow-through cell apparatus, for the study of ibuprofen release from implantable loaded pellets and its performance in comparison to the compendial tablet cell. In fact, the drug targeting with a local delivery system becomes increasingly used to achieve therapeutic doses directly on the implantation site while maintaining a low systemic drug level. Due to the long and expensive in vivo studies necessary to evaluate the efficacy of such delivery systems, in vitro dissolution techniques are performed despite there being no standard method in the biomaterial field. In this work, dissolution profiles obtained with the T-cell configuration clearly indicate a prolonged release of ibuprofen. Dissolution data fitted to Higuchi, Hixson-Crowell, Ritger-Peppas and Kopcha equations indicate the coexistence of diffusion and erosion mechanisms governing ibuprofen release. T-cell adapted to the standard flow-through dissolution apparatus is shown to better simulate in vivo conditions than the tablet cell. This is relevant for in vivo/in vitro correlations.     

Hydroxypropyl methylcellulose based cephalexin extended release tablets: influence of tablet formulation,hardness and storage on in vitro release kinetics

The object of this study was to develop hydroxypropyl methylcellulose (HPMC) based cephalexin extended release tablet, which can release the drug for six hours in predetermined rate. Twenty-one batches of cephalexin tablets were prepared by changing various physical and chemical parameters, in order to get required theoretical release profile. The influences of HPMC, microcrystalline cellulose powder (MCCP), granulation technique, wetting agent and tablet hardness on cephalexin release from HPMC based extended release tablets were studied. The formulated tablets were also characterized by physical and chemical parameters. The dissolution results showed that a higher amount of HPMC in tablet composition resulted in reduced drug release. Addition of MCCP resulted in faster drug release. Tablets prepared by dry granulation was released the drug slowly than the same prepared with a wet granulation technique. Addition of wetting agent in the tablets prepared with dry granulation technique showed slower release. An increase in tablet hardness resulted in faster drug release. Tablets prepared with a wet granulation technique and having a composition of 9.3% w/w HPMC with a hardness of 10-12 kg/cm(2) gave predicted release for 6 h. The in vitro release data was well fit in to Higuchi and Korsmeyer-Peppas model. Physical and chemical parameters of all formulated tablets were within acceptable limits. One batch among formulated twenty-one batches was successful and showed required theoretical release. The effect of storage on in vitro release and physicochemical parameters of successful batch was studied and was found to be in acceptable limits.     

Development of extended release coevaporates and coprecipitates of promethazine HCl with acrylic polymers: formulation considerations

The present investigation studied a novel extended release system of promethazine hydrochloride (PHC) with acrylic polymers Eudragit RLPO and Eudragit RS100 in different weight ratios (1 : 1 and 1 : 5) using coevaporation and coprecipitation techniques. Solid dispersions were characterized by Fourier-transformed infrared spectroscopy (FT-IR), Differential scanning calorimetry (DSC), Powder X-ray diffractometry (PXRD), Nuclear magnetic resonance (NMR), Scanning electron microscopy (SEM) as well as solubility and in vitro dissolution studies in 0.1 n HCl (pH 1.2), double distilled water and phosphate buffer (pH 7.4). Adsorption test from drug solution to solid polymers were also performed. Selected solid dispersion system was subjected to direct compression and compressed tablets were evaluated for in vitro dissolution studies. The progressive disappearance of drug peaks in thermotropic profiles of coevaporates were related to increasing amount of polymers while SEM studies suggested homogenous dispersion of drug in polymer. Eudragit RLPO had a greater adsorptive capacity than Eudragit RS100 and thus its coevaporates in 1 : 5 ratio exhibited higher dissolution rate with 91.90% drug release for 12 h. Among different formulations, tablets prepared by Eudragit RLPO coevaporates (1 : 5) displayed extended release of drug for 12 h with 90.87% release followed by zero order kinetics (r(2)=0.9808).     

Bipolymeric Pectin Millibeads Doped with Functional Polymers as Matrices for the Controlled and Targeted Release of Mesalazine

Targeted drug delivery systems are a very convenient method of treating inflammatory bowel disease. The properties of pectin make this biopolymer a suitable drug carrier. These properties allow pectin to overcome the diverse environment of the digestive tract and deliver the drug to the large intestine. This investigation proposed bipolymeric formulations consisting of the natural polymer pectin and a synthetic polymer containing the drug 5-aminosalicylic acid. Pectin beads were prepared via ionotropic gelation involving the interaction between the hydrophilic gel and calcium ions. The obtained formulations consisted of natural polymer, 5-aminosalicylic acid (5-ASA) and one of the synthetic polymers, such as polyacrylic acid, polyvinylpyrrolidone, polyethylene glycol or aristoflex. The release of the drug was carried out employing a basket apparatus (USP 1). The acceptor fluid was pH = 7.4 buffer with added enzyme pectinase to reflect the colon environment. The amount of the released drug was determined using UV-Vis spectrophotometry at a wavelength of λ = 330 nm. The kinetics of the drug dissolution revealed that none of the employed models was appropriate to describe the release process. A kinetic analysis of the release profile during two release stages was carried out. The fastest drug release occurred during the first stage from a formulation containing pectin and polyethylene glycol. However, according to the applied kinetic models, the dissolution of 5-ASA was rather high in the formulation without the synthetic polymer during the second stage. Depending on the formulation, 68–77% of 5-ASA was released in an 8-hour time period. The FTIR and DSC results showed that there was no interaction between the drug and the polymers, but interactions between pectin and synthetic polymers were found.     

一种抗偏头痛复方制剂体外溶出度的比较研究

 A novel in vitro dissolution profile was developed for formulated drug in combinational form containing naproxen sodium (NAP) and sumatriptan succinate (SUMA). This study was performed to understand the dissolution of the drug in the physiological temperature and pH. Dissolution testing was performed using USP 29 type II testing apparatus rotating at 50 r/min, in 900 mL deaerated buffer （pH 1.2, 4.5 and 6.8） which was maintained at (37±0.5) ℃. Quantification was performed using a developed and validated high performance liquid chromatographic (HPLC) method. Aceclofenac (ACE) was used as internal standard. SUMA, ACE and NAP were eluted at 4.8, 5.7 and 7.9 min, respectively. As expected for enteric coated immediate release (IR) tablets, the dissolution of NAP and SUMA was rapid and essentially complete within 2 h using phosphate buffer (pH 6.8). The comparison of the dissolution profiles was realized by model independent approach using a difference factor (f1), similarity factor (f2) and dissolution efficiency (DE). Statistical results showed the profiles were similar to the reference and the test products. Hence, this method demonstrated to be adequate for in vitro studies of NAP and SUMA in the combinational dosage form, since there is no official monograph, collaborating to the official codes.     

Application of nilvadipine solid dispersion to tablet formulation and manufacturing using crospovidone and methylcellulose as dispersion carriers

Nilvadipine (NIL) solid dispersion using crospovidone (Cross-linked-N-vinyl-2-pyrolidone, cl-PVP) and methylcellulose (MC) as carriers was applied to tablet formulation. Several grades of cl-PVP and MC were used, and their influence on tablet properties such as hardness, disintegration, dissolution and chemical stability were investigated. The agitation granulation method was used for preparation of solid dispersion granules, and the granules were compressed using a rotary tableting machine, and finally the obtained tablets were coated with film. As the particle size of cl-PVP decreased, hardness and apparent solubility were increased, while dissolution rate was lowered. When a higher viscosity grade of MC was used, hardness and dissolution rate were increased, and apparent solubility did not change. All batches of tablets were chemically stable at 40 degrees C, 75% relative humidity (R.H.) for six months. Finally, tablets with enhanced dissolution properties were obtained by using Polyplasdone XL-10 and Metolose SM-25 as the grades of cl-PVP and MC, respectively. These formulation tablets showed higher solubility and dissolution rate during storage as well as initial indicating good physical stability.     

Properties of gastroretentive sustained release tablets prepared by combination of melt/sublimation actions of L-menthol and penetration of molten polymers into tablets

A novel floating sustained release tablet having a cavity in the center was developed by utilizing the physicochemical properties of L-menthol and the penetration of molten hydrophobic polymer into tablets. A dry-coated tablet containing famotidine as a model drug in outer layer was prepared with a L-menthol core by direct compression. The tablet was placed in an oven at 80°C to remove the L-menthol core from tablet. The resulting tablet was then immersed in the molten hydrophobic polymers at 90°C. The buoyancy and drug release properties of tablets were investigated using United States Pharmacopeia (USP) 32 Apparatus 2 (paddle 100 rpm) and 900 ml of 0.01 N HCl. The L-menthol core in tablets disappeared completely through pathways in the outer layer with no drug outflows when placed in an oven for 90 min, resulting in a formation of a hollow tablet. The hollow tablets floated on the dissolution media for a short time and the drug release was rapid due to the disintegration of tablet. When the hollow tablets were immersed in molten hydrophobic polymers for 1 min, the rapid drug release was drastically retarded due to a formation of wax matrices within the shell of tablets and the tablets floated on the media for at least 6 h. When Lubri wax? was used as a polymer, the tablets showed the slowest sustained release. On the other hand, faster sustained release properties were obtained by using glyceryl monostearate (GMS) due to its low hydrophobic nature. The results obtained in this study suggested that the drug release rate from floating tablets could be controlled by both the choice of hydrophobic polymer and the combined use of hydrophobic polymers.     

Chrysophanol–phospholipid complex

Delivery of poorly soluble drugs results in poor absorption and low bioavailability to the systemic circulation. Chrysophanol (1,8-dihydroxy 3-methyl anthraquinone) a plant derived herbal drug is well known for its strong anti-inflammatory, anti-mutagenic, and anti-carcinogenic activities but poor aqueous solubility (hence the lower dissolution rate), is a major barrier in its intestinal absorption. To improve the bioavailability and prolong its duration in the body system, its phospholipid complex was prepared and evaluated for various physicochemical parameters like encapsulation efficiency, scanning electron microscopy, differential scanning calorimetry (DSC), X-ray powder diffractometry (X-RPD), IR spectroscopy, aqueous/n-octanol solubility, and dissolution study. The phospholipid complex of chrysophanol was found, fluffy and porous with rough surface morphology. FTIR, DSC, and X-RPD data confirmed the complex formation. The 89.1 % of chrysophanol was encapsulated in the phospholipid complex. The aqueous solubility of chrysophanol was improved from 0.60 to 30.09 μg ml^?1 in the prepared complex. The improved dissolution was shown by the complex (which showed continuous release up to 83.67 % of chrysophanol) at the end of 12 h, in comparison to free drug (which showed a total of only 45.12 % drug release at the end of 12 h of dissolution study).