scholarly journals PREPARATION AND IN VIVO EVALUATION OF CANDESARTAN CILEXETIL SOLID DISPERSIONS

Author(s):  
UPPULURU ASHOK KUMAR ◽  
GANDE SURESH

Objective: The present study aims at development of solid dispersions (SD) of candesartan cilexetil for enhanced solubility and bioavailability. Methods: About 18 SD formulations of candesartan cilexetil were prepared by solvent evaporation technique and evaluated. The in vitro release studies were conducted and the best formulation chosen was further characterized for Fourier transform infrared spectroscopy, Scanning electron microscope, X-ray, and stability. The in vivo evaluation study conducted in rats. Results: The formulation SD16 containing drug and Soluplus in 1:3 ratio along with 2% selective laser sintering was chosen optimal based on drug content (99.08%), and drug release (99.7%). In vivo studies conducted on SD16 showed that mean time to peak concentration (Tmax) was 2.0±0.05 and 4±0.2 h for the optimized and pure drug, respectively, while mean maximum drug concentration (Cmax) was 570.63±2.65 ng/mL and was significant as compared to the candesartan pure drug 175.146±0.07 ng/mL. Area under curve AUC0-∞ infinity for candesartan SD16 was higher (4860.61±1.05 ng.h/ml) than pure drug suspension 1480±1.72 ng.h/ml. Conclusion: Hence, the developed SD formulations enhanced the bioavailability of drug by 3 folds.

Author(s):  
Venu Madhav K ◽  
Somnath De ◽  
Chandra Shekar Bonagiri ◽  
Sridhar Babu Gummadi

Fenofibrate (FN) is used in the treatment of hypercholesterolemia. It shows poor dissolution and poor oral bioavailability after oral administration due to high liphophilicity and low aqueous solubility. Hence, solid dispersions (SDs) of FN (FN-SDs) were develop that might enhance the dissolution and subsequently oral bioavailability. FN-SDs were prepared by solvent casting method using different carriers (PEG 4000, PEG 6000, β cyclodextrin and HP β cyclodextrin) in different proportions (0.25%, 0.5%, 0.75% and 1% w/v). FN-SDs were evaluated solubility, assay and in vitro release studies for the optimization of SD formulation. Differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM) analysis was performed for crystalline and morphology analysis, respectively. Further, optimized FN-SD formulation evaluated for pharmacokinetic performance in Wistar rats, in vivo in comparison with FN suspension.  From the results, FN-SD3 and FN-SD6 have showed 102.9 ±1.3% and 105.5±3.1% drug release, respectively in 2 h. DSC and PXRD studies revealed that conversion of crystalline to amorphous nature of FN from FT-SD formulation. SEM studies revealed the change in the orientation of FN when incorporated in SDs. The oral bioavailability FN-SD3 and FN-SD6 formulations exhibited 2.5-folds and 3.1-folds improvement when compared to FN suspension as control. Overall, SD of FN could be considered as an alternative dosage form for the enhancement of oral delivery of poorly water-soluble FN.


Author(s):  
Mohini Sihare ◽  
Rajendra Chouksey

Aim: Nateglinide is a quick acting anti-diabetic medication whose potent activity lasts for a short duration. One of the dangerous side effects of nateglinide administration is rapid hypoglycemia, a condition that needs to be monitored carefully to prevent unnecessary fatalities. The aim of the study was to develop a longer lasting and slower releasing formulation of nateglinide that could be administered just once daily. Methods: Matrix tablets of nateglinide were prepared in combination with the polymers hydroxypropylmethylcellulose (HPMC), eudragits, ethyl cellulose and polyethylene oxide and the formulated drug release patterns were evaluated using in vitro and in vivo studies. Conclusion: Of the seventeen formulated matrix tablets tested, only one formulation labelled HA-2 that contained 15% HPMC K4M demonstrated release profile we had aimed for. Further, swelling studies and scanning electron microscopic analysis confirmed the drug release mechanism of HA-2. The optimized formulation HA-2 was found to be stable at accelerated storage conditions for 3 months with respect to drug content and physical appearance. Mathematical analysis of the release kinetics of HA-2 indicated a coupling of diffusion and erosion mechanisms. In-vitro release studies and pharmacokinetic in vivo studies of HA-2 in rabbits confirmed the sustained drug release profile we had aimed for. Keywords: Hydroxypropylmethylcellulose, Matrix tablets, Nateglinide, Sustained release


Author(s):  
S Srikanth Reddy ◽  
G Suresh

The current research is aimed at developing liquid self-nanoemulsifying drug delivery system (liquid-SNEDDS) of Manidipine for enhanced solubility and oral bioavailability. The Manidipine SNEDDS are formulated with excipients comprising of Capmul MCM (oil phase), Transcutol P (surfactant) Lutrol L 300 as co-surfactant. The prepared fifteen formulations of Manidipine SNEDDS analysed for emulsification time, percentage transmittance, particle size, in vitro drug release, and stability studies. In vivo pharmacokinetic studies of the optimized formulation were carried out in Wistar rats in comparison with control (pure drug). The morphology of Manidipine SNEDDS indicates spherical shape with uniform particle distribution. The percentage drug release from optimized formulation F14 is 98.24 ± 5.14%. The particle size F14 formulation was 22.4 nm and Z-Average 23.3 nm. The PDI and zeta potential of Manidipine SNEDDS optimized formulation (F14) were 0.313 and-5.1mV respectively. From in vivo bioavailability data the optimized formulation exhibited a significantly greater Cmax and Tmax of the SNEDDS was found to be 3.42 ± 0.46ng/ml and 2.00 ± 0.05 h respectively. AUC0-∞ infinity for formulation was significantly higher (11.25 ± 3.45 ng.h/ml) than pure drug (7.45 ± 2.24ng. h/ml). Hence a potential SNEDDS formulation of Manidipine developed with enhanced solubility and bioavailability.


Author(s):  
ASHWIN K ◽  
RAMA MOHAN REDDY T

Objective: The aim was to design, formulate, and evaluate the trilayer matrix tablets incorporated with quinapril for extend drug release. Methods: Quinapril trilayer matrix tablets were formulated using design of experiment software wherein initially 27 formulations (QF1-QF27) were designed for active layer from which one best formulation was chosen based on drug content, swelling index and in vitro release studies. The chosen formulation was formulated into extended release trilayed matrix tablet by varying proportions of polymers by direct compression and was evaluated for various physicochemical parameters, drug release. Best formulation was characterized for Fourier transform infrared (FTIR), stability, and pharmacokinetic study. Results: Out of 27 formulations highest drug release was exhibited by QF16 (98.85%) which was formulated into trilayer matrix tablets (AQF16- HQF16). Out of which EQF16 was found to exhibit highest values with 98.42% swelling index, 99.56% drug content, and 99.72% drug release in 24 h. All quinapril trilayer formulations showed zero-order and first-order for marketed product. The optimized formulation EQF16 was found to exhibit no interaction with excipients interpreted by FTIR and no significant changes were observed after loading for stability. In vivo studies conducted using optimized formulation EQF16 attained peak drug concentration (Tmax) of 4.0±0.06 and 1.0±0.03 h for the optimized and commercial formulations, respectively, while mean maximum drug concentration (Cmax) was 302.64±0.07 ng/mL and was significant (p<0.05) as compared to the quinapril marketed product formulation 358.78±0.75 ng/mL. Conclusion: Hence, quinapril was successfully formulated into trilayer matrix tablet and found to be stable.


Author(s):  
Revathi M. ◽  
Indira Y.

This study elucidates the enhancement of the permeation of bosentan monohydrate through skin by encapsulating it in vesicles loaded transdermal delivery system. Niosomal vesicles were formulated by ether injection method. Formulation FN7 (span 60: cholesterol: poloxamer 401, 1.25:1:0.25) showed maximum entrapment efficiency of 96.7±0.037% and was optimized for loading in to transdermal system. Transdermal systems were formulated using both hydrophilic and hydrophobic polymers like HPMC, HEC and EC. Formulation F1 with HPMC was optimized based on in vitro release (99.21±1.45 %) and was further evaluated for ex-vivo permeation. The results indicate that the ex vivo release (98.13±1.65%) was as par with in vitro release and followed zero order super case- II transport mechanism. The in vivo studies were done on New Zealand male rabbits for oral and transdermal route. The results inferred no significant change in half-life of drug but a substantial difference in Tmax, AUC and MRT was observed in transdermal systems. A two fold increase in AUC was observed in transdermal route (18.609±7.251µg/ml/h) when compared to oral route (9.644±5.621µg/ml/h). A controlled release was attained up to 35h and reservoir effect was observed and this may be due to the barrier properties of skin. Drug encapsulated niosomes were released in to the skin by loosening the lipid layers and the surfactant acted as penetration enhancer. The study infers that niosomes loaded transdermal patches of bosentan monohydrate can enhance the bioavailability and provided controlled release for better therapeutic efficacy and safety of drug.


Author(s):  
Bhikshapathi D. V. R. N. ◽  
Kanteepan P

Rebamipide, an amino acid derivative of 2-(1H)-quinolinone, is used for mucosal protection, healing of gastroduodenal ulcers, and treatment of gastritis. The current research study aimed to develop novel gastro-retentive mucoadhesive microspheres of rebamipide using ionotropic gelation technique. Studies of micromeritic properties confirmed that microspheres were free flowing with good packability. The in vitro drug release showed the sustained release of rebamipide up to 99.23 ± 0.13% within 12 h whereas marketed product displayed the drug release of 95.15 ± 0.23% within 1 h. The release mechanism from microspheres followed the zero-order and Korsmeyer-Peppas (R2 = 0.915, 0.969), respectively. The optimized M12 formulation displayed optimum features, such as entrapment efficiency 97%, particle size 61.94 ± 0.11 µm, percentage yield 98%, swelling index 95% and mucoadhesiveness was 97%. FTIR studies revealed no major incompatibility between drug and excipients. SEM confirmed the particles were of spherical in shape. Optimized formulation (M12) were stable at 40°C ± 2°C/75% RH ± 5% RH for 6 months. In vivo studies were performed and kinetic parameters like Cmax, Tmax, AUC0-t, AUC0-∞, t1/2, and Kel  were calculated. The marketed product Cmax (3.15 ± 0.05 ng/mL) was higher than optimized formulation (2.58 ± 0.03 ng/mL). The optimized formulation AUC0-t (15.25 ± 1.14 ng.hr/mL), AUC0-∞ (19.42 ± 1.24 ng.hr/mL) was significantly higher than that of marketed product AUC0-t (10.21 ± 1.26 ng.hr/mL) and AUC0-∞ (13.15 ± 0.05 ng.hr/mL). These results indicate an optimized formulation bioavailability of 2.5-fold greater than marketed product.  


Author(s):  
Narendar Dudhipala ◽  
Arjun Narala ◽  
Dinesh Suram ◽  
Karthik Yadav Janga

The objective of this present study is to develop a semisolid dispersion (SSD) of zaleplon with the aid of self-emulsifying lipid based amphiphilic carriers (TPGS E or Gelucire 44/14) addressing the poor solubility of this drug. A linear relationship between the solubility of drug with respect to increase in the concentration of lipid surfactant in aqueous medium resulting in AL type phase diagram was observed from phase solubility studies. Fusion method was employed to obtain semisolid dispersions (SSD) of zaleplon which showed high content uniformity of drug. The absence of chemical interactions between the pure drug, excipients and formulations were conferred by Fourier transmission infrared spectroscopic examinations. The photographic images from polarized optical microscopic studies revealed the change in crystalline form of drug to amorphous or molecular state. The superior dissolution parameters of zaleplon from SSD over pure crystalline drug interpreted from in vitro dissolution studies envisage the ability of these lipid surfactants as solubility enhancers. Further, the caliber of TPGS E or Gelucire 44/14 in encouraging the GI absorption of drug was evident with the higher human effective permeability coefficient and fraction oral dose of drug absorbed from SSD in situ intestinal permeation study. In conclusion, in vivo studies in Wister rats demonstrated an improvement in the oral bioavailability of zaleplon from SSD over control pure drug suspension suggesting the competence of Gelucire 44/14 and TPGS E as conscientious carriers to augment the dissolution rate limited bioavailability of this active


Author(s):  
Moon Rajkumar ◽  
Gattani Surendra

 Objective: The objective of this study was to increase the solubility and dissolution rate of paliperidone (PAL) by preparing its nanocrystals using different hydrophilic carriers by antisolvent precipitation technique.Methods: The nanoparticles (NP) were characterized for aqueous solubility, drug content, Fourier transform infrared spectroscopy, differential scanning calorimetry, X-ray diffraction, scanning electron microscopy, particle size, and in vitro-in vivo analysis.Results: The results showed improved solubility and dissolution rate of NPs when compared to pure drug and physical mixture (PM). Solubility data showed a linear graph giving an indication that there is a gradual increase in the solubility profile of the drug with an increase in concentration of the carriers. At highest concentration, the solubility of NPs with Plasdone S630, Povidone K-25, and PVP K-30 found to be increased by 12 folds, 9 folds and 6 folds, respectively, as compared to pure drug. The release profile of NPs with Plasdone S630 in terms of dissolution efficiency at 60 min (DE60), initial dissolution rate (IDR), amount release in 15 min (Q15 min), and time for 75% release (t75%) shows better results when compared to pure drug, PM, and also NPs with povidone 25 and povidone 30. In vivo study reveals that optimized NPs elicited significant induction of cataleptic behavior which is the indication of antipsychotic agent(s) effect.Conclusion: The process antisolvent precipitation under constant stirring may be a promising method to produce stable PAL NPs with markedly enhanced solubility and dissolution rate due to nanonization with the increased surface area, improved wettability, and reduced diffusion pathway.


Author(s):  
NAGADANI SWARNALATHA ◽  
VIDYAVATHI MARAVAJHALA

Objective: The aim of the present research work was to prepare and evaluate taste-masked oral disintegrating tablets (ODT) of Fexofenadine hydrochloride. Methods: In the present work, Eudragit EPO, a taste masking agent and Karaya gum (GK) (natural), Sodium starch glycolate, and Croscarmellose sodium (CCS) (semi-synthetic) super disintegrants in three ratios (3, 6,9%) were used. Taste masked granules were prepared by different ratios of the drug: Eudragit EPO (1:1, 1:1.5, 1:2) by wet granulation method. The optimized taste-masked granules (1:2) were selected by sensory evaluation test to prepare 9 Fexofenadine ODT (FH1-FH9) formulations. These were evaluated for different parameters. Then desirability function (DF) was calculated for all formulations using disintegration time (DT), time taken for the tablet to release 90% of the drug (t 90%), and % drug dissolved in 10 min (Q10) as significant parameters. Results: The best formulation (FH6) showed the highest DF value due to less DT and 100% in vitro drug release within 15 min. Thus, FH6 formulation containing 9% CCS was selected as the best among the prepared formulations to which in vivo studies were performed on rabbits to find maximum plasma concentration (Cmax), time taken to reach maximum concentration (tmax), area under the curve (AUC), rate of elimination (Kel), absorption rate (Ka) and half-life(t1/2) and compared with Fexofenadine (Allegra) marketed tablets. Total bioavailability was increased for the test formulation compared to the reference formulation. Conclusion: Fexofenadine was successfully prepared as ODT with increased AUC and decreased tmax to which stability studies were conducted which were found to be stable.


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