scholarly journals Formulation and evaluation of colon targeted tablets containing simvastatin solid dispersion

2011 ◽  
Vol 1 (1) ◽  
pp. 16 ◽  
Author(s):  
Ahmed Abd Elbary ◽  
Howida K. Ibrahim ◽  
Balquees S. Hazaa

Solid dispersions (SDs) of simvastatin with mannitol, Ineutic®, Pluronic® F-68, PEG 4000 and PVP K-30 were prepared and evaluated to deliver simvastatin to the colon in a pre-solubilized form. The formula of choice was compressed into fast disintegrating tablets using drug compatible excipients and was coated with Eudragit® S100 as a pH-responsive polymer. We investigated the effects of several variables related to both SD preparation (carrier type, combined carriers and drug to carrier ratio) and tablet coating (coat level and type of plasticizer) on drug dissolution. Differential scanning caloremitry (DSC) and scanning electron microscopy (SEM) proved drug amorphization in SDs. The 1:5 simvastatin/ Pluronic® SDs showed the greatest improvement in dissolution efficiency (12.2-fold) at the lowest carrier ratio. The coating level was critical for determining the duration of the lagphase. Best results were given by the 10% coat (20:2:1 w/w Eudragit S100/ triethylcitrate/ talc). This formula resisted pre-colonic pH values and showed an adequate lag time for the intended colonic targeting (4 h), followed by an immediate release phase (t50%=249 min) in pH 7.4. The proposed coated tablets may provide a colonic delivery system for simvastatin with improved bioavailability.

Author(s):  
Prasanthi Boddu ◽  
Venkata Lakshmi Cherakapu ◽  
Uma Devi Ponukumati

  Objective: Nateglinide (NTG) is a potent short-acting biopharmaceutical classification system class II antidiabetic medication. The primary objective of the present investigation was to prepare and evaluate solid dispersions of NTG to enhance the component solubility and immediate release (IR) profile. The secondary objective was to formulate sustained release (SR) matrix layer of NTG for prolonging its effect in the body and to decrease oscillations in plasma concentration level.Methods: NTG (270 mg) SR layer was formulated using release retardant polymers such as Carbopol, ethyl cellulose (EC), hydroxy EC, hydroxypropyl methylcellulose (HPMC), Kollidon, and locust bean gum at concentrations of 15% and 30%. IR layer of NTG (60 mg) was formulated using drug: Polymer inclusion complexes (1:1 and 1:2) of β-cyclodextrin (CD), HP β-CD, polyvinylpyrrolidone (PVP) K-15, and PVP K-30 by physical mixing and kneading methods (KMs).Results: Among the all the carriers tested HP β-CD at 1:2 ratio prepared by KM (I3) gave highest enhancement of dissolution rate and dissolution efficiency with acceptable f1 (10.5) and f2 (51.0) values in comparison to marketed IR tablets (Starlix-60®). The SR formulation S12 was able to show a minimum amount of drug release (15%) within 1 hr comparatively, with a complete and sustained effect on drug release.Conclusion: Thus, HPMC K-100M at a concentration of 30% in the SR layer in combination with HP β-CD (1:2) solid dispersions in the IR layer may be used in the design of oral controlled drug delivery system for NTG. 


2002 ◽  
Vol 70 (3) ◽  
pp. 309-316
Author(s):  
Okonogi S ◽  
Sirithunyalung J ◽  
Sirithunyalig B ◽  
Wolschann P ◽  
Viernstein H

Solid dispersions of ofloxacin (OFX) and of a number of carriers including chitosan and the water soluble polymers polyethylene glycol (PEG) 4000, PEG 20000, and polyvinylpyrrolidone K- 90 were prepared by solvent evaporation method in order to increase the dissolution of the drug. The solid dispersions were subjected to X-ray diffraction, DSC, and dissolution to characterize their physicochemical and dissolution properties. The results demonstrated a decrease in drug crystallinity at higher amounts of carrier. Dissolution studies indicated that the dissolution rate of OFX was markedly increased in these solid dispersion systems compared with the pure drug. The results also showed that the increase in dissolution rate was higher when the weight fraction of carriers increased. An influence of molecular weight of PEG on OFX dissolution could also be observed. In solid dispersion with 1:9 ratio drug to carrier, PEG 4000 gave highest drug dissolution rate, whereas in 1:1 ratio, chitosan seems to be the best carrier for drug release. It was concluded that chitosan might be the carrier of choice for dissolution enhancement in solid dispersions with high content of drug.


Author(s):  
Preeti Mehra ◽  
Vishal Kapoor ◽  
Naveen Gupta ◽  
Dharmendra Singh Rajpoot ◽  
Neeraj Sharma

Rofecoxib, a new non-steroidal anti-inflammatory agent mainly used for the treatment of osteoarthritis and rheumatoid arthritis. The major drawback of Rofecoxib is its very low water solubility, which results in poor bioavailability after oral administration. Hence, an attempt was made to formulate fast dissolving tablets of Rofecoxib. The solid dispersions of Rofecoxib were prepared with PEG-4000 and PVP K30 by solvent evaporation method. The characterization of prepared solid dispersions by FTIR, XRPD and DSC, which reveals lack of interaction with carriers and dictates amorphous state of solid dispersions. Solid dispersion of Rofecoxib with PVP K30 (1:6) showed maximum dissolution, therefore compressed into tablets by using microcrystalline cellulose, lactose and crosspovidone. The dissolution profile of developed fast dissolving tablets containing solid dispersion of Rofecoxib (1:6) was studied. The formulated formulations showed optimum dissolution efficiency.


2017 ◽  
Vol 4 (1) ◽  
pp. 23-31 ◽  
Author(s):  
Pankaj V. Dangre ◽  
Vikesh B. Sormare ◽  
Mangesh D. Godbole

Background: Bosentan monohydrate (BM), a dual endothelin receptor antagonist, is indicated for the treatment of patients with pulmonary arterial hypertension (PAH). It is poorly soluble in water, and having absolute bioavailability of 50%. Objective: The aim of the present work is to develop and evaluate the solid dispersions (SD) of a poorly water soluble drug bosentan monohydrate (BM). Method: Solid dispersions (SDs) systems of BM were prepared with Hydroxy propyle β-cyclodextrin (HPβ-CD) and Polyethylene glycol (PEG-4000) polymers using a spray drying technique. Result: The significant rise in a saturation solubility 174.23±1.36 mg/mL; and drug dissolution 95.11±1.22%; was observed with optimized formulation (SD 6). The solid state characterization of optimized formulation (SD 6) by SEM, DSC, and XRPD revealed the absence of crystalline nature of BM in solid dispersion. High dissolution rate of solid dispersion (SD 6) compared with pure drug indicated the increase in dissolution characteristics. Conclusion: In conclusion, our studies illustrated that spray drying technique could be useful large scale producing method to prepare the solid dispersion of bosentan with HP β-CD, which can improve the solubility as well as stability of the formulation.


Author(s):  
Hafsa Mohammadi ◽  
V Hemanath Kumar

The aim of the present work is to develop fast dissolving tablets from the solid dispersion of Tenoxicam for enhancement of solubility. The solid dispersions of Tenoxicam were prepared with Kollidon CL, PVP K30 and Poloxamer 127, in 1:1:1, 1:2:1 and 1:3:1 by using solvent evaporation method. The prepared solid dispersions were analyzed for all the physical parameters, drug: carrier interactions like FTIR, SEM, XRD. Solid dispersions showed a better dissolution compared to the pure drugs and among all the other formulations SD9 shows high percentage drug release i.e. 99.11 ± 5.17% for 90 min and selected as an optimized formulation for the preparation of fast disintegrating tablets of Tenoxicam. Gellan Gum, Fenugreek Seed Mucilage and L-HPC (low, middle and high concentrations) used in the preparation of fast disintegrating tablets prepared by direct compression method using 33 Response surface method. The post compression parameters of all the prepared tablets were within the limits. TF13 was selected as optimized formulation based on its highest disintegration time 36 sec and drug release 99.68 ± 1.52% for 10 min. Drug-excipients characterization also revealed that there is no interaction. Hence it concluded that solid dispersions incorporated fast disintegrating tablets is very useful approach for immediate release of Tenoxicam in the efficient management of inflammation and pain.


2020 ◽  
Vol 10 (4) ◽  
pp. 656-661
Author(s):  
Fatima Molavi ◽  
Hamed Hamishehkar ◽  
Ali Nokhodchi

Purpose : The aim of this study was to evaluate the influence of the geometric shape on the dissolution rate of the domperidone, a drug model for immediate release dosage form. In this regard, a lack of sufficient information about the effective dissolution rate of the drugs regarding their shapes has made this issue an interesting subject for researchers. Methods: For this purpose, three tablet shapes, namely flat and biconvex both in a round and oblong shapes, with different four sizes were modelled for the preparation of domperidone tablet. In vitro dissolution test was accomplished using a USP dissolution apparatus II. The drug dissolution rate was assessed by calculating various dissolution parameters; e.g., dissolution efficiency (DE), mean dissolution rate (MDR), mean dissolution time (MDT), and difference and similarity factors (f1 and f2 ). Results: Regarding the disintegration time, the larger tablets showed a faster disintegration time. When the size of the tablets was smaller, the amount of released drug was significantly decreased. In addition, #9 tablets with a flat or biconvex geometry had obvious effects on the DE values. Generally, biconvex tablets had higher DE percentage than the flat tablets. Conclusion: Noticeable differences in dissolution parameters by considering the different geometric shapes play an important role in the drug release kinetics which makes a significant effect on quick onset of action in oral administration.


Author(s):  
V A. Vamshi Priya ◽  
G. Chandra Sekhara Rao ◽  
D. Srinivas Reddy ◽  
V. Prabhakar Reddy

The purpose of this study was to investigate the efficiency of superdisintegrants: sodium starch glycolate, croscarmellose sodium and crospovidone in promoting tablet disintegration and drug dissolution of Topiramate immediate release tablets. The efficiency of superdisintegrants was tested, by considering four concentrations, viz., like 2%, 3%, 4% and 5% in the formulations. The dissolution was carried out in USP apparatus II at 50 rpm with distilled water as a dissolution medium. The dissolution rate of the model drug topiramate was found highly dependent on the tablet disintegration, on the particle size of the superdisintegrant, on the solubility of the drug and also on the type of superdisintegrant in the dissolution medium. There was no effect of the diluent (Lactose monohydrate) on the disintegration of different concentrations of superdisintegrants. These results suggest that, as determined by the f2 metric (similarity factor), the dissolution profile of the formulation containing 4% sodium starch glycolate and lactose monohydrate as a diluent was similar to that of a marketed product.


Author(s):  
Kumar P ◽  
S Kumar ◽  
A Kumar ◽  
M Chander

The purpose of this study was to prepare and characterize solid dispersions of the antibacterial agent Cefdinir with PEG 4000 and PVP K-30 with a view to improve its dissolution properties. Investigations of the properties of the dispersions were performed using release studies, X-ray powder diffraction (XRD) and Fourier transform infrared (FTIR). The results obtained showed that the rate of dissolution of Cefdinir was considerably improved when formulated in solid dispersions with PVP K-30 and PEG 4000 as compared with pure drug and physical mixtures. The results from XRD studies showed the transition of crystalline nature of drug to amorphous form, while FTIR studies demonstrated the absence of drug-carriers interaction.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Zhongmei Chi ◽  
Irfan Azhar ◽  
Habib Khan ◽  
Li Yang ◽  
Yunxiang Feng

AbstractDissolution testing plays many important roles throughout the pharmaceutical industry, from the research and development of drug products to the control and evaluation of drug quality. However, it is a challenging task to perform both high-efficient separation and high-temporal detection to achieve accurate dissolution profile of each active ingredient dissolved from a drug tablet. In our study, we report a novel non-manual-operation method for performing the automatic dissolution testing of drug tablets, by combining a program-controlled sequential analysis and high-speed capillary electrophoresis for efficient separation of active ingredients. The feasibility of the method for dissolution testing of real drug tablets as well as the performance of the proposed system has been demonstrated. The accuracy of drug dissolution testing is ensured by the excellent repeatability of the sequential analysis, as well as the similarity of the evaluation of dissolution testing. Our study show that the proposed method is capable to achieve simultaneous dissolution testing of multiple ingredients, and the matrix interferences can be avoided. Therefore it is of potential valuable applications in various fields of pharmaceutical research and drug regulation.


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