scholarly journals DESIGN AND EVALUATION OF CONTROLLED-RELEASE OCULAR INSERTS OF BRIMONIDINE-TARTRATE AND TIMOLOL MALEATE

Author(s):  
Preethi G. B. ◽  
Prashanth Kunal

<p><strong>Objective: </strong>The current work was attempted to formulate and evaluate a controlled-release matrix-type ocular inserts containing a combination of brimonidine tartrate and timolol maleate, with a view to sustain the drug release in the cul-de-sac of the eye.<strong></strong></p><p><strong>Methods: </strong>Initially, the infrared studies were done to determine the drug–polymer interactions. Sodium alginate-loaded ocuserts were prepared by solvent casting technique. Varying the concentrations of polymer—sodium alginate, plasticizer—glycerine, and cross-linking agent—calcium chloride by keeping the drug concentration constant, made a total of nine formulations. These formulations were evaluated for its appearance, drug content, weight uniformity, thickness uniformity, percentage moisture loss, percentage moisture absorption, and <em>in vitro </em>release profile of the ocuserts. Finally, accelerated stability studies and the release kinetics were performed on the optimised formulation.<strong></strong></p><p><strong>Results: </strong>It was perceived that polymer, plasticizer, and calcium chloride had a significant influence on the drug release. The data obtained from the formulations showed that formulation—F9 was the optimised formulation, which exhibited better drug release. The release data of the optimised formulation tested on the kinetic models revealed that it exhibited first-order release kinetics. <strong></strong></p><p><strong>Conclusion: </strong>It can be concluded that a natural bioadhesive hydrophilic polymer such as sodium alginate can be used as a film former to load water soluble and hydrophilic drugs like brimonidine tartrate and timolol maleate. Among all formulations, F9 with 400 mg sodium alginate, 2% calcium chloride and 60 mg glycerin were found to be the most suitable insert in terms of appearance, ease of handling, thickness, <em>in vitro</em> drug release and stability.</p>

2020 ◽  
Vol 15 ◽  
Author(s):  
Balaji Maddiboyina ◽  
Vikas Jhawat ◽  
Gandhi Sivaraman ◽  
Om Prakash Sunnapu ◽  
Ramya Krishna Nakkala ◽  
...  

Background: Venlafaxine HCl is a selective serotonin reuptake inhibitor which is given in the treatment of depression. The delivery of the drug at a controlled rate can be of great importance for prolonged effect. Objective: The objective was to prepare and optimize the controlled release core in cup matrix tablet of venlafaxine HCl using the combination of hydrophilic and hydrophobic polymers to prolong the effect with rate controlled drug release. Methods: The controlled release core in cup matrix tablets of venlafaxine HCl were prepared using HPMC K5, K4, K15, HCO, IPA, aerosol, magnesium sterate, hydrogenated castor oil and micro crystalline cellulose PVOK-900 using wet granulation technique. Total ten formulations with varying concentrations of polymers were prepared and evaluated for different physicochemical parameters such FTIR analysis for drug identification, In-vitro drug dissolution study was performed to evaluate the amount of drug release in 24 hrs, drug release kinetics study was performed to fit the data in zero order, first order, Hixson–crowell and Higuchi equation to determine the mechanism of drug release and stability studies for 3 months as observed. Results: The results of hardness, thickness, weight variation, friability and drug content study were in acceptable range for all formulations. Based on the In vitro dissolution profile, formulation F-9 was considered to be the optimized extending the release of 98.32% of drug up to 24 hrs. The data fitting study showed that the optimized formulation followed the zero order release rate kinetics and also compared with innovator product (flavix XR) showed better drug release profile. Conclusion: The core-in-cup technology has a potential to control the release rate of freely water soluble drugs for single administration per day by optimization with combined use of hydrophilic and hydrophobic polymers.


2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Chukwuebuka H. Ozoude ◽  
Chukwuemeka P. Azubuike ◽  
Modupe O. Ologunagba ◽  
Sejoro S. Tonuewa ◽  
Cecilia I. Igwilo

Abstract Background Khaya gum is a bark exudate from Khaya senegalensis (Maliaecae) that has drug carrier potential. This study aimed to formulate and comparatively evaluate metformin-loaded microspheres using blends of khaya gum and sodium alginate. Khaya gum was extracted and subjected to preformulation studies using established protocols while three formulations (FA; FB and FC) of metformin (1% w/v)-loaded microspheres were prepared by the ionic gelation method using 5% zinc chloride solution as the cross-linker. The formulations contained 2% w/v blends of khaya gum and sodium alginate in the ratios of 2:3, 9:11, and 1:1, respectively. The microspheres were evaluated by scanning electron microscopy, Fourier transform-infrared spectroscopy, differential scanning calorimetry, entrapment efficiency, swelling index, and in vitro release studies. Results Yield of 28.48%, pH of 4.00 ± 0.05, moisture content (14.59% ± 0.50), and fair flow properties (Carr’s index 23.68 ± 1.91 and Hausner’s ratio 1.31 ± 0.03) of the khaya gum were obtained. FTIR analyses showed no significant interaction between pure metformin hydrochloride with excipients. Discrete spherical microspheres with sizes ranging from 1200 to 1420 μm were obtained. Drug entrapment efficiency of the microspheres ranged from 65.6 to 81.5%. The release of the drug from microspheres was sustained for the 9 h of the study as the cumulative release was 62% (FA), 73% (FB), and 80% (FC). The release kinetics followed Korsmeyer-Peppas model with super case-II transport mechanism. Conclusion Blends of Khaya senegalensis gum and sodium alginate are promising polymer combination for the preparation of controlled-release formulations. The blend of the khaya gum and sodium alginate produced microspheres with controlled release properties. However, the formulation containing 2:3 ratio of khaya gum and sodium alginate respectively produced microspheres with comparable controlled release profiles to the commercial brand metformin tablet.


Author(s):  
Barkat Khan ◽  
Faheem Haider ◽  
Kifayat Shah ◽  
Bushra Uzair ◽  
Kaijian Hou ◽  
...  

This study was carried out to formulate and evaluate controlled release (CR) matrix tablets of Acyclovir using combination of hydrophilic and hydrophobic polymers. Acyclovir is a guanine derivative and is its half-life is short hence administered five times a day using immediate release tablets. Six formulations (F1-F6) were developed using Ethocel and Carbopol in equal combinations at drug-polymer (D:P) ratio of 10:5, 10:6, 10:7, 10:8, 10:9 and 10:10. Solubility study was performed using six different solvents. The compatibility studies were carried out using FTIR and DSC. According to USP, Quality Control and dimensional tests (hardness, friability, disintegration and thickness) were executed. In-vitro drug release studies of Acyclovir was carried out in dissolution apparatus using using 0.1 N HCl medium at constant temperature of 37 ± 0.5 ºC. In order to analyze the drug release kinetics, five different mathematical models were applied to the release data. The results showed that there was no incompatibility between drug and polymers. Physical QC tests were found within limits of USP. The release was retarded upto 24 hrs and non-fickian in-vitro drug release mechanism was found. A formulation developed using blend of polymers, showed excellent retention and desired release profiles thus providing absolute control for 24 hrs.


2018 ◽  
Vol 8 (5) ◽  
pp. 465-474
Author(s):  
S PADMA PRIYA ◽  
AN Rajalakshmi ◽  
P Ilaveni

Objective: The objective of this research work is to develop and evaluate mucoadhesive microspheres of an anti-migraine drug for sustained release. Materials and Methods:  Mucoadhesive microspheres were prepared by emulsification method using Sodium alginate (SA), polyvinyl pyrrolidone (PVP) and Chitosan in the various drug-polymer ratios of 1:1, 1:2 and 1:3. Nine  formulations were formulated and  evaluated for  possible drug polymer interactions, percentage yield, micromeritic properties, particle size, drug content, drug entrapment efficiency, drug loading, swelling index, In-vitro wash off test, in vitro  drug release, surface morphology and release kinetics. Results: The results showed that no significant drug polymer interaction in FTIR studies. Among all the formulations SF3 containing sodium alginate showed 77.18% drug release in 6hrs. Conclusion: Amongst the developed mucoadhesive microspheres, SF3 formulation containing sodium alginate exhibited slow and sustained release in a controlled manner and it is a promising formulation for sustained release of Sumatriptan succinate. Keywords: Mucoadhesive microspheres, Sodium alginate, polyvinyl pyrrolidone, Chitosan, sustained release.


Author(s):  
O. SREEKANTH REDDY ◽  
M. C. S. SUBHA ◽  
T. JITHENDRA ◽  
C. MADHAVI ◽  
K. CHOWDOJI RAO ◽  
...  

Objective: The aim of the present study was to fabricate and evaluate the drug release studies using Sodium Alginate (SA) and Gelatin (GE) microbeads intercalated with Kaolin (KA) nanoclay for sustained release of D-Penicillamine (D-PA). Methods: Sodium alginate/gelatin/Kaolin blend microbeads were prepared by an extrusion method by using glutaraldehyde (GA) as a crosslinker. The obtained microbeads were characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and X–ray diffraction (XRD). Drug release kinetics of the microbeads was investigated in simulated intestinal fluid (pH 7.4) at 37 °C. Results: Microbeads formation was confirmed by FTIR spectroscopy. X-RD reveals that the KA should be intercalated with the drug and also it confirms the molecular level dispersion of D-Penicillamine into microbeads. Scanning Electron Microscopy (SEM) studies reveal that the beads were in spherical shape with some wrinkled depressions on the surface. The in vitro release study indicates the D-Penicillamine released in a controlled manner. The in vitro release kinetics was assessed by Korsmeyer-Peppas equation and the ‘n’ value lies in between 0.557-0.693 indicates Non-Fickian diffusion process. Conclusion: The results suggest that the developed KA intercalated microbeads are good potential drug carrier for the controlled release of D-PA.


Author(s):  
Koyel Kar ◽  
R. N. Pal ◽  
N. N. Bala

Objective: The major objective of the research work was to design, characterise and evaluate controlled release microspheres of ropinirole hydrochloride by using non-aqueous solvent evaporation technique to facilitate the delivery of the drug at a predetermined rate for a specific period of time.Methods: Ropinirole hydrochloride microspheres were prepared by using different low-density polymers such as eudragit RL 100, eudragit RS 100 and ethylcellulose either alone or in combination with the help of non-aqueous solvent evaporation technique. All the formulated microparticles were subjected to various evaluation parameters such as particle size analysis, micrometric properties, drug entrapment efficiency, percentage drug loading, percentage yield and in vitro drug release study. The compatibility of the drug and polymers was confirmed by physical compatibility study, fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and x-ray diffraction study (XRD). The formation of the most optimized batch of the microsphere (F12) was confirmed by scanning electron microscopy (SEM), DSC, FTIR, and XRD. In vitro drug release study and in vitro drug release kinetics study of the formulated microspheres were also carried out.Results: Drug-polymer compatibility studies performed with the help of FTIR and DSC indicated that there were no interactions. Results revealed that non-aqueous solvent evaporation technique was a suitable technique for the preparation of microspheres as most of the formulations were discrete, free-flowing and spherical in shape with a good yield of 55.67% to 80.09%, percentage drug loading of 35.52% to 94.50% and percentage drug entrapment efficiency of 36.24% to 95.07%. Different drug-polymer ratios, as well as the combination of polymers, played a significant role in the variation of over-all characteristics of formulations. Based on the data of various evaluation parameters such as particle size analysis, percentage drug loading, percentage drug entrapment, percentage yield, rheological studies and in vitro drug release characteristics, formulation F12 was found to fulfil the criteria of ideal controlled release drug delivery system. F12 showed controlled release till the 14th hour (97.99%) and its in vitro release kinetics was best explained by zero-order kinetics and followed Korsemeyer-Pappas model (Non-Fickian mechanism). SEM of F12 revealed the formation of spherical structures. The FTIR study of F12 confirmed the stable nature of ropinirole in the drug-loaded microspheres. DSC and XRD patterns showed that ropinirole hydrochloride was dispersed at the molecular level in the polymer matrix.Conclusion: The controlled release microparticles were successfully prepared and from this study, it was concluded that the developed microspheres of ropinirole hydrochloride can be used for controlled drug release to improve the bioavailability and patient compliance and to maintain a constant drug level in the blood target tissue by releasing the drug in zero order pattern.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Yaowalak Srisuwan ◽  
Yodthong Baimark

Silk fibroin (SF)/alginate blend films have been prepared for controlled release of tetracycline hydrochloride, an antimicrobial model drug. The blend films were analysed by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and UV-vis spectroscopy. The functional groups of the SF/alginate blends were monitored from their FTIR spectra. The homogeneity of the blend films was observed from SEM images. The dissolution and film transparency of the blend films depended on the SF/alginate blend ratio. Thein vitrodrug release profile of the blend films was determined by plotting the cumulative drug release versus time. It was found that the drug release significantly decreased as the SF/alginate blend ratio increased. The results demonstrated that the SF/alginate blend films should be a useful controlled-release delivery system for water-soluble drugs.


2020 ◽  
pp. 41-61
Author(s):  
Liliana Mariel Cáceres ◽  
Gustavo Adolfo Velasco ◽  
Eliana Paola Dagnino ◽  
Ester R Chamorro

Essential grapefruit oil with high concentrations of limonene is used in food, cosmetic and pharmaceutical industries due to its antimicrobial properties, fragrance, and flavor. To facilitate its manipulation and protect it from adverse environmental factors, the microencapsulation is used. The objective of this work was to optimize the microencapsulation process of grapefruit oil using external ionic gelation coupled to extrusion with sodium alginate and calcium chloride. We achieved the best encapsulation conditions with calcium chloride concentration at 7.4% w/v and a crosslinking time of 58 minutes, obtaining a yield of 62% and an efficiency of 100% with an oil loading capacity of 10% w/w. The chemical adsorption of calcium as well during the crosslinking process was studied, observing a significant fit with the Elovich equation. And an adjustment of the controlled release of the oil was obtained to the empirical kinetic model of Korsmeyer and Peppas.


Author(s):  
S. DUBEY ◽  
S. P. VYAS

Objective: The objective of the present study was to formulate and characterize paclitaxel (Ptx) loaded sterically stabilized emulsomes to provide non-toxic and biocompatible carriers with high Ptx loading efficiency. Methods: Plain (P-Es) and sterically stabilized emulsomes (SS-Es) were prepared by a modified solvent evaporation method using tristearin as solid lipid and optimized for lipid to (DSPC+CHOL+DSPE-PEG)/ tristearin ratio, lipid/lipid-PEG (DSPC+CHOL/DSPE-PEG) molar ratio, solid lipid concentration, phospholipid concentration, organic to aqueous phase volume and homogenization time based on their effect particle size and entrapment efficiency. Optimized emulsomes were characterized for morphological features, in vitro drug release kinetics and protection from plasma protein. Results: The emulsomes so formed were uniform in size with a mean particle diameter of 275±5.52 and 195±6.4 nm for P-Es and SS-Es respectively. All the formulations showed pH dependent drug release with a slow and sustained release profile. Slower drug release was observed from sterically stabilized emulsomes than the plain emulsomes. The drug release profile followed the Higuchi model with the Fickian diffusion pattern. The Pegylation of emulsomes significantly reduced the in vitro protein absorption. Conclusion: The sterically stabilized emulsome can serve as a novel non-toxic platform with longer circulatory time for the delivery of Paclitaxel and other poorly water-soluble drugs as well.


Author(s):  
Kiran Kumar Vangara ◽  
Kishore K. Konda ◽  
Shiva K. Ravula ◽  
Pradeep K Vuppala ◽  
Vijay K. Sripuram ◽  
...  

It is challenging to develop a controlled release (CR) formulation for a freely water soluble drug molecule without using rate controlling polymers in the core matrix. This study is aimed to develop and evaluate cost-effective ethyl cellulose (EC)-polyvinyl pyrrolidone (PVP) film coating that can effectively control the release of freely water soluble drug, metoprolol succinate (MS) and to match that of release profile with its marketed tablet. Simple core tables of MS were compressed and coated with a solution composed of hydrophobic rate controlling polymer, EC and water soluble pore forming polymer, PVP. The effect of formulation parameters such as the ratio of EC to PVP and tablet coating weight gain on the in-vitro drug release were evaluated. Release profile of the optimized formulation at different pH conditions was determined and the similarity factor (f2) with marketed release profile was calculated.It was observed that drug release rate increased with a decrease in the ratio of ethyl cellulose to PVP and decreased with increased weight gain of the coating membrane. Among all the formulations, the formulation with EC and PVP at a ratio of 60:40 %w/w and 9% weight gain showed matching release profile to marketed tablet with f2 value of 72.25. The optimized formulation showed pH independent in-vitro release. This study successfully demonstrated that EC-PVP film coating can effectively control the release rate of freely soluble drugs. Once a day CR formulation of metoprolol succinate pharmaceutically equivalent to marketed tablet was developed.  


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