Mathematical Model for In Vitro Drug Release from Controlled Release Dosage Forms Applied to Propoxyphene Hydrochloride Pellets

1982 ◽  
Vol 71 (6) ◽  
pp. 694-699 ◽  
Author(s):  
Finn Norring Christensen ◽  
Flemming Yssing Hansen ◽  
Helle Bechgaard
Author(s):  
Kranthi Kumar Kotta ◽  
L. Srinivas

The present investigation focuses on the development of mucoadhesive tablets of captopril which are designed to prolong the gastric residence time after oral administration. Matrix tablets of captopril were formulated using four mucoadhesive polymers namely guar gum, xanthan gum, HPMC K4M and HPMC K15M and studied for parameters such as weight variation, thickness, hardness, content uniformity, swelling index, mucoadhesive force and in vitro drug release. Tablets formulated Xanthan gum or HPMC K4M with HPMC K15M provide slow release of captopril over period of 12 hr and were found suitable for maintenance portion of oral controlled release tablets. The cumulative % of drug release of formulation F9 and F10 were 90 and 92, respectively. In vitro release from these tablets was diffusion controlled and followed zero order kinetics. The ‘n’ values obtained from the pappas-karsemeyer equation suggested that all the formulation showed drug release by non-fickian diffusion mechanism. Tablets formulated Xanthan gum or HPMC K4M with HPMC K15M (1:1) were established to be the optimum formulation with optimum bioadhesive force, swelling index & desired invitro drug release. This product was further subjected to stability study, the results of which indicated no significant change with respect to Adhesive strength and in vitro drug release study.


Author(s):  
Farhana Sultan ◽  
Himansu Chopra ◽  
Gyanendra Kumar Sharma

Microsponge containing Luliconazole (LCZ) with different proportion of drug:polymer (Ethyl cellulose and Eudragit RS 100) were obtained efficiently using Quasi-emulsion solvent diffusion method. Luliconazole is an anti-fungal drug used for the topical delivery. The purpose of the microsponge formulation is to control the release of LCZ drug to the skin through Microsponge Delivery System (MDS) known to be the novel technique which overcome the maximum concentration of active ingredient, frequency doses, and skin irritation. The prepared microsponges were examined using drug content, % production yield, % entrapment efficiency and in-vitro drug release. The formulation were subjected to in-vitro drug release studies for 6 hr in which it was concluded that Ethyl cellulose microsponges formulated by drug:polymer (1:1) and Eudragit RS 100 microsponges formulated by drug:polymer (1:3) showed maximum controlled release i.e., Increase in drug:polymer ratio (1:1 to 1:9) increased the production yield and entrapment efficiency of microsponges using Ethyl cellulose with no significant effect for Eudragit RS 100.Therefore, both formulation F1 and F2 was dispersed in carbopol gel preparation for controlled delivery of LCZ to the skin. Various physical parameters like pH, spreadability, viscosity and in-vitro drug diffusion studies were evaluated for the prepared gel formulations. Microsponge gel formulation i.e., FG1 showed better results for controlled release of 89.40% as compared to FG2 i.e., 92.18% over the period of 12 hrs which is performed in Franz Diffusion Cell. On basis of in-vitro diffusion studies for LCZ gel formulation, microsponges using Ethyl cellulose (FG1) was found to be best for its controlled release of LCZ for 12 hrs and followed zero order kinetics. Hence, formulated LCZ loaded gel have potential to treat fungal infections i.e., tinea pedis, tinea cruris and tinea corporis.


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.


2021 ◽  
Vol 321 ◽  
pp. 04011
Author(s):  
Navideh Abbasnezhad ◽  
Farid Bakir ◽  
Stéphane Champmartin ◽  
Mohammadali Shirinbayan

Drug-eluting stents implanted in blood vessels are subject to various dynamics of blood flow. In this study, we present the evaluation of a mathematical model considering the effect of flow rate, to simulate the kinetic profiles of drug release (Diclofenac Sodium (DS)) from in-vitro from PLGA films. This model solves a set of non-linear equation for modeling simultaneously the burst, diffusion, swelling and erosion involved in the mechanisms of liberation. The release parameters depending on the flow rate are determined using the corresponding mathematical equations. For the evaluation of the proposed model, test data obtained in our laboratory are used. To quantify DS release from drug-carrier PLGA films, we used the flow-through cell apparatus in a closed-loop. Four flow rate values are applied. For each value, the model-substance liberation kinetics showed an increase in drug released with the flow rate. The simulated release profiles show good agreement with the experimental results. Therefore, the use of this model could provide a practical tool to assess in-vitro drug release profiles from polymer matrices under continuous flow rate constraint, and could help improve the design of drug eluting stents.


Author(s):  
Michael J. Rathbone ◽  
Jingjian Shen ◽  
Colin R. Ogle ◽  
Shane Burggraaf ◽  
Craig R. Bunt

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.


INDIAN DRUGS ◽  
2018 ◽  
Vol 55 (08) ◽  
pp. 59-62
Author(s):  
M. U Paradkar ◽  
◽  
K. Hudda

The aim of the present research work was to formulate and evaluate colon targeted pellets of lornoxicam for the pain management of rheumatoid arthritis. The product and process parameters were optimized by screening methods. Pellets were prepared by extrusion spheronization method using microcrystalline cellulose (MCC) as spheronizing aid and ethyl cellulose (EC) as controlled release polymer, in different ratios. Based on the physical appearance, sphericity and % in vitro drug release, batch B17 containing EC: MCC (6:4) was optimized for core pellets. The site specificity was obtained by screening Eudragit FS30D and Eudragit S100 as coating polymers and the core pellets were coated with Eudragit S100. The batch C4 (6%) showed appropriate physical appearance and % in vitro drug release upto 24 h, indicating controlled release property. The pharmacodynamic studies performed on rat model indicated the anti-inflammatory activity of pellet formulation. Thus, it is concluded that the coated pellets can be a good candidate for site specific delivery of lornoxicam to colon by decreasing the gastric irritation, reducing dose frequency and improving patient compliance.


2017 ◽  
Vol 9 (2) ◽  
pp. 1 ◽  
Author(s):  
Ajit Kulkarni ◽  
Trushali Mandhare ◽  
Nagesh Aloorkar

Objective: To explore a novel natural polymer, pullulan for controlling the release of fenoverine from matrix tablets and to elucidate the release kinetics of fenoverine from pullulan and HPMC matrices.Methods: In this study we formulated monolithic matrix tablets containing of fenoverine as controlled-release tablets by direct compression using pullulan, HPMC (Hydroxypropyl methyl cellulose) K4M and HPMC K100M polymers and evaluated for hardness, thickness, friability, weight variation drug content, in vitro drug release characteristics and FTIR (Fourier transform infrared spectroscopy) and DSC (Differential scanning calorimetry) study.Results: All the formulations showed compliance with pharmacopoeial standards. FTIR and DSC study indicated the absence of interaction between fenoverine and excipients. The formulation was optimized on the basis of acceptable tablet properties and in vitro drug release. The results of dissolution studies indicated that the formulation F5 [drug to polymer 1: 0.35] exhibited highest % cumulative drug release of 96.82±0.75 % at the end of 12 h. Optimised batch F5 showed super case II transport mechanism and followed zero order release kinetics. Short-term stability studies of the optimized formulation indicated that there were no significant changes observed in hardness, drug content and in vitro dissolution studies at the end of three months period. Similarity factor f2 was found to be 89, which indicated similar dissolution profiles before and after stability study.Conclusion: Based on above results we conclude that pullulan can be used as a polymer for retarding the release of drug from matrix formulations.Keywords: Pullulan, Fenoverine, Hydroxypropyl methyl cellulose, Controlled release, In vitro


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