Drug Release Of Formulations Research Articles

Semi-solid materials for controlled release drug formulation: current status and future prospects

Semi-solid materials represent an important category of inactive ingredients (excipients) of pharmaceutical products. Here we review several common semisolid polymers currently used in the controlled release formulations of many drugs. These polymers are selected based on their importance and broad scope of application in FDA-approved drug products and include several polysaccharides (cellulose, starch, chitosan, alginate) and carbomers, a group of mucoadhesive synthetic polymers. Glyceride-based polymers used in self-emulsifying drug delivery systems (SEDDS) will also be discussed for its importance in formulating poorly water-soluble drugs. Unique features and advantages of each type of semi-solid materials are discussed and examples of their use in oral delivery of drugs are provided. Finally, future prospects of developing new and better semi-solid excipients are discussed with the objective of facilitating clinical translation.

Biocompatible and biodegradable alginate/poly(N‐isopropylacrylamide) hydrogels for sustained theophylline release

ABSTRACTMixed‐interpenetrated polymeric networks based on sodium alginate (ALG) and poly(N‐isopropylacryl amide) (PNIPAAm) covalently cross‐linked with N,N'‐methylenebisacrylamide are studied for their biocompatibility, nontoxicity, and biodegradability aiming their application in drug delivery. The presence of drug‐polymeric matrix interactions and the distribution of the drug in the polymeric network for theophylline‐loaded ALG/PNIPAAm hydrogels are also investigated by spectroscopic and microscopic methods. The quantitative evaluation of theophylline loaded hydrogels performed by NIR‐CI technique shows a better drug entrapment and a higher homogeneity of the samples with increased alginate content. The thermal behavior of the hydrogels is significantly modified by theophylline presence. The application of the ALG/PNIPAAm hydrogels as carriers for sustained drug release formulations was assessed by the theophylline release tests performed both by in vitro and in vivo studies. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40733.

Formulation and evaluation of pH sensitive hydrogel of camptothecin with enhanced solubility by using β-cyclodextrin

The use of a novel injectable biocompatible and biodegradable camptothecin (CPT) formulation for controlled intra-tumoral release of CPT is described. The drug delivery vehicle is an autogelling pH sensitive formulation, which is based on the natural biopolymer chitosan. The formulation was prepared by Crosslinking methods. The formulations were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, gelation time and viscosities were investigated for controlled release hydrogel formulation. The formulation, containing homogeneously dispersed CPT, was studied by MTT assay on tumor cell MCF-7. The effectiveness of treatment was measured in terms of percentage control tumor growth inhibition (TGI). The hydrogel formulation of CPT showed good release profile with polymer [chitosan (C)/glyceryl monooleate (GMO)/β-cyclodextrin (β-CD)] compare to without polymer. The gelation pH of the formulation PF, PF4, PF6, PF10 and PF12 were found to be 6.58, 7.42, 7.20, 6.98 and 7.30 respectively and calculated values of viscosity in centipoises of the formulation PF, PF4, PF6, PF10 and PF12 were 3,413.3, 5,843.1, 6,948.8, 5,212.6 and 6,972.6 respectively at 25 °C. It was found that cumulative percentage drug release for formulations prepared PF, PF4, PF6, PF10 and PF12 were released 48.48, 76.92, 83.72, 78.97 and 59.23 % respectively. The formulation PF6 showed maximum cumulative percentage drug release which has 3 % w/v chitosan, 3 % w/v GMO and 1.5 % w/v β-CD. The TGI was found that for formulations CPT, PF, PF4, PF6, PF10 and PF12 were 10.2 ± 1.22, 10.4 ± 0.85, 14.92 ± 1.06, 16.42 ± 1.11, 13.58 ± 1.21 and 11.71 ± 1.14 % respectively. The formulation PF6 showed maximum TGI in comparison to other formulation. The system formulated with CPT was found to be stable and the release profiles of a formulation with chitosan, GMO and β-CD showed all most effective release kinetics. These findings show chitosan/GMO/β-CD hydrogel to be a safe, effective, homogeneous, injectable and stable formulation for delivery of CPT and this approach represents an attractive technology platform for the delivery of other clinically important hydrophobic drugs.

Nicotinamide pelletization by fluidized hot melt granulation: L18 Hunter design to screen high risk variables

L18 Hunter design was used to investigate the practicability of applying QbD approaches to fluidized hot melt granulation (FHMG) in preparing oral controlled release systems. Eight high-risk variables obtained from risk analysis were classified into chemical factors (type and percentage of meltable binder, matrix viscosity and percentage and filler type) and process variables (size fraction of meltable binder, inlet air volume and fluidization time). The variables were screened for their impacts on pellets characteristics. The obtained results showed that the meltable binder percentage was the significant variable affecting most responses. Flow properties, size distribution, bulk, and tapped densities were significantly (P<0.05) affected by the filler type, inlet air volume, and fluidization time. On the other hand, the matrix variables were non-significant to the dissolution parameters. Out of eight critical variables, it was found that the meltable binder percentage and size fraction, inlet air volume had the most significant effects and will be optimized in the second part of the study. In conclusion, QbD paradigm not only offered a robust FHMG technique to formulate controlled release formulations of hydrophilic drugs but also provided a time and cost saving advantage to pharmaceutical industry.

Ghost pill: knowledge and awareness of this phenomenon among health care professionals

Background: Slow release (SR) drug formulations associated with the passage of intact tablet like object in faeces sometimes known as the “ghost pill” have been in the market for many years. Anecdotal evidence suggests that few health care professionals are aware of this phenomenon. Our study aims were to find out what proportion of health care professionals was aware of the ghost pill phenomena and what drug formulations and specific drugs were associated with it. Methods: A survey was conducted among health care professionals at three hospital sights in the West Midlands, UK. The subjects included doctors, nursing staff, pharmacists, and other allied professionals involved in patient care. Results: A total of 321 health care professionals were included in the final analysis. Very few, 12.8% (41) have heard of the ghost pill phenomenon and a further 14 (4.4%) have come across of a patient who has experienced it. Only 13 (4%) correctly associated the phenomenon with SR drug formulations. Conclusion: Our survey has shown that the ghost pill phenomenon, a normal outcome of a novel way of delivering orally taken SR drugs, is not well-known among health care professionals. Lack of awareness of it has implications to trainers, medical and nonmedical prescribers and nursing staff working with patients who are taking these medications. Lack of awareness among health care staff, may result in relevant information not being shared with patients at the time of prescribing or when patients enquires of it.

Impact of in situ granulation and temperature quenching on crystal habit and micromeritic properties of ibuprofen-cationic dextran conjugate crystanules

Ibuprofen was recrystallized in the presence of aqueous solution of cationic dextran derivative, Diethylaminoethyl Dextran (Ddex) using the melt-in situ granulation-crystallization technique in order to produce a stable amorphous ibuprofen-Ddex conjugates with improved morphological, micromeritic and thermo-analytical characteristics without the use of organic solvent. Ddex was used in this study because of its ability to form conjugates with various drug molecules and enhance their physicochemical characteristics and therapeutic activities. Cationic dextrans are also biocompatible and biodegradable. Mechanism of conjugation as well as the impact of conjugation on the ibuprofen crystal habit was investigated. Gaussian type normal particle size distribution was obtained and the size of the crystals in the crystanule conjugates decreased steadily, with increasing concentration of Ddex, to a minimum of 480 nm (440-folds reduction, p<0.05, n=20) at Ddex molar concentration of 0.01 mM. FT-IR spectra showed electrostatic interaction and hydrogen bonding between ibuprofen and Ddex which was confirmed with the (1)H NMR and (13)C NMR spectra. DSC curves exhibited single peaks from the binary ibuprofen-Ddex conjugate crystanules suggesting compatibility and formation of an eutectic product. The conjugate crystanules showed broad and diffuse endothermic peaks with a glass transition temperature (T(g)) of 58.3 and 59.14°C at Ddex molar concentrations of 1.56 × 10(-4) and 3.125 × 10(-4)mM respectively confirming the existence of ibuprofen-Ddex crystanule conjugates in amorphous state. Higher concentrations of Ddex decreased T(g) steadily. TGA curves showed first order degradation at low molar concentrations of Ddex up to 3.125 × 10(-4)mM which coincides with the critical granular concentration of the crystanules while higher concentrations exhibited second order degradation profile. This study provides the basis for the development of stable amorphous drug-polymer conjugates with potential practical application in controlled and extended drug release formulations.

Taguchi design for optimization and development of antibacterial drug-loaded PLGA nanoparticles

This research report was to develop Cefixime loaded polylactide-co-glycolide (PLGA) nanoparticles using modified precipitation method. TEM analysis indicated formation of well-formed, smooth, spherical nanoparticles with no aggregates whereas XRD recommended dispersion of drug in PLGA carrier system in amorphous form. The polymer and stabilizer concentration and organic to aqueous ratio were found to be significant factors for nanoparticles and their optimization using Taguchi design (L9). The design formulations showed entrapment efficiency (EE), particle size and poly-dispersity index (PDI) ranging 68.31±1.74%, 159.8–157.7nm and 0.126–0.149, respectively indicated small and stable nanoparticles with good homogeneity and encapsulation. The design optimized formulation drug release and permeation studies demonstrated that it is four times sustained release behavior and 1.74 times better permeation than free drug. The result of microbiological assay also suggested that optimized formulation has significant antibacterial activity against intracellular multidrug resistance (MDR) of Salmonella typhi.

FORMULATION AND EVALUATION OF SUSTAINED RELEASE TABLETS OF ITOPRIDE HYDROCHLORIDE

The objective of this research work was to develop sustained release tablets of Itopride HCl using different hydrophilic poly mers like HPMC K4M, HPMC K15M, Carbopol 971P, Metolose 60SH - 50, Guar g um, Xanthan gum by direct compression method. Various amounts of combination of polymers in 1:1 ratio were used in the twenty four proposed formulations (F - 1 to F - 24) for the study of release rate retardant effect at 15 %, 25 % and 35 % of total weight of tablet matrix respectively. Then the tablets were evaluated in terms of their physical parameters (weight variation, hardness, friability and thickness), drug content and In - vitro release studies. All the formulations showed compliance with pharmacopoeial standards. The In - v i t ro dissolu tion study were conducted using USP dissolution apparatus type II (paddle method) in 900 ml 0.1 N HCl for first 2 h and remaining 22 h performed in 6.8 pH phosphate buffer at 50 rpm for a total period of 24 h . Based on the d issolution data comparison with innovator, formulation F - 8 was found as the best formulation. The drug release of formulation F - 8 foll owed First Order kinetic model and the mechanism was found to be non - Fickian / anomalous according to Korsmeyer Peppas equ ation.

Pharmaceutical suspension containing both immediate/sustained-release amoxicillin-loaded gelatin nanoparticles: preparation and in vitro characterization

Pharmaceutical suspension containing oral dosage forms delivering both immediate-release and sustained-release amoxicillin was developed as a new dosage form to eradicate Helicobacter pylori. Amoxicillin-loaded gelatin nanoparticles are able to bind with the mucosal membrane after delivery to the stomach and could escalate the effectiveness of a drug, providing dual release. The objective of this study was to develop amoxicillin nanoparticles using innovative new technology – the Büchi Nano Spray Dryer B-90 – and investigate such features as drug content, particle morphology, yield, in vitro release, flow properties, and stability. The nanoparticles had an average particle size of 571 nm. The drug content and percentage yield was 89.2% ± 0.5% and 93.3% ± 0.6%, respectively. Angle of repose of nanoparticle suspension was 26.3° and bulk density was 0.59 g/cm3. In vitro drug release of formulations was best fitted by first-order and Peppas models with R2 of 0.9841 and 0.9837 respectively; release profile was 15.9%, while; for the original drug, amoxicillin, under the same conditions, 90% was released in the first 30 minutes. The nanoparticles used in this study enabled sustained release of amoxicillin over an extended period of time, up to 12 hours, and were stable for 12 months under accelerated storage conditions of 25°C ± 2°C and 60% ± 5% relative humidity.

Effect of solvent type on retardation properties of diltiazem HCl form liquisolid tablets

Liquisolid technique is a new approach to formulate sustained release dosage forms. It seems that the solubility of an active ingredient in solvent plays an important role in drug release profile. The aim of present study was to investigate the effect of solvent type on diltiazem hydrochloride release profile from liquisolid compacts. To examine aforementioned idea, the drug solubility was studied in several conventional nonvolatile solvents. Liquisolid formulations of diltiazem HCl in the different solvents were prepared and their release profiles were also obtained. Effect of aging on the hardness and drug release profile was studied as well. X-ray crystallography and differential scanning calorimetry (DSC) were used to investigate the formation of any complex between drug and carrier or any crystallinity changes during the manufacturing process. The results showed that diltiazem HCl had lowest solubility in polysorbate 20. Highest amount was devoted to polysorbate 80 and propylene glycol. Type of nonvolatile solvent and its physicochemical properties as well as solubility of the drug in the applied solvent found to have important role on release profile of the drug from liquisolid compacts. Hardness and dissolution profile of the drug were not affected by aging. Amorphous form was obtained during the process of liquisolid formulation. It follows that the optimized new technique can be used to prepare sustained release formulations of water-soluble drugs.

Controlled Release of Ropinirole Hydrochloride from a Multiple Barrier Layer Tablet Dosage Form: Effect of Polymer Type on Pharmacokinetics and IVIVC

The purpose of the present study was to control in vitro burst effect of the highly water-soluble drug, ropinirole hydrochloride to reduce in vivo dose dumping and to establish in vitro-in vivo correlation. The pharmacokinetics of two entirely different tablet formulation technologies is also explored in this study. For pharmacokinetics study, FDA recommends at least 10% difference in drug release for formulations to be studied but here a different approach was adopted. The formulations F8A and F9A having similar dissolution profiles among themselves and with Requip® XL™ (f 2 value 72, 77, 71 respectively) were evaluated. The C max of formulation F8A comprising hypromellose 100,000 cP was 1005.16 pg/ml as compared to 973.70 pg/ml of formulation F9A comprising hypromellose 4000 cP irrespective of T max of 5 and 5.75 h, respectively. The difference in release and extent of absorption in vivo was due to synergistic effect of complex RH release mechanism; however, AUC0-t and AUC0-∞ values were comparable. The level A correlation using the Wagner-Nelson method supported the findings where R (2) was 0.7597 and 0.9675 respectively for formulation F8A and F9A. Thus, in vivo studies are required for proving the therapeutic equivalency of different formulation technologies even though f 2 ≥ 50. The technology was demonstrated effectively at industrial manufacturing scale of 200,000 tablets.

Preparation, characterization and pharmacological evaluation of tolterodine hydrogels for the treatment of overactive bladder

In this study, transdermal gel formulations for tolterodine were developed to investigate the effects of gel matrix and chemical enhancers on drug skin permeation from tolterodine hydrogels. In vitro permeation studies of tolterodine through excised mouse skin were carried out using Franz-type diffusion cells. In the optimum gel formulation, Carbopol 940 was selected as the gel matrix. Compared to gels without enhancer, tolterodine hydrogels with N-methyl pyrrolidone (NMP) showed significant enhancing effect on transdermal permeation of tolterodine (p<0.05). The results of in vitro percutaneous delivery experiment showed that the relationship of the steady accumulative percutaneous amount (Q, μg cm(-2)) of tolterodine hydrogels and time was Q4-12h=770.19t(1/2)-966.99. Tolterodine permeated at the steady-state speed of 770.19 μg cm(-2)h(-1) and its release coincided with Higuchi Equation. The pharmacokinetic properties of the optimized tolterodine formulation were studied in rabbits. The absolute bioavailability of tolterodine was 11.47%. Since the absence of hepatic first-pass metabolism, only a single active compound-tolterodine was detected in the plasma. A skin irritation study was also carried out on rabbits, and the results showed tolterodine hydrogels had no skin irritation. In the pharmacodynamic study, the significant effects of tolterodine hydrogels on the inhibition of pilocarpine-induced rat urinary bladder contraction were last to 12h, indicating that tolterodine hydrogels could produce prolonged pharmacological responses. In conclusion, tolterodine hydrogels were formulated successfully using Carbopol 940 and NMP and these results helped in finding the optimum formulation for percutaneous drug release. It is quite evident that tolterodine hydrogels may offer a possibility to avoid the first-pass effect, resulting in a single active compound of tolterodine in plasma, which may profit on the patient under the dose control and the reduction of potential adverse effect from two active compounds in the body.

Development of Novel Floating Delivery System based on Psyllium: Application on Metformin Hydrochloride

psyllium, a medicinally active gel forming natural polysaccharide and a dietary fiber has been used as a medicine in myriad of conditions such as constipation and inflammatory bowel syndrome. One of its more recent uses that have received attention has been its ability to reduce blood sugar levels in diabetics. Therefore present work is an attempt to formulate anti diabetic drug Metformin as a controlled release floating delivery making use of pysllium as release retardant and to assist the drug in stabilizing blood sugar level in type II diabetics. Drug and excipients compatibility studies were monitored by thermal analysis using differential scanning calorimeter (DSC) and Fourier transform infra red (FTIR). The DSC thermogram and FTIR of drug and drug-polymer mixture did not reveal any incompatibility. psyllium was tried in different concentrations along with other polymers like HPMC K15M and carbopol 940 to achieve the desired release profile. The total drug: polymer ratio was kept between 1:0.4 to 1:0.5, and different polymer combinations were tried to achieve desired drug release for 12 hours. The prepared tablets were evaluated for in vitro release studies and floating behavior. Our conclusion from the present study indicated that pysllium could potentially be used in conjunction with other polymers to formulate controlled release formulations of anti-diabetic drugs to provide better control over blood glucose levels.

Naltrexone-loaded poly[La–(Glc–Leu)] polymeric microspheres for the treatment of alcohol dependence: in vitro characterization and in vivo biocompatibility assessment

The poly[La–(Glc–Leu)] copolymer was applied in the present investigation as polymeric carrier to fabricate naltrexone (NTX)-loaded poly[La–(Glc–Leu)] microspheres in the single emulsion solvent evaporation technique for the long-term treatment of alcohol dependence. Newly synthesized poly[La–(Glc–Leu)] copolymer exhibited diminished crystallanity, good biocompatibility and favorable biodegradability to be explored for drug delivery application. Scanning Electron Microscopy study revealed smooth and spherical-shaped NTX-loaded polymeric microspheres with a mean size of 10–90 µm. Influence of various decisive formulation variables such as amount of polymer, stabilizer concentration, homogenization speed, homogenization time, drug loading and organic-to-aqueous phase ratio on particle size, and entrapment efficiency was studied. Differential scanning calorimeter and X-ray diffractometry study confirmed the drug entrapment within polymer matrix into the microsphere environment. In vitro drug release showed the sustained drug release of formulation for the period of 28 d giving biphasic release pattern. Histological examination of NTX-loaded poly[La–(Glc–Leu)] microspheres injected intramuscularly into the thigh muscle of Wistar rats showed minimal inflammatory reaction, demonstrating that NTX-loaded microspheres were biocompatible. Insignificant increase in the serum creatine phosphokinase level (p < 0.05) as compared with the normal value revealed good muscle compatibility of the poly[La–(Glc–Leu)] microsphere system. Biocompatible nature and sustained drug-release action of poly[La–(Glc–Leu)] microspheres may have potential application in depot therapy.

Evaluation of floating press-coated pulsatile release of Aceclofenac tablets. A solution for Rheumatoid athrites

The objective of this study was to develop and evaluate of a floating presscoated pulsatile drug delivery system intended for treatment of early morning stiffness and symptomatic relief from pain in patients with rheumatoid arthritis with a distinct predetermined lag time of 8 h. Cores containing Aceclofenac as model drug were prepared by direct compression of different Sodium starch glycolate level CT-1 to CT-4) 8 %, 4%, 2% & without disinegrant and Aceclofenac as a model drug by using various proportion of polymers such Hydroxypropyl methylcellulose and Sodium bicarbonate floating layer is prepared. Fifteen formulations were prepared and formulation F15, F18, F22possessed good lag time 8 hr and showed pulsatile drug delivery pattern the tablets In- vitro evaluation tests. Results of this study indicated that by using floating-pulsatile release formulations are suitable to optimize pulsatile drug release formulation of Aceclofenac.

Formulation and Evaluation of a Pulsatile Delivery System of Losartan Potassium by Factorial Design

&#x0D; The present study was aimed to prepare a time-dependent pulsed release system for the programmed release of losartan potassium for the treatment of hypertension. The core tablets of losartan potassium were prepared using wet granulation containing a superdisintegrant. The design was based on 32 full factorial design containing 2 factors evaluated at 3 levels and the experimental trials were performed on coating of the core tablets. Eudragit S100 and Eudragit L100 were used as pH dependent polymers for coating of the tablets. Factors influenced the lag time and In-vitro drug release of formulations, called as dependent factors. Dissolution studies of coated tablets in media with pH (1.2 and 6.8) showed that drug release could be modulated by optimizing the concentration of Eudragit L100: Eudragit S100. Polynomial mathematical model generated for various response variable using multiple linear regression analysis, were found to be statistically significant. Contour plots and response surface plots were drawn and optimum formulation were selected by feasibility and desirability function. The experimental values obtained from the optimized formulation highly agreed with the predicted values. The results of in vitro dissolution studies indicated that formulation P5 is the most successful formulation of the study and exhibited lag time 5.5 h and drug release 95.23 % in 12 h. The total release pattern was very close to the theoretical release profile of pulsed release system. The study showed that lag time prior to drug release was highly affected by the coating level. The dissolution data revealed that the level of coating and the ratio of polymers are very important to achieve an optimum formulation. Stability study of the optimized formulation indicates no significant difference in release profile after a period of one month.

Development of pulsatile release of Aceclofenac tablets with swelling and rupturable layers of ethyl cellulose

The objective of this study was to develop and evaluate of Aceclofenac tablets with swelling and rupturable layers of ethyl cellulose. A tablet system consisting Intended for treatment of early morning stiffness and symptomatic relief from pain in patients with rheumatoid arthritis with a distinct predetermined lag time of 6 h. Cores containing Aceclofenac as model drug were prepared by direct compression of different Sodium starch glycolate level CT-1 to CT-4) 8 %, 4%, 2% & without disinegrant and were then coated sequentially with an inner swelling layer containing a superdisintegrant (croscarmellose sodium) and an outer rupturable layer of ethylcellulose. Seven formulations were prepared and formulation F2 possessed good lag time 6 hr and showed pulsatile drug delivery pattern the tablets In- vitro evaluation tests. Results of this study indicated that by using ethyl cellulose are suitable to optimize pulsatile drug release formulation of Aceclofenac.

Silica Aerogel Improves the Biocompatibility in a Poly-ε-Caprolactone Composite Used as a Tissue Engineering Scaffold

Poly-ε-caprolactone (PCL) is a biodegradable polyester that has received great attentions in clinical and biomedical applications as sutures, drug delivery tool, and implantable scaffold material. Silica aerogel is a material composed of SiO2that has excellent physical properties for use in drug release formulations and biomaterials for tissue engineering. The current study addresses a composite of silica aerogel with PCL as a potential bone scaffold material for bone tissue engineering. The biocompatibility evaluation of this composite indicates that the presence of silica aerogel effectively prevented any cytotoxic effects of the PCL membrane during extended tissue culture periods and improved the survival, attachment, and growth of 3T3 cells and primary mouse osteoblastic cells. The beneficial effect of silica aerogel may be due to neutralization of the acidic condition that develops during PCL degradation. Specifically, it appears that silica aerogel to PCL wt/wt ratio at 0.5 : 1 maintains a constant pH environment for up to 4 weeks and provides a better environment for cell growth.

Self-microemulsifying drug-delivery system for improved oral bioavailability of pranlukast hemihydrate: preparation and evaluation

The purpose of the present investigation was to develop and evaluate a self-microemulsifying drug delivery system (SMEDDS) for improving the oral absorption of a pranlukast hemihydrate (PLH), a very poorly water-soluble drug. An efficient self-microemulsifying vehicle for PLH was selected and optimized using solubility testing and phase diagram construction. The formulations were characterized by assessing self-emulsification performance, droplet size analysis, in vitro drug release characteristics and formulation stability studies. Optimized formulations for in vitro dissolution and bioavailability assessment were Triethylcitrate (TEC; 10%), Tween 20 (50%), Span 20 (25%), triethanolamine (5%), and benzyl alcohol (10%). The SMEDDS readily released the lipid phase to form a fine oil-in-water microemulsion with a narrow distribution size. Saturated solubilities of PLH from SMEDDS in water, pH 4.0 and 6.8, were over 150 times greater than that of plain PLH. The release of 100% PLH from SMEDDS was considerably greater compared to only 1.12% in simulated intestinal fluid (pH 6.8) from plain PLH after 2 hours. The PLH suspension with 0.5% sodium carboxymethylcellulose or 3% PLH-loaded SMEDDS was administrated at a dose of 40 mg/kg as PLH to fasted rats. The absorption of PLH from SMEDDS resulted in about a threefold increase in bioavailability compared with plain PLH aqueous suspension. Our studies illustrated that the potential use of the new SMEDDS can be used as a possible alternative to oral delivery of a poorly water-soluble drug such as PLH.

Characterization of Ethylcellulose and Hydroxypropyl Methylcellulose Microspheres for Controlled Release of Flurbiprofen

Characterization of Ethylcellulose and Hydroxypropyl Methylcellulose Microspheres for Controlled Release of Flurbiprofen The objective of this study was to design and optimize polymeric microspheres of flurbiprofen (FLB) with ethylcellulose (EC) and hydroxypropyl methylcellulose (HPMC) using response surface methodology. EC and HPMC were taken as independent variables whereas; the dependent variables were % drug release at pH 1.2, 4.5 and 7.4. FTIR spectra and TGA showed no significant difference between drug and polymers. DSC and XRD studies exhibited molecular dispersion of FLB within microspheres. Contour plots were drawn to predict the relationship between dependent and independent variables. Both polymers revealed their significant effects on drug release that followed the zero order which was further verified by the lowest values of Akaike information criterion. The mechanism of drug release followed super case II type of drug release. This study helped unraveling the influence of two factors on in-vitro drug release and thereby, proposed an appropriate sustained drug release formulation.