Development,optimization, and evaluation of emulsion‐gelled floating beads using natural polysaccharide‐blend for controlled drug release

This article describes the development, optimization, and evaluation of groundnut oil‐entrapped tamarind seed polysaccharide (TSP)‐alginate floating beads containing diclofenac sodium by emulsion‐gelation method for gastroretentive delivery. The effect of polymer to drug ratio, groundnut oil to water ratio, and sodium alginate to TSP ratio on drug entrapment, density, and drug release of floating beads was optimized using three‐factor and two‐level factorial design. The optimized floating beads showed drug entrapment efficiency of 82.48% ± 2.34%, density of 0.88 ± 0.07 g/cm³, cumulative drug release of 41.02% ± 0.86% after 8 h and floated well over 8 h in simulated gastric fluid (pH 1.2) with 8.25 min floating lag‐time. The in vitro drug release from these floating beads containing diclofenac sodium was followed controlled‐release pattern (zero‐order kinetics) with case‐II transport mechanism. The average bead size was ranged from 1.07 ± 0.03 to 1.94 ± 0.09 mm. The floating beads were characterized by SEM, FTIR, and ¹H NMR. The optimized floating beads showed excellent anti‐inflammatory activity in carrageenan‐induced rats over prolonged period after oral administration. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers     

Nanostructured Non-Ionic Surfactant Carrier-Based Gel for Topical Delivery of Desoximetasone

Psoriasis is a chronic autoimmune skin disease impacting the population globally. Pharmaceutical products developed to combat this condition commonly used in clinical settings are IV bolus or oral drug delivery routes. There are some major challenges for effectively developing new dosage forms for topical use: API physicochemical nature, the severity of the disease state, and low bioavailability present challenges for pharmaceutical product developers. For non-severe cases of psoriasis, topical drug delivery systems may be preferred or used in conjunction with oral or parenteral therapy to address local symptoms. Elastic vesicular systems, termed “niosomes”, are promising drug delivery vehicles developed to achieve improved drug delivery into biological membranes. This study aimed to effectively incorporate a corticosteroid into the niosomes for improving the drug bioavailability of desoximetasone, used to treat skin conditions via topical delivery. Niosomes characterization measurements were drug content, pH, spreadability, specific gravity, content uniformity, rheology, and physicochemical properties. Formulations used a topical gelling agent, Carbomer 980 to test for in vitro skin permeation testing (IVPT) and accelerated stability studies. The developed niosomal test gel provided approximately 93.03 ± 0.23% to 101.84 ± 0.11% drug content with yield stresses ranging from 16.12 to 225.54 Pa. The permeated amount of desoximetasone from the niosomal gel after 24 h was 9.75 ± 0.44 µg/cm² compared to 24.22 ± 4.29 µg/cm² released from the reference gel tested. Furthermore, a drug retention study compared the test gel to a reference gel, demonstrating that the skin retained 30.88 ng/mg of desoximetasone while the reference product retained 26.01 ng/mg. A controlled drug release profile was obtained with a niosomal formulation containing desoximetasone for use in a topical gel formulation showing promise for potential use to treat skin diseases like psoriasis.     

Novel Nanostructured Lipid Carriers with Photoprotective Properties Made from Carnauba Wax,Beeswax, and Kenaf Seed Oil

This study was aimed to produce a stable kenaf seed oil-nanostructured lipid carrier (KSO-NLC) sunscreen, which can help in the photoprotective effect. The nanostructured lipid carrier (NLC) formulation was optimized and selected based on the results of mean particle size, polydispersity index (PDI), and storage stability of formulas at both chilled (4 ± 2 °C) and room (25 ± 2 °C) temperatures. Uvinul A plus B was added to KSO-NLC with the optimized formula (80% w/w aqueous phase, 20% w/w lipid phase, and 7% w/w of surfactants with a ratio of 70:15:15 of Tween 20: poloxamer 188: lecithin). The mean particle size distribution (224.73 ± 1.56 nm) and PDI (0.41 ± 0.01) of KSO-NLC were determined and were found to be stable against storage without creaming or phase separation. The 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging and 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical-scavenging activities of KSO-NLC were 5.43 ± 1.00 mg Trolox equiv. g⁻¹ of NLC and 6.70 ± 0.31 mg Trolox equiv. g⁻¹ of NLC, respectively. The Sun Protection Factor (SPF) of KSO-NLC, 41.38 ± 6.03 with a UVA/UVB ratio 0.64 ± 0.01, suggested a good photoprotective effect. The sustained release of Univul A plus B from KSO-NLC accompanied by its entrapment efficiency up to 64.09 ± 0.98% and drug loading (DL) of 32.05 ± 0.49% (maximum 50% DL capacity) proved that the degradation of the ultraviolet (UV) filter could be reduced. Therefore, the KSO-NLC sunscreen was a feasible solution for the photoprotective approach by using unconventional plant seed oil with a significant enhancement (P < 0.05) in many aspects compared to the formula without KSO incorporation.     

Enhanced transdermal deposition and characterization of quercetin-loaded ethosomes

We sought to evaluate the transdermal permeation potential of quercetin-loaded ethosomes. Quercetinloaded ethosomes were prepared and characterized with regard to particle size, loading efficiency, stability, and in vitro skin permeation. The optimized formulation of ethosomes was confirmed using 2% egg phosphatidylcholine and hydrated 20% ethanol. After quercetin was applied using this formulation, the stability of the ethosomes was determined when loaded with up to 0.04% quercetin. We observed that loading efficiency was improved with increasing concentrations of quercetin. Ethosomes loaded with 0.04% quercetin showed both the greatest loading efficiency (63.9%±6.0%) and an optimal size range (132±32 nm). Ethosomes loaded with quercetin were superior in skin permeation ability (29.5±7.0 μg/cm²) compared to either ethanolic solution or liposomes. Therefore, we concluded that quercetin-loaded ethosomes increased the skin delivery of quercetin. Our results suggest that quercetin-loaded ethosomes may enhance the effect of cosmetic materials.     

Design and optimization of alginate−chitosan−pluronic nanoparticles as a novel meloxicam drug delivery system

The inflammation and pain associated with osteoarthritis are treated with nonsteroidal anti‐inflammatory drugs (NSAIDs). This treatment is accompanied by several side effects; therefore local intra articular (IA) NSAID injection can be more efficient and safe than systemic administration or topical use. In this study, alginate?chitosan?pluronic nanoparticles were considered as a new vehicle for IA meloxicam delivery. These novel nanoparticles were prepared using an ionotropic gelation method and were optimized for variables such as alginate to chitosan mass ratio, pluronic concentration, and meloxicam concentration using a 3‐factor in 3‐level Box‐Behnken design. To optimize the formulation, the dependent variables considered were particle size, zeta potential, entrapment efficiency, and mean dissolution time (MDT). The nanoparticles morphology was characterized by FESEM and AFM. The potential interactions of the drug‐polymers were investigated by ATR‐FTIR and DSC, and the delivery profile of meloxicam from the nanoparticles was obtained. The average particle size of the optimized nanoparticles was 283 nm, the zeta potential was ?16.9 mV, the meloxicam entrapment efficiency was 55%, and the MDT was 8.9 hours. The cumulative released meloxicam amount from the composite nanoparticles was 85% at pH 7.4 within 96 h. The release profile showed an initial burst release followed by a sustained release phase. The release mechanism was non‐Fickian diffusion. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42241.     

Rationally designed curcumin laden glycopolymeric nanoparticles: Implications on cellular uptake and anticancer efficacy

Overexpression of glucose transport proteins (GLUTs) plays a pivotal role in the survival of cancer cells. Hence, targeting GLUTs receptors using glucose-based polymers can fill up the lacuna of cancer treatment by confining the dissemination and accumulation of chemotherapeutic drugs on cancer cells. The present study addressed the preparation of glycohomopolymer (PMG), PEG-based di- (PEG-b-PMG) and tri-block (PMG-b-PEG-b-PMG) polymers using atom transfer radical polymerization and their potential in the development of novel nanoparticulate drug delivery system. Curcumin-loaded glycopolymer nanoparticles were fabricated by nanoprecipitation method and investigated for various physicochemical parameters such as particle size, zeta potential, polydispersity index, drug loading, morphology, and dissolution profile. Homoglycopolymer nanoparticles exhibited lower average particle size (240.16 ± 21.41 nm), higher zeta potential (−28.72 ± 4.25 mV), and entrapment efficiency (74.61 ± 5.03%) compared to their block copolymer counterparts. Optimized formulation exhibited diffusion and dissolution-controlled drug release behavior. In vitro cell line studies demonstrated significantly superior cytotoxicity, clonogenic inhibitory and cellular uptake potential in MCF-7 cells besides receptor recognizing property of optimized curcumin nanoparticulate formulation compared to free curcumin. These findings elucidate that curcumin homoglucopyranoside nanocarriers can be a promising drug delivery option for effective management of breast cancer. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48954.     

Proliposomes of lisinopril dihydrate for transdermal delivery: Formulation aspects and evaluation

We formulated and evaluated proliposomal gel of relatively low bioavailable drug lisinopril dihydrate (LDH) for transdermal delivery. Several proliposomal gel formulations of lisinopril dihydrate were prepared by modified coacervation phase separation method and examined for formation of liposomes by optical microscope and characterized by transmission electron microscopy. The formulations were evaluated for size, zeta potential, entrapment efficiency, rheological behavior, ex vivo drug permeation, skin irritation and stability. Differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) studies were performed to understand the phase transition behavior and mechanism for skin permeation, respectively. The microscopic examination revealed the formation of liposomes from proliposomal gel, and the size of the vesicles was found to be in the range of 385 nm to 635 nm. Entrapment efficiency was high for the formulation containing greater amounts of phosphatidylcholine. The DSC studies indicated the amorphous form of LDH in proliposomal gel formulation. Ex vivo permeation studies revealed sustained permeation of drug from proliposomal gels studied. The stability studies reveal that the proliposomal formulations are more stable when stored at refrigeration temperature (4 °C). In conclusion, proliposomal gels offer potential and prove to be efficient carriers for improved and sustained transdermal delivery of lisinopril dihydrate.     

Formulation and Evaluation of Polymeric Nanoparticulate Gel for Topical Delivery

The aim of the present study was to enhance the permeation of drug into the skin and to reduce the skin irritation. To achieve the objective the drug was formulated in to nanoparticles using chitosan as a polymer and these drug loaded nanoparticles were incorporated in gel. The prepared nanoparticles were characterized by FTIR, DSC, SEM, and particle size. The particle size for optimized nanoparticulate gel (NPG-4) was found to be between 49–305nm. SEM photographs showed that nanoparticles were roughly spherical in shape and free from cracks. The NPG-4 showed 43.9% of encapsulation efficiency and 18.9% drug loading. At the end of 24h the in vitro drug release was found to be 90.1% in pH 7.4 phosphate buffer saline (PBS) and in vitro skin permeation studies NPG-4 showed 2.1mg/cm² of drug permeation, which was better than the marketed formulation (NIZRAL 2%) cream, which showed only 1.2mg/cm² of drug permeation. The NPG-4 showed no primary skin irritation when tested on rabbit skin.     

Design and evaluation of a lyophilized liposomal gel of an antiviral drug for intravaginal delivery

Liposomes of antiviral drug(acyclovir) prepared by rotary evaporation method were incorporated into two bioadhesive polymers, carbopol and HPMC and freeze dried to obtain a unit dosage form. The liposomes, liposomal gels and freeze dried rods were evaluated for various parameters. TEM analysis showed the formation of unilamellar liposomes with a mean diameter ranging from 0.9 μm to 1.2 μm. As the cholesterol content increases from 0.5% to 2%w/w, the entrapment efficiency and vesicle size increased. Carbopol gels exhibited higher viscosity, spreadability, mucoadhesiveness than HPMC gels. The redipsersion of freeze dried forms in SVF was found to be slow and its ex‐vivo retention time was found to be 12 hrs while acyclovir gel retained only for 8.25 hrs. The tablet and gel released 96.93±0.15% acyclovir within 6 hrs and 92.31±0.31% by 8 hrs respectively while freeze dried forms could sustain the release upto 12 hrs. From the stability studies the optimum storage condition was found to be 4‐8°C. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39804.     

Preparation of PEGylated liposomes of docetaxel using supercritical fluid technology

The aims of this investigation were to develop a procedure to prepare and characterize docetaxel encapsulated PEGylated liposomes using supercritical carbon dioxide as antisolvent and optimize the process and formulation variables using response surface methodology. The process and formulation variables were optimized by “Box Behnken Design (BBD)” of response surface methodology (RSM) with temperature, pressure and CO₂ flow rate as independent variables and particle size and yield as dependent variables for process variables while the amount of hydrogenated soya phosphotidylcholine (HSPC), soya phosphotidylcholine (SPC) and cholesterol as independent variables and % entrapment efficiency as dependent variables for optimization of formulation variables. The optimized liposomal formulation was characterized for particle size, shape, morphology, crystallinity, zeta potential, % entrapment efficiency, residual solvent content and in vitro drug release. The process and formulation variables were optimized to achieve maximum drug entrapment efficiency and yield. Results for particle size, zeta potential, % entrapment efficiency and in vitro drug release of PEGylated liposomes were found to be 269.2 ± 2.8 nm, −27.2 ± 1.8 mV, 79.2 ± 4.4 %w/w and 37.5 ± 4.5% in 24 h, respectively. The liposomes were found to be small, unilamellar and spherical with smooth surface as seen in photomicrographs of scanning electron microscopy and transmission electron microscopy. Differential scanning calorimetry and X-ray diffraction results indicated a molecular dispersion of docetaxel in the liposomes. In this study, supercritical fluid technology was successfully used to prepare small, spherical and unilamellar liposomes of docetaxel with high entrapment. It was observed that supercritical fluid technique can be an excellent technique for preparation of docetaxel liposomes which otherwise is very difficult to prepare as a solvent free and stable liposomes.     

Microwave-assisted synthesis of alginate-g-polyvinylpyrrolidone copolymer and its application in controlled drug release

The aim of this study is to synthesize graft copolymer (NaAlg-g-PVP) in microwave oven and prepare pH-responsive beads with high entrapment efficiency. For this purpose, PVP was grafted onto sodium alginate using microwave radiation. The copolymer obtained was characterized using FTIR, ¹H-NMR, elemental analysis and thermogravimetric analysis. A series of NaAlg-g-PVP beads were prepared as drug delivery matrices for ibuprofen (IB) by cross-linking into beads via glutaraldehyde. The chemical stability of IB after encapsulation into beads was confirmed by FTIR, DSC, and X-RD analysis. Synthesis conditions of beads were optimized by considering entrapment efficiency, particle size, swelling capacity and their release data. Effects of such variables as graft yield and drug/polymer ratio were investigated at 1.2 and 7.4 pH values. Increasing the drug/polymer ratio and extent of cross-linking caused decrease in the IB release. On the other hand, increase in the graft yield led to increase in the IB release as well. The results also showed that NaAlg-g-PVP beads were positive pH-responsive.     

Formulation and Characterization of Novel Nanostructured Lipid Carriers with Photoprotective Properties Made from Carnauba Wax,Beeswax, Pumpkin Seed Oil,and UV Filters

Pumpkin seed oil (PSO) with carnauba wax and beeswax was used to develop nanostructured lipid carriers (NLC) loaded with a UV filter, Uvinul® A Plus B. The aims of the study were to optimize the concentration of PSO to develop a stable NLC formulation, determine storage stability of the NLC with and without PSO, and the synergistic effect of PSO-NLC with UV filter for photoprotective properties. The physical properties of NLC were optimized based on the mean particle size, polydispersity index, and storage stability. The optimized NLC consisted 10% lipid phase (3.5% carnauba wax, 3.5% beeswax, and 3.0% PSO) and 90% aqueous phase. After optimization, Uvinul® A Plus B was added in the optimized PSO-NLC to produce a photoprotective formulation. Uvinul® A Plus B consisted of both UVA (Diethylamino Hydroxybenzoyl Hexyl Benzoate) and UVB (Ethylhexyl Methoxycinnamate) filters. The NLC produced with PSO and Uvinul® A Plus B had mean particle size of 135 ± 2 nm and showed good physical stability under storage time. Besides that, the NLC produced also proven to have positive effect in enhancing the entrapment efficiency and drug loading, which were 82.86 ± 0.15% and 55.41 ± 0.04%, respectively, and showed sun protection factor value of 16.61 ± 3.45. The results indicated the presence of synergistic effect among the PSO-NLC with Uvinul® A Plus B.     

Modulation of serratiopeptidase transdermal patch by lipid-based transfersomes

Serratiopeptidase is a proteolytic enzyme obtained from serratia marcescens strain E-15 and used as anti-inflammatory and analgesic drug. Serratiopeptidase undergoes first pass metabolism, causes the gastrointestinal disturbance and systemic toxicity after oral administration. To overcome the limitations of serratiopeptidase, transdermal drug delivery system is an alternative method. So, the aim of present work was to modulate serratiopeptidase transdermal patch by lipid-based transfersomes. Particle size of drug was the major concern to cross stratum corneum which acts as a barrier. This difficulty was surmounted by modulating the vesicles such as transfersomes which carries the drug into the skin by passing the barrier of stratum corneum. Serratiopeptidase was encapsulated in transfersomes in different ratios of lecithin and cholesterol. Particle size of transfersomes, folding endurance, thickness, tensile strength, adhesion test, encapsulation efficiency, in vitro and in vivo release, Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimeter (DSC) studies of patch were used as characterization parameters. Serratiopeptidase transfersomes size was found to be 50 µm with smooth surface. The promising entrapment efficiencies of transfersomes and formulation were found to be 96.76 and 98.7%, respectively. In vitro and in vivo release studies showed controlled and steady release of serratiopeptidase for 24 h. FTIR and DSC confirmed the encapsulation of drug in patch without interaction. It is concluded that transfersomes are interesting carriers for enzymatic drugs for topical application.     

Methoxy polyethylene glycol–cholesterol modified soy lecithin liposomes for poorly water-soluble anticancer drug delivery

Soy lecithin liposomes (SLP) were prepared and partially surface modified with methoxy polyethylene glycol-cholesterol conjugate (mPEG-Chol) to improve its poorly-soluble-water-anticancer-drugs delivery efficiency. Paclitaxel (PTX) was used as the model drug and the PTX/SLP@mPEG was successfully developed with the optimal mass ratio of mPEG-Chol determined at 4% in the SLP@mPEG formulation. The optimal SLP@mPEG formulation had a particle size range of 161.80 ± 1.51 nm and a negative surface charge of −54.30 ± 1.40 mV. Besides, a sustained drug release profile of 72 h and an encapsulation efficiency of 87.48 ± 0.70% was recorded. Moreover, in vitro cytotoxicity assays demonstrated that SLP@mPEG is nontoxic and cytocompatible. Overall, these obtained results provide insights into the potential of SLP@mPEG as a platform for the development of more effective therapies against cancers.     

Optimization of spray-dried diclofenac sodium-loaded microspheres by screening design

The aim of the present study was to investigate the effect of formulation and operating parameters of the laboratory spray dryer on polymeric microspheres intended to be used for sustaining drug delivery of diclofenac sodium (DS). Four operating and four formulation parameters were investigated by Plackett–Burman design to enhance the encapsulation efficiency (EE). The independent variables were air inlet temperature, aspirator, feed flow rate, spray nozzle diameter, amount of drug, amount of polymers, and volume of organic solvent. The resultant microspheres were characterized for their EE. The microspheres having high EE were further characterized for particle size, morphology, and in vitro drug release. Interaction between the drug and the polymer were investigated by Fourier transform infrared (FTIR) spectroscopy and X-ray powder diffractometry (XRPD). The Pareto chart showed that amount of Eudragit® RS100, amount of ethylcellulose, and aspirator were identified as significant factors. The microspheres showed high EE (47.55?±?0.006% to 67.99?±?0.007%). The microspheres were found to be discrete, spherical with smooth surface. The FTIR analysis confirmed the compatibility of DS with the polymers without interaction. The XRPD revealed the dispersion of drug within microspheres formulation. The in vitro drug release from these DS-loaded microspheres showed sustained release of DS over a period of 12?h and followed the Korsmeyer–Peppas model [R²?=?0.9920 (Run 1) and 0.9957 (Run 13)] with a value of the slope (n)?≤?0.43. This n value, however, appears to indicate that Fickian release is the dominant mechanism of drug release with these formulations.     

Development of pellets of nifedipine using HPMC K15 M and κ-carrageenan as mucoadhesive sustained delivery system and in vitro evaluation

Polymeric mucoadhesive pellets of nifedipine were designed using computer software and they were prepared by extrusion-spheronization using HPMC K15M and κ-carrageenan with microcrystalline cellulose. A randomized rotatable two factor central composite design was applied for assessment of influence of two independent variables such as concentration of κ-carrageenan and HPMC K15M on dependent variables. Pellets were characterized by FTIR, DSC, SEM, flow properties, particle size, abrasion resistance, sphericity, drug content, percent production yield, in vitro drug release, ex vivo mucoadhesion, stability studies and similarity factor. The optimized formulation was selected based on criteria of sphericity nearest to 1.0 with maximum cumulative drug release percentage. Formulation NF6 exhibited sufficient porous spheres, free flowing and smooth surface mucoadhesion of 91.34 % and drug content 98.22 ± 0.37 %. Kinetic modeling revealed that the formulation followed the Higuchi model and showed the Quassi-Fickian drug release mechanism. The similarity factor, F2 value, was found to be 74 ± 6 and there was no significant change in drug content and ex vivo mucoadhesion after 90 days at 40 ± 2 °C, and 75 ± 5 % RH clearly indicated the optimized batch NF6 was stable. Thus, it can be concluded that use of κ-carrageenan, microcrystalline cellulose and HPMC K15M at the 20:35:10 w/w ratio could provide an effective carrier for enhancement of sphericity and sustained release of matrix pellets.     

Cytarabine trapping in poly(2-hydroxyethyl methacrylate-co-acrylamide) hydrogels: drug delivery studies

Copolymeric hydrogels of poly(2-hydroxyethyl methacrylate-co-acrylamide) [p(HEMA-co-A)] crosslinked with ethylene glycol dimethacrylate, with a high equilibrium degree of swelling (37–65 wt%) in saline solution (NaCl 0.9 wt%) were synthesized as devices for controlled release of cytarabine (ara-C). Two compositions of the copolymer, each with a different degree of crosslinking have been studied, HEMA80/A20 and HEMA60/A40. The antineoplasic drug was included in the feed mixture of polymerization, and discs 3.7 ± 0.4 mm thick and 11.8 ± 0.2 mm in diameter with 5–40 mg (1.0–8.3 wt%) of ara-C were obtained. The diffusion studies followed Fick's second law. The diffusion coefficients for swelling of the gels were between 3.60 × 10⁻¹¹ and 15.8 × 10⁻¹¹ m² s⁻¹; those for release of ara-C were between 0.31 × 10⁻¹¹ and 7.18 × 10⁻¹¹ m² s⁻¹. The activation energies for swelling were in the range 23.4–31.9 kJ mol⁻¹ and those for ara-C release were 42.2–61.6 kJ mol⁻¹; their values indicate that the drug release process depends on drug–matrix and drug–water interactions that are influenced by the aqueous solution content and the network size of the gels. Total release of the drug takes place between 17 h from H60/A40/E2 at 310 K and 6 days from H80/A20/E10 at 288 K. Ara-C degradation was not observed either during loading of the gels or during drug release. © 1999 Society of Chemical Industry     

pH‐Sensitive pectin polymeric rafts for controlled‐release delivery of pantoprazole sodium sesquihydrate

The aim of the present work was to develop pectin raft‐forming tablets for controlled‐release delivery of pantoprazole sodium sesquihydrate (PSS). A Box–Behnken design was used to optimize 15 formulations with three independent and three dependent variables. The physical tests of all compressed formulations were within pharmacopoeial limits. The rafts were characterized by their strength, thickness, resilience, reflux resistance, acid‐neutralizing capacity, floating lag time, and total floating time. The raft strength, thickness, resilience, and reflux resistance through a 10‐mm orifice of optimized formulation PR9 were 7.43 ± 0.019 g, 5.8 ± 0.245 cm, greater than 480 min, and 2490 ± 0.004 g, respectively. The buffering and neutralizing capacity was 11.2 ± 1.01 meq and 6.5 ± 0.56 meq, respectively. Dissolution studies were performed by using simulated gastric fluid at pH 1.2, and the cumulative percentage release of PR9 was found to be 97%. First‐order release kinetics were followed, and non‐Fickian diffusion was observed as the value of n was greater than 0.45 in the Korsmeyer–Peppas model. The Fourier transform infrared spectra of the PSS, polymers, and optimized raft formulation PR9 showed peaks at 3223.09 cm^?1, 1688.17 cm^?1, 1586.67 cm^?1, 1302.64 cm^?1, and 1027.74 cm^?1 that are due to ? OH stretching, ester carbonyl group (C?O) stretching, the existence of water and carboxylic groups in the raft, C? N stretching, and ? OH bending vibrations and showed no interaction between them. The developed raft was suitable for sustained‐release delivery of PSS. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44442.     

Development of topical gel containing aceclofenac-crospovidone solid dispersion by “Quality by Design (QbD)” approach

This article describes the development, optimization, and evaluation of Carbopol 940 topical gel containing aceclofenac-crospovidone (1:4) solid dispersion using “Quality by Design (QbD)” approach based on 2³ factorial design. The effect of crospovidone, tri-ethanolamine, and ethyl alcohol amount on the drug permeation profile of the topical gel containing aceclofenac-crospovidone solid dispersion was optimized by 2³ factorial design. The optimized gel showed improved permeation profile with cumulative drug permeation of 26.262 ± 2.157%, and permeation flux of 0.059 ± 0.011 μg/cm²/h. These gels were characterized by pH, viscosity, gel strength and FTIR study. The in vivo anti-inflammatory activity of the optimized gel was evaluated in rats using carrageenan-induced rat-paw oedema model and found excellent anti-inflammatory comparable with a marketed gel without producing any skin irritation.     

Development of diclofenac potassium gel from hydrophobically modified HPMC

An improved topical gel was developed which could allow fast release of drug and having appropriate organoleptic (texture) and rheological properties (viscosity). In vitro release of diclofenac potassium from hydrophobically modified hydroxypropyl methyl cellulose (hm-HPMC, 90L grade) based gels (F1, F2 and F3 at 1, 1.5 and 2 % (w/v) concentration, respectively) was compared with conventional hydrophilic hydroxypropyl methylcellulose (HPMC, 50 mPa s) based gels (F4 and F5 at 12 and 15 % (w/v) concentration, respectively). This study was performed in Franz diffusion cell using cellulose dialysis membrane. The hm-HPMC-based gels of higher viscosity release remarkable quantity of the drug in comparison to conventional hydrophilic HPMC-based gels of lower viscosity. So in the drug-release process polymer concentration is more important and a determinant factor compared to viscosity. Texture profile and viscosity of hm-HPMC-based gels were compared with a commercial gel and all the rheological data obtained from the experiments confirm the suitability of these hm-HPMC-based gels for use as a topical drug delivery system. In order to achieve percutaneous penetration of drug, permeation enhancers (n-octanol and propylene glycol) were added in hm-HPMC-based gels. Both enhancers have shown enhancement of drug penetration through rat skin. Propylene glycol at both lower concentration (2 %) and higher concentration (5 %) exhibited a greater increase in the permeation flux as well as more antinociceptive activity than formulations without enhancer or with n-octanol as enhancer.