Prabhakara Prabhu

Formulation and evaluation of fast dissolving films of levocitirizine di hydrochloride

Introduction: Levocetirizine dihydrochloride is an orally active, third-generation non-sedative antihistamine used in the symptomatic relief of seasonal and perennial allergic rhinitis. The present work aimed at preparing quick release films of levocetirizine with the purpose of developing a dosage form for a very quick onset of action, which is beneficial in managing severe conditions of allergies, aiding in the enhancement of bioavailability, and is very convenient for administration, without the problem of swallowing and using water. Materials and Methods: The films of levocetirizine dihydrochloride were prepared by using polymers such as hydroxypropyl methylcellulose (HPMC) and polyvinyl alcohol (PVA), as either single polymer or in combination of two, by a solvent casting method. They were evaluated for physical characteristics such as uniformity of weight, thickness, folding endurance, drug content uniformity, surface pH, percentage elongation, and tensile strength, and gave satisfactory results. The formulations were subjected to disintegration, in vitro drug release tests, and in vivo studies on rats. Results: A marked increase in the dissolution rate was exhibited by fast-dissolving films of levocetirizine dihydrochloride containing HPMC as a polymer, when compared to conventional tablets. The haloperidol-induced catalepsy, milk-induced leukocytosis, and nasal provocation in vivo studies in rats proved that the fast-dissolving films of levocetirizine dihydrochloride produced a faster onset of action compared to the conventional tablets. Conclusions: Fast dissolving films of levocetirizine dihydrochloride can be considered suitable for clinical use in the treatment of allergic rhinitis and other conditions of allergies, where a quicker onset of action for a dosage form is desirable along with the convenience of administration.

Investigation of nano lipid vesicles of methotrexate for anti-rheumatoid activity

Background The purpose of this study was to formulate and evaluate nano lipid vesicles of methotrexate (MTX) for its anti-rheumatoid activity. Methods In this study the principle of both active as well as passive targeting using MTX-loaded stealth liposomes as per the magic gun approach was followed. Stealth liposomes of MTX were prepared by thin-film hydration method using a PEGylated phospholipid-like DSPE-MPEG 2000. Similarly, conventional liposomes were prepared using phospholipids like DPPC and DSPC. Conventional liposomes were coated with a hydrophilic biocompatible polymer like chitosan. They were investigated for their physical properties and in vitro release profile. Further, in vivo screening of the formulations for their anti-rheumatoid efficacy was carried out in rats. Rheumatoid arthritis was induced in male Wistar-Lewis rats using complete Freund’s adjuvant (1 mg/mL Mycobacterium tuberculosis, heat killed in mineral oil). Results It was found that chitosan coating of the conventional liposomes increased the physical stability of the liposomal suspension as well as its entrapment efficiency. The size of the unsonicated lipid vesicles was found to be in the range of 8–10 μm, and the sonicated lipid vesicles in the range of 210–260 nm, with good polydispersity index. Further, chitosan-coated conventional liposomes and the PEGylated liposomes released the drug for a prolonged period of time, compared to the uncoated conventional liposomes. It was found that there was a significant reduction in edema volume in the rat group administered with the test stealth liposomal formulations and chitosan-coated conventional liposomes (PEGylated and chitosan-coated conventional) compared to that of the control and standard (administered with free MTX) group of rats. PEGylated liposomes showed almost equal efficacy as that of the chitosan-coated conventional liposomes. Conclusion Lipid nano vesicles of MTX can be administered by intravenous route, whereby the drug selectively reaches the target site with reduced toxicity to other organs.

In vitro and in vivo evaluation of chitosan buccal films of ondansetron hydrochloride

Buccal films of ondanstron hydrochloride were fabricated from mucoadhesive polymer, chitosan, and polyvinyl pyrrolidone (PVP K30) for the purpose of prolonging drug release and improving its bioavailability. All fabricated film formulations prepared were smooth and translucent, with good flexibility. The weight and thickness of all the formulations were found to be uniform. Drug content in the films ranged from 98 – 99%, indicating favorable drug loading and uniformity. The inclusion of PVP K30, a hydrophilic polymer, significantly reduced the bioadhesive strength and in vitro mucoadhesion time of the films, although the degree of swelling increased. In vitro drug release studies in simulated saliva showed a prolonged release of over five to six hours for all formulations, except C4, with 99.98% release in 1.5 hours. Kinetic analysis of the release data indicated that the best fit model with the highest correlation coefficient for all formulations was the Peppas model. In vivo studies, on selected films in rabbits, were conducted, to determine the pharmacokinetic parameters such as Cmax, Tmax, and AUC0-∞, using model-independent methods with nonlinear least-squares regression analysis. The AUC and values of Cmax of ondansetron hydrochloride were found to be significantly greater (P < 0.005) than the selected films C2 and C3, as compared to those from the oral solution, thereby confirming improved bioavailability via the buccal route. The Tmax values were also significantly greater (P < 0.005), indicating the slower release of the drug from buccal films, thereby, providing prolonged effects. Good in vitro-in vivo correlation was observed with R2 values exceeding 0.98, when the percentage of drug released was correlated with the percentage of drug absorbed.

Nanostructured lipid carriers for the topical delivery of tretinoin

Cosmetic skin care products currently in the market demonstrate an increasing trend toward antiaging products. Selection of the right formulation approach is the key to successful consumer acceptance. Nanostructured lipid carriers (NLCs) for dermal application can render added benefits to the formulation. Tretinoin a derivative of vitamin A, is a retinoid with anti-aging and anti-acne potential. The present study was aimed at formulating NLCs of tretinoin for reducing the skin irritation potential, increasing the drug loading capacity and prolonging the duration of action. The NLCs were optimized using the response surface methodology based on the particle size. Preliminary study, suggested the use of stearic acid, oleic acid, Tween 80 and Span 60 as solid lipid, liquid lipid and surfactants respectively formed a stable dispersion. NLCs of tretinoin were prepared by hot melt microemulsion and hot melt probe sonication methods. The properties of the optimized NLCs such as morphology, size, Zeta potential, stability and in vitro drug release were investigated. Tretinoin loaded NLCs in carbopol gel showed a sustained release pattern with isopropyl alcohol as the receptor fluid compared to the marketed gel using Franz diffusion cells. Eight prepared gel formulations tested were found to follow the Higuchi model of drug release. Stability studies indicated that the formulations stored at refrigeration and room temperature showed no noticeable differences in the drug content and release profiles in vitro, after a period of 4 weeks. In vivo skin irritation test on male Wister rats indicated no irritation or erythema after application of the NLCs loaded gel repeated for a period of 7 days compared to the application of marketed tretinoin gel which showed irritation and slight erythema within 3 days. The results showed that the irritation potential of tretinoin was reduced, the drug loading was increased and the drug release was prolonged by the incorporation into the NLCs.

Formulation and evaluation of stimuli-sensitive hydrogels of timolol maleate and brimonidine tartrate for the treatment of glaucoma

Background: Stimuli-sensitive hydrogels are hydrophilic, three-dimensional, polymeric network structure capable of imbibing large amounts of water or biological fluids on stimulation, such as pH, temperature, and ionic change. Owing to the drawback of conventional therapy for ocular delivery, and to provide additive effect on intraocular pressure (IOP) reduction, stimuli sensitive hydrogel membranes containing a combination of timolol maleate and brimonidine tartrate were formulated for the treatment of glaucoma. Materials and Methods: Stimuli-sensitive hydrogel were formulated by timolol maleate and brimonidine tartrate. Poly acrylic acid (carbopol C 934p) is used as a gelling agent, hydroxylpropyl methylcellulose as viscolizer, sodium chloride as tonicity agent. Bezalkonium chloride as preservative. White rabbits of both sexes, weighing between 2 and 3 kg were used for the study. Stirring of ingredients in pH 4 phosphate buffers at high speed was carried out. Result: Viscosity of the prepared hydrogels lies in the optimum range that is, 25-55 cps. Infrared spectroscopy studies show that there is no interaction between the drug and polymer. Drug released up to 90% at the end of 8 h. The hydrogel membranes were found to be sterile, nonirritant to the eye. Marketed formulation showed a decrease in IOP up to 14 mmHg at the end of 5 h and then elimination of drug, F2 and F6 maintain the sustained effect up to 12 h. Conclusion: Stimuli-sensitive hydrogels was successfully formulated and evaluated for rheological studies, drug release studies, drug interaction studies, sterility studies, ocular irritation studies, and in vivo studies. IOP lowering activity of the combination of timolol maleate and brimonidine tartrate in stimuli-sensitive hydrogel was better when compared with alone medication, which shows the additive effect of combination medication.

Formulation and evaluation of buccal film of Ivabradine hydrochloride for the treatment of stable angina pectoris.

Background: Ivabradine hydrochloride is an anti-anginal drug with a biological half-life of about 2 h, and repeated daily administration is needed to maintain effective plasma level. Present investigation of buccal films of Ivabradine hydrochloride is an attempt to avoid the repeated administration and release of drug in more controlled fashion, thereby, to improve the bioavailability. Materials and Methods: Buccal patches were fabricated by solvent casting technique and were evaluated for its physical properties like physical appearance, weight uniformity, thickness, swelling index, surface pH, mucoadhesive time, and folding endurance, in vitro and ex vivo release studies. Results: A combination of hydroxypropyl methyl cellulose (HPMC) K15M and K100M with carbopol 940, PEG 6000 gave promising results. Further, the drug content of all the formulations was determined and was found to be uniform. All the formulations were subjected to in vitro release study using phosphate buffer pH 6.6. Patches exhibited drug release in the range of 90.36% ± 0.854 to 98.37% ± 0.589 at the end of six hrs. The best formulations (F2 and F5) containing the composition of HPMC K15-37.50 mg, carbopol-0.42 mg, PEG6000-16.87 mg, Aspertane-0.28 mg, Tween-0.0023 mg and HPMC K100-37.50 mg, carbopol-0.42 mg, PEG6000-16.87 mg, Aspertane-0.28 mg, Tween-0.0023 mg respectively exhibited in vitro drug release of 97.61% ± 0.589 and 98.37% ± 0.114 respectively. The results of ex vivo diffusion using goat cheek pouch revealed that the drug release rate was retarded up to seven hrs. Films prepared with permeation enhancer (Tween 80) showed faster drug release. Finally, stability studies were carried out by using human saliva for the optimized formulation (F2-F5). Conclusion: The present study indicated enormous potential of mucoadhesive buccal patches containing Ivabradine for systemic delivery with an added advantage of circumventing hepatic first pass metabolism. Further work is recommended to support its efficacy claims by long term pharmacokinetic and pharmacodynamic studies in human beings.

Investigation of hydrogel membranes containing combination of gentamicin and dexamethasone for ocular delivery

Background: Hydrogel is a cross-linked network of polymers. Water penetrates these network causing swelling and giving the hydrogel a soft and rubbery consistency and there by maintaining the integrity of the membrane. Due to the drawback of conventional therapy for ocular delivery, hydrogel membranes containing the combination of gentamicin (GT) sulfate and dexamethasone (DX) were formulated for the treatment of conjunctivitis. The objective of this study was to formulate and evaluate the hydrogel membranes containing the combination of GT and DX for the treatment of conjunctivitis. Materials and Methods: In the present investigation, hydrogel membranes were prepared by using polymers such as gelatin, polyvinyl alcohol, and chitosan, which were cross-linked using physical/chemical methods. Results: The cross-linking of the membranes was confirmed by Fourier transform infra-red studies. The pH of the membranes ranged from 7.19 to 7.45 and drug content ranged from 69.82% to 89.19%. The hydrogels showed a considerably good swelling ratio ranging from 22.5% to 365.56%. The in vitro drug release study showed that there was a slow and sustained release of the drug from the membranes which were sufficiently cross-linked and followed zero order release. In vivo studies showed that the severity of conjunctivitis was remarkably lowered at day 3 with hydrogel membrane compared to marketed eye drops. Results of unpaired t-test of significance between two groups indicated that the hydrogel membrane showed a better response in the treatment of conjunctivitis compared to the marketed products. Stability studies proved that the formulations could be stable when stored at room temperature. Conclusion: Results of the study indicated that it is possible to develop a safe and physiologically effective hydrogels which are patient compliant.

Nano-lipid Complex of Rutin: Development, Characterisation and In Vivo Investigation of Hepatoprotective, Antioxidant Activity and Bioavailability Study in Rats

The current study was aimed to develop an amphiphilic drug-lipid nano-complex of rutin:egg phosphatidylcholine (EPC) to enhance its poor absorption and bioavailability, and investigated the impact of the complex on hepatoprotective and antioxidant activity. Rutin nano-complexes were prepared by solvent evaporation, salting out and lyophilisation methods and compared for the complex formation. For the selected lyophilisation method, principal solvent DMSO, co-solvent (t-butyl alcohol) and rutin:EPC ratios (1:1, 1:2 and 1:3) were selected after optimisation. The properties of the nano-complexes such as complexation, thermal behaviour, surface morphology, molecular crystallinity, particle size, zeta potential, drug content, solubility, in vitro stability study, in vitro drug release, in vitro and in vivo antioxidant study, in vivo hepatoprotective activity and oral bioavailability/pharmacokinetic studies were investigated. Rutin nano-complexes were developed successfully via the lyophilisation method and found to be in nanometric range. Rutin nano-complexes significantly improved the solubility and in vitro drug release, and kinetic studies confirmed the diffusion-controlled release of the drug from the formulation. The nano-complex showed better antioxidant activity in vitro and exhibited well in vitro stability in different pH media. The in vivo study showed better hepatoprotective activity of the formulation compared to pure rutin at the same dose levels with improved oral bioavailability. Carbon tetrachloride (CCl4)-treated animals (group II) failed to restore the normal levels of serum hepatic marker enzymes and liver antioxidant enzyme compared to the nano-complex-treated animals. The results obtained from solubility, hepatoprotective activity and oral bioavailability studies proved the better efficacy of the nano-complex compared to the pure drug.

Formulation and evaluation of fast-dissolving films of lisinopril

Objective The aim of this study was to formulate and evaluate the oral fast-dissolving film of lisinopril for the effective management of hypertension and cardiac diseases. Materials and methods Fast-dissolving films were prepared by the solvent-casting method using a combination of different polymers, HPMC E5 LV, HPMC E 3 and HPMC 4KM, along with PEG as a plasticizer. The Fourier-transform infrared study for the drug-polymer interaction was carried out. Evaluation of physical parameters such as physical appearance, surface texture, uniformity of weight, uniformity of strip thickness, surface pH, folding endurance, uniformity of drug content and percentage of moisture absorption were performed. Kinetic data analysis for the release study and the stability study were also performed. Result and conclusion Results of uniformity of weight, thickness, folding endurance, surface pH, tensile strength, percentage drug content, swelling index, tensile strength and percentage elongation of all the films were found to be satisfactory with respect to variation of these parameters between films of same formulation. The Fourier-transform infrared study indicated that there was no interaction between the drug and the polymers. The in-vitro drug release study showed that a better rate of drug release was achieved by formulations FA3, FB1, FB4 FC8 and FD10 compared with other formulations. The stability study did not show any significant difference in the external appearance, the drug content and the in-vitro drug release. The ex-vivo study indicated that the drug has a better ability to cross the sublingual barrier at a faster rate, and hence the delivery system was found to be promising as it has the potential of overcoming the drawbacks associated with tablet formulations available in the market presently.