Synthesis and Evaluation of Cytotoxicity of Novel Coumarin Peptide Alcohol Derivatives.

BACKGROUND: Coumarins are naturally occurring biologically active heterocyclic molecules endowed with a wide range of biological properties, including antibacterial, antifungal, and antitumor activities. OBJECTIVE: The present work was aimed to synthesize new coumarin-containing compounds and to investigate their cytotoxic activity. METHODS: Coumarin peptide and coumarin amino alcohols were prepared by treating epoxidecontaining coumarin derivatives with suitable aromatic amines and peptides in trifluoroethanol as a solvent at 50°C. These derivatives were evaluated for their cytotoxic activity on three different cell lines: HeLa, MDA-MB-231 and L-132. Cell viability was determined by MTT (3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. RESULTS: A new protocol was developed for the synthesis of thirteen novel coumarin peptide and coumarin amino alcohol derivatives. Among the tested compounds, three derivatives showed significant activity against all the tested cell lines. Docking studies indicated favorable interactions of the disubstituted peptide coumarin derivatives with the Asp 351 and Thr 347 amino acids at the active site of the human estrogen receptor. CONCLUSIONS: The results suggest that the synthesized compounds may be promising candidates in the research of new antitumor compounds.

Development of Emulgel Delivery of Mupirocin for Treatment of Skin Infection.

AIM: To design controlled release topical delivery of mupirocin for the treatment of skin infection. BACKGROUND: Mupirocin is an antibacterial drug. Mupirocin works to kill the bacteria, which include strains of Staphylococcus aureus and Streptococcus pyogenes. It is also used for the treatment of inflammation of a hair follicle. The half-life of mupirocin is only 20-40 min. It has very slight solubility in water. Patent literature had shown work on ointment, antibiotic composition, nasal and topical composition. Emulgel is a duel control release system for the topical delivery of hydrophobic drugs. OBJECTIVE: The objective was to formulate emulgel with controlled delivery of mupirocin using Sepineo P 600. METHODS: Soya oil, tween 80 and polyethylene glycol 400 (Oil:Surfactant:Cosurfactant) were used for emulsion formulation. Emulgel was optimized by 32 factorial design. Sepineo P 600 and hydroxy propyl methyl cellulose K4M were used as independent variables. Drug excipient compatibility analysis was carried out by FTIR, UV and DSC spectra. Emulgel was evaluated for its physical characterization, in vitro release, ex vivo release, antimicrobial and anti-inflammatory study. RESULTS: DSC, UV and FTIR analysis confirmed drug excipient compatibility. FE SEM showed a size range between 228-255 nm. Zeta potential was found to be -25.1 mV, which showed good stability of the emulsion. Design expert software showed F2 as an optimized batch. Release studies indicated that the controlled release of drugs forms Sepineo P 600 gel due to its higher gelling capacity. Batch F2 showed comparable results with marketed formulation against Staphylococcus aureus. For batch F2, 40 µg/ml was the minimal inhibitory concentration. CONCLUSION: Antimicrobial and anti-inflammatory study proved successful development of stably controlled release mupirocin emulgel.

Development of Microemulsion Based Nabumetone Transdermal Delivery for Treatment of Arthritis.

BACKGROUND: Nabumetone is biopharmaceutics classification system (BCS) class II drug, widely used in the treatment of osteoarthritis and rheumatoid arthritis. The most frequently reported adverse reactions for the drug involve disturbance in gastrointestinal tract, diarrhea, dyspepsia and abdominal pain. Microemulgel has advantages of microemulsion for improving solubility for hydrophobic drug. Patent literature had shown that the work for drug has been carried on spray chilling, enteric coated tablet, and topical formulation which gave an idea for present research work for the development of transdermal delivery. OBJECTIVE: The objective of the present research work was to optimize transdermal microemulgel delivery for Nabumetone for the treatment of arthritis. METHODS: Oil, surfactant and co-surfactant were selected based on solubility study of the drug. Gelling agents used were Carbopol 934 and HPMC K100M. Optimization was carried out using 32 factorial design. Characterization and evaluation were carried out for microemulsion and microemulsion based gel. RESULTS: Field emission-scanning electron microscopy (FE-SEM) study of the microemulsion revealed globules of 50-200 nm size. Zeta potential -9.50 mV indicated good stability of microemulsion. Globule size measured by dynamic light scattering (zetasizer) was 160nm. Design expert gave optimized batch as F7 which contain 0.2% w/w drug, 4.3% w/w liquid paraffin, 0.71% w/w tween 80, 0.35% w/w propylene glycol, 0.124% w/w Carbopol 934, 0.187% w/w HPMC K100M and 11.68% w/w water. In-vitro diffusion study for F7 batch showed 99.16±2.10 % drug release through egg membrane and 99.15±2.73% drug release in ex-vivo study. CONCLUSION: Nabumetone microemulgel exhibiting good in-vitro and ex-vivo controlled drug release was optimized.

Optimization of Time Controlled 6-mercaptopurine Delivery for Site- Specific Targeting to Colon Diseases.

BACKGROUND: 6-MP has short elimination time (<2 h) and low bioavailability (~ 50%). Present study was aimed to develop time controlled and site targeted delivery of 6-Mercaptopurine (6-MP) for treatment of colon diseases. METHODS: Compression coating technique was used. 32 full factorial design was designed for optimization of the outer coat for the core tablet. For outer coat amount of Eudragit RS 100 and hydroxypropyl methylcellulose (HPMC K100) were employed as independent variables each at three levels while responses evaluated were swelling index and bursting time. Direct compression method was used for tablets formulation. RESULTS: 80% w/w of microcrystalline cellulose and 20% w/w of croscarmellose sodium were found to be optimum concentration for the core tablet. The outer coat of optimized batch (ED) contains 21.05% w/w Eudragit RS 100 and 78.95% w/w HPMC K100 of total polymer weight. In-vitro dissolution study indicated that combination of polymer retards the drug release in gastric region and releases ≥95% of drug in colonic region after ≥7 h. Whereas in case of in-vivo placebo x-ray imaging study had shown that the tablet reaches colonic part after 5±0.5 h providing the proof of arrival in the colon. Stability study indicated that the optimized formulation were physically and chemically stable. CONCLUSION: Present research work concluded that compression coating by Eudragit RS 100 and HPMC K100 to 6-MP core provides potential colon targeted system with advantages of reduced gastric exposure and enhanced bioavailability. Formulation can be considered as potential and promising candidate for the treatment of colon diseases.

Application of design of experiment for polyox and xanthan gum coated floating pulsatile delivery of sumatriptan succinate in migraine treatment.

Migraine follows circadian rhythm in which headache is more painful at the awakening time. This needs administration of dosage form at night time to release drug after lag period when pain gets worse. Sumatriptan succinate is a drug of choice for migraine. Sumatriptan succinate has bitter taste, low oral bioavailability, and shorter half-life. Present work deals with application of design of experiment for polyox and xanthan gum in development of press coated floating pulsatile tablet. Floating pulsatile concept was applied to increase gastric residence of the dosage form. Burst release was achieved through immediate release tablet using crospovidone as superdisintegrant (10%). Pulse lag time was achieved using swellable polymer polyox WSR 205 and xanthan gum. 3(2) experimental design was applied. Optimized formulation was evaluated for physical characteristics and in-vitro and in-vivo study. From results, it can be concluded that optimized batch F8 containing polyox WSR205 (72.72%) and xanthan gum (27.27%) of total weight of polymer has shown floating lag time of 55 ± 2 sec, drug content of 100.35 ± 0.4%, hardness of 6 ± 0.1 Kg/cm(2), and 98.69 ± 2% drug release in pulse manner with lag time of 7 ± 0.1 h. Optimized batch showed prolong gastric residence which was confirmed by in-vivo X-ray study.

Design and evaluation of polyox and pluronic controlled gastroretentive delivery of troxipide.

Objective. Objective of the present work was to develop site-specific gastroretentive drug delivery of Troxipide using polymers Pluronic F127 and Polyox 205 WSR. Troxipide is a novel gastroprotective agent with antiulcer, anti-inflammatory, and mucus secreting properties with elimination half-life of 7.4 hrs. Troxipide inhibits H. pylori-derived urease. It is mainly absorbed from stomach. Methods. 3(2) factorial design was applied to study the effect of independent variable. Effects of concentration of polymer on dependant variables as swelling index, hardness, and % drug release were studied. Pluronic F127 and Polyox 205 WSR were used as rate controlled polymer. Sodium bicarbonate and citric acid were used as effervescent-generating agent. Results. From the factorial batches, it was observed that formulation F5 (19% Pluronic F127 and 80% Polyox 205 WSR) showed optimum controlled drug release (98.60% ± 1.82) for 10 hrs with ability to float >12 hrs. Optimized formulation characterized by FTIR and DSC studies confirmed no chemical interactions between drug and polymer. Gastroretention for 6 hrs for optimized formulations was confirmed by in vivo X-ray placebo study. Conclusion. Results demonstrated feasibility of Troxipide in the development of gastroretentive site-specific drug delivery.

Development of press-coated, floating-pulsatile drug delivery of lisinopril.

Lisinopril is an angiotensin-converting enzyme (ACE) inhibitor, primarily used for the treatment of hypertension, congestive heart failure, and heart attack. It belongs to BCS class III having a half-life of 12 hrs and 25% bioavailability. The purpose of the present work was to develop a press-coated, floating-pulsatile drug delivery system. The core tablet was formulated using the super-disintegrants crosprovidone and croscarmellose sodium. A press-coated tablet (barrier layer) contained the polymer carrageenan, xanthan gum, HPMC K4M, and HPMC K15M. The buoyant layer was optimized with HPMC K100M, sodium bicarbonate, and citric acid. The tablets were evaluated for physical characteristics, floating lag time, swelling index, FTIR, DSC, and in vitro and in vivo behavior. The 5% superdisintgrant showed good results. The FTIR and DSC study predicted no chemical interactions between the drug and excipients. The formulation containing xanthan gum showed drug retaining abilities, but failed to float. The tablet containing HPMC K15M showed a high swelling index. The lag time for the tablet coated with 200 mg carrageenan was 3±0.1 hrs with 99.99±1.5% drug release; with 140 mg HPMC K4M, the lag time was 3±0.1 hrs with 99.71±1.2% drug release; and with 120 mg HPMC K15M, the lag time was 3±0.2 hrs with 99.98±1.7% drug release. The release mechanism of the tablet followed the Korsmeyer-Peppas equation and a first-order release pattern. Floating and lag time behavior have shown good in vitro and in vivo correlations.

Development and optimization of press coated floating pulsatile drug delivery of sumatriptan succinate.

Floating pulsatile is combined approach designed according to circadian rhythm to deliver the drug at right time, in right quantity and at right site as per pathophysiological need of disease with prolong gastric residence and lag phase followed by burst release. As the migraine follows circadian rhythm in which headache is more painful at the awakening time, the dosage form should be given during night time to release drug when pain get worsen. Present work deals with formulation and optimization of floating pulsatile tablet of sumatriptan succinate. Core tablet containing crospovidone as superdisintegrant (10%) showed burst release. Lag time was maintained using swellable polymer as polyoxN12K and xanthum gum. 3(2) experimental design was carried out. Developed formulations were evaluated for physical characteristics, in vitro and in vivo study. Optimized batch F2 with concentration of polyox N12K (73.43%) and xanthum gum (26.56%) of total polymer weight showed floating lag time 15±2 sec, drug content 99.58±0.2 %, hardness 6±0.2 Kg/cm(2) and drug release 99.54±2% with pulsatile manner followed lag period of 7±0.1h. In vivo x-ray study confirms prolong gastric residence of system. Programmable pulsatile release has been achieved by formulation F2 which meet demand of chronotherapeutic objective of migraine.

Optimization studies on compression coated floating-pulsatile drug delivery of bisoprolol.

The purpose of the present work was to design and optimize compression coated floating pulsatile drug delivery systems of bisoprolol. Floating pulsatile concept was applied to increase the gastric residence of the dosage form having lag phase followed by a burst release. The prepared system consisted of two parts: a core tablet containing the active ingredient and an erodible outer shell with gas generating agent. The rapid release core tablet (RRCT) was prepared by using superdisintegrants with active ingredient. Press coating of optimized RRCT was done by polymer. A 3² full factorial design was used for optimization. The amount of Polyox WSR205 and Polyox WSR N12K was selected as independent variables. Lag period, drug release, and swelling index were selected as dependent variables. Floating pulsatile release formulation (FPRT) F13 at level 0 (55 mg) for Polyox WSR205 and level +1 (65 mg) for Polyox WSR N12K showed lag time of 4 h with >90% drug release. The data were statistically analyzed using ANOVA, and P < 0.05 was statistically significant. Release kinetics of the optimized formulation best fitted the zero order model. In vivo study confirms burst effect at 4 h in indicating the optimization of the dosage form.

Application of design of experiment for floating drug delivery of tapentadol hydrochloride.

The aim of the present study was to apply design of experiment (DOE) to optimize floating drug delivery of tapentadol hydrochloride. Tapentadol hydrochloride is a synthetic opioid used as a centrally acting analgesic and effective in both experimental and clinical pain. The half-life of the drug is about 4 hours and oral dose is 50 to 250 mg twice a day. For optimization 3(2) full factorial design was employed for formulation of tapentadol hydrochloride tablets. Sodium bicarbonate was incorporated as a gas-generating agent. Combination of polymers Xanthan gum and Locust bean gum was used to achieve controlled release effect. The concentration of polymers was considered as the independent variables and dependent variables were floating lag time and swelling index of the tablets. From the factorial batches, it was observed that formulation containing combination of 20% sodium bicarbonate and 10% citric acid shows optimum floating ability whereas the formulation containing 20% Xanthan gum and 28% Locust bean gum shows optimum sustained drug release pattern with adequate floating.

Formulation, development, and evaluation of floating pulsatile drug delivery system of atenolol.

The objective of this work was to develop and evaluate a floating-pulsatile drug delivery of atenolol. The floating-pulsatile concept was applied to increase the gastric residence of the dosage form by having lag phase followed by a burst release. The system was generated which consisted of three different parts: a core tablet, containing the active ingredient; an erodible outer shell; and a top cover buoyant layer. The dry, coated tablet consists in a drug-containing core, coated by a hydrophilic erodible polymer responsible for a lag phase in the onset of pulsatile release. The buoyant layer, prepared with hydroxypropyl methylcellulose (HPMC) K100 M, citric acid, and sodium bicarbonate, provides buoyancy to increase the retention of the oral dosage form in the stomach. The effect of the hydrophilic erodible polymer characteristics on the lag time and drug release was investigated. Developed formulations were evaluated for their physical properties in vitro release as well as in vivo behavior. The results showed that K3 (180 mg of HPMC K4 M) and K6 (290 mg of HPMC E15 LV) with a buoyant layer were the best formulation, with lag times of 5.2 ± 0.1 h and 4.1 ± 0.2 h, respectively. Floating time was controlled by the quantity and composition of the buoyant layer. In-vitro results point out the capability of the system with its prolonged residence of the tablets in the stomach and release of drug after a programmed lag time. This was confirmed by in vivo x-ray technique. LAY ABSTRACT: The objective of the present work was to develop a floating-pulsatile oral drug delivery system of atenolol with addition of hydroxylpropyl methylcellulose (HPMC) K100 M, HPMC K4 M, and HPMC E15 LV in different ratios with citric acid and sodium bicarbonate as gas-forming agents. The system consist of three different parts: a core tablet, containing the active ingredient; a bottom layer that erodes; and a top cover floating layer. Atenolol, a ß-blocker, is prescribed widely in diverse cardiovascular diseases, for example, hypertension, angina pectoris, arrhythmias, and myocardial infarction. Developed formulations were evaluated for their physical properties and vitro release as well as in vivo behavior. The results showed that K3 (180 mg HPMC K4 M) and K6 (290 mg of HPMC E15 LV) with a buoyant layer were the best formulations with the lag times of 5.2 ± 0.1 h and 4.1 ± 0.2 h, respectively, and were found to be the best choice for manufacturing tablets.

Dissolution Rate Enhancement, Design and Development of Buccal Drug Delivery of Darifenacin Hydroxypropyl ß-Cyclodextrin Inclusion Complexes.

Darifenacin is a urinary antispasmodic. The oral absorption of darifenacin is poor due to its low solubility and poor bioavailability (15-19%). Darifenacin was complexed with hydroxylropyl beta-cyclodextrin (Hpß-CD). The best results were obtained with the coevaporation that interacts in a 1 : 1 drug : cyclodextrin molar ratio. The solid inclusion complexes were found to be amorphous in the characterization. The dissolution rate of darifenacin from the Hpß-CD solid inclusion complex was increased compared to the powdered drug. The controlled release buccoadhesive patches for the delivery of darifenacin were prepared using HPMC K100M CR and HPMC K15. The coevaporation complex of the drug was used in the formulation due to its increased saturation solubility and increased ease of dissolution. The patches were evaluated for their surface pH, folding endurance, swelling, mucoadhesive properties, in vitro residence time, vapour transmission test, and in vitro and ex vivo release studies. Formulations Hb2 (2%) and Pb4 (4%) were found to be optimized. These two formulations can be used for buccal delivery of darifenacin which avoids first pass effect and leads to increased bioavailability of darifenacin.

Solubility Enhancement and Formulation of Mouth Dissolving Tablet of Clonazepam with Solid Dispersion Technology

Clonazepam (CLZ) is an anticonvulsant benzodiazepine widely used in the treatment of epilepsy. CLZ is a BCS Class II drug and its bioavailability is thus dissolution limited. The objective of the present study was to prepare solid dispersions (SDs) of CLZ by various techniques, using the amphiphilic carrier Gelucire 50/13 in various proportions, to increase its water solubility. Drug-polymer interactions were investigated by Fourier-transform infrared (FTIR) and Ultra-Violet (UV) spectroscopy. The SDs were characterized physically by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). A phase solubility study was performed and the stability constant (Ks) was found to be 275.27, while the negative Gibbs free energy (?Gotr) indicated spontaneous solubilization of the drug. The dissolution study showed that the SDs considerably enhanced the dissolution rate of the drug. The FTIR and UV spectra revealed no chemical incompatibility between the drug and Gelucire 50/13. XRD patterns and the DSC profiles indicated the CLZ was in the amorphous form, which explains the improved dissolution rate of the drug from its SDs. Finally, mouth dissolving tablets (MDTs) were prepared from the optimized batches (kneading method) of solid dispersion, using crospovidone and Doshion P544 resin as superdisintegrants. The tablets were characterized by in-vitro disintegration and dissolution tests. The study of the MDTs showed disintegration times in the range 32.0±0.85 to 20.0±1.30 sec and dissolution was faster than for the commercial preparation. In conclusion, this investigation demonstrated the potential of solid dispersions of a drug with Gelucire 50/13 for promoting the dissolution of the drug and contributed to the understanding of the effect of a superdisintegrant on mouth dissolving tablets containing a solid dispersion of a hydrophobic drug.

Pulsatile multiparticulate drug delivery system for metoprolol succinate.

Cardiovascular diseases and their treatment pose a great challenge. Many instances of cardiovascular disease occur in the early morning hours. Hence, the objective of this study was to develop a time-controlled release formulation of metoprolol succinate based on a pulsatile multiparticulate (pellets) drug delivery system. The formulation was intended to be administered in the evening at 22:00 hours to evaluate symptoms of cardiovascular disease that are experienced in the early morning hours (from 04:00 to 06:00). Drug layering followed by a swelling layer and finally by an insoluble coat application was done using a Sanmour fluid bed processor. Metoprolol succinate layered on sugar pellets (74% w/w) layered with 20% (w/w) ion doshion resin P-547 and coated with 15% (w/w) ethocel with the addition of 20% castor oil showed a lag time of 4 h and was then followed a sigmoidal release pattern with more than 95% drug having been released by the 10(th) h.

Superdisintegrant Selection for Tramadol Dispersible Tablets

The selection of a suitable superdisintegrant for a rapidly disintegrating dosage form is of the utmost importance, since disintegration time (DT) is a critical parameter. An experimental design was implemented, to find out the effects of superdisintegrants (sodium starch glycolate, crospovidone, croscarmellose sodium and methacrylic copolymer with divinyl benzene), at 2, 4, 6% w/w, on tablet hardness, with respect to DT. Methacrylic copolymer with divinyl benzene (at 4 wt%) was selected as the best superdisintegrant, adequate for the formulation of dispersible Tramadol tablets. With increasing hardness, there was a considerable increase in DT at all concentrations of superdisintegrants. A combination of crospovidone and methacrylic copolymer with divinyl benzene showed a remarkable drop in DT to 0.33 min. The stability of the batch with lowest DT was also tested under various conditions and the results suggested that there was no degradation over the test period.

Formulation and evaluation of gastroretentive drug delivery system of propranolol hydrochloride.

The objective of present study was to develop a gastroretentive drug delivery system of propranolol hydrochloride. The biggest problem in oral drug delivery is low and erratic drug bioavailability. The ability of various polymers to retain the drug when used in different concentrations was investigated. Hydroxypropyl methylcellulose (HPMC) K4 M, HPMC E 15 LV, hydroxypropyl cellulose (HPC; Klucel HF), xanthan gum, and sodium alginate (Keltose) were evaluated for their gel-forming abilities. One of the disadvantages in using propranolol is extensive first pass metabolism of drug and only 25% reaches systemic circulation. The bioavailability of propranolol increases in presence of food. Also, the absorption of various drugs such as propranolol through P-glycoprotein (P-gp) efflux transporter is low and erratic. The density of P-gp increases toward the distal part of the gastrointestinal tract (GIT). Therefore, it was decided to formulate floating tablet of propranolol so that it remains in the upper part of GIT for longer time. They were evaluated for physical properties, in vitro release as well as in vivo behavior. In preliminary trials, tablets formulated with HPC, sodium alginate, and HPMC E 15 LV failed to produce matrix of required strength, whereas formulation containing xanthan gum showed good drug retaining abilities but floating abilities were found to be poor. Finally, floating tablets were formulated with HPMC K4 M and HPC.

Antihyperglycemic, antistress and nootropic activity of roots of Rubia cordifolia Linn.

Effect of alcoholic extract of roots of Rubia cordifolia was studied on elevated blood glucose level in alloxan treated animals. The extract reduced the blood sugar level raised by alloxan. Effect of alcoholic extract was also investigated on cold restraint induced stress and on scopolamine-induced memory impairment. Alcoholic extract enhanced brain gamma-amino-n-butyric acid (GABA) levels and decreased brain dopamine and plasma corticosterone levels. Acidity and ulcers caused due to cold restraint stress were inhibited by alcoholic extract. Animals treated with alcoholic extract spent more time in open arm in elevated plus maze model. It also antagonized scopolamine induced learning and memory impairment. Baclofen induced catatonia was potentiated by alcoholic extract.