Showed Drug Release Research Articles

Preparation of self micro emulsifying drug delivery system(smedds) of poorly soluble drug eprosartan mesylate and its in vitro evaluation

Eprosartan Mesylate (EM), an angiotensin II receptor blocker used in the treatment of high blood pressure. But poor solubility and bioavailability (13%) of eprosartan mesylate is a major challenging factor for improving its drug release rate. The main objective of the present work to develop and characterize self micro emulsifying drug delivery system of eprosartan mesylate by using compatible oil, surfactant and co-surfactant. For the selection of oil, surfactant and cosurfactant, solubility screening studies has been carried out. The nine formulations are prepared using peppermint oil, tween 80 and PEG 400. A pseudo ternary phase diagram was prepared to determine the self emulsion region. Four optimized formulations were prepared at 1:1 ratio(a mixture of surfactant and cosurfactant). These four formulations were evaluated for self-emulsification time, droplet size measurement, drug content analysis robustness to dilution test, viscosity analysis, f.t.i.r. The study and in-vitro diffusion studies. The ratio of scosmix (a mixture of surfactant and cosurfactant) of optimized formulation (pf5) was varied to pfa1 (2:1), pf2 (3:1), pfa3 (1:2) and compared with pure drug. The formulation having pfa1 (2:1) shown drug release of 93.13 % in 330 minutes where as pure drug showed a drug release of 54.51% in 330 minutes. So the prepared SMEDDS formulations were efficient and better than the pure drug, and it followed Korsmeyer pappes due to highest r2 value followed by Hixon crowel. It was concluded that incorporation of eprosartan mesylate in selfmicroemulsifying system is a great potential for improving the solubility and dissolution rate of eprosartan mesylate.

APPLICATION OF SYNTHETIC AND NATURAL POLYMERS IN PREPARATION AND CHARACTERIZATION OF DOMPERIDONE FAST-DISSOLVING FILMS

Objective: The present research work is mainly focused on solubility enhancement of domperidone which is a biopharmaceutical classification system Class II drug using natural and synthetic polymers.
 Methods: The solubility was enhanced by the kneading method with the drug: polymer (1:0.5, 1:0.75, and 1:1) using β-cyclodextrin. The fast dissolving films (FDFs) of domperidone were prepared by incorporating the solid dispersion (SD) SDK3 by solvent casting method using hydroxypropyl methylcellulose K15 M (HPMC) and gellan gum in various concentrations for preparing FDFs. Various pre- and post-compression parameters, drug and excipients compatibility studies were evaluated by Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), and X-ray diffraction analysis (XRD).
 Results: The maximum drug release of 98.86 % was achieved within 30 min for 1:1 ratio of solid dispersion using β-cyclodextrin, was optimized and taken for further development of FDFs. From the in vitro drug release studies films prepared with 10% w/w of HPMC K 15 (FH5) and 10% w/w of gellan gum (FG5) showed enhanced dissolution rate compared to other formulations. The formulation FHG with combination of polymers, namely, HPMC K 15 and gellan gum in 1:1 ratio showed drug release of 97.22% within 15 min only when compared with the optimized formulations. FTIR and DSC studies revealed that there were no interactions between drug and excipients. XRD studies revealed slight conversion of crystalline form to amorphous. The optimized formulation FHG found to be stable under accelerated stability studies.
 Conclusions: The polymers in combination are a potential candidate for use in the formulation of FDF.

FORMULATION, DEVELOPMENT AND CHARACTERIZATION OF ETHOSOMES OF ATORVASTATIN

Objectives: The main objective of the present investigation was to develop transdermal delivery of Atorvastatin, a HMG-CoAreductase inhibitor used in the treatment of congestive heart failure (CHF). Atorvastatin was formulated into ethosomal formulation to reduce the first pass metabolism and increase the systemic bioavailability. Methods: Cold method was used to formulate ethosomes by using suitable phosphatidylcholine and permeation enhancer. All the formulation were characterized for vesicle morphology, particle size and entrapment efficiency by Transmission Electron Microscopy, Differential light scattering and centrifugation respectively. The effect of different formulation variable on skin permeation of Atorvastatin was studied via synthetic semipermeable membrane or skin of new born mice by using diffusion cell. Results: The optimized ethosomal formulation showed enhanced drug delivery with no first pass metabolism, entrapment efficiency was found to be 98.65 ± 0.63% and showed drug release 98.13 ± 3.67% for ethosomal formulation across rat skin as compared to 52.37 ± 3.62% for hydroethanolic solution. Conclusion: Finally it was concluded from the study that, ethosomes can increase the transdermal flux, prolong the release and present an attractive route for sustained delivery of Atorvastatin.

PREPARATION, EVALUATION AND OPTIMIZATION OF MUCOADHESIVE MINI TABLETS OF TELMISARTAN BY USING SINGLE UNIT ENCAPSULATION SYSTEM

The objective of the present study was to develop and optimize capsule filled oral mucoadhesive minitablets of telmisartan. Wet granulation method was employed for the development of minitablets. All the formulations (F1- F13) exhibited more than 21% drug release at 4h and at the end of 12h it showed drug release more than 90%. During the dissolution study it was observed that the capsule shell in which the minitablets were filled got completely dissolved in the first 5 min. FTIR and UV study showed absence of any significant physical and chemical interaction between drug and polymers. Formulation F 10 was found to possess higher drug release at 4h and 12 h. Combination of HPMC and Carbopol was found to be suitable for formulation of mucoadhesive minitablets, showed promising mucoadhesive strength and exhibited controlled drug release over an extended period of time.

FORMULATION AND EVALUATION OF MOUTH DISSOLVING TABLET OF AMLODIPINE BESYLATE

Objective: The main objective of this research work was to formulate and evaluate the mouth dissolving tablet of amlodipine besylate for the treatment of hypertension and coronary artery disease.
 Methods: In this study, mouth dissolving tablet were prepared by direct compression method by using croscarmellose sodium and sodium starch glycolate as superdisintegrants. The designed tablets were subjected to various assessment parameters like friability test, hardness test, disintegration test, wetting time, in vitro drug release and drug content.
 Results: All the prepared formulations were subjected to various assessment parameters, and the findings obtain within the prescribed limit. The calibration curve of pure drug using various solvents like phosphate buffer pH 6.8, methanol was plotted. F1-F9 containing croscarmellose sodium and sodium starch glycolate in various concentration demonstrate the minimum disintegration time. Among all these formulations F9 shows disintegration time up to 22±1.12 seconds due to the high concentration of superdisintegrants. In vitro drug release was tested in phosphate buffer pH 6.8 at a time interval of 0, 1, 2, 3, 4, 5 min. The F9 shows drug release 100.22±1.08%. Accelerated stability study of optimized formulation (F9) up to 2 mo showed there was no change in disintegration time and percentage drug release.
 Conclusion: The results obtained in the research work clearly showed a promising potential of mouth dissolving tablets containing a specific ratio of croscarmellose sodium and sodium starch glycolate as superdisintegrants for the effective treatment of hypertension and coronary artery disease.

Modified pH independent/ time controlled explosion system (TES) for targeted drug delivery in the lower intestinal tract: Formulation and pharmacokinetic evaluation in healthy volunteers

The current work aimed to formulate a modified pH independent/time controlled release tablet for delayed drug delivery. The effect of different coating levels and polymer combination on drug release was investigated. Propranolol HCl (PRO) was chosen as a freely water soluble model drug. Statistical analysis of data revealed the significant (P < 0.05) influences of (i) coating level of swelling layer (SL), (ii) Different ethyl cellulose/hydrophilic polymer combination in rupturable layer and (iii) coating level of the rupturable layer (RL) on tL (lag time) and t90 (time for 90% drug release). The best achieved system; formed of 10% coating level croscarmellose sodium as inner swelling layer, 7% coating level of ethylcellulose/polyethylene oxide 205 (50:50) as an outer rupturable layer showed a tL of (10 h) followed by 90% drug release in the following 2 h. The in vivo pharmacokinetics of PRO following oral administration of the best achieved system (PF8) and Inderal® were assessed in healthy volunteers. The in vivo studies showed drug release of PRO following a tLof 6 h and a tmax of 8 h. The developed systems pave the way for delayed pulsatile release of other water soluble drugs for pH independent delayed drug delivery.

Development of α-tocopherol surface-modified targeted delivery of 5-fluorouracil-loaded poly-D, L-lactic-co-glycolic acid nanoparticles against oral squamous cell carcinoma

The aim of the study to develop surface modified targeted moiety α-tocopherol (α-t) encapsulated with 5-fluorouracil (5-FU)-poly-D, L-lactic-co-glycolic acid nanoparticles (PLGA NPs) toward the anticancer activity against oral squamous cell carcinoma (OSCC). 5-FU was conjugated with the polymer, PLGA by ionic cross-linking and α-tocopherol use as a functionalized surface moiety. Characterization, drug entrapment efficiency, and in-vitro drug release system were optimized at different pH 7.4 and pH 4.5. The in-vitro cell was performed to optimize the anticancer activity through MTT assay and apoptotic staining assay was also performed by flow cytometry to evaluate the cellular apoptotic activity and cellular uptake. The particle size was distributed within an average range of 145-162 nm, the polydispersity index values lie 0.16-0.30, and the surface charge was at the negative side, -17mV to -23mV. The in vitro drug release system showed more sympathetic situation at pH 7.4 as compared to pH 4.5, for targeted NPs, approximately 86% and 69%, respectively. The non-targeted 5-FU-PLGA NPs showed drug release of 83% and 64% at pH 7.4 and 4.5 subsequently. In vitro anticancer activity confirmed the intense inhibition by α-t-FU-PLGA NPs of 79.98% after 96 h treatment of SCC15 cells and confirmed the steady-state inhibition of 83.74% after 160 h incubation in comparison to 5-FU-PLGA NPs. Subsequently, the early apoptosis, 27.98%, and 16.45%, and late apoptosis, 47.29%, and 32.57%, suggested the higher apoptosis rate in targeted NPs against OSCC. The surface modified α-t-FU-PLGA NP was treated over SCC15 cells, and the oral cancer cells have shown the high intensity of cellular uptake, which confirmed that the target moiety has successfully invaded over the surface of cancer cells and shown advanced targeted delivery against OSCC.

Anhydrous nanoprecipitation for the preparation of nanodispersions of tenofovir disoproxil fumarate in oils as candidate long-acting injectable depot formulations.

The facile formation of drug nanoparticles in injectable/ingestible oils, of water-soluble antiretroviral tenofovir disoproxil fumarate, using a novel nanoprecipitation is presented with studies showing drug release into relevant aqueous media.

Development and Characterization of Lornoxicam loaded microsponge gel for Rheumatoid arthritis

Transdermal delivery, a successful novel approach aimed at achieving systematically active level of drug. The drug lornoxicam is a non-steroidal anti-inflammatory drug bearing analgesic, anti-inflammatory, and antipyretic property. The micro sponge technology used to facilitate the controlled release of active drug into the skin in order to reduce the systematic exposure and minimize local cutaneous reactions of active drugs. The main objective of this work was to design and evaluate the gel formation of microsponge entrapped lornoxicam to increase the effectiveness of the treatment. The microsponges were prepared by quasi emulsion solvent diffusion method. The internal phase consisting eudragit RS-100 dissolved in dichloromethane, drug is slowly added to polymer solution with continuous stirring for 4 h, and then mixture was filtered to separate the microsponges. Microsponges was characterized by parameters like scanning electron microscopy, drug content, particle size analysis, compatibility studies using differential scanning calorimetry. Microsponge-loaded gel was characterized by physical parameters of gel, measurement of PH, viscosity study, Drug content study, in-vitro release studies using Franz diffusion cell, cellophane membrane. The prepared gel were subjected to different kinetics models showed that the release data, rheological study, thixotrophy analysis, FT-IR spectral analysis. The release profile of the lornoxicam in the form of microsponges gel was compared with that of pure lornoxicam gel. From the results it can be concluded that microsponges gel LMSG-2 formulation shows drug release in a controlled manner could sustain the drug release over period of 8 hours.

Transethosomes of Econazole Nitrate for Transdermal Delivery: Development, In-vitro Characterization, and Ex-vivo Assessment.

Transdermal drug delivery is an attractive approach for both local and systemic therapeutics of various diseases. Transdermal drug delivery systems show various advantages like reduction of local irritation, prevention of first-pass hepatic metabolism, and bioavailability enhancement of bioactive molecules over conventional drug delivery systems. The main objective of the present research work was to develop and characterize (in-vitro and ex-vivo) econazole nitrate loaded transethosomes and their comparison with marketed cream of econazole nitrate [Ecoderm, Brown and Burk Pharmaceutical (Pvt.) Ltd., Bengaluru, India] for effective transdermal delivery. Transethosomes loaded with econazole nitrate were developed by homogenization method and evaluated for entrapment (%), vesicular size, zeta potential, polydispersity index (PDI), and invitro drug release. Furthermore, optimized econazole nitrate loaded transethosomes were added to Carbopol 934 gel and this gel was evaluated for viscosity, pH, drug content, ex-vivo skin permeation and retention studies followed by in-vitro antifungal activity against C. albicans fungus. The optimized transethosomes loaded with econazole nitrate showed vesicle size of 159.3 ± 4.3 nm, entrapment efficiency about 78.3 ± 2.8%, acceptable colloidal properties like (zeta potential = -27.13 ± 0.33 mV, PDI = 0.244 ± 0.045), approximately 57.56 ± 2.33% drug release up to 24 h. Results of DSC analysis confirmed the encapsulation of econazole nitrate inside transethosomes. Optimized transethosomes showed drug release following zero order through diffusion mechanism. Transethosomal gel showed high drug content (92.35 ± 0.63%) and acceptable values of pH (5.68 ± 0.86) or viscosity (10390 ± 111 cPs). Transethosomal gel showed less ex-vivo skin penetration (17.53 ± 1.20%), high ex-vivo skin retention (38.75 ± 2.88%), and high in-vitro antifungal activity compared to the marketed cream of econazole nitrate. Therefore, it can be concluded that econazole nitrate loaded transethosomes are effective to deliver econazole nitrate transdermally in a controlled fashion for effective elimination of cutaneous candidiasis.

Effect of Paclitaxel-Loaded PLGA Nanoparticles on MDA-MB Type Cell Lines: Apoptosis and Cytotoxicity Studies.

Triple-Negative Breast Cancer is an aggressive type of breast cancer, which is not treatable by chemotherapy drugs, due to the lack of Estrogen Receptor (ER), Progesterone Receptor (PR) expression and Human Epidermal Growth Factor Receptor 2 (HER2) on the cell surface. The aim of this study was to compare the effect of paclitaxel loaded PLGA nanoparticle (PTX-NPs) on the cytotoxicity and apoptosis of the different MDA-MB type of cell lines. PTX-NPs were prepared by nanoprecipitation method and characterized earlier. The cytotoxicity of PTX-NPs was evaluated by MTT and LDH assay, later apoptosis was calculated by flow cytometry analysis. The prepared NP size of 317.5 nm and zetapontial of -12.7 mV showed drug release of 89.1 % at 48 h. MDA-MB-231 type cell showed significant cytotoxicity by MTT method of 47.4 ± 1.2 % at 24 h, 34.6 ± 0.8 % at 48 h and 23.5 ± 0.5 % at 72 h and LDH method of 35.9 ± 1.5 % at 24 h, 25.4 ± 0.6 % at 48 h and 19.8 ± 2.2 % at 72 h with apoptosis of 47.3 ± 0.4 %. We have found that PTX-NPs showed the cytotoxic effect on all the MDA-MB cancer cell lines and showed potent anticancer activities against MDA-MB-231 cell line via induction of apoptosis.

FORMULATION AND IN VITRO EVALUATION OF FAST DISSOLVING TABLET OF VERAPAMIL HYDROCHLORIDE

Objective: The main objective of this research work was to formulate and evaluate fast dissolving tablet of verapamil hydrochloride for the treatment of hypertension.Methods: In this study, fast dissolving tablet were prepared by wet granulation method by using croscarmellose sodium and sodium starch glycolate as superdisintegrants in the concentration of 2%, 4%, and 6%. Polyvinyl pyrollidone K30 is used as a binder. The designed tablets were subjected to various assessment parameters like friability test, hardness test, disintegration test, wetting time, in vitro drug release and drug content.Results: All the prepared formulations were subjected to various assessment parameters, and the findings obtain within the prescribed limit. The calibration curve of pure drug using various solvents like distilled water, phosphate buffer pH 6.8 was plotted. F1-F9 containing croscarmellose sodium and sodium starch glycolate in various concentration demonstrate the minimum disintegration time. Among all these formulations F8 shows disintegration time upto 19±0.06 seconds due to the high concentration of superdisintegrants. In vitro drug release was tested in phosphate buffer pH 6.8 at a time interval of 0, 1, 3,6,9,12,15 min. The F8 shows drug release 98.5±0.567%. Accelerated stability study of optimized formulation (F8) up to 2 mo showed there was no change in disintegration time and percentage drug release.Conclusion: The results obtained in the research work clearly showed a promising potential of fast dissolving tablets containing a specific ratio of crosscarmellose sodium and sodium starch glycolate as superdisintegrants for the effective treatment of hypertension.

An Overview on Various Approaches and Recent Patents on Gastroretentive Drug Delivery Systems.

Drugs having absorption window in the stomach or upper small intestine have restricted bioavailability with conventional dosage forms. The gastric residence time of these dosage forms is usually short and they do not show drug release for prolonged period of time. To avoid these problems and to enhance the bioavailability and gastric retention time of these drugs, controlled drug delivery systems with prolonged gastric retention time are currently being developed. This review highlights the various pharmaceutical approaches for gastroretention such as floating drug delivery systems, mucoadhesive systems, high-density systems, expandable and swelling systems, super porous hydrogels systems, magnetic systems, ion exchange resin system and recent patents filed or granted for these approaches. Recently, some patents are also reported where a combination of various approaches is being employed to achieve very effective gastroretention. The various patent search sites were used to collect and analyze the information on gastroretentive drug delivery systems. The present study provides valuable information, advantages, limitations and future outlook of various gastroretentive drug delivery systems.

FORMULATION AND CHARACTERIZATION OF SUSTAINED RELEASE COATED MATRIX GRANULES OF METFORMIN HYDROCHLORIDE

Objective: Metformin hydrochloride is a biguanide antihyperglycemic agent which is a generally recommended first-line drug for the treatment of diabetes mellitus (Type II). The purpose of this investigation is to prepare sustained release matrix granules of metformin hydrochloride which are coated to extend the drug release over a longer time period.Methods: Metformin hydrochloride granules were prepared by mixing all the dry powders in a V-cone blender and wetting the powder mix with aqueous solution of hydroxypropyl methyl cellulose K100. The prepared granules (MG1-MG5) were investigated for drug release. The batch of granules which exhibited extended release for up to 4 h was coated in a standard coating pan with blends of Eudragit RS and RL to further enhance release period. These were marked as coated metformin granules (CMG3) and CMG4 which were later filled into empty capsules. The granules were characterized for micromeritic properties, percentage yield, particle size distribution, percentage of drug content, and in vitro release of the drug.Results: All the formulations showed percentage yield in the range of 77.66–82.86% and drug content in the range of 78.23–96.62%. CMG3 showed drug release of 97.02% for 12 h. Fourier-transform infrared spectroscopy and differential scanning calorimetry studies indicated that no possible interaction existed between the drug and the polymers used. Scanning electron microscopy images revealed that the granules were spherical in shape with smooth surface and completely covered with a coating of polymer. Kinetic analysis of drug release confirmed that drug release followed zero-order kinetics where it is independent of the concentration.Conclusion: From the results, it was analyzed that design of coated granules employing the polymers used in the present work can produce a sustained release of the drug over a period of 12 h.

GASTRO-FLOATING TABLETS OF REPAGLINIDE: PREPARATION AND IN VIVO EVALUATION

Objective: Current research concerns the expansion of repaglinide matrix floating tablets, which are designed to prolong the gastric residence time, increase the drug bioavailability, and diminish the side effects.Methods: Different formulations of repaglinide floating tablets were prepared with different grades of hydroxypropyl methylcellulose (HPMC) and other agents. Evaluation parameters and in vivo bioavailability studies were conducted in the suitable model.Results: Among all the formulations, F21 containing HPMC K1500 PH PRM, Polyox WSR 303, and sodium bicarbonate, as gas generating agent was selected as optimized formulation based on physicochemical properties, floating lag time (36 s), and total floating time (&gt;24 h). From in vitro dissolution studies, the optimized formulation F21 showed drug release of 98.92±5.19% within 24 h whereas 95.09±5.01% of the drug was released from the marketed product within 1 h.Conclusion: From in vitro and in vivo bioavailability studies repaglinide floating tablets expected to give a new choice for safe, economical, and increased bioavailability for effective management of diabetes mellitus.

Design and Preclinical Evaluation of Gastroretentive Floating Tablets of Quetiapine Fumerate

The present study was focused on gastro-retentive tablets of quetiapine fumarate using hydrophilic polymers HPMC K250 PH PRM, HPMC K750 PH PRM and HPMC K1500 PH PRM as release retarding agents. WSR 301 was chosen as resin, sodium bicarbonate was used as effervescent agents. FTIR studies revealed that there is no interaction between the drug and polymers used for the formulation. The tablets were prepared by direct compression method and the release rate was found to decrease with proportional increase in the ratio of polymer to drug. Quetiapine fumarate is absorbed well from stomach and therefore is a very good drug to be formulated into gastro retentive floating dosage form. In-vitro release profile of quetiapine fumarate and marketed product when compared, the optimized formulation F19 showed drug release of 98.65% within 24 h whereas 96.78% of the drug was released from the marketed product within 1h. The optimized formulation remained stable when subjected to accelerated stability studies. In vivo radiographic studies of quetiapine fumarate optimized formulation (F19) supported the expectations in prolonging the gastric residence time in the fasted state in beagle dogs. Cmax and AUC values of optimized formulation were found to be significantly higher than of marketed product. In conclusion, gastro-retention can be a promising approach to enhance bioavailability of quetiapine fumarate with narrow absorption window in upper GIT.

In-vitro and pharmacodynamic characterization of solidified self microemulsified system of quetiapine fumarate

Quetiapine fumarate has possessed low solubility and extremely poor bioavailability, which restricts its oral administration. In order to address this concern, microemulsification technique was envisaged. Solubility of quetiapine was assessed in various liquid vehicles (oils, surfactants and cosurfactants) for the selection of carriers in self microemulsifying drug delivery system (SMEDDS) formulation. Microemulsion region was identified from the pseudoternary phase diagram. Quetiapine was loaded in preconcetrates of the predetermined microemulsion region. Quetiapine loaded SMEDDS were characterized for FTIR, pH, viscosity, zeta potential, and evaluated for drug content, in-vitro dissolution, in-vitro diffusion, and ex-vivo permeation. Optimized liquid SMEDDS were renewed into S-SMEDDS by adsorption and melt granulation technique. Formulated S-SMEDDS were characterized for micromeritics, DSC, SEM, and evaluated for drug content, reconstitution time, drug release, stability and anti-psychotic activity in animals for amphetamine induced stereotypy and swimming normalization test. The formulations of O11, O13, C6 and C10 liquid SMEDDS had shown drug release of 92, 94.16, 68.59 and 55.03% respectively at the end of 1 h. S-SMEDDS exhibited good micromeritics with a drug content of 80 to 90% and released drug up to 96%. AO13 of S-SMEDDS had 1.2 years of shelf life and exhibited better anti-psychotic activity owing to enhanced biomembrane permeation in the presence of tweens as surfactants. The spontaneous formation of microemulsion from adsorption based S-SMEDDS resulted in hasty drug release. Thus the results of the study indicated that self microemulsification of quetiapine and subsequent solidification is the better alternative in affording optimal pharmacotherapy of psychosis.

Topical Delivery of Erythromycin Through Cubosomes for Acne.

Topical delivery is an attractive route for local and systemic treatment. The novel topical application has many advantages like averting the GI-irritation, preventing the metabolism of drugs in the liver and increasing the bioavailability of the drug over the conventional dosage forms. The aim of present work was to prepare and characterized erythromycin encapsulated cubosomes using different concentrations of glyceryl monooleate and poloxamer 407 by the emulsification method. The prepared dispersion of cubosomes was characterized for surface morphology, particle size, entrapment efficiency and in vitro release. Further, optimized formulation was converted to cubosomal gel by incorporating carbopol 934 at different concentrations. The prepared gel was characterized for homogeneity, pH, viscosity, spreadibility, drug content and in vitro drug release study. The result of optimized cubosomes showed average particle size of 264.5±2.84nm and entrapment efficiency about 95.29±1.32 % and the pH of optimized cubosomal was found to be 6.5, viscosity 2475-8901(cp), drug content 95.29% and the spreadability was found to be 11.74 gm.cm/sec. The in vitro drug release kinetics of optimized formulation was found to follow Korsmeyer peppas model having highest R2 value 0.835 and in vitro drug release of optimized erythromycin loaded cubosomal gel and plain drug gel in 24 hr was found to be 89.91±0.73 and 88.64±2.16, while in 36 hr plain drug gel and cubosomal gel showed drug release about 87.64±0.97 and 91.55±1.09, and sustained release was obtained after 24 hr in case of cubosomal gel. Thus, as a whole it can be concluded that erythromycin loaded cubosomes are effective in topically delivering drug in sustained and non-invasive manner for treatment and prevention of acne.

Development and In Vitro – In Vivo Evaluation of Gastro-retentive Floating Tablets Containing Repaglinide

The present investigation concerns the development of the repaglinide floating matrix tablets, which after oral administration are designed to prolong the gastric residence time, increase the drug bioavailability and diminish the side effects of irritating drugs. FTIR studies revealed that there is no interaction between the drug and polymers used for the formulation. Among all the formulations F21 containing HPMC K1500 PH PRM, Polyox WSR-303 and Sodium bicarbonate, as gas generating agent was selected as optimized formulation based on physico chemical properties, floating lag time (36 sec) and total floating time (&gt;24 h). From in vitro dissolution studies, the optimized formulation F21 showed drug release of 98.92±5.19% within 24h whereas 95.09±5.01% of the drug was released from the marketed product within 1h. The major mechanism of drug release follows zero order kinetics and non-Fickian transport by coupled diffusion and erosion. In vivo experiments supported the expectations in prolonging the gastric residence time in the fasted state in beagle dogs. The mean gastric residence time for the tested tablets was 270 min±60. This result is encouraging, because a longer gastric residence time is an important condition for higher bioavailability of the drugs included in the prolonged or controlled release dosage forms.

Kinetics And Stability Studies Of Formulated Micro/Nano Suspension Of Metronidazole

Kinetic models describe the overall release of drugs from dosage form because qualitative and quantitative changes do occur in a formulation. These changes may alter drug release and in vivo performance hence the application of methods that facilitates product development and thereby reducing the necessity of bio studies, this leads to the adoption of in vitro drug dissolution analysis that involves the use of dialysis membrane and adopting a diffusion method. Stability studies revealed that the formulated nano/micro suspension was more stable at refrigerated condition (4 O C) showing no significant change in particle size distribution, %EE and release characteristics after 3months of study. The in vitro drug release analysis shows drug release from the various formulations (S, Y and W) to follow zero order release kinetics and this was confirmed after determination of line of best fit and from the correlation coefficients values obtained following the consideration of various kinetic models such as: first order, zero order, Korsmeyer- Peppas and Higuchi models. The stability studies and shelf life determinations of the formulations show formulation S, having a shelf life of 4.598 months, while that of formulation Y and W,  are 4.808 months and 3.085 months respectively. These values could be related to the size of the particles formed using the various polymers which might influence their film forming and protective ability over the particles. The protective ability of tragacanth when used alone seem not to be sustained over a long period of time and this reduced stability effect could lead to short shelf life as a result of the tendency of Ostwald ripening and agglomeration of particles after a short period of storage but when compared to the formulation involving C.olitorious gum used alone or that consisting of C.olitorious and Tragacanth, stability was sustained signifying better protective ability of the polymer.