Halloysite nanotubes-cellulose ether based biocomposite matrix, a potential sustained release system for BCS class I drug verapamil hydrochloride: Compression characterization, in-vitro release kinetics, and in-vivo mechanistic physiologically based pharmacokinetic modeling studies

This study investigated the ability of natural nanotubular clay mineral (Halloysite) and cellulose ether based biocomposite matrix as a controlled release agent for Verapamil HCl (BCS Class-I). Drug-loaded halloysite was prepared and tablet formulations were designed by varying amount of hydroxy propyl methyl cellulose (HPMC K4M). Physical characterization was carried out using SEM, FTIR, and DSC. Tabletability profiles were evaluated using USP1062 guidelines. Drug release kinetics were studied, and physiologically based pharmacokinetic (PBPK) modeling was performed. Compressed tablets possess satisfactory yield pressure of 625 MPa with adequate hardness and disintegration within 30 min. The initial release of the drug was due to surface drug on tablets, while the prolonged release at later time points (around 80 % drug release at 12 h) were due to halloysite loading. The FTIR spectra exhibited electrostatic attraction between the positively charged drug and the negatively charged Si-O-Si functional group of halloysite, while the thermogram showed Verapamil HCl melting point at ~146 °C with enthalpy change of -126.82 J/g. PBPK modeling exhibited PK parameters of optimized matrix formulation (VER-HNT3%) comparable to in vivo data. The study effectively demonstrated the potential of prepared biocomposite matrix as a commercially viable oral release modifying agent for highly soluble drugs.

Graduate and postgraduate educational challenges during the COVID-19 pandemic period: its impact and innovations-a scoping review

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic has transformed the global view of education, including graduate and postgraduate education making the development of an alternative approach in times of social isolation an academic imperative. The present review aims to investigate the challenges experienced among undergraduate and postgraduate education and the strategies adopted to address these challenges during the pandemic.

METHOD

The preferred reporting items for the systematic review and meta-analyses extension for Scoping Reviews (PRISMA-ScR) were followed. The aim was to include journal articles published in the English language that discussed the influence of the pandemic on educational processes and applied innovative approaches as a solution to educational challenges. From January to August 2020, PubMed, EMBASE, and Google Scholar were searched for articles, yielding 10,019 articles. Two groups of authors examined the retrieved articles separately to avoid any risk of bias. The title and abstract of the articles were used for scrutiny, followed by full-text screening based on the established inclusion and exclusion criteria. The facts and findings of the studies were also discussed based on per capita income, literacy rate, and Internet accessibility.

RESULTS

Thirty of the obtained articles were included in the study. The selected articles were from North and South/Latin America, Asia & Pacific, South Africa, and Europe regions. Nineteen of the selected articles dealt with undergraduate education, ten with postgraduate, and one with both groups. The affordability of digital devices and the availability of Internet services were the major challenges for low- and middle-income economies. The ZOOM platform has been adopted by more than 90% of the education systems.

CONCLUSION

Means of communication, including visual media, digitized content, and other web-based platforms, have been recognized as efficient learning and training tools, but have not been fully accessible for mass application and use due to the lack of availability of resources, their cost, and insufficient training among the users. In light of this review, it is suggested that harmonized and collaborative efforts should be made to develop cost-effective and user-friendly tools to overcome the current challenges and prevent future educational crises.

SYSTEMIC REVIEW REGISTRATION

The review was not registered.

Formulation development, in vivo bioequivalence and pediatric PBPK modeling studies of taste-masked ciprofloxacin chewable tablets

A taste-masked chewable tablet of ciprofloxacin using ion exchange resin Kyron T-134 for enhancing compliance for the paediatric population was developed. The drug-to-resin ratio was optimized for maximum taste masking by studying the effects of soaking time (X1) and mixing time (X2) on complexation (%) using Central Composite Rotatable Design (CCRD). The resin complexes were characterized by bitterness score, DSC, FTIR, and PXRD. The complex was further formulated and optimized into chewable tablets through full factorial design, The optimized formulation was subjected to a bioequivalence study, and a virtual approach of PBPK modelling was adapted to predict the pharmacokinetics of the drug in the paediatric group. The drug resin ratio of 1:1.5 yielded an optimum drug loading of 99.05%. The optimized formulation shows minimum disintegration time with more than 99% drug release within 30 min. The formulation F-9 was found to be bioequivalent with a geometric mean ratio of Cmax, Tmax, AUC0-t, and AUC0-∞ within 90% CI. It was concluded that quality by design approach can successfully be applied to optimize the drug resin ratio and PBPK modeling is a successful predictive tool for estimating the pharmacokinetics of ciprofloxacin HCl in the paediatric population.

SeDeM expert system with I-optimal mixture design for oral multiparticulate drug delivery: An encapsulated floating minitablets of loxoprofen Na and its in silico physiologically based pharmacokinetic modeling

Introduction: A SeDeM expert tool-driven I-optimal mixture design has been used to develop a directly compressible multiparticulate based extended release minitablets for gastro-retentive drug delivery systems using loxoprofen sodium as a model drug. Methods: Powder blends were subjected to stress drug-excipient compatibility studies using FTIR, thermogravimetric analysis, and DSC. SeDeM diagram expert tool was utilized to assess the suitability of the drug and excipients for direct compression. The formulations were designed using an I-optimal mixture design with proportions of methocel K100M, ethocel 10P and NaHCO₃ as variables. Powder was compressed into minitablets and encapsulated. After physicochemical evaluation lag-time, floating time, and drug release were studied. Heckel analysis for yield pressure and accelerated stability studies were performed as per ICH guidelines. The in silico PBPK Advanced Compartmental and Transit model of GastroPlus™ was used for predicting in vivo pharmacokinetic parameters. Results: Drug release follows first-order kinetics with fickian diffusion as the main mechanism for most of the formulations; however, a few formulations followed anomalous transport as the mechanism of drug release. The in-silico-based pharmacokinetic revealed relative bioavailability of 97.0%. Discussion: SeDeM expert system effectively used in QbD based development of encapsulated multiparticulates for once daily administration of loxoprofen sodium having predictable in-vivo bioavailability.

SeDeM tool-driven full factorial design for osmotic drug delivery of tramadol HCl: Formulation development, physicochemical evaluation, and in-silico PBPK modeling for predictive pharmacokinetic evaluation using GastroPlus™

The study is based on using SeDeM expert system in developing controlled-release tramadol HCl osmotic tablets and its in-silico physiologically based pharmacokinetic (PBPK) modeling for in-vivo pharmacokinetic evaluation. A Quality by Design (QbD) based approach in developing SeDEM-driven full factorial osmotic drug delivery was applied. A 2⁴ Full-factorial design was used to make the trial formulations of tramadol HCl osmotic tablets using NaCl as osmogen, Methocel K4M as rate controlling polymer, and avicel pH 101 as diluent. The preformulation characteristics of formulations (F1-F16) were determined by applying SeDeM Expert Tool. The formulation was optimized followed by in-vivo predictive pharmacokinetic assessment using PBPK “ACAT” model of GastroPlus™. The FTIR results showed no interaction among the ingredients. The index of good compressibility (ICG) values of all trial formulation blends were ≥5, suggesting direct compression is the best-suited method. Formulation F3 and F4 were optimized based on drug release at 2, 10, and 16 h with a zero-order kinetic release (r² = 0.992 and 0.994). The SEM images confirmed micropores formation on the surface of the osmotic tablet after complete drug release. F3 and F4 were also stable (shelf life 29.41 and 23.46 months). The in vivo simulation of the pharmacokinetics of the PBPK in-silico model revealed excellent relative bioavailability of F3 and F4 with reference to tramadol HCl 50 mg IR formulations. The SeDeM expert tool was best utilized to evaluate the compression characteristics of selected formulation excipients and their blends for direct compression method in designing once-daily osmotically controlled-release tramadol HCl tablets. The in-silico GastroPlus™ PBPK modeling provided a thorough pharmacokinetic assessment of the optimized formulation as an alternative to tramadol HCl in vivo studies.

Nanoclay-Based Composite Films for Transdermal Drug Delivery: Development, Characterization, and in silico Modeling and Simulation

Purpose

Halloysite nanotubes (HNTs) are a versatile and highly investigated clay mineral due to their natural availability, low cost, strong mechanical strength, biocompatibility, and binding properties. The present work explores its role for retarding and controlling the drug release from the composite polymer matrix material.

Methods

For this purpose, nanocomposite films comprising propranolol HCl and different concentrations of HNTs were formulated using the “solution casting method”. The menthol in a concentration of 1% w/v was used as a permeation enhancer, and its effect on release and permeation was also determined. Quality characteristics of the nanocomposite were determined, and in vitro release and permeation studies were performed using the Franz diffusion system. The data was analyzed using various mathematical models and permeation parameters. Optimized formulation was also subjected to skin irritation test, FTIR, DSC, and SEM study. Systemic absorption and disposition of propranolol HCl from the nanocomposites were predicted using the GastroPlus TCAT® model.

Results

The control in drug release rate was associated with the higher concentration of HNTs. F8 released 50% of propranolol within 8 hours (drug, HNTs ratio, 1:2). The optimized formulation (F6) with drug: HNTs (2:1), exhibited drug release 80% in 4 hours, with maximum flux of 145.812 µg/cm²hr. The optimized formulation was found to be a non-irritant for skin with a shelf life of 35.46 months (28–30 ℃). The in silico model predicted C_max, T_max, AUC_t, and AUC_inf as 32.113 ng/mL, 16.58 h, 942.34 ng/mL×h, and 1102.9 ng/mL×h, respectively.

Conclusion

The study demonstrated that HNTs could be effectively used as rate controlling agent in matrix type transdermal formulations.

Evaluation of pharmacokinetic interactions of amoxicillin with ranitidine in healthy human volunteers of Karachi, Pakistan

Polypharmacy may be considered as the customary practice to provide optimum care services to patients but inter resulted in augmented probability of multiple drug interaction. Keeping in view the importance of drug interaction possibility, this study was designed to evaluate the effect of ranitidine on pharmacokinetics of amoxicillin in the local population of Karachi, Pakistan. Amoxicillin and ranitidine are the most commonly prescribed drugs to treat duodenal ulcer caused by Helicobacter pylori. The current investigation was carried out as a single center, open label, two phase, single dose, randomized way in cross over manner to evaluate the potential of pharmacokinetic interaction among amoxicillin formulation and ranitidine in adult healthy male volunteers. Post dosing blood samples were collected at multiple time points that are 0.5, 1, 1.5, 2, 3, 4, 6, 8 and 10 hours after administering amoxicillin 250mg capsule with and without ranitidine. For estimation of amoxicillin concentration in plasma, an HPLC method was developed and validated. The solvent system consisted of 0.025M phosphate buffer: acetonitrile (94:6 v/v). C18 column was employed with a flow rate of 1.0 ml/minute and at 230nm. A linear pattern with a correlation coefficient of 0.999 in the concentration ranges of 25μg/mL to 0.097μg/mL for amoxicillin and 25μg/mL to 0.048μg/mL for ranitidine was observed. Amoxicillin retention time was about 8 minutes and ranitidine retention time was around 12 minutes. Amoxicillin levels were computed and the concentrations were applied to calculate the pharmacokinetic parameters. Pharmacokinetic parameters were estimated by Kinetica TM 4.4.1 (Thermo Electron Corp. USA). The analysis of variance (two way) and t test (two one sided) were applied on log transformed pharmacokinetic parameters of amoxicillin. The T_max was determined between amoxicillin alone and amoxicillin with ranitidine by Friedman test. The 90% confidence interval values for C_max(calc) (0.687–0.743) and T_max(calc) (1.148–1.742) for amoxicillin with or without ranitidine were not found within the FDA acceptable limits of 0.8–1.25. Study demonstrated the significant reduction in peak plasma levels of amoxicillin in presence of ranitidine. It is advisable to administer both drugs with time interval to avoid such interactions and increases in the bactericidal efficacy of amoxicillin.

Green Synthesis and Characterization of Carboxymethyl Cellulose Fabricated Silver-Based Nanocomposite for Various Therapeutic Applications

Purpose

The current study proposed the simple, eco-friendly and cost-effective synthesis of carboxymethyl cellulose (CMC) structured silver-based nanocomposite (CMC-AgNPs) using Syzygium aromaticum buds extract.

Methods

The CMC-AgNPs were characterized by ultraviolet (UV) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transmission infra-red (FTIR), energy-dispersive X-ray (EDX), and dynamic light scattering (DLS) techniques. The synthesized nanocomposites were evaluated for their bactericidal kinetics, in-vivo anti-inflammatory, anti-leishmaniasis, antioxidant and cytotoxic activities using different in-vitro and in-vivo models.

Results

The spherical shape nanocomposite of CMC-AgNPs was synthesized with the mean size range of 20–30 nm, and the average pore diameter is 18.2 nm while the mean zeta potential of −31.6 ± 3.64 mV. The highly significant (P < 0.005) antibacterial activity was found against six bacterial strains with the ZIs of 24.6 to 27.9 mm. More drop counts were observed in Gram-negative strains after 10 min exposure with CMC-AgNPs. Significant damage in bacterial cell membrane was also observed in atomic force microscopy (AFM) after treated with CMC-AgNPs. Nanocomposite showed highly significant anti-inflammatory activity in cotton pellet induced granuloma model (Phase I) in rats with the mean inhibitions of 43.13% and 48.68% at the doses of 0.025 and 0.05 mg/kg, respectively, when compared to control. Reduction in rat paw edema (Phase II) was also highly significant (0.025 mg/kg; 42.39%; 0.05 mg/kg, 47.82%). At dose of 0.05 mg/kg, CMC-AgNPs caused highly significant decrease in leukocyte counts (922 ± 83), levels of CRP (8.4 ± 0.73 mg/mL), IL-1 (177.4 ± 21.3 pg/mL), IL-2 (83.7 ± 11.5 pg/mL), IL-6 (83.7 ± 11.5 pg/mL) and TNF-α (18.3 ± 5.3 pg/mL) as compared to control group. CMC-AgNPs produced highly effective anti-leishmaniasis activity with the viable Leishmania major counts decreased up to 36.7% within 24 h, and the IC₅₀ was found to be 28.41 μg/mL. The potent DPPH radical scavenging potential was also observed for CMC-AgNPs with the IC₅₀ value of 112 μg/mL. Furthermore, the cytotoxicity was assessed using HeLa cell lines with the LC₅₀ of 108.2 μg/mL.

Conclusion

The current findings demonstrate positive attributes of CMC fabricated AgNPs as a promising antibacterial, anti-inflammatory, anti-leishmaniasis, and antioxidant agent with low cytotoxic potential.

A Review on Toxicity and Challenges in Transferability of Surface-functionalized Metallic Nanoparticles from Animal Models to Humans

Abstract The unique size and surface morphology of nanoparticles (NPs) have substantially influenced all aspects of human life, making nanotechnology a novel and promising field for various applications in biomedical sciences. Metallic NPs have gained immense interest over the last few decades due to their promising optical, electrical, and biological properties. However, the aggregation and the toxic nature of these NPs have restricted their utilization in more optimized applications. The optimum selection of biopolymers and biological macromolecules for surface functionalization of metallic NPs will significantly improve their biological applicability and biocompatibility. The present mini-review attempts to stress the overview of recent strategies involved in surface functionalization of metallic NPs, their specific biomedical applications, and comparison of their in vitro, ex vivo, and in vivo toxicities with non-functionalized metallic NPs. In addition, this review also discusses the various challenges for metallic NPs to undergo human clinical trials.

Investigating Halloysite Nanotubes as a Potential Platform for Oral Modified Delivery of Different BCS Class Drugs: Characterization, Optimization, and Evaluation of Drug Release Kinetics

Purpose

This study systematically investigated the potential of four model drugs (verapamil HCl, flurbiprofen, atenolol, and furosemide), each belonging to a different class of Biopharmaceutics Classification Systems (BCS) to be developed into oral modified release dosage forms after loading with halloysite nanotubes (HNTs).

Methods

The drugs were studied for their loading (mass gain %) by varying solvent system, method, pH, and ratios of loading into the nanotubes using D-optimal split-plot design with the help of Design Expert software. Drug-loaded halloysites were characterized by XRD, DTA, FTIR, SEM, and HPLC-UV-based assay procedures. Dissolution studies were also performed in dissolution media with pH 1.2, 4.5, and 6.8. Moreover, the optimized samples were evaluated under stress stability conditions for determining prospects for the development of oral dosage forms.

Results

As confirmed with the results of XRD and DTA, the drugs were found to be converted into amorphous form after loading with halloysite (HNTs). The drugs were loaded in the range of ~7–9% for the four drugs, with agitation providing satisfactory and equivalent loading as compared to vacuum plus agitation based reported methods. FTIR results revealed either only weak electrostatic (verapamil HCl and flurbiprofen) or no interaction with the surface structure of the HNTs. The dissolution profiling depicted significantly retarded release of drugs with Fickian diffusion from a polydisperse system as a model that suits well for the development of oral dosage forms. HPLC-UV-based assay indicated that except furosemide (BCS class IV), the other three drugs are quite suitable for development for oral dosage forms.

Conclusion

The four drugs investigated undergo phase transformation with HNTs. While agitation is an optimum method for loading drugs with various physicochemical attributes into HNTs; solvent system, loading ratios and pH play an important role in the loading efficiency respective to the drug properties. The study supports the capability of developing HNT-based modified release oral dosage forms for drugs with high solubility.

A Journey From SARS-CoV-2 to COVID-19 and Beyond: A Comprehensive Insight of Epidemiology, Diagnosis, Pathogenesis, and Overview of the Progress into Its Therapeutic Management

The 2019 novel coronavirus (2019-nCoV), commonly known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or coronavirus disease 2019 (COVID-19), was first revealed in late 2019 in Wuhan city, Hubei province, China. It was subsequently spread globally and thereby declared as a pandemic by WHO in March 2020. The disease causes severe acute respiratory illness and is highly contagious due to the fast-onward transmission. As of the mid of November 2020, the disease has affected 220 countries with more than 16 million active cases and 1.3 million deaths worldwide. Males, pregnant women, the elderly, immunosuppressed patients, and those with underlying medical conditions are more vulnerable to the disease than the general healthy population. Unfortunately, no definite treatment is available. Although remdesivir as an antiviral had been approved for use in those above 12 years of age and 40 kg weight group, it has been observed to be ineffective in large-scale SOLIDARITY trials by WHO. Moreover, dexamethasone has been found to increase the recovery rate of ventilated patients; oxygen and inhaled nitric oxide as a vasodilator have been given emergency expanded access. In addition, more than 57 clinical trials are being conducted for the development of the vaccines on various platforms. Two vaccines were found to be significantly promising in phase III results. It is concluded that till the approval of a specific treatment or development of a vaccine against this deadly disease, the preventive measures should be followed strictly to reduce the spread of the disease.

Quality by Design (QbD)-Based Numerical and Graphical Optimization Technique for the Development of Osmotic Pump Controlled-Release Metoclopramide HCl Tablets

PURPOSE

To develop the osmotically controlled-release gastroprokinetic metoclopramide HCl tablets, using quality by design (QbD)-numerical and graphical optimization technique for the treatment of gastroparesis and prophylaxis of delayed nausea and vomiting induced by low-high emetogenic chemotherapy.

METHODS

Formulations were designed by central composite design using Design Expert version 11.0.0, with osmogen concentration (X1), orifice size (X2), and tablet weight gain after coating (X3) as input and in-vitro drug release at 1hr. (Y1), 6 hrs. (Y2), and 12 hrs. (Y3), and the regression coefficient of drug release data fitted to zero-order, RSQ zero (Y4) as output variables. Core tablets prepared by direct compression were coated with Opadry® CA. The experimental design was validated by the polynomial equation. A correlation between predicted and observed values was evaluated by random checkpoint analysis. The optimized formulations were characterized for drug release, pH effect, osmolarity, agitation intensity, surface morphology, and stability study, and were subjected to accelerated studies according to ICH guidelines.

RESULTS

The interaction charts and response surface plots deduced a significant simultaneous effect of X variables on in vitro drug release and RSQ zero. The numerical optimization model predicted >90% drug release with X1 (13.30%), X2 (0.6 mm), and X3 (7.96%). Random checkpoint analysis showed a good correlation between predicted and observed values. The optimized formulation followed zero-order kinetics (r2=0.9703) drug release. Shelf life calculated was 2.8 years as per ICH guidelines.

CONCLUSION

The QbD-based approach was found successful in developing controlled release osmotic tablets of metoclopramide HCl, for reducing the dosage frequency, better emetic control, and improve patient compliance.

Synergistic Nanocomposites of Different Antibiotics Coupled with Green Synthesized Chitosan-Based Silver Nanoparticles: Characterization, Antibacterial, in vivo Toxicological and Biodistribution Studies

Purpose

The present study reports chitosan functionalized green synthesized CS-AgNPs, conjugated with amoxicillin (AMX), cefixime (CEF), and levofloxacin (LVX) for safe and enhanced antibacterial activity.

Methods

The CS-AgNPs and conjugates CS-AgNPs+AMX CS-AgNPs+CEF, and CS-AgNPs+LVX were characterized by UV–Vis, FTIR, SEM, TEM, EDX spectroscopy. The size distribution and zeta potential were measured using the dynamic light scattering (DLS) technique. The interaction between CS-AgNPs and antibiotic molecules was also investigated using UV–Vis spectroscopy at the concentrations of 5, 50, 500, and 5000 µM for each antibiotic. Antibacterial activity and synergism were assessed by the Fractional Inhibitory Concentration (FIC) index. The mechanism for synergistic activity was investigated by the detection of hydroxyl species based on the chemiluminescence of luminol. The biocompatibility index (BI) was calculated from IC₅₀ using the HeLa cell line. In vivo toxicity and tissue distribution of silver ions were evaluated on Sprague Dawley rats. Physical interactions of antibiotics and significant (P<0.05) antibacterial activity were observed after loading on CS-AgNPs surfaces.

Results

The spherical shape nanocomposites of CS-AgNPs with different antibiotics were prepared with mean size ranges of 80–120 nm. IC₅₀ of antibiotics-conjugated CS-AgNPs decreased compared to CS-AgNPs. The biocompatibility (BI) index showed that antibiotics-conjugated CS-AgNPs have high antibacterial potential and low toxicity. Highly significant (P<0.005) increase in the generation of hydroxyl species indicated the radical scavenging mechanism for synergistic activity of CS-AgNPs after combined with different antibiotics. Biochemical analysis and histopathological examinations confirmed low toxicity with minor hepatotoxicity at higher doses. After oral administration, extensive distribution of Ag ion was observed in spleen and liver.

Conclusion

The study demonstrates positive attributes of antibiotics-conjugated CS-AgNPs, as a promising antibacterial agent with low toxicity.

QbD based Eudragit coated Meclizine HCl immediate and extended release multiparticulates: formulation, characterization and pharmacokinetic evaluation using HPLC-Fluorescence detection method

This study is based on the QbD development of extended-release (ER) extruded-spheronized pellets of Meclizine HCl and its comparative pharmacokinetic evaluation with immediate-release (IR) pellets. HPLC-fluorescence method was developed and validated for plasma drug analysis. IR drug cores were prepared from lactose, MCC, and PVP using water as granulating fluid. Three-level, three-factor CCRD was applied for modeling and optimization to study the influence of Eudragit (RL100-RS100), TEC, and talc on drug release and sphericity of coated pellets. HPLC-fluorescence method was sensitive with LLOQ 1 ng/ml and linearity between 10 and 200 ng/ml with R² > 0.999. Pharmacokinetic parameters were obtained by non-compartmental analysis and results were statistically compared using logarithmically transformed data, where p > 0.05 was considered as non-significant with a 90% CI limit of 0.8-1.25. The AUC_0-t and AUC_0-∞ of ER pellets were not significantly different with geometric mean ratio 1.0096 and 1.0093, respectively. The C_max of IR pellets (98.051 ng/ml) was higher than the ER pellets (84.052 ng/ml) and the T_max of ER pellets (5.116 h) was higher than the IR pellets (3.029 h). No significant food effect was observed on key pharmacokinetic parameters of ER pellets. Eudragit RL100 (6%) coated Meclizine HCl pellets have a potential therapeutic effect for an extended time period.

HPLC-UV method for simultaneous quantitation of artemether and lumefantrine in fixed dose combination orodispersible tablet formulation

This paper describes the development and validation of a high performance liquid chromatography (HPLC-UV) method for the simultaneous quantitative determination of artemether and lumefantrine in fixed dose combination tablets. Chromatographic quantitation was carried out on a C-18 column Mediterrania Sea 18 (250×4.6 mm i.d.; 5 µm particle size) using a mobile phase consisting of 80:20 v/v mixture of acetonitrile and 0.05 % trifluoroacetic acid with final pH adjusted to 2.35 at flow rate of 1 ml/minute. The eluents was detected using photo diode array detector at wavelength of 210nm for artemether and 286 nm for lumefantrine. The retention times were ~5.8 mins for artemether and ~7.3 mins for lumefantrine. The newly developed method was validated and was found linear (r2 &gt;0.99), precise (R.S.D. &lt;2.0%), accurate, specific and robust. The artemether contents in the tablet formulation varied from 99.026 % to 99.347%, while lumefantrine contents were 99.546-99.728 %.

Antibacterial, anticoagulant and cytotoxic evaluation of biocompatible nanocomposite of chitosan loaded green synthesized bioinspired silver nanoparticles

Present work reports the green synthesis of chitosan functionalized silver nanoparticles (CS-AgNPs) using ethanolic buds extract of Sygyzium aromaticum. CS-AgNPs were characterized physically, evaluated for antibacterial, anticoagulant and antiplatelet activities, and toxicity profile. The physical characterization of CS-AgNPs was done by UV/vis, SEM, TEM, FTIR and EDX. The sphericity was found uniform. FTIR and EXD showed noninterfering few impurities. The antibacterial activity against VRSA (ZI, 23.2 ± 0.51 mm) and MRSA (ZI, 25.8 ± 0.32 mm) were determined. The rise in bleeding and thromboplastin was observed highly significant while increased in prothrombin and activated partial prothrombin time in significant manner at both the doses of CS-AgNPs (0.025 mg/kg and 0.05 mg/kg). Reduction in the levels of fibrinogen was also highly significant. Platelet aggregation decreased at high dose of CS-AgNPs i.e. 55.14 ± 8.25% (arachidonic acid) and 13.06 ± 2.17% (collagen). Thrombin antithrombin (TAT) complex activity was found highest for CS-AgNPs. Cytotoxicity was assessed using HeLa cell lines (LC₅₀; 125 μg/ml) and brine shrimp lethality tests (LC_50; 518 μg/ml). The work suggests that green synthesized chitosan functionalized silver nanoparticles may be utilized as an effective antibacterial agent and anticoagulant with low toxicity. The current findings will open a new window for nanomedicine development and future clinical application.

Antidiarrheal potential of lactobacillus strains isolated from pharmaceutical formulations for the treatment of pediatric diarrhea

The consumption of probiotics in the prevention and treatment of diarrhea have been clinically justified, comprehensive studied and explored in many products around the world. In Pakistan, recommendation of probiotic formulations is being emerged to control the increased mortality and morbidity from diarrhea under 5 years of age children. The objective of the study was to evaluate the antimicrobial potential of isolated Lactobacillus strains against diarrheagenic Escherichia coli. Twelve strains were isolated from different probiotic pharmaceutical formulations available in Pakistan. Physiological and biochemical characteristics of isolates were analyzed. Selective media was used for the growth of probiotic isolates and E. coli. Agar spot and well diffusion methods were employed to evaluate the antimicrobial activity of isolates and measured as a zone of inhibition (mm). Changes in cell morphology was observed by Scanning Electron Microscopy. Statistical analysis was adopted with a level of significance p<0.05. L. reuteri (28 mm) and L.plantarum (26 mm) showed significant inhibitory actions against E. coli due to increased organic acids and bacteriocins formations. Rest of isolates exhibited mild to moderate activity with an average inhibition (20 mm). L. sporogenes demonstrated weak antagonistic behavior. Use of multiple strains of Lactobacillus along with L. reuteri or L.plantarum as a therapeutic agent or in nutritional supplements could be a novel approach for the prevention and treatment of pediatric diarrhea.

Effect of permeation enhancers on in vitro release and transdermal delivery of lamotrigine from Eudragit®RS100 polymer matrix-type drug in adhesive patches

The drug-in-adhesive (DIA)-type matrix patches of lamotrigine are developed using variable permeation enhancers (oleic acid, PG, lemon oil and aloe vera), and drug in vitro release and its permeation are evaluated. Lamotrigine has been long used as an anti-epileptic, mood stabilizer, to treat bipolar disorder in adults and off label as an antidepressant. lamotrigine matrix patches comprising of Eudragit®RS100 (rate-controlling polymer) and DuroTak® 387-2510 (adhesive) were prepared by pouring the solution on backing membrane (3M-9720). The thickness of 120 µm was adjusted through micrometer film applicator. USP Apparatus V was used for the evaluation of release profile, which was fitted into various mathematical models. Quality characteristics of patches were determined through weight variation, moisture content, moisture uptake and drug content evaluation. FTIR studies were performed for drug-excipient compatibility; Franz diffusion cell was employed for studying in vitro permeation parameters such as flux, lag time, and ER. Skin sensitivity study of optimized patch was also performed. The release from patches comprising of PG and oleic acid was maximum, i.e., 96.24 ± 1.15% and 91.12 ± 1.11%, respectively. Formulations (A1-A5) exhibited Makoid-Banakar release profile. Formulation A3 consisting of oleic acid was optimized due to enhanced permeation of drug across skin compared to other enhancers with enhancement ratio of 3.55. Skin sensitivity study revealed patch as safe and non-allergenic. The study demonstrates that oleic acid can be used as a suitable permeation enhancer for transdermal delivery of lamotrigine from matrix-type patches.

Comparative pharmacokinetic evaluation of extended release itopride HCl pellets with once daily tablet formulation in healthy human subjects: a two treatment, four period crossover study in fasted and fed condition

OBJECTIVE

In this study, pharmacokinetics (PKs) and bioavailability of newly developed extended release (ER) Itopride HCl 150 mg encapsulated ER pellets (test) and 150 mg Ganaton ER once-daily (OD) tablets (reference) were compared and evaluated under fasted and fed conditions.

METHODS

Twelve healthy human subjects were enrolled in a single dose, randomized; two treatments, two sequences, four period crossover study. A modified and validated liquid chromatographic method was used for the estimation of Itopride HCl in plasma samples. The data were analyzed through non-compartmental model using PK software Phoenix Winnonlin version 7. The outcome was measured on logarithmically transformed data, where p > 0.05 was considered as non-significant with 90% CI limit of 0.8-1.25.

RESULTS

The C_max, AUC_0-t, and AUC_0-∞ values of Itopride HCl 150 mg ER pellets versus that of OD 150 mg tablets, in fed and fasted states, were within the limits specified by FDA to establish bioequivalence. The relative bioavailability of Itopride HCl 150 mg ER pellets were 1.019 (fed) and 1.081(fasted). The 90% CIs of AUC values for Itopride HCl 150 mg ER pellets and OD 150 mg tablets in fed versus fast were significantly greater and were not within 80-125% limit.

CONCLUSION

The test and reference formulations had similar pharmacokinetic parameters in each condition studied. However, an increase in the amount of drug was observed in the fed state.

Development and validation of liquidchromatographic method for quantitative determination of Loxoprofen in mobilephase and in human plasma

A Simple, sensitive and accurate high-performance liquid chromatographic (HPLC) method for effective and specific analysis of Loxoprofen (LXP) in the mobilephase and human plasma was developed. Effective chromatographic separation was attained on a Mediterranean Sea C18 column (250×4.6mm, 5um) with mobilephase containing acetonitrile and 0.01 M NaH2PO4 buffer (55:45) by adjusting pH 6.5 with sodium dihydrogen phosphate buffer at a flow rate of 1ml/min. Calibration ranges from 0.1ppm to 10 ppm with a coefficient of relation value (R2=0.999) by using a linear regression method and lower limit of quantification was 0.1ppm. The current method showed inter-day and intra-day accuracy and precision within the range of ±10%. % RSD was found to be less than 5 %. Analytical recovery was more than 90% which confirmed the reliability of current method. The proposed method was found appropriate for assessment of LXP in pharmacokinetic and bioequivalence study.

Development and optimization of intermediate release ketoprofen tablets by central composite design

In this study cost effective direct compression technique was used for the development and optimization of intermediate release (IntR) ketoprofen tablets using central composite design (CCRD). Fifteen different formulations (F1-F15) were developed using (X1) microcrystalline cellulose (Avicel PH-102) (18-51%), (X₂) methocel K4M (0.1-25%) and (X3) starch (1.5-18%) as selected variables while responses were % friability and Carr's Index (compressibility index). Powder blends of all formulations were evaluated using Angle of Repose, Carr's Index and porosity. Results of powder blends comply with USP standards and are classified as Fair Excellent. From F1-F15 only four formulations i.e. F6, F7, F14 and F15 were selected on acceptable weight basis, micromeritic properties and on the concentration of excipients. For the assessment of physico chemical properties of the optimized formulations different tests were performed. All results were found to be adequate range. In vitro assessment of the optimized formulations were also carried out in different dissolution media i.e. pH 1.2, phosphate buffer 4.5, pH 6.8 and pH 7.5. Release behaviour of F6, F7, F14 and F15 were estimated by using one - way ANOVA, model - independent, model dependent methods. Results of f₁ and f₂ showed that all the test formulations i.e. F6, F7, F14 were found to be similar with the reference formulation i.e. F15 at various dissolution media. Also all the formulations followed Hixson-Crowell kinetic model. The parameter n showed Anomalous transport (non - fickian diffusion). The mean dissolution time (MDT) was found to be in the range of 2.632-2.922. Results of ANOVA indicated no significant difference within and between formulations at different dissolution media as p values were found to be >0.05. Also all the selected formulations were found to be stable at accelerated conditions.

Effect of lipid and cellulose based matrix former on the release of highly soluble drug from extruded/spheronized, sintered and compacted pellets

Background

The study was to develop an extended release (ER) encapsulated and compacted pellets of Atenolol using hydrophobic (wax based and polymeric based) and high viscosity grade hydrophilic matrix formers to control the release of this highly water soluble drug by extrusion/spheronization (ES). Atenolol is used for cardiovascular diseases and available as an immediate release (IR) tablet dosage form. The lipids, Carnauba wax (CW), Glyceryl monostearate (GMS) and cellulose based i.e. Hydroxypropyl methylcellulose (HPMC) and Ethyl cellulose (EC) were used in preparing Atenolol ER pellets. Thermal sintering and compaction techniques were also applied to control the burst release of Atenolol.

Method

For this purpose, thirty-six trial formulations (F1-F36) were designed by Response Surface Methodology (RSM), using Design-Expert 10 software, keeping (HPMC K4M, K15 M & K100 M), (EC 7FP, 10FP & 100FP), waxes (GMS, & CW), their combinations, sintering temperature and duration, as input variables. Dissolution studies were performed in pH, 1.2, 4.5 and 6.8 dissolution media. Drug release kinetics using different models such as zero order, first order, Korsmeyer-Peppas, Hixon Crowell, Baker-Lonsdale and Higuchi kinetics were studied with the help of DDsolver, an excel based add-in program.

Results

The formulations F35 and F36 showed compliance with Korsmeyer-Peppas Super case II transport model (R² = 0.975–0.971) in dissolution medium pH 4.5. No drug excipient interaction observed by FTIR. Stereomicroscopy showed that sintered combination pellets, (F35), were highly spherical (AR = 1.061, and sphericity = 0.943). The cross-sectional SEM magnification (at 7000X) of F34 and F35 showed dense cross-linking. The results revealed that the optimized formulations were F35 (sintered pellets) and F36 (compacted pellets) effectively controlling the drug release for 12 h.

Conclusion

Extended-release encapsulated, and compacted pellets were successfully prepared after the combination of lipids CW (10%) and GMS (20%) with EC (10FP 20% & 100FP 20%). Sintering and compaction, in addition, stabilized the system and controlled the initial burst release of the drug. Extended release (ER) Atenolol is an effective alternative of IR tablets in controlling hypertension and treating other cardiovascular diseases.

Chromatographic method development and validation for the determination of valsartan in biological fluid

A swift, precise and simple HPLC bioanalytical technique with UV detection was established and validated for quantitative estimation of valsartan in human plasma. The analyte was separated from plasma by protein precipitation with acetonitrile and chromatographically separated on Zorbax SB-C18 (5μm, 4.6mm × 15cm) column. The solvent mixture system consisting of acetonitrile, water and glacial acetic acid (40:59:1 v/v), was pumped using isocratic mode at 1mL/min flow rate. Samples' detection of drug was made spectrophotometrically at a wavelength of 264nm. The analyte response was instituted to be linear from 0.06 to 8μg/mL with a regression value of 0.999. The accuracy of the proposed method was ranged between 97.2-100.3% with 5% RSD. The analytical recovery (>95%) was consistently observed and satisfactory sample stability was also found at different environmental conditions. In conclusion the reported bio-analytical method is easy and robust that was successfully utilized in estimation of valsartan in a pharmacokinetic study.

Development and validation of HPLC method for the determination of Cefpodoxime Proxetil in human plasma

A new, simple, accurate, precise and specific method has been developed for the analysis of Cefpodoxime Proxetil in human plasma. The proposed method was developed and validated with the aim to be used in Bioavailability/Bioequivalence studies for quantification of drug in human plasma. The mobile phase components were acetonitrile, methanol, and water in the ratio of 20:50:30. Ortho phosphoric acid was used to adjust at pH5.0. Flow rate and wavelength were kept 1ml/min and 247nm respectively. The column was C-18 HPLC column 5um particle size, L x 1.d. 25cm x4.6mm. (Supelcosil). Retention time of Cefpodoxime Proxetil was found to be 10.967min. The developed method was validated for selectivity, recovery, accuracy, precision, repeatability, reproducibility, stability and linearity in the range of 0.195mcg/ml to 50mcg/ml. The accuracy and Precision of the proposed method were well within the predefined limits i.e. ±15% for all the calibration standards other than LLOQ (Lower Limit of Quantification) where it was well within ±20% of the nominal value. The analytical recovery was always above 89% showing satisfactory recovery. The coefficient of correlation (R2 ) was 0.999. The developed method was found suitable for the estimation of Cefpodoxime Proxetil in plasma.

HPLC method development and validation for the determination of Cefaclor in human plasma

Cefaclor was analyzed in the human plasma by developing a simple, precise and accurate assay method which was then validated for its accuracy, specificity and precision. The mobile phase comprised of a mixture of sodium 1-pentanesulfonate, water, triethylamine and methanol. Phosphoric acid was used to adjust the pH to 2.5±0.1. The flow rate was maintained at 1.5ml/min and the wavelength was set at 265 nm. A C-18 HPLC, column 5um particle size, L x 1.D. 25cm x 4.6mm (Supelcosil) was utilized for chromatographic separation. The retention time of Cefaclor was found to be 17min. This method was validated for selectivity, accuracy, precision, repeatability, reproducibility, recovery, linearity, and stability. Calibration curves were found linear were in the range of 0.39µg/ml to50µg/mland the coefficient of correlation (R²) was found to be 0.999. Hence, this method has been found useful for the determination of Cefaclor in plasma.

Pharmacokinetic and bioequivalence studies of fast dispersible ketoprofen tablets in healthy volunteers

In the present study the pharmacokinetic and bioequivalence parameter of Ketoprofen 100 mg fast dispersible tablets (test) were measured with marketed (reference) product. This study was accomplished following FDA guidance. A single dose, open labeled, cross over (two way), randomized study design was used to conduct investigation on 12 Pakistani healthy volunteers. At various time points blood samples (10mL) were drawn i.e. at 0.25, 0.5, 1, 1.5, 2, 3, 4, 8, 12 and 13hr. Plasma was then separated and ketoprofen concentrations were estimated by validated HPLC technique using LC 20A pump (Shimadzu Corp, Japan) and Spectrophotometric SPD-20Adetector (Shimadzu Corp, Japan). Ketoprofen concentrations were then analyzed by Kinetica^TM 4.4.1 (Thermo electron corp, USA) to estimate various compartmental and noncompartmental pharmacokinetic parameters. Various parameters of bioequivalence including AUC_tot, AUC_0-oo, AUC_last, T_maxcalc and C_maxcalcw ere compared using ANOVA method (two way). For log and non-log transformed data the 90% confidence interval values for AUC _oo0-oo, (1.0087-1.0704; 1.0099-1.0714), AUC _tot , (0.95482- 1.0093; 0.95486-1.0098), AUC_last (0.93373-0.98605; 0.93404-0.98603), C_maxcalc (0.92978-0.9955; 0.92962-0.99663) and T_maxcalc (0.89019-0.94116; 0.89095-0.94288) for test and reference products respectively. Results were found to be within the FDA satisfactory range. For the results verification, Schuirman's one sided t test was used. SPSS 17.0 (SPSS Inc.) was utilized for the determination of wilcoxon sign rank test. Results showed no carry over effect after first study period. Also test product met the regulatory criteria for bioequivalence with the reference product. Both the formulations were well tolerated.

Impact of different organic acids on solubility enhancement of cefpodxime proxetil immediate release tablet and its stability studies

Cefpodoxime proxetil is a third generation cephalosporin antibiotic demonstrates pH dependent solubility and is highly soluble only in acidic pH. The purpose of this investigation was to design and develop immediate release tablets of cefpodoxime proxetil by direct compression method and determine the effect of different solid buffers (organic acids) such as fumaric acid (formulations F1-F4), maleic acid (formulations M1-M4) and citric acid (formulations C1-C4) by using cefpodoxime and acid in the ratios of 4:1, 2:1, 1:1 and 1:2 to achieve pH-independent release of the drug. Physical parameters and assay were found to be within the acceptable range as prescribed in USP 36 / NF 31. In vitro dissolution studies of each formulation were performed in distilled water, USP dissolution medium, HCl buffer solution of pH 1.2, phosphate buffer solutions of pH 4.5 and 6.8 to observe the drug release. The formulations F3, F4, M4 were selected for film coating on the basis of better drug release profile, to protect the drug from chemical degradation through hydrolysis. Film coated formulation F3, F4 and M4 showed a remarkable in vitro release of the drug (72.88±0.43 to 92.67±0.71%) within 30min of observation in all dissolution media and further evaluated by model independent and model dependent approaches. The drug release was found to be best fit to Weibull model as highest r2adjusted (0.924-0.998) and lowest AIC (18.416-54.710) values were obtained in all dissolution media. R Gui® applied for stability studies of F3 and F4 formulations, showing shelf lives of 28 & 27months at ambient and 33 months at accelerated temperatures. Formulation F4 was chosen as best formulation on the basis of physical properties, highest dissolution rate and stability studies.

Pharmaceutical and in vitro therapeutic equivalence studies of ketoprofen enteric coated 100 mg tablets

The objective of this study was to assess the quality of six different brands of enteric coated Ketoprofen 100 mg tablets, KPB₂ to KPB6 are available in commercial market of Karachi, Pakistan, while KPB1 was obtained from international source. We performed different physico-chemical assessments i.e. weight variation, diameter, hardness, friability, thickness, disintegration, content uniformity, assay and dissolution test. Results of all the investigations were found to be in adequate limits. Also pharmaceutical equivalence was determined by selecting different tests and assay assessment. Furthermore, in vitro therapeutic equivalence was also estimated at phosphate buffer pH 6.8 and 7.5. Results were evaluated by one way ANOVA, model independent and model dependent methods. ANOVA results showed that release behaviour were found to be similar as p values >0.05, also KPB ₁ - KPB₆ followed Weibull model at different dissolution media. Results indicated that innovator and brands not only passes the pharmaceutical equivalence assessment but also comply with the in vitro therapeutic equivalence.

Formulation development and comparative in vitro study of metoprolol tartrate (IR) tablets

The objective of the present work was to develop Immediate Release (IR) tablets of Metoprolol Tartrate (MT) and to compare trial formulations to a reference product. Six formulations (F1-F6) were designed using central composite method and compared to a reference brand (A). Two marketed products (brands B and C) were also evaluated. F1-F6 were prepared with Avicel PH101 (filler), Crospovidone (disintegrant) and Magnesium Stearate (lubricant) by direct compression. Pharmacopoeial and non-pharmacopoeial methods were used to assess their quality. Furthermore, drug profiles were characterized using model dependent and independent (f(2)) approaches. Brands B and C and F5 and F6 did not qualify the tests for content uniformity. Moreover, brand B did not meet weight variation criteria and brand C did not satisfy requirements for single point dissolution test. Of the trial formulations, F2 failed the test for uniformity in thickness while F4 did not disintegrate within time limit. Only F1 and F3 met all quality parameters and were subjected to accelerated stability testing without significant alterations in their physicochemical characteristics. Based on AIC and r(2)(adjusted) values obtained by applying various kinetic models, drug release was determined to most closely follow Hixson-Crowell cube root law. F1 was determined to be the optimized formulation.

Formulation development and optimization: Encapsulated system of Atenolol and Glyburide

PURPOSE

Objective of this study is to develop; tablet-in-a capsule system, to deliver Atenolol 25mg and Glyburide 5mg in the hard gelatin capsule. In order to improve patient compliance and reduce problems associated with complex therapeutic regimen Atenolol (cardio-selective beta-blocker) and Glyburide (anti-diabetic; sulfonylurea) are commonly, prescribed to the diabetic hypertensive patient. Metgod: In present work six different formulations of Atenolol (AF1-AF6) and Glyburide (GF1-GF6) were prepared by direct compression method using Avicel, Lactose DC, Crospovidone and Magnesium Stearate in different proportions and encapsulated in hard gelatin shells. Post compression parameters i.e. weight variation, diameter variation, thickness variation, hardness variation, % friability, disintegration, % drug release were determined at different pH 1.2, 4.5 and 6.8, and subjected to dissolution profile comparison through similarity factor (ƒ2).

RESULTS

Stability studies were performed and shelf lives were calculated by R-Gui Stab R console 2.15.2 and determined to be 15 and 27 months for Atenolol and Glyburide respectively. The percentage drug contents of Atenolol and Glyburide were estimated spectrophotometerically at 286 nm and 314.7 nm respectively. Formulations CF1-CF6 (encapsulated) were subjected to weight variation, disintegration and dissolution tests and subjected to model dependant analysis for dissolution studies. The simultaneous quantitation of Atenolol and Glyburide for content assay was done by HPLC method of analysis.

CONCLUSION

formulation CF6 is showing highest coefficient of correlation values for all models applied. So we can conclude that the proposed system can improve patient compliance by increasing the ease of administration of two drugs together.

Simultaneous quantitation of Ofloxacin, Fexofenadine HCl and Diclofenac Potassium in affixed dose combinative formulation by HPLC-UV method

A high-pressure liquid chromatography (HPLC-UV) based simple and specific method for simultaneous quantitative determination of Ofloxacin, Fexofenadine HCl and Diclofenac Potassium has been developed and validated according to ICH guidelines. Chromatographic separation of the three drugs was carried out on 4.6 x 250 mm x 5 µ Licrospher RP Select B Column, using mobile phase constituted of methanol and phosphate buffer pH 3.5 (650: 350), pH adjusted to 3.5 ± 0.05 with dilute ortho-phosphoric acid and delivered at a flow rate of 1 ml/min. The eluents were detected at UV wavelength of 220 nm and the retention times for Ofloxacin, Fexofenadine HCl and Diclofenac Potassium were 2.5 minutes, 4 minutes and 11.5 minutes, respectively. This method is suitable and specific for the three drugs and was found to be linear (R² > 0.996), accurate, specific, reproducible and robust over a concentration range of 0.05 to 0.15 mg/ml for Ofloxacin, 0.015 to 0.045 mg/ml for Fexofenadine HCl and 0.0125 to 0.0375 mg/ml for Diclofenac Potassium. The proposed method is simple and convenient, hence easily utilized for the characterization and quantitation of the three drugs in a single formulation for combination therapy of rheumatoid arthritis, sepsis, infection with fever and flu.

Quality evaluation and in vitro interaction studies between levofloxacin 250mg and diclofenac sodium 50mg tablets

Fluoroquinolones are broad-spectrum antibiotics, work against Gram-positive and Gram-negative bacteria and are a clinically proven option for many resistant infections. Among fluoroquinolones Levofloxacin works best against acute sinusitis, inflammation of the lower airways, acute exacerbation of chronic bronchitis, community acquired pneumonia, complicated urinary tract infection including Pyelonephritis, chronic bacterial prostatitis and skin and soft tissue infection. Levofloxacin is a frequently prescribed antibacterial agent with Diclofenac Sodium for pain management in infectious conditions. The objective of the present work is to evaluate the level of interaction between Levofloxacin and Diclofenac Sodium. In this work market available brands of both drugs were also evaluated for quality.The physiochemical parameters like weight variation, thickness variation, and mechanical strength were determined. Similarly the percentage drug release and content uniformity test were also analyzed; the tested quality attributes were found within the recommended pharmacopeia ranges except brand L(6) that had high drug content 124.629±3.614 while brand L(4) and L(5) were not found similar in pH 1.2. When subjected to model dependent analysis Levofloxacin showed compliance with (first order, Higuchi, Hixson Crowell and Weibull) at pH (1.2, 4.5 and 6.8). However Diclofenac Sodium showed adherence with (first order, Hixson Crowell and Weibull) at pH (1.2, 4.5 and 6.8) but following Higuchi at pH 1.2 and 4.5 only. The interaction studies were also performed spectrophotometrically and simultaneous equation was used to estimate the percentage availability of both the drugs at pH 4.5, 6.8, FaSSGF and FaSSIF. The studies showed that the percent availability of Levofloxacin was increased significantly in FaSSIF i.e. 129.173±0.323 at 45 minutes in the presence of Diclofenac Sodium.

Use of hydrophilic and hydrophobic polymers for the development of controlled release tizanidine matrix tablets

The aim of the present study was to develop tizanidine controlled release matrix. Formulations were designed using central composite method with the help of design expert version 7.0 software. Avicel pH 101 in the range of 14-50% was used as a filler, while HPMC K4M and K100M in the range of 25-55%, Ethylcellulose 10 ST and 10FP in the range of 15 - 45% and Kollidon SR in the range of 25-60% were used as controlled release agents in designing different formulations. Various physical parameters including powder flow for blends and weight variation, thickness, hardness, friability, disintegration time and in-vitro release were tested for tablets. Assay of tablets were also performed as specified in USP 35 NF 32. Physical parameters of both powder blend and compressed tablets such as compressibility index, angle of repose, weight variation, thickness, hardness, friability, disintegration time and assay were evaluated and found to be satisfactory for formulations K4M2, K4M3, K4M9, K100M2, K100M3, K100M9, E10FP2, E10FP9, KSR2, KSR3 & KSR9. In vitro dissolution study was conducted in 900 ml of 0.1N HCl, phosphate buffer pH 4.5 and 6.8 medium using USP Apparatus II. In vitro release profiles indicated that formulations prepared with Ethocel 10 standard were unable to control the release of drug while formulations K4M2, K100M9, E10FP2 & KSR2 having polymer content ranging from 40-55% showed a controlled drug release pattern in the above mentioned medium. Zero-order drug release kinetics was observed for formulations K4M2, K100M9, E10FP2 & KSR2. Similarity test (f2) results for K4M2, E10FP2 & KSR2 were found to be comparable with reference formulation K100M9. Response Surface plots were also prepared for evaluating the effect of independent variable on the responses. Stability study was performed as per ICH guidelines and the calculated shelf life was 24-30 months for formulation K4M2, K100M9 and E10FP2.

Simultaneous quantitation of aspirin, amlodipine and simvastatin in a fixed dose combination of encapsulated tablet formulation by HPLC-UV method

A high-pressure liquid chromatography (HPLC-UV) based simple and specific method for simultaneous quantitative determination of aspirin, amlodipine besylate and simvastatin in a capsule formulation has been developed and validated according to ICH guidelines. Chromatographic separation of the three drugs was carried out by aSpherisorbODS2 reverse phase column (4.6 x 250 mm; 5 μm) using amobile phase, which consisted of 70: 30 (v/v) mixture of acetonitrile and triethylamine phosphate buffer (pH 3; 0.015 M) with final pH adjusted to 2.5 using dilute ortho-phosphoric acid, at a flow rate of 1mL/min. The eluents were detected at UV wavelength of 237 nm and the retention times for aspirin, amlodipine besylate and simvastatin were ~2.7 mins, ~6.1 mins and ~10.5mins, respectively. This method is suitable and specific for the three drugs and was found to be linear (R2>0.995), accurate, specific, reproducible and robust in the concentration range of 375 to 1125mcg/ml for aspirin, 25 to 75mcg/ml for amlodipine besylate and 50 to 150mcg/ml for simvastatin. This simple and convenient method could be easily utilized for the characterization and quantitation of the three drugs in a single formulation for combination therapy of cardiovascular diseases.

Drug utilization evaluation of meropenem and correlation of side effects with renal status of patients in a teaching based hospital

Meropenem is a restricted, broad spectrum and expensive antibiotic. The major consequences of irrational use of restricted antibiotics are increase drug resistance and drug expenditure. The use of antibiotics, specifically restricted antibiotics, must be monitored continuously to increase its adherence to the standard guidelines to avoid such problems. The objective of this study was to evaluate the appropriateness of meropenem use with respect to renal status of patients in a teaching based hospital. A retrospective study was carried out from 1st January 2013 to 30th June 2013 to determine the evaluation of meropenem use in accordance to the criteria developed through national (Infectious disease society of Pakistan) and international guidelines (Health care infection control practices advisory committee). The data was recorded on data collection form by thorough reviewing of patients' medical records. Main outcomes measured were indication, dose, interval, duration, creatinine clearance, complete blood count and culture sensitivity test. Correlation of different variable (side effects and generalized health) was also observed with reference to renal status of patients. Statistical analyses were performed using descriptive statistics. A total of 201 cases of meropenem prescription were identified during the study period. The variable, which was most consistent with the criteria was 'indication', in which 97.52% of meropenem prescription was indicated in diseases encouraged by guidelines. However, the use of meropenem as an empirical therapy was the major problem reported in this study as it adhered to in only 43% of the cases. It was also noted that prevalence of side effects increased when meropenem was prescribed in renal compromised patients, and also observed that generalized health of patients decreased with meronem use in renal unstable patients. Thrombocytopenia was the major problem associated with the meropenem use (37.81%). The study detected various areas where use of meropenem was not according to the standards. Strict policies and procedures need to be implemented to use meropenem in line with the standard guidelines.

Practice nurses and pharmacists: a perspective on the expectation and experience of nurses for future collaboration

OBJECTIVES

To explore the nurses' expectations and experience about pharmacists in private sector hospitals of Karachi, Pakistan.

METHODS

A cross-sectional study was conducted from June to September 2012 in five private sector hospitals of Karachi, Pakistan. A convenient sample of nurses (n=377) were enrolled in this study. Data was obtained through a previously validated questionnaire. Responses were statistically analyzed using SPSSv.17.

RESULTS

Questionnaires were returned giving a response rate of 63.6% of which 20 were unusable (n=240). Out of the remaining 220, 24.1% (n=53) responded that they never or rarely interacted with a pharmacist. Respondents who expect pharmacists to collaborate with nurses to solve drug related problems were 45% (n=99). Nurses' experience of pharmacists was not substantial as only 44.5% (n=98) respondents consider pharmacists as a reliable source of clinical drug information.

CONCLUSION

The role of pharmacists is not well appreciated among nurses in Pakistan. Hence, pharmacists must bridge the observed gap and use a more strategic and consistent approach to build a more positive image in line with other healthcare professionals and in providing patient-centred pharmaceutical care. This research would impress upon the pharmacists the need to redefine their role in the healthcare settings.

Formulation development of intermediate release Nimesulide tablets by CCRD for IVIVC studies

Simple and cost effective study consisting of three steps, comparison of micromeritic properties of different blends i.e. placebo without API and Nimesulide containing, Use of central composite design (CCRD) for intermediate release Nimesulide tablets and stability results of three selected Nimesulide tablet formulations which were calculated by using R Gui. Different concentrations of Avicel, hydroxypropyl methyl cellulose (HPMC) and magnesium stearate were used as variables in central composite design and two types blend i.e., with or without Nimesulide were selected for bulk density, tap density, percentage compressibility; angle of repose and Hausner's ratio. Blending rate constant was performed after applying the different mixing times like 3, 6, 9 and 12 minutes. Twenty intermediate release formulations were designed and three formulations were chosen for compression by direct compression method on the basis of compressibility index. Physicochemical properties and best release pattern in four hours in different dissolution medium were successfully measured. Relative densities, porosity of tablets were compared with tensile strength of tablet and weight variation, hardness, friability and dissolution was performed by simple experiments. Presence of Nimesulide in the bulk increased all micromeratic tests while 9 minutes was best mixing time. The hardness of NM containing tablets increased with the increase of relative density. The release pattern was further analyzed by model dependent i.e. zero order, first order and Higuchi, Korse-meyer and Pappas, Hixson Crowell and model independent kinetic model i.e., f2 value respectively. R Gui explained the F16 formulation shows the best result in stability studies with shelf life 72 months.

Incidence of medication error associated with the use of beta-blockers in Pakistan

Medication errors (ME) are human errors, which are very frequent in cardiovascular patients and result in patient morbidity and mortality. This study was focused to evaluate the quality of prescriptions and to emphasize the placement of clinical pharmacist in health care team. This study was carried out in different outpatient settings of (in) Karachi, Pakistan. The study period was June 2011 till June 2012. Retrospective data was analyzed for the outpatients' prescription of beta blocker drugs. During the study, prescriptions (n=450) were collected from different outpatient settings of (in) Karachi, Pakistan. Prescription containing beta-blockers were analyzed for the essential elements to be mentioned in prescription. Drug-drug interactions were identified by the Micromedex.2.0 Drug-Reax database and severity of medication error was determined by NCCMERP Index. A total of 1627 medication errors were identified in 450 prescriptions. The most frequent error was not mentioning the patient's weight (95%), followed by missing diagnosis (79.4%) and drug-drug interactions (69.5%). Twenty-two prescriptions were placed in the most severe category I (4.88%). Average number of drugs per prescription was 4.76. Significant difference was observed (χ(2)=52.418, p<0.05) using SPSS 19 for those prescription orders having more than 5 drugs with Beta-blockers. This indicates that the errors in prescription such as drug-drug interactions, wrong dose etc. was significantly increased with the number of drugs per prescription. Results showed that medication errors are very frequent in prescription written in outpatient setting of various hospitals and clinics in Karachi. This shows that the irrational prescribing is a common practice in developing countries. Placement of skilled pharmacist in the health care system is the only solution for avoidance of these medication related problems.

Staphylococcal resistance against five groups of life saving antibiotics in the year 2003-2005

In the year 2003 to 2005 a prospective study was conducted to find out the predominance of Staphylococcus (Staphylococcus aureus) resistance pattern in opposition to five life saving antibiotics as these are the sole agents to treat critically ill patients in hospitals. During the period of two years almost 2500 samples of bacterial culture were taken from different pathological laboratories and hospitals in Karachi. Among these 1500 were Gram positive cocci and 1000 samples were identified as Staphylococcus aureus. Life saving antibiotics were taken from five different groups and by mean of disk diffusion technique antibiogram of Staphylococcus aureus against these antibiotic were determined. During the course of study imipenem showed 11%, amikacin exhibited 58%, cefipime showed 31%, vancomycin and piperacillin/tazobactam displayed 24% resistance against Staphylococcus aureus. Imipenem was found to be most effective against Staphylococcus aureus.Resistance to other antibiotics developed quickly in Staphylococcus aureus collected from clinical areas where these antimicrobial agents are extensively used.

Formulation development and evaluation of Diltiazem HCl sustained release matrix tablets using HPMC K4M and K100M

The aim of this study was to develop a sustained release hydrophilic matrix tablet of Diltiazem HCl and evaluates the effect of formulation variables (e.g. lubricant, binder, polymer content and viscosity grades of HPMC) on drug release. Twelve different formulations (F1-F12) were prepared by direct compression. The results of the physical parameters and assay were found to be within the acceptable range. Rate of drug release was found to be slow as the fraction of the polymer was increased from 20-50%. The drug release rate from tablets containing K4M was effectively controlled by increasing the talc concentration, whereas the burst effect was reduced by increasing binder content. The drug release was higher with K4M as compare to K100M. Model-dependent and independent methods were used for data analysis and the best results were observed for K4M in Higuchi (R(2)=0.9903-0.9962) and K100M in Baker and Lonsdale (R(2)=0.9779-0.9941). The release mechanism of all formulations was non-Fickian. F7 (50% K4M, 2% talc, 10% Avicel PH101) and F11 (40% K100M) were very close to targeted release profile. F12 (50% K100M) exhibited highest degree of swelling and lowest erosion. The f1 and f2 test were performed taking F11 as a reference formulation.