Attending Prof Andrei Zvelindovsky’s seminar yesterday brought back memories of my blogging journey. When I applied for a job at UCLAN naturally I went to the website to look at their research. The most interesting was the blog from the Theoretical Physics Group. I was impressed for several reasons.
- The work was of high quality and interesting.
- Photographs of group members showed them having fun with their research.
- The group had an international following.
After arriving at UCLAN I asked about Andrei and his work and was told by colleagues that his work was very good and he is an eccentric academic who hides in the basement with his research group. After several months I saw him at school meetings and finally spoke to him. I found him interesting and very friendly. Much later on he told me to start a blog but I thought it would be a waste of time and complicated to do and keep up to date so ignored his suggestion. Andrei was persistent and passionate about blogging and its benefits so he set one up for me. I procrastinated and didn’t do anything for about six months. Andrei then set up an email system for me where all I had to do was send an email to a unique address and the blog would be populated and organised.
I started blogging and learned by trial and error and made numerous stupid mistakes. Andrei was always there to help. I started blogging regularly and got addicted. Now you can to the popular seminars which Andrei delivers through the year. Keep an eye out for the calender for next one in the series and make sure your there. Don’t miss it.
Why I blog?
- To inspire and encourage research students to fulfill their potential.
- To get useful information across.
How I blog?
- I decide on a topic to write about.
- I allocate a fixed amount of time to writing the post. Initially stared once a week and set aside 1 hour.
- I plan the points I want to make and then write.
- I post the first draft on the blog. Usually it is full of spelling mistakes and poor grammar but I am happy because I got some points across that may be useful to a research student
- I read the blog and make changes. I correct spelling mistakes and grammar.
- I post it to my Linkedin and Facebook.
What I blog about?
- How to carry out research
- How to write reports, papers and thesis
- How to solve problems that you may encounter along your research journey.
- How to organise, overcome obstacles and set big goals and achieve them.
- Tell interesting stories.
10 benefits I got from blogging?
- raised my profile internationally
- helped me to organise your thoughts on a topic and write down as a permanent record.
- saved time and effort. In the past I had to repeat the same information to each individual student. Now I summarise quickly and then point them to a blog post.
- helped me recruit research students.
- cultivated and developed new research links
- helped me to get invitations to give keynote talks at international conferences
- got me invitation to guest edit special issues of journals and to write and edit books
- helped me to a good foster group spirit and develop cohesion
- improved recruitment of research students and help you expand my research group
- helped get UCLAN known in remote places all over the world
Don’t do what I did, take Prof Andrei’s advice and start blogging now. I can’t wait to learn about your blogging journey.
Tapas Sen, Sarah J. Sheppard, Tim Mercer, Abdelbary Elihissi. Fabrication of lipid bilayer coated stable superparamagnetic core-shell nanoparticles in suspension for in vitro investigation of anticancer drug mitomycin C. RSC Advances, In press.
N. R. Khalid, Ejaz Ahmed, M. Ikram, M. Ahmad, David A. Phoenix, Abdelbary Elhissi, Waqar Ahmed and Mark J. Jackson. Effects of Calcination on Structural, Photocatalytic Properties of TiO2 Nanopowders Via TiCl4 Hydrolysis. Journal of Materials Engineering and Performance, In press.
Abdelbary M.A. Elhissi, Waqar Ahmed, Israr Ul Hassan, Vinod R. Dhanak, Antony D’Emanuele. Carbon nanotubes in cancer therapy and drug delivery. Journal of Drug Delivery, in press.
Maha Nasr, Samrana Nawaz, Abdelbary Elhissi. Amphotericin B lipid nanoemulsion aerosols for targeting peripheral respiratory airways via nebulization. International Journal of Pharmaceutics, 436 (2012) 611-616.
Abdelbary M. Elhissi, Joanna Giebultowicz, P. Wroczynski, Ana A. Stec, Waqar Ahmed, Mohamed A. Alhnan, David Phoenix, Kevin M. Taylor. Nebulization of ultradeformable liposomes: The influence of aerosolization mechanism and formulation excipients. International Journal of Pharmaceutics, 436 (2012) 519-526.
Abdelbary M.A. Elhissi, Waqar Ahmed, Kevin M.G. Taylor. Laser diffraction and electron microscopy studies on inhalable liposomes generated from particulate-based proliposomes within a medical nebulizer. Journal of Nanoscince and Nanotechnology, 12 (2012) 6693-6699.
Abdelbary M.A. Elhissi, Waqar Ahmed, David McCarthy, Kevin M.G. Taylor. A study of size, microscopic morphology and dispersion mechanism of structures generated on hydration of proliposomes. Journal of Dispersion Science and Technology, 33 (2012) 1121-1126.
Mukhtar Ahmed, T. Byrne, Abdelbary Elhissi, David Phoenix, Waqar Ahmed. Vibrational and AFM studies of the adsorption of glycine on DLC and si-DLC samples. Journal of Materials Science, 47 (2012) 1729-1736.
Abdelbary Elhissi, H. Gill, Waqar Ahmed, Kevin Taylor. Vibrating-mesh nebulization of liposomes generated using an ethanol-based proliposome technology. Journal of Liposome Research, 21 (2011) 173-180.
Abdelbary M.A. Elhissi, Michael O’Neill, Waqar Ahmed, Kevin M.G. Taylor. High-sensitivity differential scanning calorimetry for measurement of steroid entrapment in nebulised liposomes generated from proliposomes. Micro & Nano Letters, 6 (2011) 694-697.
Michael Taylor, Abdelbary M. Elhissi. Predicting the physical properties of tablets from ATR-FTIR spectra using partial least squares regression. Pharmaceutical Development and Technology, 16 (2011) 110-117.
Abdelbary M.A. Elhissi, M. Ashraful Islam, Basel Arafat, Michael Taylor, Waqar Ahmed. Development and characterisation of freeze-dried liposomes containing two anti-asthma drugs. Micro and Nano Letters, 5 (2010) 184-188.
Thu Ghazanfari, Abdelbary M. Elhissi, Zhea Ding, Kevin M. Taylor. The influence of fluid physicochemical properties on vibrating-mesh nebulization. International Journal of Pharmaceutics, 339 (2007) 103-111.
Abdelbary M. Elhissi, M.Faizi, Waseem F. Naji, H.S. Gill, Kevin M. Taylor.Physical stability and aerosol properties of liposomes delivered using an air-jet nebulizer and a novel micropump device with large mesh apertures. International Journal of Pharmaceutics, 334 (2007) 62-70
Abdelbary M. Elhissi, Kiran K. Karnam, M.R. Danesh-Azari, H.S. Gill, Kevin M. Taylor. Formulations generated from ethanol-based proliposomes for delivery via medical nebulizers. Journal of Pharmacy and Pharmacology, 58 (2006) 887-894.
Abdelbary M. Elhissi, Michael A. O’Neill, Simon A. Roberts, Kevin M. Taylor. A calorimetric study of dimyristoylphosphatidylcholine phase transitions and steroid-liposome interactions for liposomes prepared by thin film and proliposome methods. International Journal of Pharmaceutics, 320 (2006) 124-130.
Abdelbary M.A. Elhissi, Kevin M.G. Taylor. Delivery of liposomes generated from proliposomes using air-jet, ultrasonic, and vibrating-mesh nebulisers. Journal of Drug Delivery Science and Technology 15 (2005) 261-265.
Mukhtar H. Ahmed, J.A. Byrne, T.E. Keyes, Waqar Ahmed, Abdelbary Elhissi, Mark J. Jackson, Ejaz Ahmed B. Zakariya. Chapter 1: Characteristics and applications of titanium oxide as a biomaterial for medical implants. In: “The design and manufacture of medical devices”, ed. J.P. Davim, WoodHead, Cambridge, UK, in press
Waqar Ahmed, Abdelbary Elhissi, Mark J. Jackson, Ejaz Ahmed, B. Zakariya. Chapter 2: Precision machining of medical devices. In: “The design and manufacture of medical devices”, ed. J.P.Davim, WoodHead, Cambridge, UK, in press
Abdelbary Elhissi, Waqar Ahmed. Chapter 1: Advances in design and technology of devices manufactured for drug delivery applications. In: “Medical Device Manufacturing”, ed. M.J. Jackson, J.P. Davim, Nova Publishers, USA, 2011.
Tapas Sen, Sarah Sheppard, Tim Mercer, Abdelbary Elhissi. “Magnetoliposomes: Stability of magnetic nanoparticles in suspension for drug delivery” NSTI-Nanotech 2010, http://www.nsti.org., ISBN 978-1-4398-3401-5 Vol.1, 2010, page 924-927, CRC press, Taylor & Francis group.
Kevin M.G Taylor, Abdelbary M.A. Elhissi. Preparation of liposomes for delivery from medical nebulizers. Liposome Technology Volume I, 2007, Gregoriadis G., ed. Informa Healthcare, USA. pp67- 84.
Abdelbary M.A. Elhissi, Kevin M.G. Taylor, Waqar Ahmed. Nanocarrier Systems for Drug Delivery for the Treatment of Asthma. Lambert Academic Publishing: Germany; 2011.
J. Dyke, Abdelbary Elhissi, Paul Joyce, Peter Lumsden. Impact: Linking Teaching and Research, School of Pharmacy and Pharmaceutical Sciences- Published by Centre for Research Informed Teaching, University of Central Lancashire, UK (2010).
Chitosan is natural biodegradable polymer and highly mucoadhesion properties which are used to enhance the residence time of drug particles in the nasal cavity, until now the detail of degradation of chitosan microspheres have not been studied in detail. For this purpose four formulation of ropinirole loaded chitosan microspheres were prepared using Mini B-290 Buchi spray dryer in various drug to polymer ratio.
Summary by Sneha Subramanian – 22/06/2012
Current Drug Delivery, 2008, 5, 207-214 207
1567-2018/08 $55.00+.00 © 2008 Bentham Science Publishers Ltd.
Sanjay K. Jain*, Yashwant Gupta, Anekant Jain and Sadia Amin
In this experiment, elastic liposomes are used for the delivery of Meloxicam-β-Cyclodextrin vie skin.
Meloxicam has anti-inflammatory activity which is used for the treatment of ostereostasis and rheumatoid arthritis. This drug is poorly soluble in water; hence, its absorption from GI track is prolonged. This leads to many side effects like ulceration and bleeding. Cyclodextrin has hydrophobic central cavity and hydrophilic outer surface. They form inclusion complex with the drug and improves stability, solubility and dissolution rate of the drug. Recently various vesicles are used for the effective delivery of drug via Transdermal route, they include liposomes and niosomeswhich have their own mechanism to deliver drug. These vesicles are obstructed by the layer of the skin called stratum corneum which is very thick. Hence, a specialised vesicle which is elastic is developed to overcome this problem. They vary from liposomes and niosomes by their characterisctic fluid membrane and can easily pass through the tough stratum corneum. They have the ability to sqeeze and bend, hence, can pass though small intracellular space. Transdermal water gradient aids it in this movement of elastic liposomes. This work aims at he delivery of Meloxicam-β-Cyclodextrin complex along with the elastic vesicle to exploit the characteristics of both the carriers.
Meloxicam-β-Cyclodextrin complex was taken in the molar ratio 1:2. This complex was watted in water and was kneaded to paste. This method is called kneading method. This paste was stirred continuously till it peeled off the walls of the mortar. This preparation was then dried in rotary evaporator at 45° which was then sieved. The particles below 50-100µm was used for this experiment.
Solubility studies – This was carried out according to the method given by Higuchi and Connors. In this method excess amount of Meloxicam was transferred into 25ml of aqueous solution containing β –Cyclodextrin from 0-10M/L concentration. It is also shaken for 48hours at room temperature. After filtration, their spectrophotometric studies were carried out at 361nm to estimate the quantity of Meloxicam. Their mixtures were shaken till three consecutive samples estimated same amount of drug.
Differential scanning calorimetry – All samples were taken in 0.5-1mg size range and scanned in temperature 100-270°C/10°/min under nitrogen atmosphere.
X- ray powder Diffractometry (XRD) – was used for the interval of 10-60°/20. The conditions were taken as follows: voltage, 50 kV; current , 200mA; angular speed, 3°/min and angular step of 0.02°
FTIR studies – In this technique, the samples are vacuum drived for 12 hours before studies. The samples- Meloxicam, β-Cyclodextrin and Meloxicam-β-Cyclodextrin mixed with potassium bromine (100mg) and compressed with palate.
Elastic liposomes are prepared by conventional rotary evaporation sonication method. Here HSPC and span80 (85:15w/w) was taken in a clean dry round bottom flask. To this organic solvent- chloroform:methanol (2:1 v/v) was used to dissolve the lipid phase. This organic solvent was removed rotary evaporation above phase transition temperature. This thin film was hydrated with PBS (pH 6.5) containing Meloxicam/ Meloxicam-β-Cyclodextrin complex by rotation at 60rpm for 1hour at 55°C. This was kept for annealing for 2 hours to form multilamellar vesicles (MLVs) and was then was sonicated using probe sonicator for 20mins at 40W. This sonicated vesicles were extruded between 100-200nm polycarbonate membranes. The final lipid drug concentration was 5% wv and 1%wv and similarly Rhodaminered loaded elastic liposomes were prepared.
Morphology was visualised using TEM at voltage of 100KV. For this a drop of sample was kept of the carbon-coated copper and to leave a thin film and before drying was negatively stained with 1% PTA. After the sample was stained and dried and was viewed under TEM. The size and size distribution was determined using DLS method-dynamic light scattering . All measures were conducted in triplicates
Unentrapped drugs were separated using minicolumn centrifuge method. The separated liposomes were separated using 0.1% triton X-100 and was analysed for drug content at 361nm.
These elastic vesicles were extruded through the polycarbonate filter of 50nm diameter with 200ml capacity barrel at 2.5 bar pressure for 10mins. Vesicular sizes were compared before and after extrusion and were repeated.
The in-vitro studies were carried out using dialysis membrane and Franz diffusion cell.
The maximum drug solubility was at 4mM/L concentration of Meloxicam-β-Cyclodextrin. The stability constant (Kc) of Meloxicam and Meloxicam-β-Cyclodextrin complex was calculated
The thermal behaviour of Meloxicam and Meloxicam-β-Cyclodextrin was studies using DSC to confirm the formation of solid complex. The thermogram of Meloxicam-β-Cyclodextrin shows an endothermic peak at 173.8°C while the DSC pattern showed a very diminished melting endotherm of Meloxicam which was shifted to 249°C suggesting a complex formation in 1:2 molar ratio and indicating that the drug has been engulfed in the Cyclodextrin cavity.
The X-ray pattern of Meloxicam and β-Cyclodextrin are shown in the above figure.The XRD of pure of Meloxicam and β-Cyclodextrin are intense and sharp. Thus, inclusion complex indicates their crystalline nature. The inclusion complex shows a completly different pattern which cannot be distinguished from the peak of of Meloxicam. This confirms the existence of new compound at 1:2 molar ratio.
TEM revealed that they are unilamellar and spherical in shape. Precipitation of dry crystals was observed in drug loaded liposomes. This was due to the lower stability of the complex of Meloxicam with native cyclodextrin, part of the drug, less strongly complexed with Cyclodextrin was recrystalized in the aqueous solution during the elastic liposome preparation.
It is observed that the size of drug loaded liposome and empty liposome are almost similar. Larger vesicles are obtained in the presence of Meloxicam-β-Cyclodextrin complex. Polydispersion index is less than 1 indicating narrow size distribution of both formulations. After the entrapment studies , high entrapment of Meloxicam was observed due to its small size as compared to Meloxicam-β-Cyclodextrin complex. This may be due to the lower stability of the complex of Meloxicam with mature cyclodextrin.
The combined effect of using both elastic liposomes and cyclodextrin for Transdermal delivery was studies in this experiment Anti-inflamatory drug Meloxicam was used as a sample drug. Use of cyclodextrin increased the drug’s dissolution property. This increase in water solubility increased its entrapment in the internal aqueous phase of elastic vesicle. This in turn improved the permeability of drug through the skin.
This post by Iftikhar Khan
Corticosteroid drugs are oftenly used as a prophylaxis for asthmatic patients and the method of administration is m ore important for its proper activity. Beclomethasone dipropionate (BDP) produce s some systemic side effects like skin changes, adrenocortical suppression and cataract formation by using dry formulation. In addition, pulmonary delivery of BDP causes Candida infection. For minimising the side effect the drug formulation should be applied to the specific side of action. However, it was noticed that only 10% of the dry powder formulation reaches to the deep lung using Rotahaler, Spinhaler and Diskhaler because most of the drug deposit to the upper respiratory tract from where they swallowed and absorbed systemically through gastrointestinal tract (GIT). So, by preparing the better formulation and drug delivery method reduces most of the side effects. And in this experiment a drug Beclomethasone dipropionate (BDP) was mixed with carrier lactose in two different forms i.e. coarse and fine lactose. The formulation of all three content as a ternary mixture was checked for their homogeneity and with the delivery of BDP. And it was found that the combination of coarse lactose with fine lactose and BDP minimise the aggregation and maximise the dispersion. However, the controlled amounts of both lactose (CL and FL) play a key role in the flowability of powder, dispersion and stability of the powder formulation.
Coarse lactose (CL) was prepared using air jet sieve and the lactose particles were collected from 63- 90 um in size after 15 minutes of shaking. Air-jet mill was used for the micronisation of fine lactose (FL) and particle less than 63 um was passed once through the jet mill. Both the sample were collected and stored at 50 C for 24 hours and then placed in dedicator over silica gel to protect it from moisture and to use for further investigation. Particle size characterization was done by using Scanning electron microscopy (SEM), where sample was placed on the stub and then coated with gold. Six formulation were prepared using CL, FL and BDP altogether with different mixing sequence and using two different ratios i.e. 64.1 : 3.4 : 1 and 65.8 : 1.7 : 1 w/w. A Turbula mixer was used for powder mixing at 90-95 rpm. In each formulation the first two components were mixed for a predetermined time (15 or 60 minutes) and than a third ingredient was added and mixed for the same time (15 or 60 minutes) for both ratios. BDP and CL in an only ratio of 67.1 : 1 was used as control.
High performance liquid chromatography (HPLC) was used for the analysis of BDP. Methanol and water (7:3) ratio was used as a mobile phase with 0.8 ml/min of flow rate and UV detector was set at 239nm. A calibration curve was prepared from standard solution between 0.1-20.0 ug/ml in range. Each formulation containing a sample of 33 + mg was taken and assayed for by HPLC for the content of BDP.
Particle size of aerosolised BDP was measured using twin stage impinger (TI), a Rotahaler was used containing 33 + mg of powder as a delivery device. A mobile phase (7 ml) was placed in each of the upper and lower parts of the twin impinger. Capsule was placed in the Rotahaler and a rubber moulded mouthpiece was used to attach Rotahaler with throat piece of the impinger. A vacuum pump was set at 60 l/min of flow rate and the dose was released for 5 seconds under these conditions and re-run for the further 7 seconds. The same procedure was repeated for 5 capsules in total for each formulation. The capsule shells, mouth piece and the Rotahaler were washed with the mobile phase to analyse it for the retained amount of drug. The samples from both upper and lower parts of TI were collected and analysed using HPLC method.
In conclusion the addition of fine lactose to the mixture of BDP with coarse lactose as a binary mixture did not affect the mixing uniformity. The addition of BDP into the binary mixture of CL and FL (became ternary mixture) however showed a reduced in the homogeneity. And the presence of 2.5 % w/w fine lactose in the formulation exhibited an increase dispersion and deaggregation of BDP during aerosolization with an improved fine particle fraction (FPF) and fine particle dispersion (FPD). In addition, it was observed that 60 minutes mixing is better regardless of the mixing pattern of the ingredients than 15 minutes mixing.
Summary by Sneha Subramanian on the paper
Proniosomes used as a drug delivery
Proniosome is basically a dry formulation in which a carrier is coated with a suitable non-ionic surfactant (2000. Hu and Rhodes) and cholesterol (increase the rigidity of niosomal membrane) by dissolving them into an organic solvent. They can be prepared by slurry method using rotary evaporator. In this method a carrier (sucrose, lactose, trehalose and mannitol) is taken in a round bottom flask and a non-ionic surfactant (span 20, 60, 80) with cholesterol and drug (hydrophobic) is dissolved in organic solvent (ethanol or chloroform). Then this solvent is poured into the round bottom flask to make slurry, if the solvent is not enough to make slurry then extra organic solvent can be used to get the desire material. A vacuum and water bath is used in the rotary evaporator to evaporate the organic solvent and allow the solvent phase to make a layer of lipid phase over the carrier. The proniosome can be flushed with nitrogen to remove all the organic solvent. This method can be used to increase the stability of the formulation. Non-ionic surfactant are used instead of phospholipids to get the higher physical and chemical stability (2000. Hu and Rhodes). These substances are biodegradable, biocompatible and have low toxicity (2003. Youan) (2008. Abdelbary) for example sucrose stearate consists of both polar and non-polar group and the combination is due to the ester formation between these two molecules. Sucrose belongs to carbohydrates class and Stearate from fatty acid (palmitic, lauric, stearic acid). So, it acts the same as phospholipid and can entrapped both hydrophilic and lipophilic drugs (2008.Abdelbary).
It is converted into niosomal dispersion by hydration with aqueous solution before administration (2010. Sankar et al), (1998. Vora et al). Niosomes derived from Proniosomes are better (size distribution) than the niosomes prepared from conventional method (2010.Sudhamani.) (2010. Sankar et al). The Proniosomes-based niosomes are more stable both during storage and sterilization. Proniosomes decreases the problems associated with niosomes like fusion, aggregation and leakage of drug (2008.Abdelbary) (2000.Hu and Rhodes). Proniosomes (dry formulation) enhance the transportation, measurement, distribution and storage (2007. Solanki et al) (2010. Sudhamani), (2008. Abdelbary). And this is the property which makes it potentially more suitable for active pharmaceutical Ingredients (2007.Solanki).
One of the advantages is that proniosomes can be converted immediately into niosomes aerosol by hydration in hot water (2001a. Blazek), (2010. Sudhamani), (2007. Solanki.) and form multilamellar niosomes (2000. Hu and Rhodes.). Proniosomes act as a reservoir (carrier) and have been used for the targeted delivery to control the drug release and to achieve a prolong action. As proniosomes-derived niosomes have the ability to encapsulate both hydrophilic (within bilayer) and lipophilic (in central compartmental core) drug (2000.Hu and Rhodes.) so, verity of drug can be delivered to the targeted area (2010.Sudhamani).
The preparation of proniosomes and their evaluation was done by a number of authors (1998. Vora), (2000. Hu and Rhodes), (2001a and 2001 b. Blazek-welsh), (2001. Fang), (2005.Alsara), (2007. Gupta), (2007. Solanki), (2008. Azeem) and (2008. Abdelbary) for their different drug delivery system. Most of them used Proniosomes for the transdermal studies. Proniosomes are potentially very important because of their stability and large scale production. They were highly prepared for the transdermal application due to the non-toxicity and high penetration of non-ionic surfactant through skin (2010.Sankar. last conclusion). However, in future, they will be using for a verity of drug and target areas.
This is a post by Urwashi Sharad Naik on the paper:
Nanosized ethosmes bearing ketoprofen for improved transdermal delivery
Manish K. Chourasia, Lifeng Kang, Sui Yung Chan
Transdermal delivery of the drug provides excellent route of administration of the drug to enhance the oral absorption of the drug. Our human skin contains the major barrier called stratum corneum layer which is a greatest challenge for transdermal delivery of drugs. Various approaches have been adopted to pass this major barrier such as micro needles, chemicals, surfactants, iontophoresis, chemicals and lipid based systems. The lipid based systems are of the best mechanism to carry out transdermal drug delivery as the lipids are biocompatible to our skin lipids. Conventional liposomes are used for transdermal drug delivery. However, these conventional liposomes are unable to cross the major stratum corneum barrier due to which the drug is unable to delivery deep inside the skin. These conventional liposomes have been modified by introduction of two novel carriers called as transfersomes and ethosomes. Transfersomes are ultradeformable lipid vesicles which consist of one layer of phospholipid and other layer of surfactants which allows them to squeeze through the stratum corneum layer and enhances the transdermal delivery of the drug. One the other hand, ethosomes are the vesicles contain higher concentration of the ethanol which acts as penetration enhancer allowing them to be more flexible than liposomes. The preparations of ethosomes are similar to liposomes but in liposomal preparation cholesterol and phospholipids are present but in ethosomes higher concentration of ethanol is present in place of cholesterol. As reported by Elsayed et al., ethosomes seems to be more superior than tansferosomes with respect to increase the permeability of entrapped ketotifen.
Ketotifen is non-steroidal anti-inflammatory drug. This drug have been tried to pass through other modes of transdermal delivery such as gels/patches which are available in the market. However, the drug delivery has been poorly observed previously. In this experiment, ketotifen have been entrapped in the ethosomal bilayer and the invitro and invivo transdermal delivery of this drug have been studied using varies techniques of characterization such as laser diffraction, zeta charger, HPLC (for drug entrapment), confocal laser scanning microscopy and micro column centrifugation. The in vivo studies were performed using the skin samples of female adult mice.
For in vitro studies, the experimental procedure was setup by placing the cellophone membrane dialysis tubing with both the ends sealed and suspended into a beaker containing PBS solution (pH 7.4)of 100 ml at 37 ± 1 ᵒC. The buffer of the solution was stirred at 45 mins intervals and sample was collected at 24,6,8,10,12,18 and 24 hr time intervals by replacing with equal quantities of fresh buffer and drug contain was analysed using HPLC. Different ethosomal formutions were evaluated for drug release and compared with hydroaloholic drug solutions.
For in vitro studies, the permeation was checked through diffusion cell system consisting of 16 channel peristaltic cassette pump, a circulating water bath, a fraction collector and flow through diffusion cells. Adult Chinese female skin was used in the experiment, the skin was thawed and hydrated with saline solution containing 1% v/v antibiotic antimitotic solution. For experiment the skin was immersed into water bath (60ᵒC) for 2 mins, peeled off and then stored at -80ᵒC.The receptor solution was pumped into the peristaltic cassette continuously through receptor compartment and drained into sample collection tubes. Sample collection was performed at various time intervals.
Penetration of ethosomes were confirmed using confocal laser scanning microscopy. The formulations were loaded with dye called fluorescent probe Rhodamine 123 insread of ketoprofen. Skin sample was mounted between the donar and the receiver compartment and either 1 ml of either hydroalcoholic probe solution was placed in the donar compartment and covered with paraflim to prevent contamination and evaporation at 37oC. Skin was removed and washed after 4 hours and scanned at different increments through Z- axis of confocal laser scanning microscopy.
Drug quantitative studies was performed using HPLC using C18 column (Agilent, 5µm 4.0 x 250 mm) and using a mobile phase of phosphate buffer (pH 3.5) and acetonitrile in ratio of 50:50 at wavemenght 254 nm. The experiments were statistically performed using ANOVA. at p < 0.05 with mean ± standard deviation. The size of the vesicles were seems to be decrease with increase in concentration of alcohol contained. Higher concentration of ethanol confers net negative charges to the vesicular systems. As the keptoprofen is hydrophobic drug, it was expected to be encapsulated within the non-polar region of the bilayer as the bilayer amount increases the drug holding capacity also increases.
|SPC (1%)||Ethanol (20%)||42.9 ±3.7 %|
|(3%)||Ethanol (20%)||63.1 ±5.8 % SPC|
Entrapment efficiency of vesicles
The above table show that the entrapment efficiency of the vesicles increases with increase in phospholipid concentration even though keeping the concentration of the alcohol constant.
In vitro drug release through cellophane membrane shows that the hydroacoholic drug release was 3-4 hours slower than the drug release from the ethosomal preparation indicating that the drug diffusion in ethosomes is rate limiting step. The increase drug release may be due to increase in alcohol contain within the bilayer membrane.