Liquid loadable tablets of neusilin® us2 - a new approach to tabletting lipid formulations, the case of cyclosporine a
Liquid loadable tablets of Neusilin® US2 - A new approach to tabletting lipid formulations, the case of Cyclosporine A "The liquid loadable tablets of Neusilin® US2 was able to absorb up to 2.2 ml/g of Cyclosporine A in lipid formulation according to a new study by Camilla Sander and Per Holm (2009). Furthermore, bioavailability of Cyclosporine A from liquid loadable tablets of Neusilin® US2 was almost equal with soft gelatin and hard gelatin capsule formulations."
Are you facing the chal enges of converting SMEDDS/SEDDS formulations into oral solid dosageforms? A simple way to achieve could be through liquid loadable tablets of Neusilin® US2. Introduction The transformation of self-micro emulsifying drug delivery systems (SMEDDS) or lipid formulations into a solid dosage form can be carried out by capsule fil ing, spray drying, adsorption on to solid carriers, and melt granulation as wel as other techniques. Among these techniques, capsule fil ing and absorption on to solid carrier techniques are more popular. However, the capsule fil ing techniques are usual y associated with some problems such as leaking, leaching of liquid through the capsule shel , and incompatibilities with capsule materials. On the other hand, adsorption onto solid carrier techniques also has some concerns such as large amount of carrier required or large dosage volume, sticking, liquid exudation, and low tablet hardness. In a new study by Camil a Sander and Per Holm (2009), Cyclosporine A (CyA) SMEDDS with Neusilin® was used as a drug model for liquid loadable tablets (LLT). Placebo tablets of Neusilin® US2 (Magnesium Aluminometasilicate or MAMS) prepared by direct compression was loaded with CyA-SMEDDS to prepare liquid loadable tablets. This is a novel approach to transform liquid lipid formulations into solid dosage forms [1].
Fig.1 Preparation of liquid loadable tablets
Cyclosporin A is an immunosuppressant drug widely used in post-al ogeneic organ transplant to reducethe activity of the patient's immune system. Cyclosporine A exhibits very poor solubility in water, and,as a consequence, suspension and emulsion forms of the drug have been developed for oraladministration and for injection. Experimental methods The test formulations are showed in Table 1. The LLTs of approximately 250 mg were made by direct compression of Neusilin® US2 with and without crospovidone, assigned as LLT-2 and LLT-1, respectively (Fig.1). The composition of LLT-1 (F2) was MAMS/Magnesium stearate (99:1w/w%), whereas the composition of LLT-2 (F6) was MAMS/Crospovidone/Magnesium stearate (89:10:1w/w%). The placebo tablets with hardness above 50 N and porosity of approximately 80% were achieved at compression forces around 15-22 MPa with conventional tabletting equipments. The LLTs were placed in excess of CyA-SMEDDS and allowed to absorb until constant tablet weight was reached. Excess liquid on the surface was removed by tissue paper. The tablets were dried by storage for few hours. No leaking was observed. Bioavailability tests were carried out using beagle dogs. Table1. Test formulations
CyA-SMEDDS and filled hard gelatincapsule
Results The volume-based loading capacity of the LLTs was found to be comparable to soft gelatin capsule and hard gelatin capsules, 458.3 mg and 250.5 mg of CyA-SMEDDS for LLT-1 and LLT-2, respectively. Addition of 10% disintegrant into LLT-2 improved the dissolution rate markedly to approximately 50% in comparison with dissolution rate of LLT-1. The LLTs of Neusilin® US2 were able to absorb up to 2.2 ml/g of CyA-SMEDDS. Bioavailability of CyA from LLT-2 (F6) was almost equal with soft gelatin capsule (F3, Neoral® from Novartis Healthcare A/S) and hard gelatin capsule (F5, Capsugel, Pfizer Inc.). Notably, formulation F5 using Neusilin® US2 as adsorption carrier of CyA-SMEDDS had the same bioavailability to that of soft gelatin capsule (F3) (Table 2).
Neusilin® US2 with large specific surface area (≈300 m2/g) and high adsorption capacity (≈3 ml/g) hasproved to be an excel ent excipient for manufacturing LLTs of SMEDDS formulations. In addition,Neusilin® US2 could also be used as an adsorbent carrier to prepare hard gelatin capsules toovercome the problems such as leaking, leaching of liquid through the capsule shell, or incompatibilitieswith capsule materials. Table2. Mean pharmacokinetic parameters after single-dose administration of CyA in dog *: Relative bioavailability is compared with Neoral® F3 Conclusions The study showed successful approach using Neusilin® US2 as a suitable adsorption carrier for liquid loadable tablets to transform SMEDDS into solid dosage forms, as wel as for hard gelatin capsules. In the case of CyA, the LLTs of Neusilin® US2 demonstrated some advantages:
Consistent content of CyA, high tablet hardness, and high loading capacity were achieved. Bioavailability of CyA from the LLTs was comparable to bioavailability from capsules.
The LLTs were easily prepared by direct compression with conventional tabletting equipments. No leaking of the liquid content on the surface of the LLTs. The manufacturing process can easily be scaled up.
In conclusion, the LLT technology can be a promising approach to achieve oral solid dosage formsfrom liquid lipid formulations. Reference 1. Sander C, Holm P. Porous magnesium aluminometasilicate tablets as carrier of a cyclosporine self-emulsifying formulation. AAPS PharmSciTech. 2009. 10:1388-95
Neusilin® is a trademark or registered trademark of Fuji Chemical Industry Co., Ltd in Japan, United States
of America, Europe and/or other countries.
To ensure to receive this newsletter in your inbox, please add [email protected] to your address book.
The information found in this publication is presented in good faith with no guarantee or obligation as to accuracy and noassumption of liability. Users should make their own tests to determine the suitability of these products for their own particularpurposes. However, because of numerous factors affecting results, Fuji Chemical Industry makes no warranty of any kind, expressor implied, including those of merchantability and fitness for particular purpose other than the material conforms to its applicablecurrent standard specifications. Statements concerning the use of the products or formulations described herein are not to beconstrued as recommending the infringement of any patent and seller assumes no liability for the infringement arising out of suchuse.
®2011 - Fuji Chemical Industry Co., Ltd. - All Rights Reserved
Michael Anderson is a registered Psychologist in private practice in Torquay, Victoria. He has been practicing mindfulness meditation consistently since 1987. In 1990 he became increasingly interested in Buddhism and mindfulness practice, and has from this time worked to integrate Western psychology and Without a personal practice of mindfulness Mindfulness mindfulness
H.E. Professor Olugbemiro Jegede Secretary General Association of African Universities (AAU) Accra – GHANA An invited Keynote Speech at the Special Congregation for the Award of First and Higher Degrees and the Presentation of Prizes of the 6th Convocation Ceremony Holding at Covenant University, Ota, Nigeria on Friday July 22, 2011 Page 1 of 11 Introductio