Conventional drug delivery systems are known to provide an immediate release of drug, in which one can not control the release of the drug and can not maintain effective concentration at the target site for longer time. Controlled drug delivery systems offer spatial control over the drug release. Osmotic pumps are most promising systems for controlled drug delivery. These systems are used for both oral administration and implantation. Osmotic pumps consist of an inner core containing drug and osmogens, coated with a semipermeable membrane. As the core absorbs water, it expands in volume, which pushes the drug solution out through the delivery ports. Osmotic pumps release drug at a rate that is independent of the pH and hydrodynamics of the dissolution medium. The historical development of osmotic systems includes development of the Rose-Nelson pump, the Higuchi-Leeper pumps, the Alzet and Osmet systems, the elementary osmotic pump, and the push-pull system. Recent advances include development of the controlled porosity osmotic pump, and systems based on asymmetric membranes. This paper highlights the principle of osmosis, materials used for fabrication of pumps, types of pumps, advantages, disadvantages, and marketed products of this system. 1. Introduction The pharmaceutical field over the past decade has faced continuing challenges in bringing new drug entity to market. In addition, the cost of developing new drug entity keeps rising and today stands at more than US$ 800？M per new drug entity. Drug delivery research continues to find new therapies for the prevention and treatment of exiting and new diseases. So, a valuable role is played by drug delivery system by providing optimized products for existing drugs in terms of either enhanced or improved presentation of drug to the systemic circulation [1, 2]. Treatment of an acute disease or a chronic illness has been mostly accomplished by delivery of drugs to patients using various pharmaceutical dosage forms. Traditionally, the oral drug delivery has been most widely utilized route of administration among all the routes that have been explored for the systemic delivery of drugs. Conventional oral drug delivery systems are known to provide an immediate release of drug, in which one cannot control the release of the drug and cannot maintain effective concentration at the target site for longer period of time. The oral bioavailability of some drug by conventional drug delivery is very low due to presence of food, in stabilization at pH of the GI tract, degradation by enzymes of GI fluid, change in GI
References
[1]
L. F. Prescott, “The need for improved drug delivery in clinical practice,” in Novel Drug Delivery and Its Therapeutic application, pp. 1–11, John Wiley and Sons, West Susset, UK, 1989.
[2]
R. K. Verma and S. Garg, “Current status of drug delivery technologies and future directions,” Pharmaceutical Technology, vol. 25, no. 2, pp. 1–14, 2001.
[3]
P. Dwarakanadha Reddy and D. Swarnalatha, “Recent Advances in Novel Drug Delivery systems,” International Journal of PharmTech Research, vol. 2, no. 3, pp. 2025–2027, 2010.
[4]
S. K. Rastogi, N. Vaya, and B. Mishra, “Osmotic pump: a novel concept in rate controlled oral drug delivery,” Eastern Pharmacist, vol. 38, pp. 79–82, 1995.
[5]
R. W. Banker, Control Release of Biologically Active Agent, John Wiley and Son, New York, NY, USA, 1987.
[6]
Y. W. Chein, Novel Drug Delivery System, Marcel Dekker, New York, NY, USA, 2nd edition, 2005.
[7]
R. Jerzewski and Y. Chien, “Osmotic drug delivery,” in Treatise on Controlled Drug Delivery: Fundamentals, Optimization, Application, pp. 225–253, Marcel Dekker, 1992.
[8]
B .S. Rao, N. R. Kumar, K. Madhuri, P. S. Narayan, and K. V. R. Murthy, “Osmotic drug delivery systems,” The Eastern pharmacist, vol. 521, pp. 21–28, 2001.
[9]
R. K. Verma, D. M. Krishna, and S. Garg, “Formulation aspects in the development of osmotically controlled oral drug delivery systems,” Journal of Controlled Release, vol. 79, no. 1–3, pp. 7–27, 2002.
[10]
G. Santus and R. W. Baker, “Osmotic drug delivery: a review of the patent literature,” Journal of Controlled Release, vol. 35, no. 1, pp. 1–21, 1995.
[11]
R. K. Verma and S. Garg, “Development and evaluation of osmotically controlled oral drug delivery system of glipizide,” European Journal of Pharmaceutics and Biopharmaceutics, vol. 57, no. 3, pp. 513–525, 2004.
[12]
B. Eckenhoff, F. Theeuwes, and J. Urquhart, “Osmotically actuated dosage forms for rate-controlled drug delivery,” Pharmaceutical Technology, vol. 5, no. 1, pp. 35–44, 1981.
[13]
A. G. Thombre, L. E. Appel, M. B. Chidlaw et al., “Osmotic drug delivery using swellable-core technology,” Journal of Controlled Release, vol. 94, no. 1, pp. 75–89, 2004.
[14]
A. M. Kaushal and S. Garg, “An update on osmotic drug delivery patents,” Pharmaceutical Technology, pp. 38–44, 2003.
[15]
X. Li and B. R. Jasti, “Osmotic controlled drug delivery systems,” in Design of Controlled Release of Drug Delivery Systems, pp. 203–229, McGraw Hill, 2006.
[16]
S. Rose and J. F. Nelson, “A continuous long-term injector,” The Australian Journal of Experimental Biology and Medical Science, vol. 33, no. 4, pp. 415–419, 1955.
[17]
T. Higuchi, “Osmotic dispenser with collapsible supply container,” US Patent No. 3, 760,805, 1973.
[18]
J. W. Fara, “Osmotic delivery systems for research,” Methods in Enzymology, vol. 112, pp. 470–484, 1985.
[19]
F. Theeuwes, “Elementary osmotic pump,” Journal of Pharmaceutical Sciences, vol. 64, no. 12, pp. 1987–1991, 1975.
[20]
R. Cortese and F. Theeuwes, “Osmotic device with hydrogel driving member,” US Patent No. 4, 327,725, 1982.
[21]
G. M. Zentner, G. A. McClelland, and S. C. Sutton, “Controlled porosity solubility- and resin-modulated osmotic drug delivery systems for release of diltiazem hydrochloride,” Journal of Controlled Release, vol. 16, no. 1-2, pp. 237–244, 1991.
[22]
A. G. Thombre, G. M. Zentner, and K. J. Himmelstein, “Mechanism of water transport in controlled porosity osmotic devices,” Journal of Membrane Science, vol. 40, no. 3, pp. 279–310, 1989.
[23]
S. M. Herbig, J. R. Cardinal, R. W. Korsmeyer, and K. L. Smith, “Asymmetric-membrane tablet coatings for osmotic drug delivery,” Journal of Controlled Release, vol. 35, no. 2-3, pp. 127–136, 1995.
[24]
A. G. Thombre, J. R. Cardinal, A. R. DeNoto, S. M. Herbig, and K. L. Smith, “Asymmetric membrane capsules for osmotic drug delivery. I. Development of a manufacturing process,” Journal of Controlled Release, vol. 57, no. 1, pp. 55–64, 1999.
[25]
A. G. Thombre, A. R. DeNoto, and D. C. Gibbes, “Delivery of glipizide from asymmetric membrane capsules using encapsulated excipients,” Journal of Controlled Release, vol. 60, no. 2-3, pp. 333–341, 1999.
[26]
B. Lindstedt, G. Ragnarsson, and J. Hjartstam, “Osmotic pumping as a release mechanism for membrane-coated drug formulations,” International Journal of Pharmaceutics, vol. 56, no. 3, pp. 261–268, 1989.
[27]
L. A. Seminoff and G. M. Zentner, “Cellulosic coating,” US patent 5,126,146, 1992.
[28]
J. L. Jensen, L. E. Appel, J. H. Clair, and G. M. Zentner, “Variables that affect the mechanism of drug release from osmotic pumps coated with acrylate/methacrylate copolymer latexes,” Journal of Pharmaceutical Sciences, vol. 84, no. 5, pp. 530–533, 1995.
[29]
G. M. Zentner, G. S. Rork, and K. J. Himmelstein, “The controlled porosity osmotic pump,” Journal of Controlled Release, vol. 1, no. 4, pp. 269–282, 1985.
[30]
L. Dong, K. Shafi, J. Wan, and P. A. Wong, “novel osmotic delivery system: L-OROS Soft cap,” in Proceedings of the International Symposium on controlled Release of Bioactive Materials, Paris, France, 2000.
[31]
N. S. Parmar and S. K. Vyas, Advances in Controlled and Novel Drug Delivery, CBS, 2008.
[32]
T. Ghosh and A. Ghosh, “Drug delivery through osmotic systems—an overview,” Journal of Applied Pharmaceutical Science, vol. 2, pp. 38–49, 2011.
[33]
E. M. Rudnic, B. A. Burnside, H. H. Flanner, et al., Patent 6,110,498, 2000.
[34]
S. Gupta, R. P. Singh, R. Sharma, R. Kalyanwat, and P. Lokwani, Osmotic Pumps: A Review, vol. 1, no. 6, Pharmacie Globale (IJCP), 2011.
[35]
G. A. McClelland, S. C. Sutton, K. Engle, and G. M. Zentner, “The solubility-modulated osmotic pump: in vitro/in vivo release of diltiazem hydrochloride,” Pharmaceutical Research, vol. 8, no. 1, pp. 88–92, 1991.
[36]
R. L. Jerzewski and Y. W. Chien, “Osmotic drug delivery,” in Treatise on Controlled Drug Delivery: Fundamentals, Optimization, Application, A. Kydonieus, Ed., pp. 225–253, Marcel Dekker, New York, NY, USA, 1992.
[37]
J. H. Guo, “Effects of plasticizers on water permeation and mechanical properties of cellulose acetate: antiplasticization in slightly plasticized polymer,” Drug Development and Industrial Pharmacy, vol. 19, no. 13, pp. 1541–1555, 1993.
[38]
C. Bindschaedler, R. Gurny, and E. Doelker, “Mechanically strong films produced from cellulose acetate latexes,” Journal of Pharmacy and Pharmacology, vol. 39, no. 5, pp. 335–338, 1987.
[39]
J. H. Guo, “An investigation into the formation of plasticizer channels in plasticized polymer films,” Drug Development and Industrial Pharmacy, vol. 20, no. 11, pp. 1883–1893, 1994.
[40]
G. M. Zentner, G. S. Rork, and K. J. Himmelstein, “Osmotic flow through controlled porosity films: an approach to delivery of water soluble compounds,” Journal of Controlled Release, vol. 2, pp. 217–229, 1985.
[41]
G. M. Zentner, G. S. Rork, and K. J. Himmelstein, “Controlled porosity osmotic pump,” US patent 4,968,507, 1990.
[42]
M. Kelbert and S. R. Bechard, “Evaluation of a cellulose acetate (CA) latex as coating material for controlled release products,” Drug Development and Industrial Pharmacy, vol. 18, no. 5, pp. 519–538, 1992.
[43]
R. K. Verma and B. Mishra, “Studies on formulation and evaluation of oral osmotic pumps of nimesulide,” Pharmazie, vol. 54, no. 1, pp. 74–75, 1999.
[44]
F. Theeuwes, R. J. Saunders, and W. S. Mefford, “Process for forming outlet passageways in pills using a laser,” US patent No. 4088864, 1978.
[45]
C. Chen, D. Lee, and J. Xie, “Controlled release formulation for water insoluble drugs in which a passageway is formed in situ,” US patent No. 5736159, 1998.
[46]
T. Higuchi and H. M. Leeper, “Osmotic disperser,” US Patent No. 3732865, 1973.
[47]
T. Higuchi and H. M. Leeper, “Improved osmotic dispenser employing magnesium sulfate and magnesium chloride,” US Patent No. 3760804, 1973.
[48]
L. Liu, J. Ku, G. Khana, B. Lee, J. M. Rhee, and H. B. Lee, “Development of new trend of pulsatile drug delivery,” Journal of Controlled Release, vol. 68, pp. 145–156, 2000.
[49]
T. Higuchi and H. M. Leeper, “Osmotic dispenser with means for dispensing active agent responsive to osmotic gradient,” US Patent No. 3995631, 1976.
[50]
F. Theeuwes and S. I. Yum, “Principles of the design and operation of generic osmotic pumps for the delivery of semisolid or liquid drug formulations,” Annals of Biomedical Engineering, vol. 4, no. 4, pp. 343–353, 1976.
[51]
F. Theeuwes, “Osmotic system for delivering selected beneficial agents having varying degrees of solubility,” US Patent No. 4111201, 1978.
[52]
P. S. I. Wong, B. Barclay, J. C. Deters, and F. Theeuwes, “Osmotic device with dual thermodynamic activity,” US Patent 4612008, 1986.
[53]
D. Ouyang, S. Nie, W. Li, H. Guo, H. Liu, and W. Pan, “Design and evaluation of compound metformin/glipizide elementary osmotic pump tablets,” Journal of Pharmacy and Pharmacology, vol. 57, no. 7, pp. 817–820, 2005.
[54]
J. L. Haslam and G. S. Rork, “Controlled Porosity Osmotic Pump,” U.S. Patent No. 4880631, 1989.
[55]
L. Liu, J. Ku, G. Khang, B. Lee, J. M. Rhee, and H. B. Lee, “Nifedipine controlled delivery by sandwiched osmotic tablet system,” Journal of Controlled Release, vol. 68, no. 2, pp. 145–156, 2000.
[56]
R. Kumaravelrajan, N. Narayanan, and V. Suba, “Development and evaluation of controlled porosity osmotic pump for Nifedipine and Metoprolol combination,” Lipids in Health and Disease, vol. 10, article 51, 2011.
[57]
L. Dong, K. Shafi, J. Wan, and P. Wong, “A novel osmotic delivery system: L-OROS Soft cap,” in Proceedings of the International Symposium on controlled Release of Bioactive Materials, Paris, France, 2000.
[58]
G. M. Zentner, G. S. Rork, and K. J. Himmelstein, “The controlled porosity osmotic pump,” Journal of Controlled Release, vol. 1, no. 4, pp. 269–282, 1985.
[59]
C. Ajay Babu, M. Prasada Rao, and J. Vijaya Ratna, “Controlled-porosity osmotic pump tablets-an overview,” Journal of Pharmaceutical Research and Health Care, vol. 2, no. 1, pp. 114–126, 2010.
[60]
R. Kumaravelrajan, N. Narayanan, V. Suba, and K. Bhaskar, “Simultaneous delivery of Nifedipine and Metoprolol tartarate using sandwiched osmotic pump tablet system,” International Journal of Pharmaceutics, vol. 399, no. 1-2, pp. 60–70, 2010.
