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Singh S, Aparna, Sharma N, Gupta J, Kyada A, Nathiya D, Behl T, Gupta S, Anwer MK, Gulati M, Sachdeva M. Application of nano- and micro-particle-based approaches for selected bronchodilators in management of asthma. 3 Biotech 2024; 14:208. [PMID: 39184911 PMCID: PMC11343956 DOI: 10.1007/s13205-024-04051-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2024] [Accepted: 08/09/2024] [Indexed: 08/27/2024] Open
Abstract
Asthma is a chronic inflammatory condition that affects the airways, posing a substantial health threat to a large number of people worldwide. Bronchodilators effectively alleviate symptoms of airway obstruction by inducing relaxation of the smooth muscles in the airways, thereby reducing breathlessness and enhancing overall quality of life. The drug targeting to lungs poses significant challenges; however, this issue can be resolved by employing nano- and micro-particles drug delivery systems. This review provides brief insights about underlying mechanisms of asthma, including the role of several inflammatory mediators that contribute to the development and progression of this disease. This article provides an overview of the physicochemical features, pharmacokinetics, and mechanism of action of particular groups of bronchodilators, including sympathomimetics, PDE-4 inhibitors (phosphodiesterase-4 inhibitors), methylxanthines, and anticholinergics. This study presents a detailed summary of the most recent developments in incorporation of bronchodilators in nano- and micro-particle-based delivery systems which include solid lipid nanoparticles, bilosomes, novasomes, liposomes, polymeric nano- and micro-particles. Specifically, it focuses on breakthroughs in the categories of sympathomimetics, methylxanthines, PDE-4 inhibitors, and anticholinergics. These medications have the ability to specifically target alveolar macrophages, leading to a higher concentration of pharmaceuticals in the lung tissues.
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Affiliation(s)
- Sukhbir Singh
- Department of Pharmaceutics, MM College of Pharmacy, Maharishi Markandeshwar (Deemed to Be University), Mullana-Ambala, 133207 Haryana India
| | - Aparna
- Department of Pharmaceutics, MM College of Pharmacy, Maharishi Markandeshwar (Deemed to Be University), Mullana-Ambala, 133207 Haryana India
| | - Neelam Sharma
- Department of Pharmaceutics, MM College of Pharmacy, Maharishi Markandeshwar (Deemed to Be University), Mullana-Ambala, 133207 Haryana India
| | - Jitendra Gupta
- Institute of Pharmaceutical Research, GLA University, Mathura, 281406 Uttar Pradesh India
| | - Ashishkumar Kyada
- Department of Pharmacy, Faculty of Health Sciences, Marwadi University Research Center, Marwadi University, Rajkot, 360003 Gujarat India
| | - Deepak Nathiya
- Department of Pharmacy Practice, Institute of Pharmacy, NIMS University, Rajasthan, Jaipur India
| | - Tapan Behl
- Amity School of Pharmaceutical Sciences, Amity University, Punjab, India
| | - Sumeet Gupta
- Department of Pharmaceutics, MM College of Pharmacy, Maharishi Markandeshwar (Deemed to Be University), Mullana-Ambala, 133207 Haryana India
| | - Md. Khalid Anwer
- Department of Pharmaceutics, College of Pharmacy, Prince Sattam Bin Abdulaziz University, 11942 Alkharj, Saudi Arabia
| | - Monica Gulati
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, 1444411 Punjab India
- Faculty of Health, ARCCIM, University of Technology Sydney, Ultimo, NSW 20227 Australia
| | - Monika Sachdeva
- Fatima College of Health Sciences, Al Ain, United Arab Emirates
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Çiçek Kırkayak N, Kondolot Solak E. Controlled release of theophylline from ethyl cellulose coated PVA/NaCMC-theophylline microspheres. INT J POLYM MATER PO 2022. [DOI: 10.1080/00914037.2022.2063288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
| | - Ebru Kondolot Solak
- Department of Advanced Technologies, Gazi University, Ankara, Turkey
- Department of Chemistry and Chemical Processing Technologies, Technical Sciences Vocational School, Gazi University, Ankara, Turkey
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3
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Karavana SY, Şenyiğit ZA, Çalışkan Ç, Sevin G, Özdemir Dİ, Erzurumlu Y, Şen S, Baloğlu E. Gemcitabine hydrochloride microspheres used for intravesical treatment of superficial bladder cancer: a comprehensive in vitro/ex vivo/in vivo evaluation. Drug Des Devel Ther 2018; 12:1959-1975. [PMID: 29997433 PMCID: PMC6033088 DOI: 10.2147/dddt.s164704] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
INTRODUCTION Bladder cancer is responsible for more than 130,000 deaths annually worldwide. Intravesical delivery of chemotherapeutic agents provides effective drug localization to the target area to reduce toxicity and increase efficacy. This study aimed to develop an intravesical delivery system of gemcitabine HCl (Gem-HCl) to provide a sustained-release profile, to prolong residence time, and to enhance its efficiency in the treatment of bladder cancer. MATERIALS AND METHODS For this purpose, bioadhesive microspheres were successfully prepared with average particle size, encapsulation efficiency, and loading capacity of 98.4 µm, 82.657%±5.817%, and 12.501±0.881 mg, respectively. For intravesical administration, bioadhesive microspheres were dispersed in mucoadhesive chitosan or in situ poloxamer gels and characterized in terms of gelation temperature, viscosity, mechanical, syringeability, and bioadhesive and rheological properties. The cytotoxic effects of Gem-HCl solution, Gem-HCl microspheres, and Gem-HCl microsphere-loaded gel formulations were evaluated in two different bladder cancer cell lines: T24 (ATCC HTB4TM) and RT4 (ATCC HTB2TM). RESULTS According to cell-culture studies, Gem-HCl microsphere-loaded poloxamer gel was more cytotoxic than Gem-HCl microsphere-loaded chitosan gel. Antitumor efficacy of newly developed formulations were investigated by in vivo studies using bladder-tumor-induced rats. CONCLUSION According to in vivo studies, Gem-HCl microsphere-loaded poloxamer gel was found to be an effective and promising alternative for current intravesical delivery-system therapies.
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MESH Headings
- Administration, Intravesical
- Animals
- Antimetabolites, Antineoplastic/administration & dosage
- Antimetabolites, Antineoplastic/chemistry
- Antimetabolites, Antineoplastic/therapeutic use
- Cell Line, Tumor
- Deoxycytidine/administration & dosage
- Deoxycytidine/analogs & derivatives
- Deoxycytidine/chemistry
- Deoxycytidine/therapeutic use
- Drug Compounding
- Humans
- In Vitro Techniques
- Microscopy, Electron, Scanning
- Microspheres
- Neoplasms, Experimental/drug therapy
- Neoplasms, Experimental/pathology
- Particle Size
- Rats
- Rats, Sprague-Dawley
- Rheology
- Urinary Bladder Neoplasms/drug therapy
- Urinary Bladder Neoplasms/pathology
- Viscosity
- Gemcitabine
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Affiliation(s)
- Sinem Yaprak Karavana
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Ege University, Izmir, Turkey,
| | - Zeynep Ay Şenyiğit
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Izmir Katip Çelebi University, Izmir, Turkey
| | - Çağrı Çalışkan
- Department of Radiopharmacy, Faculty of Pharmacy, Ege University, Izmir, Turkey
| | - Gülnur Sevin
- Department of Pharmacology, Faculty of Pharmacy, Ege University, Izmir, Turkey
| | - Derya İlem Özdemir
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Izmir Katip Çelebi University, Izmir, Turkey
| | - Yalçın Erzurumlu
- Department of Biochemistry, Faculty of Pharmacy, Ege University, Izmir, Turkey
| | - Sait Şen
- Department of Pathology, Faculty of Medicine, Ege University, Izmir, Turkey
| | - Esra Baloğlu
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Ege University, Izmir, Turkey,
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4
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Bettencourt A, Almeida AJ. Poly(methyl methacrylate) particulate carriers in drug delivery. J Microencapsul 2012; 29:353-67. [PMID: 22251239 DOI: 10.3109/02652048.2011.651500] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Poly(methyl methacrylate) (PMMA) is one of the most widely explored biomedical materials because of its biocompatibility, and recent publications have shown an increasing interest in its applications as a drug carrier. PMMA-based particulate carriers (PMMA(P)) can be prepared either by polymerization methods or from pre-formed polymer-based techniques. Potential biomedical application of these particles includes their use as adjuvant for vaccines and carrier of many drugs as antibiotics and antioxidants via different routes of administration. Release of drugs from PMMA(P) occurs typically in a biphasic way with an incomplete drug release. To improve release profiles, recent strategies are focusing on increasing polymer hydrophilicity by synthesizing functionalized PMMA microspheres or by formulating PMMA composites with hydrophilic polymers. This review examines the current status of preparation techniques, drug release kinetics, biomedical applications and toxicity of these nano/micro PMMA-based particulate carriers.
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Affiliation(s)
- Ana Bettencourt
- Faculty of Pharmacy, Research Institute for Medicines and Pharmaceutical Sciences-iMed.UL, University of Lisbon , Av. Prof. Gama Pinto, 1649-003 Lisbon, Portugal.
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5
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Thakare M, Israel B, Garner ST, Ahmed H, Garner P, Elder D, Price JC, Capomacchia AC. Formulation parameters and release mechanism of theophylline loaded ethyl cellulose microspheres: effect of different dual surfactant ratios. Pharm Dev Technol 2011; 18:1213-9. [DOI: 10.3109/10837450.2011.620969] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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6
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Derakhshandeh K, Fashi M, Seifoleslami S. Thermosensitive Pluronic hydrogel: prolonged injectable formulation for drug abuse. DRUG DESIGN DEVELOPMENT AND THERAPY 2010; 4:255-62. [PMID: 20957216 PMCID: PMC2948935 DOI: 10.2147/dddt.s13289] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2010] [Indexed: 12/03/2022]
Abstract
Objective: The main objective of this study was to investigate thermosensitive Pluronic® F-127 (PF-127) hydrogel for the modified release of a potent alcohol and opioid antagonist, naltrexone (NTX) hydrochloride, in a subcutaneous injectable dosage form. Methods: The NTX hydrogels were prepared by the cold method, and the in vitro release profiles of various formulations were evaluated at 37°C using the Franz diffusion cell system. We examined the different PF-127 concentrations, pH of solution, and inorganic salts on drug release from these gels. Results: The data showed an increase in PF-127 content from 20% to 35%, resulting in a decrease in the rate of NTX release. Among the formulations prepared in different pH solutions, pH 7.4 produced the slowest drug release rate. The addition of inorganic salts had no significant effect on drug release. However, these factors appeared to have limited effects on drug release rate. Therefore, to achieve a sustained-release formulation, a NTX and triacetyl β-cyclodextrin (TAβCD) complex was evaluated. The binary systems of NTX/TAβCD in different molar ratios were prepared by the kneading method, and complex formation was demonstrated by differential scanning calorimetry. Conclusion: The results of the current in vitro study indicate that PF-127 gel formulations containing drug complexes with hydrophobic cyclodextrin could be useful for the preparation of a controlled delivery system of water-soluble drugs such as NTX, for a period of more than 140 hours.
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Affiliation(s)
- Katayoun Derakhshandeh
- Department of Pharmaceutics, Faculty of Pharmacy, University of Medical Science, Kermanshah, Iran.
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7
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Satpathy G, Rosenberg M. Encapsulation of chlorothiazide in whey proteins: Effects of wall-to-core ratio and cross-linking conditions on microcapsule properties and drug release. J Microencapsul 2010. [DOI: 10.3109/02652040309178064] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- G. Satpathy
- Department of Food Science and Technology, University of California, Davis, CA, 95616, USA
| | - M. Rosenberg
- Department of Food Science and Technology, University of California, Davis, CA, 95616, USA
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8
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Valot P, Baba M, Nedelec JM, Sintes-Zydowicz N. Effects of process parameters on the properties of biocompatible Ibuprofen-loaded microcapsules. Int J Pharm 2009; 369:53-63. [DOI: 10.1016/j.ijpharm.2008.10.037] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2008] [Revised: 10/24/2008] [Accepted: 10/28/2008] [Indexed: 11/27/2022]
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9
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Pandit SS, Hase DP, Bankar MM, Patil AT, Gaikwad NJ. Ketoprofen-loaded Eudragit RSPO microspheres: An influence of sodium carbonate onin vitrodrug release and surface topology. J Microencapsul 2008; 26:195-201. [DOI: 10.1080/02652040802224793] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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10
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Horoz BB, Kiliçarslan M, Yüksel N, Baykara T. Effect of different dispersing agents on the characteristics of Eudragit microspheres prepared by a solvent evaporation method. J Microencapsul 2008; 21:191-202. [PMID: 15198430 DOI: 10.1080/02652040310001637893] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Eudragit RS microspheres containing verapamil HCl for oral use were prepared using three different dispersing agents: aluminium tristearate, magnesium stearate and sucrose stearate, by a solvent evaporation method. The effects of the type and concentration of the dispersing agents and the inner phase polymer concentration on the size and T63.2%, (the time at which 63.2% of the drug is released) of microspheres were determined by multiple linear regression analysis. The morphology of microspheres was characterized by scanning electron microscopy. The surface of microspheres prepared with sucrose stearate was smoother and non-porous and the drug release from these microspheres was the fastest. When aluminium tristearate or magnesium stearate were used as dispersing agents, the particle size of microspheres became smaller. Increasing amounts of these two dispersing agents led to the accumulation of their free particles onto the surfaces of the microspheres. The drug release from the microspheres was slower than that of the microspheres from sucrose stearate depending on their hydrophobic structures. According to the results of the multiple linear regression analysis among the dispersing agents used, aluminium tristearate showed the best correlation between the examined input (dispersing agent and polymer concentrations) and output (T63.2%. and particle size) variables.
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Affiliation(s)
- B B Horoz
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Ankara University, 06100, Tandoğan, Ankara, Turkey
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11
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Haznedar S, Dortunç B. Preparation and in vitro evaluation of Eudragit microspheres containing acetazolamide. Int J Pharm 2004; 269:131-40. [PMID: 14698584 DOI: 10.1016/j.ijpharm.2003.09.015] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The aim of this study was to prepare and evaluate Eudragit (RS and RL) microspheres containing acetazolamide. Microspheres were prepared by solvent evaporation method using acetone/liquid paraffin system. The influence of formulation factors (stirring speed, polymer:drug ratio, type of polymer, ratio of the combination of polymers) on particle size, encapsulation efficiency and in vitro release characteristics of the microspheres were investigated. The yields of preparation and the encapsulation efficiencies were high for all formulations the microspheres were obtained. Mean particle size changed by changing the polymer:drug ratio or the stirring speed of the system. Although acetazolamide release rates from Eudragit RS microspheres were very slow and incomplete for all formulations, they were fast from Eudragit RL microspheres. When Eudragit RS was added to Eudragit RL microsphere formulations, release rates slowed down and achieved the release profile suitable for peroral administration.
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Affiliation(s)
- S Haznedar
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Marmara University, Haydarpasa, 34668 Istanbul, Turkey
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12
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Sivakuma M, Rao KP. In vitro release of ibuprofen and gentamicin from PMMA functional microspheres. JOURNAL OF BIOMATERIALS SCIENCE. POLYMER EDITION 2002; 13:111-26. [PMID: 12022744 DOI: 10.1163/156856202317414311] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Drug-containing microspheres based on synthetic polymers such as poly(methyl methacrylate) (PMMA) and PMMA derivatives are known for their medical applications, particularly for hard tissue repair and regeneration. In our earlier work, we have reported that the synthesis of PMMA and carboxyl group-containing PMMA functional (PMMA-F) microspheres and these microspheres were fully characterized by various techniques. In the present investigation, an attempt was made to prepare drug-containing PMMA (without carboxylic functional groups) and PMMA-F (with carboxylic functional groups) microspheres by solvent evaporation technique. The presence of characteristic groups in the drug-containing PMMA and PMMA-F microspheres was confirmed using 1H-FT-NMR spectroscopy. Equilibrium swelling experiments of both microspheres was carried out in pH 7.4 phosphate buffer and pH 1.2 gastric medium. PMMA-F microspheres were able to float in the pH 1.2 and 7.4 media, whereas PMMA microspheres settled in both. Optical and scanning electron micrographs indicated that the microspheres are spherical and porous in nature. The carboxylic groups of PMMA-F microspheres were coupled with amino groups of gentamicin using 1-ethyl-3(3-dimethylpropyl) carbodiamide as coupling agent, whereas in the case of PMMA microspheres, the gentamicin was incorporated in the porous site of the microspheres. The ibuprofen drug was incorporated in the porous site of PMMA and PMMA-F microspheres. The cumulative in vitro release profiles of gentamicin and ibuprofen from PMMA and PMMA-F microspheres were performed in PBS pH 7.4 at 37 degrees C. It shows that gentamicin containing PMMA-F microspheres releases the drug ones a longer period compared to PMMA microspheres.
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Affiliation(s)
- M Sivakuma
- Biomaterials Division, Central Leather Research Institute, Adyar, Chennai, India.
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13
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14
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Lee SJ, Rosenberg M. Microencapsulation of theophylline in whey proteins: effects of core-to-wall ratio. Int J Pharm 2000; 205:147-58. [PMID: 11000551 DOI: 10.1016/s0378-5173(00)00504-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Effects of core-to-wall ratio ranging from 1:1.5 to 5:1.5 on formation, properties and core release from whey protein-based microcapsules containing theophylline were investigated. Microcapsules were cross-linked by glutaraldehyde-saturated toluene (GAST) in an organic phase. Size distribution of microcapsules, core content and core retention were affected by core-to-wall ratio. Proportion of small capsules was inversely related to core-to-wall ratio. Core content in microcapsules ranged from 6.7 to 65.7% (w/w) and core retention ranged from 16.8 to 85.4%. Outer topography and inner structure of microcapsules were influenced by core-to-wall ratio. Core release into simulated intestinal- and gastric-fluids was influenced by a combined effect of type of dissolution medium and core-to-wall ratio, through its influence on size, core content and structure of microcapsules. Results indicated that in order to attain a desired core content and release profile, the ratio of core-to-wall components, in suspensions consisting of whey proteins and theophylline, has to be carefully considered and adjusted.
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Affiliation(s)
- S J Lee
- Department of Food Science and Technology, University of California, Davis, CA 95616, USA
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15
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Bibby DC, Davies NM, Tucker IG. Mechanisms by which cyclodextrins modify drug release from polymeric drug delivery systems. Int J Pharm 2000; 197:1-11. [PMID: 10704788 DOI: 10.1016/s0378-5173(00)00335-5] [Citation(s) in RCA: 208] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
For many drug candidates a modified in vivo drug release is desired to improve efficacy, sustain effect or minimise toxicity. Polymeric delivery systems, such as microspheres, nanospheres and polymeric films, have been extensively researched in an attempt to achieve modified drug release. Cyclodextrins offer an alternative approach. These cyclic oligosaccharides have the ability to form non-covalent complexes with a number of drugs and in so doing alter their physicochemical properties. In addition, the primary and secondary hydroxyl groups of the native (alpha, beta, gamma-) cyclodextrins are potential sites for chemical modification. It follows that the incorporation of these agents into polymeric drug delivery systems, as physical mixtures, covalently bound conjugates or cross-linking agents, frequently permits a greater degree of control of drug release. This paper reviews the incorporation of various cyclodextrins into polymeric formulations. The mechanisms by which cyclodextrin/polymer formulations act to modify drug release are considered.
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Affiliation(s)
- D C Bibby
- Formulation and Drug Delivery Group, School of Pharmacy, University of Otago, PO Box 913, Dunedin, New Zealand.
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16
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Khidr SH, Niazy EM, el-Sayed YM. Development and in-vitro evaluation of sustained-release meclofenamic acid microspheres. J Microencapsul 1998; 15:153-62. [PMID: 9532521 DOI: 10.3109/02652049809006845] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Meclofenamic acid (MFA) sustained-release microspheres were prepared by the solvent evaporation method using cellulose propionate (CP) polymer and acetone as the polymer solvent. Polyethylene glycol (PEG) was used as a channelling agent to improve the release properties of MFA at 1:2:1 drug to polymer to PEG ratio. The microspheres prepared at three different speeds (600, 800 and 1000 rpm) were characterized with regard to their surface morphology, average drug content, particle size distribution and release profiles in phosphate buffer, pH 8.0 at 37 degrees C. The microspheres were stored under accelerated conditions for 3 months and the effect of storage on the different characteristics was studied. Spherical particles with essentially smooth surface and few residual drug crystals on the surface were formed. Smaller particles were formed at higher agitation speeds. The release rate of MFA from these microspheres was not affected by the molecular weight of CP polymer. PEG 2000 was found to have a more enhancing effect on the rate of the release than PEG 4000. The physical properties of the microspheres and their release characteristics were not altered by storing the product at 40 degrees C/80% relative humidity (R.H.) for 3 months.
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Affiliation(s)
- S H Khidr
- Department of Pharmaceutics, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
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17
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Chan LW, Heng PW, Wan LS. Effect of cellulose derivatives on alginate microspheres prepared by emulsification. J Microencapsul 1997; 14:545-55. [PMID: 9292431 DOI: 10.3109/02652049709006808] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Generally discrete and spherical calcium alginate microspheres with a high drug encapsulation efficiency were readily prepared by an emulsification process. They were found to release drug rapidly. In the present study, co-polymer in the form of cellulose derivatives was added to sodium alginate in an attempt to modify the drug release profiles of the microspheres. The effects of cellulose derivatives on the morphology and drug encapsulation efficiency of the microspheres were also evaluated. The cellulose derivatives increased the degree of agglomeration of the microspheres. Small and spherical microspheres were produced from cellulose derivatives of low viscosity while larger microspheres which tended to be elongated were produced from cellulose derivatives of high viscosity. The drug encapsulation efficiency and the drug release profiles were influenced by the chemical nature of the cellulose derivative as well as its viscosity. The efficiency of drug encapsulation generally increased while the rate of drug release decreased with increasing viscosity of the cellulose derivatives. Less hydrophilic cellulose derivatives such as methyl cellulose and hydroxypropylmethyl cellulose were found to increase the efficiency of encapsulating sulphaguanidine, while more hydrophilic cellulose derivatives such as hydroxypropyl cellulose and carboxymethyl cellulose had the opposite effect. Among the cellulose derivatives used, only hydroxypropyl cellulose retarded the drug release of the microspheres.
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Affiliation(s)
- L W Chan
- Department of Pharmacy, National University of Singapore, Singapore
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18
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Subhaga CS, Ravi KG, Sunny MC, Jayakrishnan A. Evaluation of an aliphatic polyurethane as a microsphere matrix for sustained theophylline delivery. J Microencapsul 1995; 12:617-25. [PMID: 8558384 DOI: 10.3109/02652049509006792] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
In spite of several biomedical applications of polyurethanes, very little attention has been focused on these polymers for controlled drug delivery. In this study, an aliphatic polyurethane, Tecoflex, was evaluated as a microsphere matrix for the controlled release of theophylline. Polyurethane microspheres containing theophylline were prepared using a solvent evaporation technique from a dichloromethane solution of the polymer containing the drug. A dilute solution of poly(vinyl alcohol) served as the dispersion medium. Microspheres of good spherical geometry having theophylline content of 35% could be prepared by the technique. The release of the drug from the microspheres was examined in simulated gastric and intestinal fluids at 37 degrees C. While a large burst effect was observed in gastric fluid, in the intestinal fluid a close to zero-order release was seen. Attempts were made to modulate the release by incorporating poly(ethylene glycol) in the matrix and also coating the spheres with paraffin wax. Preliminary data indicate that polyurethanes could be interesting matrices for controlled drug delivery.
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Affiliation(s)
- C S Subhaga
- College of Pharmaceutical Sciences, Medical College, Trivandrum, India
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19
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Khidr SH, Niazy EM, el-Sayed YM. Preparation and in-vitro evaluation of sustained-release metoclopramide hydrochloride microspheres. J Microencapsul 1995; 12:651-60. [PMID: 8558387 DOI: 10.3109/02652049509006795] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Sustained-release metoclopramide microspheres were successfully prepared using cellulose propionate polymer at 1:2 drug to polymer ratio employing solvent evaporation technique and using acetone as the polymer solvent. The prepared microspheres at three stirring speeds were characterized with regard to their drug content, particle size distribution, surface topography using SEM and their release profiles at two different pHs at 37 degrees C. The surface of all samples was smooth with very few irregular elevations or depressions. The average particle size decreases as the rotational speed increases and was found to be 1320, 774 and 345 microns at 600, 900 and 1200 rpm, respectively. The average % drug entrapped was found to be 90.5, 100.1 and 60.0% at 600, 900 and 1200 rpm, respectively. Small differences in the release rate were observed due to different rotation speeds with an apparent lower dissolution for batches produced at 1200 rpm probably due to the properties of the coat. The effect of storage under accelerated conditions for 10 weeks on the release characteristics of these microspheres was also studied. The release properties of the microspheres did not change after storing them at 40 degrees C/80% relative humidity for 10 weeks.
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Affiliation(s)
- S H Khidr
- Department of Pharmaceutics, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
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Latha MS, Jayakrishnan A. Glutaraldehyde cross-linked bovine casein microspheres as a matrix for the controlled release of theophylline: in-vitro studies. J Pharm Pharmacol 1994; 46:8-13. [PMID: 8201534 DOI: 10.1111/j.2042-7158.1994.tb03711.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A controlled release dosage form of theophylline in the form of microspheres using the milk protein casein as the matrix is described. Glutaraldehyde cross-linking of an aqueous alkaline solution of the protein containing the drug, dispersed in a mixture of dichloromethane/hexane having ca. 1% of an aliphatic polyurethane as the suspension stabilizer, led to the formation of the drug-loaded microspheres. Drug incorporation efficiency of around 80% could be achieved by the technique. Release profiles of the drug were examined in simulated gastric and intestinal fluids at 37 degrees C. It was observed that the release was diffusion-controlled and followed the Higuchi model. Release characteristics were influenced by the cross-linking density, particle size and the extent of loading. Data obtained indicate that the natural milk protein casein could be used as a matrix for sustained release oral dosage forms.
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Affiliation(s)
- M S Latha
- Polymer Chemistry Division, Sree Chitra Tirunal Institute for Medical Sciences & Technology, Trivandrum, India
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Lin SY, Tzan YL, Weng CN, Lee CJ. Preparation of enteric-coated microspheres of Mycoplasma hyopneumoniae vaccine with cellulose acetate phthalate: (II). Effect of temperature and pH on the stability and release behaviour of microspheres. J Microencapsul 1991; 8:537-45. [PMID: 1798023 DOI: 10.3109/02652049109021877] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The in vitro stability (temperature and pH) and dissolution study (pH 7.4 phosphate buffer solution and pH changed medium) of the enteric-coated microspheres containing Mycoplasma hyopneumoniae vaccine (MHV) were examined. The MHV microspheres were thermally more stable than the unencapsulated MHV. More than 90% of antigenicity was retained in the MHV microspheres for 3 weeks when stored at 4 degrees C. The MHV microspheres in pH 1.2 and pH 3.0 medium were more stable than the unencapsulated MHV. The MHV enteric-coated microspheres exhibited an excellent enteric function to prevent pH-related inactivation. The influence of particle size, CAP concentration and span 80 concentration on the MHV released from microspheres was also determined. The smaller the particle size, the higher the dissolution rate due to the larger surface area of the smaller particle. The higher the concentration of span 80 used, the more the greater the amount of MHV released. This was attributed to the more porous structure of microspheres prepared by the higher concentration of span 80. By increasing the CAP concentration, however, the release rate of MHV was decreased due to the larger amount of CAP and the more compact structure of microspheres.
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Affiliation(s)
- S Y Lin
- Department of Medical Research, Veterans General Hospital-Taipei, Republic of China
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22
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Influence of valence and concentration of electrolytes on the ?-potential of polyacrylic lattices. Colloid Polym Sci 1991. [DOI: 10.1007/bf00665499] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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23
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Maruyama K, Pongpaibul Y, Iwatsuru M. Bioavailability of theophylline-containing poly(methyl methacrylate) microspheres in rabbits. J Control Release 1989. [DOI: 10.1016/0168-3659(89)90060-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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