Clemence Tarirai
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Clemence Tarirai has a total of 42 co-authors. Here are the top co-authors by number of shared publications:
- Bisrat Bekele
Department of Anatomy, Physiology and Pharmacology, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
2 shared publications - Charles Maibvise
University of Hertfordshire School of Life and Medical Sciences
2 shared publications - Eltony Mugomeri
Department of Pharmacy, Faculty of Health Sciences, National University of Lesotho, Maseru, Lesotho
2 shared publications Gillian Mary-Anne Enslin
Department of Pharmaceutical Sciences, Tshwane University of Technology, Arcadia, South Africa
2 shared publications- Kingsley Chimaeze Mbara
Nanomedicines Manufacturing, Biopharmaceutics and Diagnostics Research Laboratory, Department of Pharmaceutical Sciences, Tshwane University of Technology, Private Bag X680, Pretoria 0001, South Africa
2 shared publications Poloko Stephen Kheoane
Department of Pharmaceutical Sciences, Tshwane University of Technology, 175 N. Mandela Drive, Arcadia 0001, South Africa; Department of Pharmacy, National University of Lesotho, P.O. Box Roma 180, Lesotho
2 shared publications
Latest Publications
- Open Access
Apoptotic Effects of Agapanthus africanus Extracts and Identification of Volatile Compounds from the n-Butanol Fraction
Agapanthus africanus (L.) Hoffmanns. is a medicinal plant traditionally used in South Africa for its promise as a source of bioactive compounds with anticancer properties. This study aimed to investigate the apoptotic effects of A. africanus fractions on cancer cell lines and to identify the bioactive phytochemical constituents using gas chromatography-mass spectrometry analysis. To test for cytotoxicity, MCF-7, A549, and HeLa cancer cells were treated with crude extract, n-hexane, n-butanol, dichloromethane, and aqueous fractions of A. africanus extracts at different concentrations (0.00–1000 µg/mL). Total apoptosis was quantified using Annexin V/PI staining. The 4′,6-diamidino-2-phenylindole was used to detect nuclear morphological changes and the Caspase-GLO 3/7 assay was employed to check the caspase activation in the cancer cells. Expression of apoptosis-related (caspase-3, bax, bcl-2) genes was evaluated using real time-polymerase chain reaction. The crude extract of A. africanus exhibited dose-dependent cytotoxicity against MCF-7, A549, and HeLa cells, with IC50 values of 130 µg/mL, 380 µg/mL, and n-butanol fraction showed cytotoxicity towards MCF-7 cells with an IC50 value of n-hexane, dichloromethane and the aqueous fractions exhibited higher IC50 values against cancer cells. Flow cytometry analysis, which was applied to quantify total apoptosis, revealed that the crude extract of A. africanus induced apoptosis by (~60%) compared to the n-butanol fraction, which exhibited a moderate apoptotic effect (~27%). DAPI nuclear staining showed nuclear shrinkage and chromatin condensation in the MCF-7 cell line, whereas in Caspase-GLO 3/7, the crude extract and n-butanol fraction resulted in significant luminescence, indicating activation of caspase-3/7. Caspase-3/7 analysis showed A. africanus treatments produced varying levels of apoptotic activation. The crude extract increased caspase activity by 2.9-fold, while the n-butanol fraction induced a 1.7-fold rise compared with untreated cells. GC-MS chromatograms detected and identified 16 compounds in the fractionated n-butanol and 23 compounds from the crude extract of A. africanus. The major compounds identified from the n-butanol fraction included n-hexadecanoic acid; α-tocopherol and 9,12,15-octadecatrienoic acid, while the GC–MS profile of the crude extract was dominated by 6,10,14-trimethylpentadecan-2-one; 1,3,5-Triphenylcyclohexane and phytol. The study indicates the pro-apoptotic potential of A. africanus, particularly in its crude form, supporting its ethnopharmacological use and suggesting its relevance as a candidate for anticancer drug discovery.
Open AccessApoptotic Effects of Agapanthus africanus Extracts and Identification of Volatile Compounds from the n-Butanol Fraction
Agapanthus africanus (L.) Hoffmanns. is a medicinal plant traditionally used in South Africa for its promise as a source of bioactive compounds with anticancer properties. This study aimed to investigate the apoptotic effects of A. africanus fractions on cancer cell lines and to identify the bioactive phytochemical constituents using gas chromatography-mass spectrometry analysis. To test for cytotoxicity, MCF-7, A549, and HeLa cancer cells were treated with crude extract, n-hexane, n-butanol, dichloromethane, and aqueous fractions of A. africanus extracts at different concentrations (0.00–1000 µg/mL). Total apoptosis was quantified using Annexin V/PI staining. The 4′,6-diamidino-2-phenylindole was used to detect nuclear morphological changes and the Caspase-GLO 3/7 assay was employed to check the caspase activation in the cancer cells. Expression of apoptosis-related (caspase-3, bax, bcl-2) genes was evaluated using real time-polymerase chain reaction. The crude extract of A. africanus exhibited dose-dependent cytotoxicity against MCF-7, A549, and HeLa cells, with IC50 values of 130 µg/mL, 380 µg/mL, and n-butanol fraction showed cytotoxicity towards MCF-7 cells with an IC50 value of n-hexane, dichloromethane and the aqueous fractions exhibited higher IC50 values against cancer cells. Flow cytometry analysis, which was applied to quantify total apoptosis, revealed that the crude extract of A. africanus induced apoptosis by (~60%) compared to the n-butanol fraction, which exhibited a moderate apoptotic effect (~27%). DAPI nuclear staining showed nuclear shrinkage and chromatin condensation in the MCF-7 cell line, whereas in Caspase-GLO 3/7, the crude extract and n-butanol fraction resulted in significant luminescence, indicating activation of caspase-3/7. Caspase-3/7 analysis showed A. africanus treatments produced varying levels of apoptotic activation. The crude extract increased caspase activity by 2.9-fold, while the n-butanol fraction induced a 1.7-fold rise compared with untreated cells. GC-MS chromatograms detected and identified 16 compounds in the fractionated n-butanol and 23 compounds from the crude extract of A. africanus. The major compounds identified from the n-butanol fraction included n-hexadecanoic acid; α-tocopherol and 9,12,15-octadecatrienoic acid, while the GC–MS profile of the crude extract was dominated by 6,10,14-trimethylpentadecan-2-one; 1,3,5-Triphenylcyclohexane and phytol. The study indicates the pro-apoptotic potential of A. africanus, particularly in its crude form, supporting its ethnopharmacological use and suggesting its relevance as a candidate for anticancer drug discovery.
- Open Access
- 24 May 2024
- Published by Elsevier in Current Research in Pharmacology and Drug Discovery
- Vol. 6, 100184
Endoplasmic reticulum stress in pancreatic β-cell dysfunction: The potential therapeutic role of dietary flavonoids
- 24 May 2024
- Published by Elsevier in Current Research in Pharmacology and Drug Discovery
- Vol. 6, 100184
Open AccessEndoplasmic reticulum stress in pancreatic β-cell dysfunction: The potential therapeutic role of dietary flavonoids
- Open Access
- 30 September 2023
- Published by MDPI AG in Pharmaceuticals
- Vol. 16 (10) , 1390
Ethnomedicinal Uses, Phytochemistry and Pharmacological Properties of Suregada Genus: A Review
Plants of the Suregada Roxb. ex Rottler (formerly Gelonium Roxb. ex Willd) are utilized to treat various ailments, namely, hepatic, gum diseases, pyrexia, eczema, and venereal diseases. This review links the reported compounds to ethnomedicinal uses through pharmacological activities. The compounds possess anticancer, anti-allergic, antibacterial, anti-inflammatory, antioxidant, and anti-HIV properties. From the previous reports, 32 known species of the Suregada genus have been investigated morphologically, and nine were investigated for their phytochemistry and pharmacology. Phytochemistry, ethnomedicinal, and pharmacological uses of the other 23 Suregada species are not known and/or not reported. In this review, abietane diterpenoids are the main compounds expressed by the Suregada, accounting for 71 of the 114 reported compounds. Ten triterpenoids and sterols, one aliphatic, two lignans, five flavonoids, and twenty-one nitrogen-containing compounds have been reported from the genus.
- 30 September 2023
- Published by MDPI AG in Pharmaceuticals
- Vol. 16 (10) , 1390
Open AccessEthnomedicinal Uses, Phytochemistry and Pharmacological Properties of Suregada Genus: A Review
Plants of the Suregada Roxb. ex Rottler (formerly Gelonium Roxb. ex Willd) are utilized to treat various ailments, namely, hepatic, gum diseases, pyrexia, eczema, and venereal diseases. This review links the reported compounds to ethnomedicinal uses through pharmacological activities. The compounds possess anticancer, anti-allergic, antibacterial, anti-inflammatory, antioxidant, and anti-HIV properties. From the previous reports, 32 known species of the Suregada genus have been investigated morphologically, and nine were investigated for their phytochemistry and pharmacology. Phytochemistry, ethnomedicinal, and pharmacological uses of the other 23 Suregada species are not known and/or not reported. In this review, abietane diterpenoids are the main compounds expressed by the Suregada, accounting for 71 of the 114 reported compounds. Ten triterpenoids and sterols, one aliphatic, two lignans, five flavonoids, and twenty-one nitrogen-containing compounds have been reported from the genus.
- 28 November 2022
- Published by Springer Nature in Drug Delivery and Translational Research
- Vol. 13 (5) , 1358-1371
Formulation and characterization of liposomes containing drug absorption enhancers for optimized anti-HIV and antimalarial drug delivery
Most of the current clinically used anti-HIV and antimalarial drugs have low bioavailability, either due to poor solubility and permeability, rapid clearance from anatomical reservoirs and poor retention at their site of action (e.g. due to the p-glycoprotein efflux system), and extreme first-pass metabolism (e.g. by the cytochrome P450 enzymes). Hence, new approaches such as the incorporation of drug absorption enhancers (DAEs) (also referred to as bioenhancers) into dosage forms, and exploration of nanocarriers such as liposomes as novel dosage forms, are needed and may provide a viable means that could improve the bioavailability of both anti-HIV and antimalarial drugs. Liposomes loaded with efavirenz or mefloquine in combination with drug absorption enhancers, as well as placebo dosage forms, were prepared using a thin-lipid film hydration technique and characterized for their particle size and zeta potentials, entrapment efficiency, in vitro drug release, and in vitro drug permeability. Liposomes were further investigated for their biocompatibility (safety) using H-4-II-E liver cells in vitro. Drug-loaded liposomes prepared using l-α-phospatidylcholine, dioleoyl (DOPC) and cholesterol (CHOL) (1:1 mol/mol) as well as liposomes made of 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC), CHOL, and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) (4:6:26 mol/mol/mol) exhibited the best results in terms of their entrapment efficiency, particle size, zeta potential, in vitro drug release, and permeability. DSPC:CHOL:DPPC liposomes released EFV-based formulations better than DPPC:CHOL liposomes for immediate release behaviour. DOPC:CHOL liposomes produced a controlled release and more drug was released in the presence of DAEs for both EFV (0.4-fold higher) and MQ-based (sevenfold higher) formulations in the first 2 h. However, these liposomes were less biocompatible (< 50% cell viability) with liver cells. DOPC:CHOL and DSPC:CHOL:DPPC liposomes could provide a useful nano-formulation platform, which could ensure drug loading, followed by sustained release of both anti-HIV and antimalaria drugs. Graphical Abstract
- 28 November 2022
- Published by Springer Nature in Drug Delivery and Translational Research
- Vol. 13 (5) , 1358-1371
Formulation and characterization of liposomes containing drug absorption enhancers for optimized anti-HIV and antimalarial drug delivery
Most of the current clinically used anti-HIV and antimalarial drugs have low bioavailability, either due to poor solubility and permeability, rapid clearance from anatomical reservoirs and poor retention at their site of action (e.g. due to the p-glycoprotein efflux system), and extreme first-pass metabolism (e.g. by the cytochrome P450 enzymes). Hence, new approaches such as the incorporation of drug absorption enhancers (DAEs) (also referred to as bioenhancers) into dosage forms, and exploration of nanocarriers such as liposomes as novel dosage forms, are needed and may provide a viable means that could improve the bioavailability of both anti-HIV and antimalarial drugs. Liposomes loaded with efavirenz or mefloquine in combination with drug absorption enhancers, as well as placebo dosage forms, were prepared using a thin-lipid film hydration technique and characterized for their particle size and zeta potentials, entrapment efficiency, in vitro drug release, and in vitro drug permeability. Liposomes were further investigated for their biocompatibility (safety) using H-4-II-E liver cells in vitro. Drug-loaded liposomes prepared using l-α-phospatidylcholine, dioleoyl (DOPC) and cholesterol (CHOL) (1:1 mol/mol) as well as liposomes made of 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC), CHOL, and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) (4:6:26 mol/mol/mol) exhibited the best results in terms of their entrapment efficiency, particle size, zeta potential, in vitro drug release, and permeability. DSPC:CHOL:DPPC liposomes released EFV-based formulations better than DPPC:CHOL liposomes for immediate release behaviour. DOPC:CHOL liposomes produced a controlled release and more drug was released in the presence of DAEs for both EFV (0.4-fold higher) and MQ-based (sevenfold higher) formulations in the first 2 h. However, these liposomes were less biocompatible (< 50% cell viability) with liver cells. DOPC:CHOL and DSPC:CHOL:DPPC liposomes could provide a useful nano-formulation platform, which could ensure drug loading, followed by sustained release of both anti-HIV and antimalaria drugs. Graphical Abstract
- 1 December 2021
- Published by Elsevier in European Journal of Pharmaceutical Sciences
- Vol. 167, 106028
Determination of effective concentrations of drug absorption enhancers using in vitro and ex vivo models
- 1 December 2021
- Published by Elsevier in European Journal of Pharmaceutical Sciences
- Vol. 167, 106028
Determination of effective concentrations of drug absorption enhancers using in vitro and ex vivo models
- Open Access
- 11 September 2017
- Published by AOSIS in Southern African Journal of Infectious Diseases
- Vol. 33 (1) , 18-23
Trends in diagnostic techniques and factors associated with tuberculosis treatment outcomes in Lesotho, 2010–2015
Tuberculosis is a global public health problem. Lesotho, a sub-Saharan country with high HIV and tuberculosis burden, launched the Three I’s programme of the World Health Organization in 2013. However, the outcomes of this intervention are scarcely known. This study evaluated the profile of tuberculosis diagnostic techniques used, treatment outcomes and the associated factors across the baseline period (2010–2012) and after the launch of the Three I’s programme (2013–2015) based on a retrospective cohort review of patient records at a major clinic in Maseru, Lesotho. In total, 812 cases with complete records from 1 066 randomly selected cases treated (every second case from the sampling frame) were included in the study. Factor analysis was based on logistic regression analysis. The use of the GeneXpert MTB/RIF technique remained below 20% throughout the study period. Overall, 28.9% (n = 812) cases had unsuccessful tuberculosis treatment. Male gender (p = 0.046), extra-pulmonary tuberculosis (p = 0.002) and treatment observation by community health workers (p = 0.001) were significantly associated with unsuccessful treatment outcome. Overall, treatment outcomes did not differ significantly (p = 0.636) before and after the launch of the intervention. These findings indicate the need to strengthen the implementation of the Three I’s programme, taking into account the significant factors in this study.
- 11 September 2017
- Published by AOSIS in Southern African Journal of Infectious Diseases
- Vol. 33 (1) , 18-23
Open AccessTrends in diagnostic techniques and factors associated with tuberculosis treatment outcomes in Lesotho, 2010–2015
Tuberculosis is a global public health problem. Lesotho, a sub-Saharan country with high HIV and tuberculosis burden, launched the Three I’s programme of the World Health Organization in 2013. However, the outcomes of this intervention are scarcely known. This study evaluated the profile of tuberculosis diagnostic techniques used, treatment outcomes and the associated factors across the baseline period (2010–2012) and after the launch of the Three I’s programme (2013–2015) based on a retrospective cohort review of patient records at a major clinic in Maseru, Lesotho. In total, 812 cases with complete records from 1 066 randomly selected cases treated (every second case from the sampling frame) were included in the study. Factor analysis was based on logistic regression analysis. The use of the GeneXpert MTB/RIF technique remained below 20% throughout the study period. Overall, 28.9% (n = 812) cases had unsuccessful tuberculosis treatment. Male gender (p = 0.046), extra-pulmonary tuberculosis (p = 0.002) and treatment observation by community health workers (p = 0.001) were significantly associated with unsuccessful treatment outcome. Overall, treatment outcomes did not differ significantly (p = 0.636) before and after the launch of the intervention. These findings indicate the need to strengthen the implementation of the Three I’s programme, taking into account the significant factors in this study.
- Open Access
- 21 March 2017
- Published by Springer Nature in Health Research Policy and Systems
- Vol. 15 (1) , 21
A 30-year bibliometric analysis of research coverage on HIV and AIDS in Lesotho
Given the well documented undesired impacts of HIV/AIDS globally, there is a need to create a statistical inventory of research output on HIV/AIDS. This need is particularly important for a country such as Lesotho, whose HIV/AIDS prevalence is one of the highest globally. Research on HIV/AIDS in sub-Saharan Africa continues to trail behind that of other regions, especially those of the developed countries. Lesotho, a sub-Saharan country, is a developing country with lower research output in this area when longitudinally compared to other countries. This study reviewed the volume and scope of the general research output on HIV/AIDS in Lesotho and assessed the coverage of the national research agenda on HIV/AIDS, making recourse to statistical principles. A bibliometric review of studies on HIV/AIDS retrieved from the SCOPUS and PubMed databases, published within the 30-year period between 1985 and 2016, was conducted. The focus of each of the studies was analysed and the studies were cross-matched with the national research agenda in accordance with bibliometric methodologies. In total, 1280 studies comprising 1181 (92.3%) journal articles, 91 (7.1%) books and 8 (0.6%) conference proceedings were retrieved. By proportion, estimation of burden of infection (40.7%) had the highest research volume, while basic (5.5%) and preventive measures (24.4%) and national planning (29.4%) had the lowest. Out of the total studies retrieved, only 516 (40.3%) matched the national research agenda. Research on maternal and child health quality of care, viral load point-of-care devices, and infant point-of-care diagnosis had hardly any publications in the high priority research category of the agenda. Notwithstanding a considerable research output on HIV/AIDS for Lesotho, there is insufficient coverage of the national research agenda in this research area. The major research gaps on general research output are in basic and preventive measures as well as national planning. There is also a need to increase targeted funding for HIV/AIDS research to appropriately address the most compelling gaps and national needs.
- 21 March 2017
- Published by Springer Nature in Health Research Policy and Systems
- Vol. 15 (1) , 21
Open AccessA 30-year bibliometric analysis of research coverage on HIV and AIDS in Lesotho
Given the well documented undesired impacts of HIV/AIDS globally, there is a need to create a statistical inventory of research output on HIV/AIDS. This need is particularly important for a country such as Lesotho, whose HIV/AIDS prevalence is one of the highest globally. Research on HIV/AIDS in sub-Saharan Africa continues to trail behind that of other regions, especially those of the developed countries. Lesotho, a sub-Saharan country, is a developing country with lower research output in this area when longitudinally compared to other countries. This study reviewed the volume and scope of the general research output on HIV/AIDS in Lesotho and assessed the coverage of the national research agenda on HIV/AIDS, making recourse to statistical principles. A bibliometric review of studies on HIV/AIDS retrieved from the SCOPUS and PubMed databases, published within the 30-year period between 1985 and 2016, was conducted. The focus of each of the studies was analysed and the studies were cross-matched with the national research agenda in accordance with bibliometric methodologies. In total, 1280 studies comprising 1181 (92.3%) journal articles, 91 (7.1%) books and 8 (0.6%) conference proceedings were retrieved. By proportion, estimation of burden of infection (40.7%) had the highest research volume, while basic (5.5%) and preventive measures (24.4%) and national planning (29.4%) had the lowest. Out of the total studies retrieved, only 516 (40.3%) matched the national research agenda. Research on maternal and child health quality of care, viral load point-of-care devices, and infant point-of-care diagnosis had hardly any publications in the high priority research category of the agenda. Notwithstanding a considerable research output on HIV/AIDS for Lesotho, there is insufficient coverage of the national research agenda in this research area. The major research gaps on general research output are in basic and preventive measures as well as national planning. There is also a need to increase targeted funding for HIV/AIDS research to appropriately address the most compelling gaps and national needs.
- Open Access
- 6 December 2016
- Published by Canadian Center of Science and Education in Journal of Food Research
- Vol. 6 (1) , 7
Antioxidant and Prebiotic Activity of Selected Edible Wild Plant Extracts
Edible wild plants were investigated as potential sources of antioxidants and prebiotics to benefit human health. Antioxidant activity, ascorbic acid and total dietary fibre contents were determined in edible wild plants from Lesotho, Swaziland and South Africa. Pure probiotic strains of Bifidobacterium animalis subsp. animalis (ATCC 25527), Lactobacillus rhamnosus (TUTBFD) and Lactobacillus acidophilus (ATCC 314) were cultured in broth containing edible wild plant extracts to assess their prebiotic activity. Cyperus esculantus had the highest arscobic acid content of 603±64.1 mg/100 g edible dry plant material followed by Rosa rubiginosa (500.8±48.8 mg/100 g). The two plants had IC50 of 10.7±0.2 µg/mL and 47.8±0.2 µg/mL for DPPH inhibition, respectively. Forty percent (40%) (n=30) of the edible wild plants had significant (p<0.01) total antioxidant activity (IC50200 mg/100 g). Nasturtium officinale reported the highest yield for soluble fibre (25%) while Hypoxis hirsute had the highest total dietary fibre content (7.3%). Rorippa nudiuscula enhanced the growth of B. animalis significantly (p=0.001), 8-fold more than inulin. Chenopodium album and Urtica dioica stimulated the growth of L. rhamnosus significantly (p=0.0001) than inulin, respectfully, while Tragopogon porrifolius significantly (p=0.0001) stimulated the growth of L. acidophilus than inulin. It was concluded that the investigated edible wild plants from southern Africa have antioxidant and prebiotic properties that may be beneficial to human health.
- 6 December 2016
- Published by Canadian Center of Science and Education in Journal of Food Research
- Vol. 6 (1) , 7
Open AccessAntioxidant and Prebiotic Activity of Selected Edible Wild Plant Extracts
Edible wild plants were investigated as potential sources of antioxidants and prebiotics to benefit human health. Antioxidant activity, ascorbic acid and total dietary fibre contents were determined in edible wild plants from Lesotho, Swaziland and South Africa. Pure probiotic strains of Bifidobacterium animalis subsp. animalis (ATCC 25527), Lactobacillus rhamnosus (TUTBFD) and Lactobacillus acidophilus (ATCC 314) were cultured in broth containing edible wild plant extracts to assess their prebiotic activity. Cyperus esculantus had the highest arscobic acid content of 603±64.1 mg/100 g edible dry plant material followed by Rosa rubiginosa (500.8±48.8 mg/100 g). The two plants had IC50 of 10.7±0.2 µg/mL and 47.8±0.2 µg/mL for DPPH inhibition, respectively. Forty percent (40%) (n=30) of the edible wild plants had significant (p<0.01) total antioxidant activity (IC50200 mg/100 g). Nasturtium officinale reported the highest yield for soluble fibre (25%) while Hypoxis hirsute had the highest total dietary fibre content (7.3%). Rorippa nudiuscula enhanced the growth of B. animalis significantly (p=0.001), 8-fold more than inulin. Chenopodium album and Urtica dioica stimulated the growth of L. rhamnosus significantly (p=0.0001) than inulin, respectfully, while Tragopogon porrifolius significantly (p=0.0001) stimulated the growth of L. acidophilus than inulin. It was concluded that the investigated edible wild plants from southern Africa have antioxidant and prebiotic properties that may be beneficial to human health.
- 9 March 2010
- Published by Taylor & Francis in Pharmaceutical Development and Technology
- Vol. 16 (4) , 295-301
Moulded cross-linked chitosan matrix systems for controlled drug release
Matrix-type drug delivery systems were prepared by moulding and drying cross-linked chitosan gels in 24-well plates and they were evaluated in terms of their physical properties, drug content, surface morphology and swelling. Furthermore, the in vitro drug release profiles were subjected to kinetic modelling at two different pH values. In general, the moulded matrix systems showed statistically significantly slower drug release compared to immediate release tablets as measured by the mean dissolution time. Drug release from the moulded matrix systems prepared from chitosan cross-linked with tripolyphosphate was pH-dependent as can be seen from the release exponent value (n) of 0.75 at pH 5.8 (anomalous transport, erosion), while the n value was only 0.40 at pH 7.4 (Fickian diffusion). The matrix systems obtained from chitosan cross-linked with sodium lauryl sulphate showed higherhttp://dx.doi.org/10.3109/1083745100366410
- 9 March 2010
- Published by Taylor & Francis in Pharmaceutical Development and Technology
- Vol. 16 (4) , 295-301
Moulded cross-linked chitosan matrix systems for controlled drug release
Matrix-type drug delivery systems were prepared by moulding and drying cross-linked chitosan gels in 24-well plates and they were evaluated in terms of their physical properties, drug content, surface morphology and swelling. Furthermore, the in vitro drug release profiles were subjected to kinetic modelling at two different pH values. In general, the moulded matrix systems showed statistically significantly slower drug release compared to immediate release tablets as measured by the mean dissolution time. Drug release from the moulded matrix systems prepared from chitosan cross-linked with tripolyphosphate was pH-dependent as can be seen from the release exponent value (n) of 0.75 at pH 5.8 (anomalous transport, erosion), while the n value was only 0.40 at pH 7.4 (Fickian diffusion). The matrix systems obtained from chitosan cross-linked with sodium lauryl sulphate showed higherhttp://dx.doi.org/10.3109/1083745100366410